diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index cd037230c2..51f14cec5f 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1,2534 +1,2534 @@
 // Copyright (c) 2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <rpc/blockchain.h>
 
 #include <amount.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <checkpoints.h>
 #include <coins.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <core_io.h>
 #include <hash.h>
 #include <index/txindex.h>
 #include <key_io.h>
 #include <policy/policy.h>
 #include <primitives/transaction.h>
 #include <rpc/server.h>
 #include <script/descriptor.h>
 #include <streams.h>
 #include <sync.h>
 #include <txdb.h>
 #include <txmempool.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <validation.h>
 #include <validationinterface.h>
 #include <warnings.h>
 
 #include <boost/algorithm/string.hpp>
 #include <boost/thread/thread.hpp> // boost::thread::interrupt
 
 #include <cassert>
 #include <condition_variable>
 #include <cstdint>
 #include <mutex>
 
 struct CUpdatedBlock {
     uint256 hash;
     int height;
 };
 
 static Mutex cs_blockchange;
 static std::condition_variable cond_blockchange;
 static CUpdatedBlock latestblock;
 
 /**
  * Calculate the difficulty for a given block index.
  */
 double GetDifficulty(const CBlockIndex *blockindex) {
     assert(blockindex);
 
     int nShift = (blockindex->nBits >> 24) & 0xff;
     double dDiff = double(0x0000ffff) / double(blockindex->nBits & 0x00ffffff);
 
     while (nShift < 29) {
         dDiff *= 256.0;
         nShift++;
     }
     while (nShift > 29) {
         dDiff /= 256.0;
         nShift--;
     }
 
     return dDiff;
 }
 
 static int ComputeNextBlockAndDepth(const CBlockIndex *tip,
                                     const CBlockIndex *blockindex,
                                     const CBlockIndex *&next) {
     next = tip->GetAncestor(blockindex->nHeight + 1);
     if (next && next->pprev == blockindex) {
         return tip->nHeight - blockindex->nHeight + 1;
     }
     next = nullptr;
     return blockindex == tip ? 1 : -1;
 }
 
 UniValue blockheaderToJSON(const CBlockIndex *tip,
                            const CBlockIndex *blockindex) {
     UniValue result(UniValue::VOBJ);
     result.pushKV("hash", blockindex->GetBlockHash().GetHex());
     const CBlockIndex *pnext;
     int confirmations = ComputeNextBlockAndDepth(tip, blockindex, pnext);
     result.pushKV("confirmations", confirmations);
     result.pushKV("height", blockindex->nHeight);
     result.pushKV("version", blockindex->nVersion);
     result.pushKV("versionHex", strprintf("%08x", blockindex->nVersion));
     result.pushKV("merkleroot", blockindex->hashMerkleRoot.GetHex());
     result.pushKV("time", int64_t(blockindex->nTime));
     result.pushKV("mediantime", int64_t(blockindex->GetMedianTimePast()));
     result.pushKV("nonce", uint64_t(blockindex->nNonce));
     result.pushKV("bits", strprintf("%08x", blockindex->nBits));
     result.pushKV("difficulty", GetDifficulty(blockindex));
     result.pushKV("chainwork", blockindex->nChainWork.GetHex());
 
     if (blockindex->pprev) {
         result.pushKV("previousblockhash",
                       blockindex->pprev->GetBlockHash().GetHex());
     }
     if (pnext) {
         result.pushKV("nextblockhash", pnext->GetBlockHash().GetHex());
     }
     return result;
 }
 
 UniValue blockToJSON(const CBlock &block, const CBlockIndex *tip,
                      const CBlockIndex *blockindex, bool txDetails) {
     UniValue result(UniValue::VOBJ);
     result.pushKV("hash", blockindex->GetBlockHash().GetHex());
     const CBlockIndex *pnext;
     int confirmations = ComputeNextBlockAndDepth(tip, blockindex, pnext);
     result.pushKV("confirmations", confirmations);
     result.pushKV("size", (int)::GetSerializeSize(block, PROTOCOL_VERSION));
     result.pushKV("height", blockindex->nHeight);
     result.pushKV("version", block.nVersion);
     result.pushKV("versionHex", strprintf("%08x", block.nVersion));
     result.pushKV("merkleroot", block.hashMerkleRoot.GetHex());
     UniValue txs(UniValue::VARR);
     for (const auto &tx : block.vtx) {
         if (txDetails) {
             UniValue objTx(UniValue::VOBJ);
             TxToUniv(*tx, uint256(), objTx, true, RPCSerializationFlags());
             txs.push_back(objTx);
         } else {
             txs.push_back(tx->GetId().GetHex());
         }
     }
     result.pushKV("tx", txs);
     result.pushKV("time", block.GetBlockTime());
     result.pushKV("mediantime", int64_t(blockindex->GetMedianTimePast()));
     result.pushKV("nonce", uint64_t(block.nNonce));
     result.pushKV("bits", strprintf("%08x", block.nBits));
     result.pushKV("difficulty", GetDifficulty(blockindex));
     result.pushKV("chainwork", blockindex->nChainWork.GetHex());
 
     if (blockindex->pprev) {
         result.pushKV("previousblockhash",
                       blockindex->pprev->GetBlockHash().GetHex());
     }
     if (pnext) {
         result.pushKV("nextblockhash", pnext->GetBlockHash().GetHex());
     }
     return result;
 }
 
 static UniValue getblockcount(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "getblockcount\n"
             "\nReturns the number of blocks in the longest blockchain.\n"
             "\nResult:\n"
             "n    (numeric) The current block count\n"
             "\nExamples:\n" +
             HelpExampleCli("getblockcount", "") +
             HelpExampleRpc("getblockcount", ""));
     }
 
     LOCK(cs_main);
     return chainActive.Height();
 }
 
 static UniValue getbestblockhash(const Config &config,
                                  const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "getbestblockhash\n"
             "\nReturns the hash of the best (tip) block in the "
             "longest blockchain.\n"
             "\nResult:\n"
             "\"hex\"      (string) the block hash hex encoded\n"
             "\nExamples:\n" +
             HelpExampleCli("getbestblockhash", "") +
             HelpExampleRpc("getbestblockhash", ""));
     }
 
     LOCK(cs_main);
     return chainActive.Tip()->GetBlockHash().GetHex();
 }
 
 UniValue getfinalizedblockhash(const Config &config,
                                const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "getfinalizedblockhash\n"
             "\nReturns the hash of the currently finalized block\n"
             "\nResult:\n"
             "\"hex\"      (string) the block hash hex encoded\n");
     }
 
     LOCK(cs_main);
     const CBlockIndex *blockIndexFinalized = GetFinalizedBlock();
     if (blockIndexFinalized) {
         return blockIndexFinalized->GetBlockHash().GetHex();
     }
     return UniValue(UniValue::VSTR);
 }
 
 void RPCNotifyBlockChange(bool ibd, const CBlockIndex *pindex) {
     if (pindex) {
         std::lock_guard<std::mutex> lock(cs_blockchange);
         latestblock.hash = pindex->GetBlockHash();
         latestblock.height = pindex->nHeight;
     }
     cond_blockchange.notify_all();
 }
 
 static UniValue waitfornewblock(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             "waitfornewblock (timeout)\n"
             "\nWaits for a specific new block and returns "
             "useful info about it.\n"
             "\nReturns the current block on timeout or exit.\n"
             "\nArguments:\n"
             "1. timeout (int, optional, default=0) Time in "
             "milliseconds to wait for a response. 0 indicates "
             "no timeout.\n"
             "\nResult:\n"
             "{                           (json object)\n"
             "  \"hash\" : {       (string) The blockhash\n"
             "  \"height\" : {     (int) Block height\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("waitfornewblock", "1000") +
             HelpExampleRpc("waitfornewblock", "1000"));
     }
 
     int timeout = 0;
     if (!request.params[0].isNull()) {
         timeout = request.params[0].get_int();
     }
 
     CUpdatedBlock block;
     {
         WAIT_LOCK(cs_blockchange, lock);
         block = latestblock;
         if (timeout) {
             cond_blockchange.wait_for(
                 lock, std::chrono::milliseconds(timeout), [&block] {
                     return latestblock.height != block.height ||
                            latestblock.hash != block.hash || !IsRPCRunning();
                 });
         } else {
             cond_blockchange.wait(lock, [&block] {
                 return latestblock.height != block.height ||
                        latestblock.hash != block.hash || !IsRPCRunning();
             });
         }
         block = latestblock;
     }
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("hash", block.hash.GetHex());
     ret.pushKV("height", block.height);
     return ret;
 }
 
 static UniValue waitforblock(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "waitforblock <blockhash> (timeout)\n"
             "\nWaits for a specific new block and returns useful info about "
             "it.\n"
             "\nReturns the current block on timeout or exit.\n"
             "\nArguments:\n"
             "1. \"blockhash\" (required, string) Block hash to wait for.\n"
             "2. timeout       (int, optional, default=0) Time in milliseconds "
             "to wait for a response. 0 indicates no timeout.\n"
             "\nResult:\n"
             "{                           (json object)\n"
             "  \"hash\" : {       (string) The blockhash\n"
             "  \"height\" : {     (int) Block height\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("waitforblock", "\"0000000000079f8ef3d2c688c244eb7a4"
                                            "570b24c9ed7b4a8c619eb02596f8862\", "
                                            "1000") +
             HelpExampleRpc("waitforblock", "\"0000000000079f8ef3d2c688c244eb7a4"
                                            "570b24c9ed7b4a8c619eb02596f8862\", "
                                            "1000"));
     }
 
     int timeout = 0;
 
     uint256 hash = uint256S(request.params[0].get_str());
 
     if (!request.params[1].isNull()) {
         timeout = request.params[1].get_int();
     }
 
     CUpdatedBlock block;
     {
         WAIT_LOCK(cs_blockchange, lock);
         if (timeout) {
             cond_blockchange.wait_for(
                 lock, std::chrono::milliseconds(timeout), [&hash] {
                     return latestblock.hash == hash || !IsRPCRunning();
                 });
         } else {
             cond_blockchange.wait(lock, [&hash] {
                 return latestblock.hash == hash || !IsRPCRunning();
             });
         }
         block = latestblock;
     }
 
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("hash", block.hash.GetHex());
     ret.pushKV("height", block.height);
     return ret;
 }
 
 static UniValue waitforblockheight(const Config &config,
                                    const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "waitforblockheight <height> (timeout)\n"
             "\nWaits for (at least) block height and returns the height and "
             "hash\n"
             "of the current tip.\n"
             "\nReturns the current block on timeout or exit.\n"
             "\nArguments:\n"
             "1. height  (required, int) Block height to wait for (int)\n"
             "2. timeout (int, optional, default=0) Time in milliseconds to "
             "wait for a response. 0 indicates no timeout.\n"
             "\nResult:\n"
             "{                           (json object)\n"
             "  \"hash\" : {       (string) The blockhash\n"
             "  \"height\" : {     (int) Block height\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("waitforblockheight", "\"100\", 1000") +
             HelpExampleRpc("waitforblockheight", "\"100\", 1000"));
     }
 
     int timeout = 0;
 
     int height = request.params[0].get_int();
 
     if (!request.params[1].isNull()) {
         timeout = request.params[1].get_int();
     }
 
     CUpdatedBlock block;
     {
         WAIT_LOCK(cs_blockchange, lock);
         if (timeout) {
             cond_blockchange.wait_for(
                 lock, std::chrono::milliseconds(timeout), [&height] {
                     return latestblock.height >= height || !IsRPCRunning();
                 });
         } else {
             cond_blockchange.wait(lock, [&height] {
                 return latestblock.height >= height || !IsRPCRunning();
             });
         }
         block = latestblock;
     }
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("hash", block.hash.GetHex());
     ret.pushKV("height", block.height);
     return ret;
 }
 
 static UniValue
 syncwithvalidationinterfacequeue(const Config &config,
                                  const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error(
             "syncwithvalidationinterfacequeue\n"
             "\nWaits for the validation interface queue to catch up on "
             "everything that was there when we entered this function.\n"
             "\nExamples:\n" +
             HelpExampleCli("syncwithvalidationinterfacequeue", "") +
             HelpExampleRpc("syncwithvalidationinterfacequeue", ""));
     }
     SyncWithValidationInterfaceQueue();
     return NullUniValue;
 }
 
 static UniValue getdifficulty(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error("getdifficulty\n"
                                  "\nReturns the proof-of-work difficulty as a "
                                  "multiple of the minimum difficulty.\n"
                                  "\nResult:\n"
                                  "n.nnn       (numeric) the proof-of-work "
                                  "difficulty as a multiple of the minimum "
                                  "difficulty.\n"
                                  "\nExamples:\n" +
                                  HelpExampleCli("getdifficulty", "") +
                                  HelpExampleRpc("getdifficulty", ""));
     }
 
     LOCK(cs_main);
     return GetDifficulty(chainActive.Tip());
 }
 
 static std::string EntryDescriptionString() {
     return "    \"size\" : n,             (numeric) transaction size.\n"
            "    \"fee\" : n,              (numeric) transaction fee in " +
            CURRENCY_UNIT + "(DEPRECATED)" +
            "\n"
            "    \"modifiedfee\" : n,      (numeric) transaction fee with fee "
            "deltas used for mining priority (DEPRECATED)\n"
            "    \"time\" : n,             (numeric) local time transaction "
            "entered pool in seconds since 1 Jan 1970 GMT\n"
            "    \"height\" : n,           (numeric) block height when "
            "transaction entered pool\n"
            "    \"startingpriority\" : n, (numeric) DEPRECATED. Priority when "
            "transaction entered pool\n"
            "    \"currentpriority\" : n,  (numeric) DEPRECATED. Transaction "
            "priority now\n"
            "    \"descendantcount\" : n,  (numeric) number of in-mempool "
            "descendant transactions (including this one)\n"
            "    \"descendantsize\" : n,   (numeric) virtual transaction size "
            "of in-mempool descendants (including this one)\n"
            "    \"descendantfees\" : n,   (numeric) modified fees (see above) "
            "of in-mempool descendants (including this one) (DEPRECATED)\n"
            "    \"ancestorcount\" : n,    (numeric) number of in-mempool "
            "ancestor transactions (including this one)\n"
            "    \"ancestorsize\" : n,     (numeric) virtual transaction size "
            "of in-mempool ancestors (including this one)\n"
            "    \"ancestorfees\" : n,     (numeric) modified fees (see above) "
            "of in-mempool ancestors (including this one) (DEPRECATED)\n"
            "    \"fees\" : {\n"
            "        \"base\" : n,         (numeric) transaction fee in " +
            CURRENCY_UNIT +
            "\n"
            "        \"modified\" : n,     (numeric) transaction fee with fee "
            "deltas used for mining priority in " +
            CURRENCY_UNIT +
            "\n"
            "        \"ancestor\" : n,     (numeric) modified fees (see above) "
            "of in-mempool ancestors (including this one) in " +
            CURRENCY_UNIT +
            "\n"
            "        \"descendant\" : n,   (numeric) modified fees (see above) "
            "of in-mempool descendants (including this one) in " +
            CURRENCY_UNIT +
            "\n"
            "    }\n"
            "    \"depends\" : [           (array) unconfirmed transactions "
            "used as inputs for this transaction\n"
            "        \"transactionid\",    (string) parent transaction id\n"
            "       ... ]\n"
            "    \"spentby\" : [           (array) unconfirmed transactions "
            "spending outputs from this transaction\n"
            "        \"transactionid\",    (string) child transaction id\n"
            "       ... ]\n";
 }
 
 static void entryToJSON(const CTxMemPool &pool, UniValue &info,
                         const CTxMemPoolEntry &e)
     EXCLUSIVE_LOCKS_REQUIRED(pool.cs) {
     AssertLockHeld(pool.cs);
 
     UniValue fees(UniValue::VOBJ);
     fees.pushKV("base", ValueFromAmount(e.GetFee()));
     fees.pushKV("modified", ValueFromAmount(e.GetModifiedFee()));
     fees.pushKV("ancestor", ValueFromAmount(e.GetModFeesWithAncestors()));
     fees.pushKV("descendant", ValueFromAmount(e.GetModFeesWithDescendants()));
     info.pushKV("fees", fees);
 
     info.pushKV("size", (int)e.GetTxSize());
     info.pushKV("fee", ValueFromAmount(e.GetFee()));
     info.pushKV("modifiedfee", ValueFromAmount(e.GetModifiedFee()));
     info.pushKV("time", e.GetTime());
     info.pushKV("height", (int)e.GetHeight());
     info.pushKV("startingpriority", e.GetPriority(e.GetHeight()));
     info.pushKV("currentpriority", e.GetPriority(chainActive.Height()));
     info.pushKV("descendantcount", e.GetCountWithDescendants());
     info.pushKV("descendantsize", e.GetSizeWithDescendants());
     info.pushKV("descendantfees", e.GetModFeesWithDescendants() / SATOSHI);
     info.pushKV("ancestorcount", e.GetCountWithAncestors());
     info.pushKV("ancestorsize", e.GetSizeWithAncestors());
     info.pushKV("ancestorfees", e.GetModFeesWithAncestors() / SATOSHI);
     const CTransaction &tx = e.GetTx();
     std::set<std::string> setDepends;
     for (const CTxIn &txin : tx.vin) {
         if (pool.exists(txin.prevout.GetTxId())) {
             setDepends.insert(txin.prevout.GetTxId().ToString());
         }
     }
 
     UniValue depends(UniValue::VARR);
     for (const std::string &dep : setDepends) {
         depends.push_back(dep);
     }
 
     info.pushKV("depends", depends);
 
     UniValue spent(UniValue::VARR);
     const CTxMemPool::txiter &it = pool.mapTx.find(tx.GetId());
     const CTxMemPool::setEntries &setChildren = pool.GetMemPoolChildren(it);
     for (CTxMemPool::txiter childiter : setChildren) {
         spent.push_back(childiter->GetTx().GetId().ToString());
     }
 
     info.pushKV("spentby", spent);
 }
 
 UniValue MempoolToJSON(const CTxMemPool &pool, bool verbose) {
     if (verbose) {
         LOCK(pool.cs);
         UniValue o(UniValue::VOBJ);
         for (const CTxMemPoolEntry &e : pool.mapTx) {
             const uint256 &txid = e.GetTx().GetId();
             UniValue info(UniValue::VOBJ);
             entryToJSON(pool, info, e);
             o.pushKV(txid.ToString(), info);
         }
         return o;
     } else {
         std::vector<uint256> vtxids;
         pool.queryHashes(vtxids);
 
         UniValue a(UniValue::VARR);
         for (const uint256 &txid : vtxids) {
             a.push_back(txid.ToString());
         }
 
         return a;
     }
 }
 
 static UniValue getrawmempool(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             "getrawmempool ( verbose )\n"
             "\nReturns all transaction ids in memory pool as a json array of "
             "string transaction ids.\n"
             "\nHint: use getmempoolentry to fetch a specific transaction from "
             "the mempool.\n"
             "\nArguments:\n"
             "1. verbose (boolean, optional, default=false) True for a json "
             "object, false for array of transaction ids\n"
             "\nResult: (for verbose = false):\n"
             "[                     (json array of string)\n"
             "  \"transactionid\"     (string) The transaction id\n"
             "  ,...\n"
             "]\n"
             "\nResult: (for verbose = true):\n"
             "{                           (json object)\n"
             "  \"transactionid\" : {       (json object)\n" +
             EntryDescriptionString() +
             "  }, ...\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getrawmempool", "true") +
             HelpExampleRpc("getrawmempool", "true"));
     }
 
     bool fVerbose = false;
     if (!request.params[0].isNull()) {
         fVerbose = request.params[0].get_bool();
     }
 
     return MempoolToJSON(::g_mempool, fVerbose);
 }
 
 static UniValue getmempoolancestors(const Config &config,
                                     const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "getmempoolancestors txid (verbose)\n"
             "\nIf txid is in the mempool, returns all in-mempool ancestors.\n"
             "\nArguments:\n"
             "1. \"txid\"                 (string, required) The transaction id "
             "(must be in mempool)\n"
             "2. verbose                  (boolean, optional, default=false) "
             "True for a json object, false for array of transaction ids\n"
             "\nResult (for verbose=false):\n"
             "[                       (json array of strings)\n"
             "  \"transactionid\"           (string) The transaction id of an "
             "in-mempool ancestor transaction\n"
             "  ,...\n"
             "]\n"
             "\nResult (for verbose=true):\n"
             "{                           (json object)\n"
             "  \"transactionid\" : {       (json object)\n" +
             EntryDescriptionString() +
             "  }, ...\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getmempoolancestors", "\"mytxid\"") +
             HelpExampleRpc("getmempoolancestors", "\"mytxid\""));
     }
 
     bool fVerbose = false;
     if (!request.params[1].isNull()) {
         fVerbose = request.params[1].get_bool();
     }
 
-    uint256 hash = ParseHashV(request.params[0], "parameter 1");
+    TxId txid(ParseHashV(request.params[0], "parameter 1"));
 
     LOCK(g_mempool.cs);
 
-    CTxMemPool::txiter it = g_mempool.mapTx.find(hash);
+    CTxMemPool::txiter it = g_mempool.mapTx.find(txid);
     if (it == g_mempool.mapTx.end()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Transaction not in mempool");
     }
 
     CTxMemPool::setEntries setAncestors;
     uint64_t noLimit = std::numeric_limits<uint64_t>::max();
     std::string dummy;
     g_mempool.CalculateMemPoolAncestors(*it, setAncestors, noLimit, noLimit,
                                         noLimit, noLimit, dummy, false);
 
     if (!fVerbose) {
         UniValue o(UniValue::VARR);
         for (CTxMemPool::txiter ancestorIt : setAncestors) {
             o.push_back(ancestorIt->GetTx().GetId().ToString());
         }
 
         return o;
     } else {
         UniValue o(UniValue::VOBJ);
         for (CTxMemPool::txiter ancestorIt : setAncestors) {
             const CTxMemPoolEntry &e = *ancestorIt;
-            const uint256 &_hash = e.GetTx().GetId();
+            const TxId &_txid = e.GetTx().GetId();
             UniValue info(UniValue::VOBJ);
             entryToJSON(::g_mempool, info, e);
-            o.pushKV(_hash.ToString(), info);
+            o.pushKV(_txid.ToString(), info);
         }
         return o;
     }
 }
 
 static UniValue getmempooldescendants(const Config &config,
                                       const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "getmempooldescendants txid (verbose)\n"
             "\nIf txid is in the mempool, returns all in-mempool descendants.\n"
             "\nArguments:\n"
             "1. \"txid\"                 (string, required) The transaction id "
             "(must be in mempool)\n"
             "2. verbose                  (boolean, optional, default=false) "
             "True for a json object, false for array of transaction ids\n"
             "\nResult (for verbose=false):\n"
             "[                       (json array of strings)\n"
             "  \"transactionid\"           (string) The transaction id of an "
             "in-mempool descendant transaction\n"
             "  ,...\n"
             "]\n"
             "\nResult (for verbose=true):\n"
             "{                           (json object)\n"
             "  \"transactionid\" : {       (json object)\n" +
             EntryDescriptionString() +
             "  }, ...\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getmempooldescendants", "\"mytxid\"") +
             HelpExampleRpc("getmempooldescendants", "\"mytxid\""));
     }
 
     bool fVerbose = false;
     if (!request.params[1].isNull()) {
         fVerbose = request.params[1].get_bool();
     }
 
-    uint256 hash = ParseHashV(request.params[0], "parameter 1");
+    TxId txid(ParseHashV(request.params[0], "parameter 1"));
 
     LOCK(g_mempool.cs);
 
-    CTxMemPool::txiter it = g_mempool.mapTx.find(hash);
+    CTxMemPool::txiter it = g_mempool.mapTx.find(txid);
     if (it == g_mempool.mapTx.end()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Transaction not in mempool");
     }
 
     CTxMemPool::setEntries setDescendants;
     g_mempool.CalculateDescendants(it, setDescendants);
     // CTxMemPool::CalculateDescendants will include the given tx
     setDescendants.erase(it);
 
     if (!fVerbose) {
         UniValue o(UniValue::VARR);
         for (CTxMemPool::txiter descendantIt : setDescendants) {
             o.push_back(descendantIt->GetTx().GetId().ToString());
         }
 
         return o;
     } else {
         UniValue o(UniValue::VOBJ);
         for (CTxMemPool::txiter descendantIt : setDescendants) {
             const CTxMemPoolEntry &e = *descendantIt;
-            const uint256 &_hash = e.GetTx().GetId();
+            const TxId &_txid = e.GetTx().GetId();
             UniValue info(UniValue::VOBJ);
             entryToJSON(::g_mempool, info, e);
-            o.pushKV(_hash.ToString(), info);
+            o.pushKV(_txid.ToString(), info);
         }
         return o;
     }
 }
 
 static UniValue getmempoolentry(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "getmempoolentry txid\n"
             "\nReturns mempool data for given transaction\n"
             "\nArguments:\n"
             "1. \"txid\"                   (string, required) "
             "The transaction id (must be in mempool)\n"
             "\nResult:\n"
             "{                           (json object)\n" +
             EntryDescriptionString() +
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getmempoolentry", "\"mytxid\"") +
             HelpExampleRpc("getmempoolentry", "\"mytxid\""));
     }
 
-    uint256 hash = ParseHashV(request.params[0], "parameter 1");
+    TxId txid(ParseHashV(request.params[0], "parameter 1"));
 
     LOCK(g_mempool.cs);
 
-    CTxMemPool::txiter it = g_mempool.mapTx.find(hash);
+    CTxMemPool::txiter it = g_mempool.mapTx.find(txid);
     if (it == g_mempool.mapTx.end()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Transaction not in mempool");
     }
 
     const CTxMemPoolEntry &e = *it;
     UniValue info(UniValue::VOBJ);
     entryToJSON(::g_mempool, info, e);
     return info;
 }
 
 static UniValue getblockhash(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "getblockhash height\n"
             "\nReturns hash of block in best-block-chain at height provided.\n"
             "\nArguments:\n"
             "1. height         (numeric, required) The height index\n"
             "\nResult:\n"
             "\"hash\"         (string) The block hash\n"
             "\nExamples:\n" +
             HelpExampleCli("getblockhash", "1000") +
             HelpExampleRpc("getblockhash", "1000"));
     }
 
     LOCK(cs_main);
 
     int nHeight = request.params[0].get_int();
     if (nHeight < 0 || nHeight > chainActive.Height()) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Block height out of range");
     }
 
     CBlockIndex *pblockindex = chainActive[nHeight];
     return pblockindex->GetBlockHash().GetHex();
 }
 
 static UniValue getblockheader(const Config &config,
                                const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "getblockheader \"hash\" ( verbose )\n"
             "\nIf verbose is false, returns a string that is serialized, "
             "hex-encoded data for blockheader 'hash'.\n"
             "If verbose is true, returns an Object with information about "
             "blockheader <hash>.\n"
             "\nArguments:\n"
             "1. \"hash\"          (string, required) The block hash\n"
             "2. verbose           (boolean, optional, default=true) true for a "
             "json object, false for the hex encoded data\n"
             "\nResult (for verbose = true):\n"
             "{\n"
             "  \"hash\" : \"hash\",     (string) the block hash (same as "
             "provided)\n"
             "  \"confirmations\" : n,   (numeric) The number of confirmations, "
             "or -1 if the block is not on the main chain\n"
             "  \"height\" : n,          (numeric) The block height or index\n"
             "  \"version\" : n,         (numeric) The block version\n"
             "  \"versionHex\" : \"00000000\", (string) The block version "
             "formatted in hexadecimal\n"
             "  \"merkleroot\" : \"xxxx\", (string) The merkle root\n"
             "  \"time\" : ttt,          (numeric) The block time in seconds "
             "since epoch (Jan 1 1970 GMT)\n"
             "  \"mediantime\" : ttt,    (numeric) The median block time in "
             "seconds since epoch (Jan 1 1970 GMT)\n"
             "  \"nonce\" : n,           (numeric) The nonce\n"
             "  \"bits\" : \"1d00ffff\", (string) The bits\n"
             "  \"difficulty\" : x.xxx,  (numeric) The difficulty\n"
             "  \"chainwork\" : \"0000...1f3\"     (string) Expected number of "
             "hashes required to produce the current chain (in hex)\n"
             "  \"previousblockhash\" : \"hash\",  (string) The hash of the "
             "previous block\n"
             "  \"nextblockhash\" : \"hash\",      (string) The hash of the "
             "next block\n"
             "}\n"
             "\nResult (for verbose=false):\n"
             "\"data\"             (string) A string that is serialized, "
             "hex-encoded data for block 'hash'.\n"
             "\nExamples:\n" +
             HelpExampleCli("getblockheader", "\"00000000c937983704a73af28acdec3"
                                              "7b049d214adbda81d7e2a3dd146f6ed09"
                                              "\"") +
             HelpExampleRpc("getblockheader", "\"00000000c937983704a73af28acdec3"
                                              "7b049d214adbda81d7e2a3dd146f6ed09"
                                              "\""));
     }
 
     LOCK(cs_main);
 
     std::string strHash = request.params[0].get_str();
     BlockHash hash(uint256S(strHash));
 
     bool fVerbose = true;
     if (!request.params[1].isNull()) {
         fVerbose = request.params[1].get_bool();
     }
 
     const CBlockIndex *pblockindex = LookupBlockIndex(hash);
     if (!pblockindex) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
     }
 
     if (!fVerbose) {
         CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION);
         ssBlock << pblockindex->GetBlockHeader();
         std::string strHex = HexStr(ssBlock.begin(), ssBlock.end());
         return strHex;
     }
 
     return blockheaderToJSON(chainActive.Tip(), pblockindex);
 }
 
 static CBlock GetBlockChecked(const Config &config,
                               const CBlockIndex *pblockindex) {
     CBlock block;
     if (fHavePruned && !pblockindex->nStatus.hasData() &&
         pblockindex->nTx > 0) {
         throw JSONRPCError(RPC_MISC_ERROR, "Block not available (pruned data)");
     }
 
     if (!ReadBlockFromDisk(block, pblockindex,
                            config.GetChainParams().GetConsensus())) {
         // Block not found on disk. This could be because we have the block
         // header in our index but don't have the block (for example if a
         // non-whitelisted node sends us an unrequested long chain of valid
         // blocks, we add the headers to our index, but don't accept the block).
         throw JSONRPCError(RPC_MISC_ERROR, "Block not found on disk");
     }
 
     return block;
 }
 
 static UniValue getblock(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "getblock \"blockhash\" ( verbosity )\n"
             "\nIf verbosity is 0 or false, returns a string that is "
             "serialized, hex-encoded data for block 'hash'.\n"
             "If verbosity is 1 or true, returns an Object with information "
             "about block <hash>.\n"
             "If verbosity is 2, returns an Object with information about block "
             "<hash> and information about each transaction.\n"
             "\nArguments:\n"
             "1. \"blockhash\"           (string, required) The block hash\n"
             "2. verbosity             (numeric, optional, default=1) 0 for "
             "hex-encoded data, 1 for a json object, and 2 for json object with "
             "transaction data\n"
             "\nResult (for verbosity = 0):\n"
             "\"data\"                   (string) A string that is serialized, "
             "hex-encoded data for block 'hash'.\n"
             "\nResult (for verbosity = 1):\n"
             "{\n"
             "  \"hash\" : \"hash\",       (string) The block hash (same as "
             "provided)\n"
             "  \"confirmations\" : n,   (numeric) The number of confirmations, "
             "or -1 if the block is not on the main chain\n"
             "  \"size\" : n,            (numeric) The block size\n"
             "  \"height\" : n,          (numeric) The block height or index\n"
             "  \"version\" : n,         (numeric) The block version\n"
             "  \"versionHex\" : \"00000000\", (string) The block version "
             "formatted in hexadecimal\n"
             "  \"merkleroot\" : \"xxxx\", (string) The merkle root\n"
             "  \"tx\" : [               (array of string) The transaction ids\n"
             "     \"transactionid\"     (string) The transaction id\n"
             "     ,...\n"
             "  ],\n"
             "  \"time\" : ttt,          (numeric) The block time in seconds "
             "since epoch (Jan 1 1970 GMT)\n"
             "  \"mediantime\" : ttt,    (numeric) The median block time in "
             "seconds since epoch (Jan 1 1970 GMT)\n"
             "  \"nonce\" : n,           (numeric) The nonce\n"
             "  \"bits\" : \"1d00ffff\",   (string) The bits\n"
             "  \"difficulty\" : x.xxx,  (numeric) The difficulty\n"
             "  \"chainwork\" : \"xxxx\",  (string) Expected number of hashes "
             "required to produce the chain up to this block (in hex)\n"
             "  \"previousblockhash\" : \"hash\",  (string) The hash of the "
             "previous block\n"
             "  \"nextblockhash\" : \"hash\"       (string) The hash of the "
             "next block\n"
             "}\n"
             "\nResult (for verbosity = 2):\n"
             "{\n"
             "  ...,                   Same output as verbosity = 1\n"
             "  \"tx\" : [               (array of Objects) The transactions in "
             "the format of the getrawtransaction RPC; different from verbosity "
             "= 1 \"tx\" result\n"
             "    ...\n"
             "  ],\n"
             "  ...                    Same output as verbosity = 1\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getblock", "\"00000000c937983704a73af28acdec37b049d"
                                        "214adbda81d7e2a3dd146f6ed09\"") +
             HelpExampleRpc("getblock", "\"00000000c937983704a73af28acdec37b049d"
                                        "214adbda81d7e2a3dd146f6ed09\""));
     }
 
     LOCK(cs_main);
 
     std::string strHash = request.params[0].get_str();
     BlockHash hash(uint256S(strHash));
 
     int verbosity = 1;
     if (!request.params[1].isNull()) {
         if (request.params[1].isNum()) {
             verbosity = request.params[1].get_int();
         } else {
             verbosity = request.params[1].get_bool() ? 1 : 0;
         }
     }
 
     const CBlockIndex *pblockindex = LookupBlockIndex(hash);
     if (!pblockindex) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
     }
 
     const CBlock block = GetBlockChecked(config, pblockindex);
 
     if (verbosity <= 0) {
         CDataStream ssBlock(SER_NETWORK,
                             PROTOCOL_VERSION | RPCSerializationFlags());
         ssBlock << block;
         std::string strHex = HexStr(ssBlock.begin(), ssBlock.end());
         return strHex;
     }
 
     return blockToJSON(block, chainActive.Tip(), pblockindex, verbosity >= 2);
 }
 
 struct CCoinsStats {
     int nHeight;
     BlockHash hashBlock;
     uint64_t nTransactions;
     uint64_t nTransactionOutputs;
     uint64_t nBogoSize;
     uint256 hashSerialized;
     uint64_t nDiskSize;
     Amount nTotalAmount;
 
     CCoinsStats()
         : nHeight(0), nTransactions(0), nTransactionOutputs(0), nBogoSize(0),
           nDiskSize(0), nTotalAmount() {}
 };
 
 static void ApplyStats(CCoinsStats &stats, CHashWriter &ss, const uint256 &hash,
                        const std::map<uint32_t, Coin> &outputs) {
     assert(!outputs.empty());
     ss << hash;
     ss << VARINT(outputs.begin()->second.GetHeight() * 2 +
                  outputs.begin()->second.IsCoinBase());
     stats.nTransactions++;
     for (const auto &output : outputs) {
         ss << VARINT(output.first + 1);
         ss << output.second.GetTxOut().scriptPubKey;
         ss << VARINT(output.second.GetTxOut().nValue / SATOSHI,
                      VarIntMode::NONNEGATIVE_SIGNED);
         stats.nTransactionOutputs++;
         stats.nTotalAmount += output.second.GetTxOut().nValue;
         stats.nBogoSize +=
             32 /* txid */ + 4 /* vout index */ + 4 /* height + coinbase */ +
             8 /* amount */ + 2 /* scriptPubKey len */ +
             output.second.GetTxOut().scriptPubKey.size() /* scriptPubKey */;
     }
     ss << VARINT(0u);
 }
 
 //! Calculate statistics about the unspent transaction output set
 static bool GetUTXOStats(CCoinsView *view, CCoinsStats &stats) {
     std::unique_ptr<CCoinsViewCursor> pcursor(view->Cursor());
     assert(pcursor);
 
     CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION);
     stats.hashBlock = pcursor->GetBestBlock();
     {
         LOCK(cs_main);
         stats.nHeight = LookupBlockIndex(stats.hashBlock)->nHeight;
     }
     ss << stats.hashBlock;
     uint256 prevkey;
     std::map<uint32_t, Coin> outputs;
     while (pcursor->Valid()) {
         boost::this_thread::interruption_point();
         COutPoint key;
         Coin coin;
         if (pcursor->GetKey(key) && pcursor->GetValue(coin)) {
             if (!outputs.empty() && key.GetTxId() != prevkey) {
                 ApplyStats(stats, ss, prevkey, outputs);
                 outputs.clear();
             }
             prevkey = key.GetTxId();
             outputs[key.GetN()] = std::move(coin);
         } else {
             return error("%s: unable to read value", __func__);
         }
         pcursor->Next();
     }
     if (!outputs.empty()) {
         ApplyStats(stats, ss, prevkey, outputs);
     }
     stats.hashSerialized = ss.GetHash();
     stats.nDiskSize = view->EstimateSize();
     return true;
 }
 
 static UniValue pruneblockchain(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "pruneblockchain\n"
             "\nArguments:\n"
             "1. \"height\"       (numeric, required) The block height to prune "
             "up to. May be set to a discrete height, or a unix timestamp\n"
             "                  to prune blocks whose block time is at least 2 "
             "hours older than the provided timestamp.\n"
             "\nResult:\n"
             "n    (numeric) Height of the last block pruned.\n"
             "\nExamples:\n" +
             HelpExampleCli("pruneblockchain", "1000") +
             HelpExampleRpc("pruneblockchain", "1000"));
     }
 
     if (!fPruneMode) {
         throw JSONRPCError(
             RPC_MISC_ERROR,
             "Cannot prune blocks because node is not in prune mode.");
     }
 
     LOCK(cs_main);
 
     int heightParam = request.params[0].get_int();
     if (heightParam < 0) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Negative block height.");
     }
 
     // Height value more than a billion is too high to be a block height, and
     // too low to be a block time (corresponds to timestamp from Sep 2001).
     if (heightParam > 1000000000) {
         // Add a 2 hour buffer to include blocks which might have had old
         // timestamps
         CBlockIndex *pindex =
             chainActive.FindEarliestAtLeast(heightParam - TIMESTAMP_WINDOW);
         if (!pindex) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Could not find block with at least the specified timestamp.");
         }
         heightParam = pindex->nHeight;
     }
 
     unsigned int height = (unsigned int)heightParam;
     unsigned int chainHeight = (unsigned int)chainActive.Height();
     if (chainHeight < config.GetChainParams().PruneAfterHeight()) {
         throw JSONRPCError(RPC_MISC_ERROR,
                            "Blockchain is too short for pruning.");
     } else if (height > chainHeight) {
         throw JSONRPCError(
             RPC_INVALID_PARAMETER,
             "Blockchain is shorter than the attempted prune height.");
     } else if (height > chainHeight - MIN_BLOCKS_TO_KEEP) {
         LogPrint(BCLog::RPC, "Attempt to prune blocks close to the tip. "
                              "Retaining the minimum number of blocks.\n");
         height = chainHeight - MIN_BLOCKS_TO_KEEP;
     }
 
     PruneBlockFilesManual(height);
     return uint64_t(height);
 }
 
 static UniValue gettxoutsetinfo(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "gettxoutsetinfo\n"
             "\nReturns statistics about the unspent transaction output set.\n"
             "Note this call may take some time.\n"
             "\nResult:\n"
             "{\n"
             "  \"height\":n,     (numeric) The current block height (index)\n"
             "  \"bestblock\": \"hex\",   (string) the best block hash hex\n"
             "  \"transactions\": n,      (numeric) The number of transactions\n"
             "  \"txouts\": n,            (numeric) The number of output "
             "transactions\n"
             "  \"bogosize\": n,          (numeric) A database-independent "
             "metric for UTXO set size\n"
             "  \"hash_serialized\": \"hash\",   (string) The serialized hash\n"
             "  \"disk_size\": n,         (numeric) The estimated size of the "
             "chainstate on disk\n"
             "  \"total_amount\": x.xxx          (numeric) The total amount\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("gettxoutsetinfo", "") +
             HelpExampleRpc("gettxoutsetinfo", ""));
     }
 
     UniValue ret(UniValue::VOBJ);
 
     CCoinsStats stats;
     FlushStateToDisk();
     if (GetUTXOStats(pcoinsdbview.get(), stats)) {
         ret.pushKV("height", int64_t(stats.nHeight));
         ret.pushKV("bestblock", stats.hashBlock.GetHex());
         ret.pushKV("transactions", int64_t(stats.nTransactions));
         ret.pushKV("txouts", int64_t(stats.nTransactionOutputs));
         ret.pushKV("bogosize", int64_t(stats.nBogoSize));
         ret.pushKV("hash_serialized", stats.hashSerialized.GetHex());
         ret.pushKV("disk_size", stats.nDiskSize);
         ret.pushKV("total_amount", ValueFromAmount(stats.nTotalAmount));
     } else {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Unable to read UTXO set");
     }
     return ret;
 }
 
 UniValue gettxout(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 3) {
         throw std::runtime_error(
             "gettxout \"txid\" n ( include_mempool )\n"
             "\nReturns details about an unspent transaction output.\n"
             "\nArguments:\n"
             "1. \"txid\"             (string, required) The transaction id\n"
             "2. \"n\"                (numeric, required) vout number\n"
             "3. \"include_mempool\"  (boolean, optional) Whether to include "
             "the mempool. Default: true."
             "     Note that an unspent output that is spent in the mempool "
             "won't appear.\n"
             "\nResult:\n"
             "{\n"
             "  \"bestblock\" : \"hash\",    (string) the block hash\n"
             "  \"confirmations\" : n,       (numeric) The number of "
             "confirmations\n"
             "  \"value\" : x.xxx,           (numeric) The transaction value "
             "in " +
             CURRENCY_UNIT +
             "\n"
             "  \"scriptPubKey\" : {         (json object)\n"
             "     \"asm\" : \"code\",       (string) \n"
             "     \"hex\" : \"hex\",        (string) \n"
             "     \"reqSigs\" : n,          (numeric) Number of required "
             "signatures\n"
             "     \"type\" : \"pubkeyhash\", (string) The type, eg pubkeyhash\n"
             "     \"addresses\" : [          (array of string) array of "
             "bitcoin addresses\n"
             "        \"address\"     (string) bitcoin address\n"
             "        ,...\n"
             "     ]\n"
             "  },\n"
             "  \"coinbase\" : true|false   (boolean) Coinbase or not\n"
             "}\n"
 
             "\nExamples:\n"
             "\nGet unspent transactions\n" +
             HelpExampleCli("listunspent", "") + "\nView the details\n" +
             HelpExampleCli("gettxout", "\"txid\" 1") +
             "\nAs a json rpc call\n" +
             HelpExampleRpc("gettxout", "\"txid\", 1"));
     }
 
     LOCK(cs_main);
 
     UniValue ret(UniValue::VOBJ);
 
     std::string strTxId = request.params[0].get_str();
     TxId txid(uint256S(strTxId));
     int n = request.params[1].get_int();
     COutPoint out(txid, n);
     bool fMempool = true;
     if (!request.params[2].isNull()) {
         fMempool = request.params[2].get_bool();
     }
 
     Coin coin;
     if (fMempool) {
         LOCK(g_mempool.cs);
         CCoinsViewMemPool view(pcoinsTip.get(), g_mempool);
         if (!view.GetCoin(out, coin) || g_mempool.isSpent(out)) {
             return NullUniValue;
         }
     } else {
         if (!pcoinsTip->GetCoin(out, coin)) {
             return NullUniValue;
         }
     }
 
     const CBlockIndex *pindex = LookupBlockIndex(pcoinsTip->GetBestBlock());
     ret.pushKV("bestblock", pindex->GetBlockHash().GetHex());
     if (coin.GetHeight() == MEMPOOL_HEIGHT) {
         ret.pushKV("confirmations", 0);
     } else {
         ret.pushKV("confirmations",
                    int64_t(pindex->nHeight - coin.GetHeight() + 1));
     }
     ret.pushKV("value", ValueFromAmount(coin.GetTxOut().nValue));
     UniValue o(UniValue::VOBJ);
     ScriptPubKeyToUniv(coin.GetTxOut().scriptPubKey, o, true);
     ret.pushKV("scriptPubKey", o);
     ret.pushKV("coinbase", coin.IsCoinBase());
 
     return ret;
 }
 
 static UniValue verifychain(const Config &config,
                             const JSONRPCRequest &request) {
     int nCheckLevel = gArgs.GetArg("-checklevel", DEFAULT_CHECKLEVEL);
     int nCheckDepth = gArgs.GetArg("-checkblocks", DEFAULT_CHECKBLOCKS);
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             "verifychain ( checklevel nblocks )\n"
             "\nVerifies blockchain database.\n"
             "\nArguments:\n"
             "1. checklevel   (numeric, optional, 0-4, default=" +
             strprintf("%d", nCheckLevel) +
             ") How thorough the block verification is.\n"
             "2. nblocks      (numeric, optional, default=" +
             strprintf("%d", nCheckDepth) +
             ", 0=all) The number of blocks to check.\n"
             "\nResult:\n"
             "true|false       (boolean) Verified or not\n"
             "\nExamples:\n" +
             HelpExampleCli("verifychain", "") +
             HelpExampleRpc("verifychain", ""));
     }
 
     LOCK(cs_main);
 
     if (!request.params[0].isNull()) {
         nCheckLevel = request.params[0].get_int();
     }
     if (!request.params[1].isNull()) {
         nCheckDepth = request.params[1].get_int();
     }
 
     return CVerifyDB().VerifyDB(config, pcoinsTip.get(), nCheckLevel,
                                 nCheckDepth);
 }
 
 UniValue getblockchaininfo(const Config &config,
                            const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "getblockchaininfo\n"
             "Returns an object containing various state info regarding "
             "blockchain processing.\n"
             "\nResult:\n"
             "{\n"
             "  \"chain\": \"xxxx\",              (string) current network name "
             "as defined in BIP70 (main, test, regtest)\n"
             "  \"blocks\": xxxxxx,             (numeric) the current number of "
             "blocks processed in the server\n"
             "  \"headers\": xxxxxx,            (numeric) the current number of "
             "headers we have validated\n"
             "  \"bestblockhash\": \"...\",       (string) the hash of the "
             "currently best block\n"
             "  \"difficulty\": xxxxxx,         (numeric) the current "
             "difficulty\n"
             "  \"mediantime\": xxxxxx,         (numeric) median time for the "
             "current best block\n"
             "  \"verificationprogress\": xxxx, (numeric) estimate of "
             "verification progress [0..1]\n"
             "  \"initialblockdownload\": xxxx, (bool) (debug information) "
             "estimate of whether this node is in Initial Block Download mode.\n"
             "  \"chainwork\": \"xxxx\"           (string) total amount of work "
             "in active chain, in hexadecimal\n"
             "  \"size_on_disk\": xxxxxx,       (numeric) the estimated size of "
             "the block and undo files on disk\n"
             "  \"pruned\": xx,                 (boolean) if the blocks are "
             "subject to pruning\n"
             "  \"pruneheight\": xxxxxx,        (numeric) lowest-height "
             "complete block stored (only present if pruning is enabled)\n"
             "  \"automatic_pruning\": xx,      (boolean) whether automatic "
             "pruning is enabled (only present if pruning is enabled)\n"
             "  \"prune_target_size\": xxxxxx,  (numeric) the target size "
             "used by pruning (only present if automatic pruning is enabled)\n"
             "  \"warnings\" : \"...\",           (string) any network and "
             "blockchain warnings.\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getblockchaininfo", "") +
             HelpExampleRpc("getblockchaininfo", ""));
     }
 
     LOCK(cs_main);
 
     const CBlockIndex *tip = chainActive.Tip();
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("chain", config.GetChainParams().NetworkIDString());
     obj.pushKV("blocks", int(chainActive.Height()));
     obj.pushKV("headers", pindexBestHeader ? pindexBestHeader->nHeight : -1);
     obj.pushKV("bestblockhash", tip->GetBlockHash().GetHex());
     obj.pushKV("difficulty", double(GetDifficulty(tip)));
     obj.pushKV("mediantime", int64_t(tip->GetMedianTimePast()));
     obj.pushKV("verificationprogress",
                GuessVerificationProgress(Params().TxData(), tip));
     obj.pushKV("initialblockdownload", IsInitialBlockDownload());
     obj.pushKV("chainwork", tip->nChainWork.GetHex());
     obj.pushKV("size_on_disk", CalculateCurrentUsage());
     obj.pushKV("pruned", fPruneMode);
 
     if (fPruneMode) {
         const CBlockIndex *block = tip;
         assert(block);
         while (block->pprev && (block->pprev->nStatus.hasData())) {
             block = block->pprev;
         }
 
         obj.pushKV("pruneheight", block->nHeight);
 
         // if 0, execution bypasses the whole if block.
         bool automatic_pruning = (gArgs.GetArg("-prune", 0) != 1);
         obj.pushKV("automatic_pruning", automatic_pruning);
         if (automatic_pruning) {
             obj.pushKV("prune_target_size", nPruneTarget);
         }
     }
 
     obj.pushKV("warnings", GetWarnings("statusbar"));
     return obj;
 }
 
 /** Comparison function for sorting the getchaintips heads.  */
 struct CompareBlocksByHeight {
     bool operator()(const CBlockIndex *a, const CBlockIndex *b) const {
         // Make sure that unequal blocks with the same height do not compare
         // equal. Use the pointers themselves to make a distinction.
         if (a->nHeight != b->nHeight) {
             return (a->nHeight > b->nHeight);
         }
 
         return a < b;
     }
 };
 
 static UniValue getchaintips(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "getchaintips\n"
             "Return information about all known tips in the block tree,"
             " including the main chain as well as orphaned branches.\n"
             "\nResult:\n"
             "[\n"
             "  {\n"
             "    \"height\": xxxx,         (numeric) height of the chain tip\n"
             "    \"hash\": \"xxxx\",         (string) block hash of the tip\n"
             "    \"branchlen\": 0          (numeric) zero for main chain\n"
             "    \"status\": \"active\"      (string) \"active\" for the main "
             "chain\n"
             "  },\n"
             "  {\n"
             "    \"height\": xxxx,\n"
             "    \"hash\": \"xxxx\",\n"
             "    \"branchlen\": 1          (numeric) length of branch "
             "connecting the tip to the main chain\n"
             "    \"status\": \"xxxx\"        (string) status of the chain "
             "(active, valid-fork, valid-headers, headers-only, invalid)\n"
             "  }\n"
             "]\n"
             "Possible values for status:\n"
             "1.  \"invalid\"               This branch contains at least one "
             "invalid block\n"
             "2.  \"parked\"                This branch contains at least one "
             "parked block\n"
             "3.  \"headers-only\"          Not all blocks for this branch are "
             "available, but the headers are valid\n"
             "4.  \"valid-headers\"         All blocks are available for this "
             "branch, but they were never fully validated\n"
             "5.  \"valid-fork\"            This branch is not part of the "
             "active chain, but is fully validated\n"
             "6.  \"active\"                This is the tip of the active main "
             "chain, which is certainly valid\n"
             "\nExamples:\n" +
             HelpExampleCli("getchaintips", "") +
             HelpExampleRpc("getchaintips", ""));
     }
 
     LOCK(cs_main);
 
     /**
      * Idea:  the set of chain tips is chainActive.tip, plus orphan blocks which
      * do not have another orphan building off of them.
      * Algorithm:
      *  - Make one pass through mapBlockIndex, picking out the orphan blocks,
      * and also storing a set of the orphan block's pprev pointers.
      *  - Iterate through the orphan blocks. If the block isn't pointed to by
      * another orphan, it is a chain tip.
      *  - add chainActive.Tip()
      */
     std::set<const CBlockIndex *, CompareBlocksByHeight> setTips;
     std::set<const CBlockIndex *> setOrphans;
     std::set<const CBlockIndex *> setPrevs;
 
     for (const std::pair<const BlockHash, CBlockIndex *> &item :
          mapBlockIndex) {
         if (!chainActive.Contains(item.second)) {
             setOrphans.insert(item.second);
             setPrevs.insert(item.second->pprev);
         }
     }
 
     for (std::set<const CBlockIndex *>::iterator it = setOrphans.begin();
          it != setOrphans.end(); ++it) {
         if (setPrevs.erase(*it) == 0) {
             setTips.insert(*it);
         }
     }
 
     // Always report the currently active tip.
     setTips.insert(chainActive.Tip());
 
     /* Construct the output array.  */
     UniValue res(UniValue::VARR);
     for (const CBlockIndex *block : setTips) {
         UniValue obj(UniValue::VOBJ);
         obj.pushKV("height", block->nHeight);
         obj.pushKV("hash", block->phashBlock->GetHex());
 
         const int branchLen =
             block->nHeight - chainActive.FindFork(block)->nHeight;
         obj.pushKV("branchlen", branchLen);
 
         std::string status;
         if (chainActive.Contains(block)) {
             // This block is part of the currently active chain.
             status = "active";
         } else if (block->nStatus.isInvalid()) {
             // This block or one of its ancestors is invalid.
             status = "invalid";
         } else if (block->nStatus.isOnParkedChain()) {
             // This block or one of its ancestors is parked.
             status = "parked";
         } else if (block->nChainTx == 0) {
             // This block cannot be connected because full block data for it or
             // one of its parents is missing.
             status = "headers-only";
         } else if (block->IsValid(BlockValidity::SCRIPTS)) {
             // This block is fully validated, but no longer part of the active
             // chain. It was probably the active block once, but was
             // reorganized.
             status = "valid-fork";
         } else if (block->IsValid(BlockValidity::TREE)) {
             // The headers for this block are valid, but it has not been
             // validated. It was probably never part of the most-work chain.
             status = "valid-headers";
         } else {
             // No clue.
             status = "unknown";
         }
         obj.pushKV("status", status);
 
         res.push_back(obj);
     }
 
     return res;
 }
 
 UniValue MempoolInfoToJSON(const CTxMemPool &pool) {
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("loaded", pool.IsLoaded());
     ret.pushKV("size", (int64_t)pool.size());
     ret.pushKV("bytes", (int64_t)pool.GetTotalTxSize());
     ret.pushKV("usage", (int64_t)pool.DynamicMemoryUsage());
     size_t maxmempool =
         gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
     ret.pushKV("maxmempool", (int64_t)maxmempool);
     ret.pushKV(
         "mempoolminfee",
         ValueFromAmount(std::max(pool.GetMinFee(maxmempool), ::minRelayTxFee)
                             .GetFeePerK()));
     ret.pushKV("minrelaytxfee", ValueFromAmount(::minRelayTxFee.GetFeePerK()));
 
     return ret;
 }
 
 static UniValue getmempoolinfo(const Config &config,
                                const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "getmempoolinfo\n"
             "\nReturns details on the active state of the TX memory pool.\n"
             "\nResult:\n"
             "{\n"
             "  \"loaded\": true|false         (boolean) True if the mempool is "
             "fully loaded\n"
             "  \"size\": xxxxx,               (numeric) Current tx count\n"
             "  \"bytes\": xxxxx,              (numeric) Transaction size.\n"
             "  \"usage\": xxxxx,              (numeric) Total memory usage for "
             "the mempool\n"
             "  \"maxmempool\": xxxxx,         (numeric) Maximum memory usage "
             "for the mempool\n"
             "  \"mempoolminfee\": xxxxx       (numeric) Minimum fee rate in " +
             CURRENCY_UNIT +
             "/kB for tx to be accepted. Is the maximum of minrelaytxfee and "
             "minimum mempool fee\n"
             "  \"minrelaytxfee\": xxxxx       (numeric) Current minimum relay "
             "fee for transactions\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getmempoolinfo", "") +
             HelpExampleRpc("getmempoolinfo", ""));
     }
 
     return MempoolInfoToJSON(::g_mempool);
 }
 
 static UniValue preciousblock(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "preciousblock \"blockhash\"\n"
             "\nTreats a block as if it were received before others with the "
             "same work.\n"
             "\nA later preciousblock call can override the effect of an "
             "earlier one.\n"
             "\nThe effects of preciousblock are not retained across restarts.\n"
             "\nArguments:\n"
             "1. \"blockhash\"   (string, required) the hash of the block to "
             "mark as precious\n"
             "\nResult:\n"
             "\nExamples:\n" +
             HelpExampleCli("preciousblock", "\"blockhash\"") +
             HelpExampleRpc("preciousblock", "\"blockhash\""));
     }
 
     std::string strHash = request.params[0].get_str();
     BlockHash hash(uint256S(strHash));
     CBlockIndex *pblockindex;
 
     {
         LOCK(cs_main);
         pblockindex = LookupBlockIndex(hash);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
     }
 
     CValidationState state;
     PreciousBlock(config, state, pblockindex);
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, state.GetRejectReason());
     }
 
     return NullUniValue;
 }
 
 UniValue finalizeblock(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "finalizeblock \"blockhash\"\n"
 
             "\nTreats a block as final. It cannot be reorged. Any chain\n"
             "that does not contain this block is invalid. Used on a less\n"
             "work chain, it can effectively PUTS YOU OUT OF CONSENSUS.\n"
             "USE WITH CAUTION!\n"
             "\nResult:\n"
             "\nExamples:\n" +
             HelpExampleCli("finalizeblock", "\"blockhash\"") +
             HelpExampleRpc("finalizeblock", "\"blockhash\""));
     }
 
     std::string strHash = request.params[0].get_str();
     BlockHash hash(uint256S(strHash));
     CValidationState state;
 
     {
         LOCK(cs_main);
         CBlockIndex *pblockindex = LookupBlockIndex(hash);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         FinalizeBlockAndInvalidate(config, state, pblockindex);
     }
 
     if (state.IsValid()) {
         ActivateBestChain(config, state);
     }
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, FormatStateMessage(state));
     }
 
     return NullUniValue;
 }
 
 static UniValue invalidateblock(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "invalidateblock \"blockhash\"\n"
             "\nPermanently marks a block as invalid, as if it "
             "violated a consensus rule.\n"
             "\nArguments:\n"
             "1. \"blockhash\"   (string, required) the hash of "
             "the block to mark as invalid\n"
             "\nResult:\n"
             "\nExamples:\n" +
             HelpExampleCli("invalidateblock", "\"blockhash\"") +
             HelpExampleRpc("invalidateblock", "\"blockhash\""));
     }
 
     const std::string strHash = request.params[0].get_str();
     const BlockHash hash(uint256S(strHash));
     CValidationState state;
 
     {
         LOCK(cs_main);
         CBlockIndex *pblockindex = LookupBlockIndex(hash);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         InvalidateBlock(config, state, pblockindex);
     }
 
     if (state.IsValid()) {
         ActivateBestChain(config, state);
     }
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, FormatStateMessage(state));
     }
 
     return NullUniValue;
 }
 
 UniValue parkblock(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error("parkblock \"blockhash\"\n"
                                  "\nMarks a block as parked.\n"
                                  "\nArguments:\n"
                                  "1. \"blockhash\"   (string, required) the "
                                  "hash of the block to park\n"
                                  "\nResult:\n"
                                  "\nExamples:\n" +
                                  HelpExampleCli("parkblock", "\"blockhash\"") +
                                  HelpExampleRpc("parkblock", "\"blockhash\""));
     }
 
     const std::string strHash = request.params[0].get_str();
     const BlockHash hash(uint256S(strHash));
     CValidationState state;
 
     {
         LOCK(cs_main);
         if (mapBlockIndex.count(hash) == 0) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         CBlockIndex *pblockindex = mapBlockIndex[hash];
         ParkBlock(config, state, pblockindex);
     }
 
     if (state.IsValid()) {
         ActivateBestChain(config, state);
     }
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, state.GetRejectReason());
     }
 
     return NullUniValue;
 }
 
 static UniValue reconsiderblock(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "reconsiderblock \"blockhash\"\n"
             "\nRemoves invalidity status of a block and its descendants, "
             "reconsider them for activation.\n"
             "This can be used to undo the effects of invalidateblock.\n"
             "\nArguments:\n"
             "1. \"blockhash\"   (string, required) the hash of the block to "
             "reconsider\n"
             "\nResult:\n"
             "\nExamples:\n" +
             HelpExampleCli("reconsiderblock", "\"blockhash\"") +
             HelpExampleRpc("reconsiderblock", "\"blockhash\""));
     }
 
     const std::string strHash = request.params[0].get_str();
     const BlockHash hash(uint256S(strHash));
 
     {
         LOCK(cs_main);
         CBlockIndex *pblockindex = LookupBlockIndex(hash);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         ResetBlockFailureFlags(pblockindex);
     }
 
     CValidationState state;
     ActivateBestChain(config, state);
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, FormatStateMessage(state));
     }
 
     return NullUniValue;
 }
 
 UniValue unparkblock(const Config &config, const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error(
             "unparkblock \"blockhash\"\n"
             "\nRemoves parked status of a block and its descendants, "
             "reconsider them for activation.\n"
             "This can be used to undo the effects of parkblock.\n"
             "\nArguments:\n"
             "1. \"blockhash\"   (string, required) the hash of the block to "
             "unpark\n"
             "\nResult:\n"
             "\nExamples:\n" +
             HelpExampleCli("unparkblock", "\"blockhash\"") +
             HelpExampleRpc("unparkblock", "\"blockhash\""));
     }
 
     const std::string strHash = request.params[0].get_str();
     const BlockHash hash(uint256S(strHash));
 
     {
         LOCK(cs_main);
         if (mapBlockIndex.count(hash) == 0) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
 
         CBlockIndex *pblockindex = mapBlockIndex[hash];
         UnparkBlockAndChildren(pblockindex);
     }
 
     CValidationState state;
     ActivateBestChain(config, state);
 
     if (!state.IsValid()) {
         throw JSONRPCError(RPC_DATABASE_ERROR, state.GetRejectReason());
     }
 
     return NullUniValue;
 }
 
 static UniValue getchaintxstats(const Config &config,
                                 const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             "getchaintxstats ( nblocks blockhash )\n"
             "\nCompute statistics about the total number and rate of "
             "transactions in the chain.\n"
             "\nArguments:\n"
             "1. nblocks      (numeric, optional) Size of the window in number "
             "of blocks (default: one month).\n"
             "2. \"blockhash\"  (string, optional) The hash of the block that "
             "ends the window.\n"
             "\nResult:\n"
             "{\n"
             "  \"time\": xxxxx,                         (numeric) The "
             "timestamp for the final block in the window in UNIX format.\n"
             "  \"txcount\": xxxxx,                      (numeric) The total "
             "number of transactions in the chain up to that point.\n"
             "  \"window_final_block_hash\": \"...\",      (string) The hash of "
             "the final block in the window.\n"
             "  \"window_block_count\": xxxxx,           (numeric) Size of "
             "the window in number of blocks.\n"
             "  \"window_tx_count\": xxxxx,              (numeric) The number "
             "of transactions in the window. Only returned if "
             "\"window_block_count\" is > 0.\n"
             "  \"window_interval\": xxxxx,              (numeric) The elapsed "
             "time in the window in seconds. Only returned if "
             "\"window_block_count\" is > 0.\n"
             "  \"txrate\": x.xx,                        (numeric) The average "
             "rate of transactions per second in the window. Only returned if "
             "\"window_interval\" is > 0.\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getchaintxstats", "") +
             HelpExampleRpc("getchaintxstats", "2016"));
     }
 
     const CBlockIndex *pindex;
 
     // By default: 1 month
     int blockcount = 30 * 24 * 60 * 60 /
                      config.GetChainParams().GetConsensus().nPowTargetSpacing;
 
     if (request.params[1].isNull()) {
         LOCK(cs_main);
         pindex = chainActive.Tip();
     } else {
         BlockHash hash(uint256S(request.params[1].get_str()));
         LOCK(cs_main);
         pindex = LookupBlockIndex(hash);
         if (!pindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
         if (!chainActive.Contains(pindex)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                "Block is not in main chain");
         }
     }
 
     assert(pindex != nullptr);
 
     if (request.params[0].isNull()) {
         blockcount = std::max(0, std::min(blockcount, pindex->nHeight - 1));
     } else {
         blockcount = request.params[0].get_int();
 
         if (blockcount < 0 ||
             (blockcount > 0 && blockcount >= pindex->nHeight)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid block count: "
                                                       "should be between 0 and "
                                                       "the block's height - 1");
         }
     }
 
     const CBlockIndex *pindexPast =
         pindex->GetAncestor(pindex->nHeight - blockcount);
     int nTimeDiff =
         pindex->GetMedianTimePast() - pindexPast->GetMedianTimePast();
     int nTxDiff = pindex->nChainTx - pindexPast->nChainTx;
 
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("time", int64_t(pindex->nTime));
     ret.pushKV("txcount", int64_t(pindex->nChainTx));
     ret.pushKV("window_final_block_hash", pindex->GetBlockHash().GetHex());
     ret.pushKV("window_block_count", blockcount);
     if (blockcount > 0) {
         ret.pushKV("window_tx_count", nTxDiff);
         ret.pushKV("window_interval", nTimeDiff);
         if (nTimeDiff > 0) {
             ret.pushKV("txrate", double(nTxDiff) / nTimeDiff);
         }
     }
 
     return ret;
 }
 
 template <typename T>
 static T CalculateTruncatedMedian(std::vector<T> &scores) {
     size_t size = scores.size();
     if (size == 0) {
         return T();
     }
 
     std::sort(scores.begin(), scores.end());
     if (size % 2 == 0) {
         return (scores[size / 2 - 1] + scores[size / 2]) / 2;
     } else {
         return scores[size / 2];
     }
 }
 
 template <typename T> static inline bool SetHasKeys(const std::set<T> &set) {
     return false;
 }
 template <typename T, typename Tk, typename... Args>
 static inline bool SetHasKeys(const std::set<T> &set, const Tk &key,
                               const Args &... args) {
     return (set.count(key) != 0) || SetHasKeys(set, args...);
 }
 
 // outpoint (needed for the utxo index) + nHeight + fCoinBase
 static constexpr size_t PER_UTXO_OVERHEAD =
     sizeof(COutPoint) + sizeof(uint32_t) + sizeof(bool);
 
 static UniValue getblockstats(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 4) {
         throw std::runtime_error(
             "getblockstats hash_or_height ( stats )\n"
             "\nCompute per block statistics for a given window. All amounts "
             "are in " +
             CURRENCY_UNIT +
             ".\n"
             "It won't work for some heights with pruning.\n"
             "It won't work without -txindex for utxo_size_inc, *fee or "
             "*feerate stats.\n"
             "\nArguments:\n"
             "1. \"hash_or_height\"     (string or numeric, required) The block "
             "hash or height of the target block\n"
             "2. \"stats\"              (array,  optional) Values to plot, by "
             "default all values (see result below)\n"
             "    [\n"
             "      \"height\",         (string, optional) Selected statistic\n"
             "      \"time\",           (string, optional) Selected statistic\n"
             "      ,...\n"
             "    ]\n"
             "\nResult:\n"
             "{                           (json object)\n"
             "  \"avgfee\": x.xxx,          (numeric) Average fee in the block\n"
             "  \"avgfeerate\": x.xxx,      (numeric) Average feerate (in " +
             CURRENCY_UNIT +
             " per byte)\n"
             "  \"avgtxsize\": xxxxx,       (numeric) Average transaction size\n"
             "  \"blockhash\": xxxxx,       (string) The block hash (to check "
             "for potential reorgs)\n"
             "  \"height\": xxxxx,          (numeric) The height of the block\n"
             "  \"ins\": xxxxx,             (numeric) The number of inputs "
             "(excluding coinbase)\n"
             "  \"maxfee\": xxxxx,          (numeric) Maximum fee in the block\n"
             "  \"maxfeerate\": xxxxx,      (numeric) Maximum feerate (in " +
             CURRENCY_UNIT +
             " per byte)\n"
             "  \"maxtxsize\": xxxxx,       (numeric) Maximum transaction size\n"
             "  \"medianfee\": x.xxx,       (numeric) Truncated median fee in "
             "the block\n"
             "  \"medianfeerate\": x.xxx,   (numeric) Truncated median feerate "
             "(in " +
             CURRENCY_UNIT +
             " per byte)\n"
             "  \"mediantime\": xxxxx,      (numeric) The block median time "
             "past\n"
             "  \"mediantxsize\": xxxxx,    (numeric) Truncated median "
             "transaction size\n"
             "  \"minfee\": x.xxx,          (numeric) Minimum fee in the block\n"
             "  \"minfeerate\": xx.xx,      (numeric) Minimum feerate (in " +
             CURRENCY_UNIT +
             " per byte)\n"
             "  \"mintxsize\": xxxxx,       (numeric) Minimum transaction size\n"
             "  \"outs\": xxxxx,            (numeric) The number of outputs\n"
             "  \"subsidy\": x.xxx,         (numeric) The block subsidy\n"
             "  \"time\": xxxxx,            (numeric) The block time\n"
             "  \"total_out\": x.xxx,       (numeric) Total amount in all "
             "outputs (excluding coinbase and thus reward [ie subsidy + "
             "totalfee])\n"
             "  \"total_size\": xxxxx,      (numeric) Total size of all "
             "non-coinbase transactions\n"
             "  \"totalfee\": x.xxx,        (numeric) The fee total\n"
             "  \"txs\": xxxxx,             (numeric) The number of "
             "transactions (excluding coinbase)\n"
             "  \"utxo_increase\": xxxxx,   (numeric) The increase/decrease in "
             "the number of unspent outputs\n"
             "  \"utxo_size_inc\": xxxxx,   (numeric) The increase/decrease in "
             "size for the utxo index (not discounting op_return and similar)\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getblockstats",
                            "1000 '[\"minfeerate\",\"avgfeerate\"]'") +
             HelpExampleRpc("getblockstats",
                            "1000 '[\"minfeerate\",\"avgfeerate\"]'"));
     }
 
     LOCK(cs_main);
 
     CBlockIndex *pindex;
     if (request.params[0].isNum()) {
         const int height = request.params[0].get_int();
         const int current_tip = chainActive.Height();
         if (height < 0) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Target block height %d is negative", height));
         }
         if (height > current_tip) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Target block height %d after current tip %d", height,
                           current_tip));
         }
 
         pindex = chainActive[height];
     } else {
         const std::string strHash = request.params[0].get_str();
         const BlockHash hash(uint256S(strHash));
         pindex = LookupBlockIndex(hash);
         if (!pindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
         if (!chainActive.Contains(pindex)) {
             throw JSONRPCError(RPC_INVALID_PARAMETER,
                                strprintf("Block is not in chain %s",
                                          Params().NetworkIDString()));
         }
     }
 
     assert(pindex != nullptr);
 
     std::set<std::string> stats;
     if (!request.params[1].isNull()) {
         const UniValue stats_univalue = request.params[1].get_array();
         for (unsigned int i = 0; i < stats_univalue.size(); i++) {
             const std::string stat = stats_univalue[i].get_str();
             stats.insert(stat);
         }
     }
 
     const CBlock block = GetBlockChecked(config, pindex);
 
     // Calculate everything if nothing selected (default)
     const bool do_all = stats.size() == 0;
     const bool do_mediantxsize = do_all || stats.count("mediantxsize") != 0;
     const bool do_medianfee = do_all || stats.count("medianfee") != 0;
     const bool do_medianfeerate = do_all || stats.count("medianfeerate") != 0;
     const bool loop_inputs =
         do_all || do_medianfee || do_medianfeerate ||
         SetHasKeys(stats, "utxo_size_inc", "totalfee", "avgfee", "avgfeerate",
                    "minfee", "maxfee", "minfeerate", "maxfeerate");
     const bool loop_outputs = do_all || loop_inputs || stats.count("total_out");
     const bool do_calculate_size =
         do_mediantxsize || loop_inputs ||
         SetHasKeys(stats, "total_size", "avgtxsize", "mintxsize", "maxtxsize");
 
     const int64_t blockMaxSize = config.GetMaxBlockSize();
     Amount maxfee = Amount::zero();
     Amount maxfeerate = Amount::zero();
     Amount minfee = MAX_MONEY;
     Amount minfeerate = MAX_MONEY;
     Amount total_out = Amount::zero();
     Amount totalfee = Amount::zero();
     int64_t inputs = 0;
     int64_t maxtxsize = 0;
     int64_t mintxsize = blockMaxSize;
     int64_t outputs = 0;
     int64_t total_size = 0;
     int64_t utxo_size_inc = 0;
     std::vector<Amount> fee_array;
     std::vector<Amount> feerate_array;
     std::vector<int64_t> txsize_array;
 
     const Consensus::Params &params = config.GetChainParams().GetConsensus();
 
     for (const auto &tx : block.vtx) {
         outputs += tx->vout.size();
         Amount tx_total_out = Amount::zero();
         if (loop_outputs) {
             for (const CTxOut &out : tx->vout) {
                 tx_total_out += out.nValue;
                 utxo_size_inc +=
                     GetSerializeSize(out, PROTOCOL_VERSION) + PER_UTXO_OVERHEAD;
             }
         }
 
         if (tx->IsCoinBase()) {
             continue;
         }
 
         // Don't count coinbase's fake input
         inputs += tx->vin.size();
         // Don't count coinbase reward
         total_out += tx_total_out;
 
         int64_t tx_size = 0;
         if (do_calculate_size) {
 
             tx_size = tx->GetTotalSize();
             if (do_mediantxsize) {
                 txsize_array.push_back(tx_size);
             }
             maxtxsize = std::max(maxtxsize, tx_size);
             mintxsize = std::min(mintxsize, tx_size);
             total_size += tx_size;
         }
 
         if (loop_inputs) {
             if (!g_txindex) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER,
                                    "One or more of the selected stats requires "
                                    "-txindex enabled");
             }
 
             Amount tx_total_in = Amount::zero();
             for (const CTxIn &in : tx->vin) {
                 CTransactionRef tx_in;
                 uint256 hashBlock;
                 if (!GetTransaction(params, in.prevout.GetTxId(), tx_in,
                                     hashBlock, false)) {
                     throw JSONRPCError(RPC_INTERNAL_ERROR,
                                        std::string("Unexpected internal error "
                                                    "(tx index seems corrupt)"));
                 }
 
                 CTxOut prevoutput = tx_in->vout[in.prevout.GetN()];
 
                 tx_total_in += prevoutput.nValue;
                 utxo_size_inc -=
                     GetSerializeSize(prevoutput, PROTOCOL_VERSION) +
                     PER_UTXO_OVERHEAD;
             }
 
             Amount txfee = tx_total_in - tx_total_out;
             assert(MoneyRange(txfee));
             if (do_medianfee) {
                 fee_array.push_back(txfee);
             }
             maxfee = std::max(maxfee, txfee);
             minfee = std::min(minfee, txfee);
             totalfee += txfee;
 
             Amount feerate = txfee / tx_size;
             if (do_medianfeerate) {
                 feerate_array.push_back(feerate);
             }
             maxfeerate = std::max(maxfeerate, feerate);
             minfeerate = std::min(minfeerate, feerate);
         }
     }
 
     UniValue ret_all(UniValue::VOBJ);
     ret_all.pushKV("avgfee",
                    ValueFromAmount((block.vtx.size() > 1)
                                        ? totalfee / int((block.vtx.size() - 1))
                                        : Amount::zero()));
     ret_all.pushKV("avgfeerate",
                    ValueFromAmount((total_size > 0) ? totalfee / total_size
                                                     : Amount::zero()));
     ret_all.pushKV("avgtxsize", (block.vtx.size() > 1)
                                     ? total_size / (block.vtx.size() - 1)
                                     : 0);
     ret_all.pushKV("blockhash", pindex->GetBlockHash().GetHex());
     ret_all.pushKV("height", (int64_t)pindex->nHeight);
     ret_all.pushKV("ins", inputs);
     ret_all.pushKV("maxfee", ValueFromAmount(maxfee));
     ret_all.pushKV("maxfeerate", ValueFromAmount(maxfeerate));
     ret_all.pushKV("maxtxsize", maxtxsize);
     ret_all.pushKV("medianfee",
                    ValueFromAmount(CalculateTruncatedMedian(fee_array)));
     ret_all.pushKV("medianfeerate",
                    ValueFromAmount(CalculateTruncatedMedian(feerate_array)));
     ret_all.pushKV("mediantime", pindex->GetMedianTimePast());
     ret_all.pushKV("mediantxsize", CalculateTruncatedMedian(txsize_array));
     ret_all.pushKV(
         "minfee",
         ValueFromAmount((minfee == MAX_MONEY) ? Amount::zero() : minfee));
     ret_all.pushKV("minfeerate",
                    ValueFromAmount((minfeerate == MAX_MONEY) ? Amount::zero()
                                                              : minfeerate));
     ret_all.pushKV("mintxsize", mintxsize == blockMaxSize ? 0 : mintxsize);
     ret_all.pushKV("outs", outputs);
     ret_all.pushKV("subsidy", ValueFromAmount(GetBlockSubsidy(
                                   pindex->nHeight, Params().GetConsensus())));
     ret_all.pushKV("time", pindex->GetBlockTime());
     ret_all.pushKV("total_out", ValueFromAmount(total_out));
     ret_all.pushKV("total_size", total_size);
     ret_all.pushKV("totalfee", ValueFromAmount(totalfee));
     ret_all.pushKV("txs", (int64_t)block.vtx.size());
     ret_all.pushKV("utxo_increase", outputs - inputs);
     ret_all.pushKV("utxo_size_inc", utxo_size_inc);
 
     if (do_all) {
         return ret_all;
     }
 
     UniValue ret(UniValue::VOBJ);
     for (const std::string &stat : stats) {
         const UniValue &value = ret_all[stat];
         if (value.isNull()) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf("Invalid selected statistic %s", stat));
         }
         ret.pushKV(stat, value);
     }
     return ret;
 }
 
 static UniValue savemempool(const Config &config,
                             const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error("savemempool\n"
                                  "\nDumps the mempool to disk. It will fail "
                                  "until the previous dump is fully loaded.\n"
                                  "\nExamples:\n" +
                                  HelpExampleCli("savemempool", "") +
                                  HelpExampleRpc("savemempool", ""));
     }
 
     if (!::g_mempool.IsLoaded()) {
         throw JSONRPCError(RPC_MISC_ERROR, "The mempool was not loaded yet");
     }
 
     if (!DumpMempool(::g_mempool)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Unable to dump mempool to disk");
     }
 
     return NullUniValue;
 }
 
 //! Search for a given set of pubkey scripts
 static bool FindScriptPubKey(std::atomic<int> &scan_progress,
                              const std::atomic<bool> &should_abort,
                              int64_t &count, CCoinsViewCursor *cursor,
                              const std::set<CScript> &needles,
                              std::map<COutPoint, Coin> &out_results) {
     scan_progress = 0;
     count = 0;
     while (cursor->Valid()) {
         COutPoint key;
         Coin coin;
         if (!cursor->GetKey(key) || !cursor->GetValue(coin)) {
             return false;
         }
         if (++count % 8192 == 0) {
             boost::this_thread::interruption_point();
             if (should_abort) {
                 // allow to abort the scan via the abort reference
                 return false;
             }
         }
         if (count % 256 == 0) {
             // update progress reference every 256 item
             const TxId &txid = key.GetTxId();
             uint32_t high = 0x100 * *txid.begin() + *(txid.begin() + 1);
             scan_progress = int(high * 100.0 / 65536.0 + 0.5);
         }
         if (needles.count(coin.GetTxOut().scriptPubKey)) {
             out_results.emplace(key, coin);
         }
         cursor->Next();
     }
     scan_progress = 100;
     return true;
 }
 
 /** RAII object to prevent concurrency issue when scanning the txout set */
 static std::mutex g_utxosetscan;
 static std::atomic<int> g_scan_progress;
 static std::atomic<bool> g_scan_in_progress;
 static std::atomic<bool> g_should_abort_scan;
 class CoinsViewScanReserver {
 private:
     bool m_could_reserve;
 
 public:
     explicit CoinsViewScanReserver() : m_could_reserve(false) {}
 
     bool reserve() {
         assert(!m_could_reserve);
         std::lock_guard<std::mutex> lock(g_utxosetscan);
         if (g_scan_in_progress) {
             return false;
         }
         g_scan_in_progress = true;
         m_could_reserve = true;
         return true;
     }
 
     ~CoinsViewScanReserver() {
         if (m_could_reserve) {
             std::lock_guard<std::mutex> lock(g_utxosetscan);
             g_scan_in_progress = false;
         }
     }
 };
 
 static UniValue scantxoutset(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "scantxoutset <action> ( <scanobjects> )\n"
             "\nEXPERIMENTAL warning: this call may be removed or changed in "
             "future releases.\n"
             "\nScans the unspent transaction output set for entries that match "
             "certain output descriptors.\n"
             "Examples of output descriptors are:\n"
             "    addr(<address>)                      Outputs whose "
             "scriptPubKey corresponds to the specified address (does not "
             "include P2PK)\n"
             "    raw(<hex script>)                    Outputs whose "
             "scriptPubKey equals the specified hex scripts\n"
             "    combo(<pubkey>)                      P2PK and P2PKH outputs "
             "for the given pubkey\n"
             "    pkh(<pubkey>)                        P2PKH outputs for the "
             "given pubkey\n"
             "    sh(multi(<n>,<pubkey>,<pubkey>,...)) P2SH-multisig outputs "
             "for the given threshold and pubkeys\n"
             "\nIn the above, <pubkey> either refers to a fixed public key in "
             "hexadecimal notation, or to an xpub/xprv optionally followed by "
             "one\n"
             "or more path elements separated by \"/\", and optionally ending "
             "in \"/*\" (unhardened), or \"/*'\" or \"/*h\" (hardened) to "
             "specify all\n"
             "unhardened or hardened child keys.\n"
             "In the latter case, a range needs to be specified by below if "
             "different from 1000.\n"
             "For more information on output descriptors, see the documentation "
             "in the doc/descriptors.md file.\n"
             "\nArguments:\n"
             "1. \"action\"                       (string, required) The action "
             "to execute\n"
             "                                      \"start\" for starting a "
             "scan\n"
             "                                      \"abort\" for aborting the "
             "current scan (returns true when abort was successful)\n"
             "                                      \"status\" for progress "
             "report (in %) of the current scan\n"
             "2. \"scanobjects\"                  (array, required) Array of "
             "scan objects\n"
             "    [                             Every scan object is either a "
             "string descriptor or an object:\n"
             "        \"descriptor\",             (string, optional) An output "
             "descriptor\n"
             "        {                         (object, optional) An object "
             "with output descriptor and metadata\n"
             "          \"desc\": \"descriptor\",   (string, required) An "
             "output descriptor\n"
             "          \"range\": n,             (numeric, optional) Up to "
             "what child index HD chains should be explored (default: 1000)\n"
             "        },\n"
             "        ...\n"
             "    ]\n"
             "\nResult:\n"
             "{\n"
             "  \"unspents\": [\n"
             "    {\n"
             "    \"txid\" : \"transactionid\",     (string) The transaction "
             "id\n"
             "    \"vout\": n,                    (numeric) the vout value\n"
             "    \"scriptPubKey\" : \"script\",    (string) the script key\n"
             "    \"amount\" : x.xxx,             (numeric) The total amount "
             "in " +
             CURRENCY_UNIT +
             " of the unspent output\n"
             "    \"height\" : n,                 (numeric) Height of the "
             "unspent transaction output\n"
             "   }\n"
             "   ,...], \n"
             " \"total_amount\" : x.xxx,          (numeric) The total amount of "
             "all found unspent outputs in " +
             CURRENCY_UNIT +
             "\n"
             "]\n");
     }
 
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VARR});
 
     UniValue result(UniValue::VOBJ);
     if (request.params[0].get_str() == "status") {
         CoinsViewScanReserver reserver;
         if (reserver.reserve()) {
             // no scan in progress
             return NullUniValue;
         }
         result.pushKV("progress", g_scan_progress);
         return result;
     } else if (request.params[0].get_str() == "abort") {
         CoinsViewScanReserver reserver;
         if (reserver.reserve()) {
             // reserve was possible which means no scan was running
             return false;
         }
         // set the abort flag
         g_should_abort_scan = true;
         return true;
     } else if (request.params[0].get_str() == "start") {
         CoinsViewScanReserver reserver;
         if (!reserver.reserve()) {
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 "Scan already in progress, use action \"abort\" or \"status\"");
         }
         std::set<CScript> needles;
         Amount total_in = Amount::zero();
 
         // loop through the scan objects
         for (const UniValue &scanobject :
              request.params[1].get_array().getValues()) {
             std::string desc_str;
             int range = 1000;
             if (scanobject.isStr()) {
                 desc_str = scanobject.get_str();
             } else if (scanobject.isObject()) {
                 UniValue desc_uni = find_value(scanobject, "desc");
                 if (desc_uni.isNull()) {
                     throw JSONRPCError(
                         RPC_INVALID_PARAMETER,
                         "Descriptor needs to be provided in scan object");
                 }
                 desc_str = desc_uni.get_str();
                 UniValue range_uni = find_value(scanobject, "range");
                 if (!range_uni.isNull()) {
                     range = range_uni.get_int();
                     if (range < 0 || range > 1000000) {
                         throw JSONRPCError(RPC_INVALID_PARAMETER,
                                            "range out of range");
                     }
                 }
             } else {
                 throw JSONRPCError(
                     RPC_INVALID_PARAMETER,
                     "Scan object needs to be either a string or an object");
             }
 
             FlatSigningProvider provider;
             auto desc = Parse(desc_str, provider);
             if (!desc) {
                 throw JSONRPCError(
                     RPC_INVALID_ADDRESS_OR_KEY,
                     strprintf("Invalid descriptor '%s'", desc_str));
             }
             if (!desc->IsRange()) {
                 range = 0;
             }
             for (int i = 0; i <= range; ++i) {
                 std::vector<CScript> scripts;
                 if (!desc->Expand(i, provider, scripts, provider)) {
                     throw JSONRPCError(
                         RPC_INVALID_ADDRESS_OR_KEY,
                         strprintf(
                             "Cannot derive script without private keys: '%s'",
                             desc_str));
                 }
                 needles.insert(scripts.begin(), scripts.end());
             }
         }
 
         // Scan the unspent transaction output set for inputs
         UniValue unspents(UniValue::VARR);
         std::vector<CTxOut> input_txos;
         std::map<COutPoint, Coin> coins;
         g_should_abort_scan = false;
         g_scan_progress = 0;
         int64_t count = 0;
         std::unique_ptr<CCoinsViewCursor> pcursor;
         {
             LOCK(cs_main);
             FlushStateToDisk();
             pcursor = std::unique_ptr<CCoinsViewCursor>(pcoinsdbview->Cursor());
             assert(pcursor);
         }
         bool res = FindScriptPubKey(g_scan_progress, g_should_abort_scan, count,
                                     pcursor.get(), needles, coins);
         result.pushKV("success", res);
         result.pushKV("searched_items", count);
 
         for (const auto &it : coins) {
             const COutPoint &outpoint = it.first;
             const Coin &coin = it.second;
             const CTxOut &txo = coin.GetTxOut();
             input_txos.push_back(txo);
             total_in += txo.nValue;
 
             UniValue unspent(UniValue::VOBJ);
             unspent.pushKV("txid", outpoint.GetTxId().GetHex());
             unspent.pushKV("vout", int32_t(outpoint.GetN()));
             unspent.pushKV("scriptPubKey", HexStr(txo.scriptPubKey.begin(),
                                                   txo.scriptPubKey.end()));
             unspent.pushKV("amount", ValueFromAmount(txo.nValue));
             unspent.pushKV("height", int32_t(coin.GetHeight()));
 
             unspents.push_back(unspent);
         }
         result.pushKV("unspents", unspents);
         result.pushKV("total_amount", ValueFromAmount(total_in));
     } else {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid command");
     }
     return result;
 }
 
 // clang-format off
 static const ContextFreeRPCCommand commands[] = {
     //  category            name                      actor (function)        argNames
     //  ------------------- ------------------------  ----------------------  ----------
     { "blockchain",         "getbestblockhash",       getbestblockhash,       {} },
     { "blockchain",         "getblock",               getblock,               {"blockhash","verbosity|verbose"} },
     { "blockchain",         "getblockchaininfo",      getblockchaininfo,      {} },
     { "blockchain",         "getblockcount",          getblockcount,          {} },
     { "blockchain",         "getblockhash",           getblockhash,           {"height"} },
     { "blockchain",         "getblockheader",         getblockheader,         {"blockhash","verbose"} },
     { "blockchain",         "getblockstats",          getblockstats,          {"hash_or_height","stats"} },
     { "blockchain",         "getchaintips",           getchaintips,           {} },
     { "blockchain",         "getchaintxstats",        getchaintxstats,        {"nblocks", "blockhash"} },
     { "blockchain",         "getdifficulty",          getdifficulty,          {} },
     { "blockchain",         "getmempoolancestors",    getmempoolancestors,    {"txid","verbose"} },
     { "blockchain",         "getmempooldescendants",  getmempooldescendants,  {"txid","verbose"} },
     { "blockchain",         "getmempoolentry",        getmempoolentry,        {"txid"} },
     { "blockchain",         "getmempoolinfo",         getmempoolinfo,         {} },
     { "blockchain",         "getrawmempool",          getrawmempool,          {"verbose"} },
     { "blockchain",         "gettxout",               gettxout,               {"txid","n","include_mempool"} },
     { "blockchain",         "gettxoutsetinfo",        gettxoutsetinfo,        {} },
     { "blockchain",         "pruneblockchain",        pruneblockchain,        {"height"} },
     { "blockchain",         "savemempool",            savemempool,            {} },
     { "blockchain",         "verifychain",            verifychain,            {"checklevel","nblocks"} },
     { "blockchain",         "preciousblock",          preciousblock,          {"blockhash"} },
     { "blockchain",         "scantxoutset",           scantxoutset,           {"action", "scanobjects"} },
 
     /* Not shown in help */
     { "hidden",             "getfinalizedblockhash",            getfinalizedblockhash,            {} },
     { "hidden",             "finalizeblock",                    finalizeblock,                    {"blockhash"} },
     { "hidden",             "invalidateblock",                  invalidateblock,                  {"blockhash"} },
     { "hidden",             "parkblock",                        parkblock,                        {"blockhash"} },
     { "hidden",             "reconsiderblock",                  reconsiderblock,                  {"blockhash"} },
     { "hidden",             "syncwithvalidationinterfacequeue", syncwithvalidationinterfacequeue, {} },
     { "hidden",             "unparkblock",                      unparkblock,                      {"blockhash"} },
     { "hidden",             "waitfornewblock",                  waitfornewblock,                  {"timeout"} },
     { "hidden",             "waitforblock",                     waitforblock,                     {"blockhash","timeout"} },
     { "hidden",             "waitforblockheight",               waitforblockheight,               {"height","timeout"} },
 };
 // clang-format on
 
 void RegisterBlockchainRPCCommands(CRPCTable &t) {
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++) {
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
     }
 }
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 263c666603..83dbd253ea 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -1,835 +1,835 @@
 // Copyright (c) 2010 Satoshi Nakamoto
 // Copyright (c) 2009-2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <amount.h>
 #include <blockvalidity.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/consensus.h>
 #include <consensus/params.h>
 #include <consensus/validation.h>
 #include <core_io.h>
 #include <key_io.h>
 #include <miner.h>
 #include <net.h>
 #include <policy/policy.h>
 #include <pow.h>
 #include <rpc/blockchain.h>
 #include <rpc/mining.h>
 #include <rpc/server.h>
 #include <shutdown.h>
 #include <txmempool.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <validation.h>
 #include <validationinterface.h>
 #include <warnings.h>
 
 #include <univalue.h>
 
 #include <cstdint>
 #include <memory>
 
 /**
  * Return average network hashes per second based on the last 'lookup' blocks,
  * or from the last difficulty change if 'lookup' is nonpositive. If 'height' is
  * nonnegative, compute the estimate at the time when a given block was found.
  */
 static UniValue GetNetworkHashPS(int lookup, int height) {
     CBlockIndex *pb = chainActive.Tip();
 
     if (height >= 0 && height < chainActive.Height()) {
         pb = chainActive[height];
     }
 
     if (pb == nullptr || !pb->nHeight) {
         return 0;
     }
 
     // If lookup is -1, then use blocks since last difficulty change.
     if (lookup <= 0) {
         lookup = pb->nHeight %
                      Params().GetConsensus().DifficultyAdjustmentInterval() +
                  1;
     }
 
     // If lookup is larger than chain, then set it to chain length.
     if (lookup > pb->nHeight) {
         lookup = pb->nHeight;
     }
 
     CBlockIndex *pb0 = pb;
     int64_t minTime = pb0->GetBlockTime();
     int64_t maxTime = minTime;
     for (int i = 0; i < lookup; i++) {
         pb0 = pb0->pprev;
         int64_t time = pb0->GetBlockTime();
         minTime = std::min(time, minTime);
         maxTime = std::max(time, maxTime);
     }
 
     // In case there's a situation where minTime == maxTime, we don't want a
     // divide by zero exception.
     if (minTime == maxTime) {
         return 0;
     }
 
     arith_uint256 workDiff = pb->nChainWork - pb0->nChainWork;
     int64_t timeDiff = maxTime - minTime;
 
     return workDiff.getdouble() / timeDiff;
 }
 
 static UniValue getnetworkhashps(const Config &config,
                                  const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 2) {
         throw std::runtime_error(
             "getnetworkhashps ( nblocks height )\n"
             "\nReturns the estimated network hashes per second based on the "
             "last n blocks.\n"
             "Pass in [blocks] to override # of blocks, -1 specifies since last "
             "difficulty change.\n"
             "Pass in [height] to estimate the network speed at the time when a "
             "certain block was found.\n"
             "\nArguments:\n"
             "1. nblocks     (numeric, optional, default=120) The number of "
             "blocks, or -1 for blocks since last difficulty change.\n"
             "2. height      (numeric, optional, default=-1) To estimate at the "
             "time of the given height.\n"
             "\nResult:\n"
             "x             (numeric) Hashes per second estimated\n"
             "\nExamples:\n" +
             HelpExampleCli("getnetworkhashps", "") +
             HelpExampleRpc("getnetworkhashps", ""));
     }
 
     LOCK(cs_main);
     return GetNetworkHashPS(
         !request.params[0].isNull() ? request.params[0].get_int() : 120,
         !request.params[1].isNull() ? request.params[1].get_int() : -1);
 }
 
 UniValue generateBlocks(const Config &config,
                         std::shared_ptr<CReserveScript> coinbaseScript,
                         int nGenerate, uint64_t nMaxTries, bool keepScript) {
     static const int nInnerLoopCount = 0x100000;
     int nHeightEnd = 0;
     int nHeight = 0;
 
     {
         // Don't keep cs_main locked.
         LOCK(cs_main);
         nHeight = chainActive.Height();
         nHeightEnd = nHeight + nGenerate;
     }
 
     unsigned int nExtraNonce = 0;
     UniValue blockHashes(UniValue::VARR);
     while (nHeight < nHeightEnd && !ShutdownRequested()) {
         std::unique_ptr<CBlockTemplate> pblocktemplate(
             BlockAssembler(config, g_mempool)
                 .CreateNewBlock(coinbaseScript->reserveScript));
 
         if (!pblocktemplate.get()) {
             throw JSONRPCError(RPC_INTERNAL_ERROR, "Couldn't create new block");
         }
 
         CBlock *pblock = &pblocktemplate->block;
 
         {
             LOCK(cs_main);
             IncrementExtraNonce(pblock, chainActive.Tip(),
                                 config.GetMaxBlockSize(), nExtraNonce);
         }
 
         while (nMaxTries > 0 && pblock->nNonce < nInnerLoopCount &&
                !CheckProofOfWork(pblock->GetHash(), pblock->nBits,
                                  config.GetChainParams().GetConsensus())) {
             ++pblock->nNonce;
             --nMaxTries;
         }
 
         if (nMaxTries == 0) {
             break;
         }
 
         if (pblock->nNonce == nInnerLoopCount) {
             continue;
         }
 
         std::shared_ptr<const CBlock> shared_pblock =
             std::make_shared<const CBlock>(*pblock);
         if (!ProcessNewBlock(config, shared_pblock, true, nullptr)) {
             throw JSONRPCError(RPC_INTERNAL_ERROR,
                                "ProcessNewBlock, block not accepted");
         }
         ++nHeight;
         blockHashes.push_back(pblock->GetHash().GetHex());
 
         // Mark script as important because it was used at least for one
         // coinbase output if the script came from the wallet.
         if (keepScript) {
             coinbaseScript->KeepScript();
         }
     }
 
     return blockHashes;
 }
 
 static UniValue generatetoaddress(const Config &config,
                                   const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() < 2 ||
         request.params.size() > 3) {
         throw std::runtime_error(
             "generatetoaddress nblocks address (maxtries)\n"
             "\nMine blocks immediately to a specified address (before the RPC "
             "call returns)\n"
             "\nArguments:\n"
             "1. nblocks      (numeric, required) How many blocks are generated "
             "immediately.\n"
             "2. address      (string, required) The address to send the newly "
             "generated bitcoin to.\n"
             "3. maxtries     (numeric, optional) How many iterations to try "
             "(default = 1000000).\n"
             "\nResult:\n"
             "[ blockhashes ]     (array) hashes of blocks generated\n"
             "\nExamples:\n"
             "\nGenerate 11 blocks to myaddress\n" +
             HelpExampleCli("generatetoaddress", "11 \"myaddress\""));
     }
 
     int nGenerate = request.params[0].get_int();
     uint64_t nMaxTries = 1000000;
     if (!request.params[2].isNull()) {
         nMaxTries = request.params[2].get_int();
     }
 
     CTxDestination destination =
         DecodeDestination(request.params[1].get_str(), config.GetChainParams());
     if (!IsValidDestination(destination)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Error: Invalid address");
     }
 
     std::shared_ptr<CReserveScript> coinbaseScript =
         std::make_shared<CReserveScript>();
     coinbaseScript->reserveScript = GetScriptForDestination(destination);
 
     return generateBlocks(config, coinbaseScript, nGenerate, nMaxTries, false);
 }
 
 static UniValue getmininginfo(const Config &config,
                               const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 0) {
         throw std::runtime_error(
             "getmininginfo\n"
             "\nReturns a json object containing mining-related information."
             "\nResult:\n"
             "{\n"
             "  \"blocks\": nnn,             (numeric) The current block\n"
             "  \"currentblocksize\": nnn,   (numeric) The last block size\n"
             "  \"currentblocktx\": nnn,     (numeric) The last block "
             "transaction\n"
             "  \"difficulty\": xxx.xxxxx    (numeric) The current difficulty\n"
             "  \"networkhashps\": nnn,      (numeric) The network hashes per "
             "second\n"
             "  \"pooledtx\": n              (numeric) The size of the mempool\n"
             "  \"chain\": \"xxxx\",           (string) current network name as "
             "defined in BIP70 (main, test, regtest)\n"
             "  \"warnings\": \"...\"          (string) any network and "
             "blockchain warnings\n"
             "}\n"
             "\nExamples:\n" +
             HelpExampleCli("getmininginfo", "") +
             HelpExampleRpc("getmininginfo", ""));
     }
 
     LOCK(cs_main);
 
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("blocks", int(chainActive.Height()));
     obj.pushKV("currentblocksize", uint64_t(nLastBlockSize));
     obj.pushKV("currentblocktx", uint64_t(nLastBlockTx));
     obj.pushKV("difficulty", double(GetDifficulty(chainActive.Tip())));
     obj.pushKV("blockprioritypercentage",
                uint8_t(gArgs.GetArg("-blockprioritypercentage",
                                     DEFAULT_BLOCK_PRIORITY_PERCENTAGE)));
     obj.pushKV("networkhashps", getnetworkhashps(config, request));
     obj.pushKV("pooledtx", uint64_t(g_mempool.size()));
     obj.pushKV("chain", config.GetChainParams().NetworkIDString());
     obj.pushKV("warnings", GetWarnings("statusbar"));
 
     return obj;
 }
 
 // NOTE: Unlike wallet RPC (which use BCH values), mining RPCs follow GBT (BIP
 // 22) in using satoshi amounts
 static UniValue prioritisetransaction(const Config &config,
                                       const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 3) {
         throw std::runtime_error(
             "prioritisetransaction <txid> <priority delta> <fee delta>\n"
             "Accepts the transaction into mined blocks at a higher (or lower) "
             "priority\n"
             "\nArguments:\n"
             "1. \"txid\"       (string, required) The transaction id.\n"
             "2. priority_delta (numeric, required) The priority to add or "
             "subtract.\n"
             "                  The transaction selection algorithm considers "
             "the tx as it would have a higher priority.\n"
             "                  (priority of a transaction is calculated: "
             "coinage * value_in_satoshis / txsize) \n"
             "3. fee_delta      (numeric, required) The fee value (in satoshis) "
             "to add (or subtract, if negative).\n"
             "                  The fee is not actually paid, only the "
             "algorithm for selecting transactions into a block\n"
             "                  considers the transaction as it would have paid "
             "a higher (or lower) fee.\n"
             "\nResult:\n"
             "true              (boolean) Returns true\n"
             "\nExamples:\n" +
             HelpExampleCli("prioritisetransaction", "\"txid\" 0.0 10000") +
             HelpExampleRpc("prioritisetransaction", "\"txid\", 0.0, 10000"));
     }
 
     LOCK(cs_main);
 
-    uint256 hash = ParseHashStr(request.params[0].get_str(), "txid");
+    TxId txid(ParseHashStr(request.params[0].get_str(), "txid"));
     Amount nAmount = request.params[2].get_int64() * SATOSHI;
 
-    g_mempool.PrioritiseTransaction(hash, request.params[1].get_real(),
+    g_mempool.PrioritiseTransaction(txid, request.params[1].get_real(),
                                     nAmount);
     return true;
 }
 
 // NOTE: Assumes a conclusive result; if result is inconclusive, it must be
 // handled by caller
 static UniValue BIP22ValidationResult(const Config &config,
                                       const CValidationState &state) {
     if (state.IsValid()) {
         return NullUniValue;
     }
 
     if (state.IsError()) {
         throw JSONRPCError(RPC_VERIFY_ERROR, FormatStateMessage(state));
     }
 
     if (state.IsInvalid()) {
         std::string strRejectReason = state.GetRejectReason();
         if (strRejectReason.empty()) {
             return "rejected";
         }
         return strRejectReason;
     }
 
     // Should be impossible.
     return "valid?";
 }
 
 static UniValue getblocktemplate(const Config &config,
                                  const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 1) {
         throw std::runtime_error(
             "getblocktemplate ( TemplateRequest )\n"
             "\nIf the request parameters include a 'mode' key, that is used to "
             "explicitly select between the default 'template' request or a "
             "'proposal'.\n"
             "It returns data needed to construct a block to work on.\n"
             "For full specification, see BIPs 22, 23, 9, and 145:\n"
             "    "
             "https://github.com/bitcoin/bips/blob/master/bip-0022.mediawiki\n"
             "    "
             "https://github.com/bitcoin/bips/blob/master/bip-0023.mediawiki\n"
             "    "
             "https://github.com/bitcoin/bips/blob/master/"
             "bip-0009.mediawiki#getblocktemplate_changes\n"
             "    "
             "https://github.com/bitcoin/bips/blob/master/bip-0145.mediawiki\n"
 
             "\nArguments:\n"
             "1. template_request         (json object, optional) A json object "
             "in the following spec\n"
             "     {\n"
             "       \"mode\":\"template\"    (string, optional) This must be "
             "set to \"template\", \"proposal\" (see BIP 23), or omitted\n"
             "       \"capabilities\":[     (array, optional) A list of "
             "strings\n"
             "           \"support\"          (string) client side supported "
             "feature, 'longpoll', 'coinbasetxn', 'coinbasevalue', 'proposal', "
             "'serverlist', 'workid'\n"
             "           ,...\n"
             "       ]\n"
             "     }\n"
             "\n"
 
             "\nResult:\n"
             "{\n"
             "  \"version\" : n,                    (numeric) The preferred "
             "block version\n"
             "  \"previousblockhash\" : \"xxxx\",     (string) The hash of "
             "current highest block\n"
             "  \"transactions\" : [                (array) contents of "
             "non-coinbase transactions that should be included in the next "
             "block\n"
             "      {\n"
             "         \"data\" : \"xxxx\",             (string) transaction "
             "data encoded in hexadecimal (byte-for-byte)\n"
             "         \"txid\" : \"xxxx\",             (string) transaction id "
             "encoded in little-endian hexadecimal\n"
             "         \"hash\" : \"xxxx\",             (string) hash encoded "
             "in little-endian hexadecimal (including witness data)\n"
             "         \"depends\" : [                (array) array of numbers "
             "\n"
             "             n                          (numeric) transactions "
             "before this one (by 1-based index in 'transactions' list) that "
             "must be present in the final block if this one is\n"
             "             ,...\n"
             "         ],\n"
             "         \"fee\": n,                    (numeric) difference in "
             "value between transaction inputs and outputs (in satoshis); for "
             "coinbase transactions, this is a negative Number of the total "
             "collected block fees (ie, not including the block subsidy); if "
             "key is not present, fee is unknown and clients MUST NOT assume "
             "there isn't one\n"
             "         \"sigops\" : n,                (numeric) total SigOps "
             "cost, as counted for purposes of block limits; if key is not "
             "present, sigop cost is unknown and clients MUST NOT assume it is "
             "zero\n"
             "         \"required\" : true|false      (boolean) if provided and "
             "true, this transaction must be in the final block\n"
             "      }\n"
             "      ,...\n"
             "  ],\n"
             "  \"coinbaseaux\" : {                 (json object) data that "
             "should be included in the coinbase's scriptSig content\n"
             "      \"flags\" : \"xx\"                  (string) key name is to "
             "be ignored, and value included in scriptSig\n"
             "  },\n"
             "  \"coinbasevalue\" : n,              (numeric) maximum allowable "
             "input to coinbase transaction, including the generation award and "
             "transaction fees (in satoshis)\n"
             "  \"coinbasetxn\" : { ... },          (json object) information "
             "for coinbase transaction\n"
             "  \"target\" : \"xxxx\",                (string) The hash target\n"
             "  \"mintime\" : xxx,                  (numeric) The minimum "
             "timestamp appropriate for next block time in seconds since epoch "
             "(Jan 1 1970 GMT)\n"
             "  \"mutable\" : [                     (array of string) list of "
             "ways the block template may be changed \n"
             "     \"value\"                          (string) A way the block "
             "template may be changed, e.g. 'time', 'transactions', "
             "'prevblock'\n"
             "     ,...\n"
             "  ],\n"
             "  \"noncerange\" : \"00000000ffffffff\",(string) A range of valid "
             "nonces\n"
             "  \"sigoplimit\" : n,                 (numeric) limit of sigops "
             "in blocks\n"
             "  \"sizelimit\" : n,                  (numeric) limit of block "
             "size\n"
             "  \"curtime\" : ttt,                  (numeric) current timestamp "
             "in seconds since epoch (Jan 1 1970 GMT)\n"
             "  \"bits\" : \"xxxxxxxx\",              (string) compressed "
             "target of next block\n"
             "  \"height\" : n                      (numeric) The height of the "
             "next block\n"
             "}\n"
 
             "\nExamples:\n" +
             HelpExampleCli("getblocktemplate", "") +
             HelpExampleRpc("getblocktemplate", ""));
     }
 
     LOCK(cs_main);
 
     std::string strMode = "template";
     UniValue lpval = NullUniValue;
     std::set<std::string> setClientRules;
     if (!request.params[0].isNull()) {
         const UniValue &oparam = request.params[0].get_obj();
         const UniValue &modeval = find_value(oparam, "mode");
         if (modeval.isStr()) {
             strMode = modeval.get_str();
         } else if (modeval.isNull()) {
             /* Do nothing */
         } else {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid mode");
         }
         lpval = find_value(oparam, "longpollid");
 
         if (strMode == "proposal") {
             const UniValue &dataval = find_value(oparam, "data");
             if (!dataval.isStr()) {
                 throw JSONRPCError(RPC_TYPE_ERROR,
                                    "Missing data String key for proposal");
             }
 
             CBlock block;
             if (!DecodeHexBlk(block, dataval.get_str())) {
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                                    "Block decode failed");
             }
 
             const BlockHash hash = block.GetHash();
             const CBlockIndex *pindex = LookupBlockIndex(hash);
             if (pindex) {
                 if (pindex->IsValid(BlockValidity::SCRIPTS)) {
                     return "duplicate";
                 }
                 if (pindex->nStatus.isInvalid()) {
                     return "duplicate-invalid";
                 }
                 return "duplicate-inconclusive";
             }
 
             CBlockIndex *const pindexPrev = chainActive.Tip();
             // TestBlockValidity only supports blocks built on the current Tip
             if (block.hashPrevBlock != pindexPrev->GetBlockHash()) {
                 return "inconclusive-not-best-prevblk";
             }
             CValidationState state;
             TestBlockValidity(state, config.GetChainParams(), block, pindexPrev,
                               BlockValidationOptions(config)
                                   .withCheckPoW(false)
                                   .withCheckMerkleRoot(true));
             return BIP22ValidationResult(config, state);
         }
     }
 
     if (strMode != "template") {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid mode");
     }
 
     if (!g_connman) {
         throw JSONRPCError(
             RPC_CLIENT_P2P_DISABLED,
             "Error: Peer-to-peer functionality missing or disabled");
     }
 
     if (g_connman->GetNodeCount(CConnman::CONNECTIONS_ALL) == 0) {
         throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED,
                            "Bitcoin is not connected!");
     }
 
     if (IsInitialBlockDownload()) {
         throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD,
                            "Bitcoin is downloading blocks...");
     }
 
     static unsigned int nTransactionsUpdatedLast;
 
     if (!lpval.isNull()) {
         // Wait to respond until either the best block changes, OR a minute has
         // passed and there are more transactions
         uint256 hashWatchedChain;
         std::chrono::steady_clock::time_point checktxtime;
         unsigned int nTransactionsUpdatedLastLP;
 
         if (lpval.isStr()) {
             // Format: <hashBestChain><nTransactionsUpdatedLast>
             std::string lpstr = lpval.get_str();
 
             hashWatchedChain.SetHex(lpstr.substr(0, 64));
             nTransactionsUpdatedLastLP = atoi64(lpstr.substr(64));
         } else {
             // NOTE: Spec does not specify behaviour for non-string longpollid,
             // but this makes testing easier
             hashWatchedChain = chainActive.Tip()->GetBlockHash();
             nTransactionsUpdatedLastLP = nTransactionsUpdatedLast;
         }
 
         // Release the wallet and main lock while waiting
         LEAVE_CRITICAL_SECTION(cs_main);
         {
             checktxtime =
                 std::chrono::steady_clock::now() + std::chrono::minutes(1);
 
             WAIT_LOCK(g_best_block_mutex, lock);
             while (g_best_block == hashWatchedChain && IsRPCRunning()) {
                 if (g_best_block_cv.wait_until(lock, checktxtime) ==
                     std::cv_status::timeout) {
                     // Timeout: Check transactions for update
                     if (g_mempool.GetTransactionsUpdated() !=
                         nTransactionsUpdatedLastLP) {
                         break;
                     }
                     checktxtime += std::chrono::seconds(10);
                 }
             }
         }
         ENTER_CRITICAL_SECTION(cs_main);
 
         if (!IsRPCRunning()) {
             throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED, "Shutting down");
         }
         // TODO: Maybe recheck connections/IBD and (if something wrong) send an
         // expires-immediately template to stop miners?
     }
 
     // Update block
     static CBlockIndex *pindexPrev;
     static int64_t nStart;
     static std::unique_ptr<CBlockTemplate> pblocktemplate;
     if (pindexPrev != chainActive.Tip() ||
         (g_mempool.GetTransactionsUpdated() != nTransactionsUpdatedLast &&
          GetTime() - nStart > 5)) {
         // Clear pindexPrev so future calls make a new block, despite any
         // failures from here on
         pindexPrev = nullptr;
 
         // Store the pindexBest used before CreateNewBlock, to avoid races
         nTransactionsUpdatedLast = g_mempool.GetTransactionsUpdated();
         CBlockIndex *pindexPrevNew = chainActive.Tip();
         nStart = GetTime();
 
         // Create new block
         CScript scriptDummy = CScript() << OP_TRUE;
         pblocktemplate =
             BlockAssembler(config, g_mempool).CreateNewBlock(scriptDummy);
         if (!pblocktemplate) {
             throw JSONRPCError(RPC_OUT_OF_MEMORY, "Out of memory");
         }
 
         // Need to update only after we know CreateNewBlock succeeded
         pindexPrev = pindexPrevNew;
     }
 
     assert(pindexPrev);
     // pointer for convenience
     CBlock *pblock = &pblocktemplate->block;
 
     // Update nTime
     UpdateTime(pblock, config.GetChainParams().GetConsensus(), pindexPrev);
     pblock->nNonce = 0;
 
     UniValue aCaps(UniValue::VARR);
     aCaps.push_back("proposal");
 
     UniValue transactions(UniValue::VARR);
     int index_in_template = 0;
     for (const auto &it : pblock->vtx) {
         const CTransaction &tx = *it;
         uint256 txId = tx.GetId();
 
         if (tx.IsCoinBase()) {
             index_in_template++;
             continue;
         }
 
         UniValue entry(UniValue::VOBJ);
         entry.pushKV("data", EncodeHexTx(tx));
         entry.pushKV("txid", txId.GetHex());
         entry.pushKV("hash", tx.GetHash().GetHex());
         entry.pushKV("fee", pblocktemplate->entries[index_in_template].txFee /
                                 SATOSHI);
         int64_t nTxSigOps = pblocktemplate->entries[index_in_template].txSigOps;
         entry.pushKV("sigops", nTxSigOps);
 
         transactions.push_back(entry);
         index_in_template++;
     }
 
     UniValue aux(UniValue::VOBJ);
     aux.pushKV("flags", HexStr(COINBASE_FLAGS.begin(), COINBASE_FLAGS.end()));
 
     arith_uint256 hashTarget = arith_uint256().SetCompact(pblock->nBits);
 
     UniValue aMutable(UniValue::VARR);
     aMutable.push_back("time");
     aMutable.push_back("transactions");
     aMutable.push_back("prevblock");
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("capabilities", aCaps);
 
     result.pushKV("version", pblock->nVersion);
 
     result.pushKV("previousblockhash", pblock->hashPrevBlock.GetHex());
     result.pushKV("transactions", transactions);
     result.pushKV("coinbaseaux", aux);
     result.pushKV("coinbasevalue",
                   int64_t(pblock->vtx[0]->vout[0].nValue / SATOSHI));
     result.pushKV("longpollid", chainActive.Tip()->GetBlockHash().GetHex() +
                                     i64tostr(nTransactionsUpdatedLast));
     result.pushKV("target", hashTarget.GetHex());
     result.pushKV("mintime", int64_t(pindexPrev->GetMedianTimePast()) + 1);
     result.pushKV("mutable", aMutable);
     result.pushKV("noncerange", "00000000ffffffff");
     // FIXME: Allow for mining block greater than 1M.
     result.pushKV("sigoplimit", GetMaxBlockSigOpsCount(DEFAULT_MAX_BLOCK_SIZE));
     result.pushKV("sizelimit", DEFAULT_MAX_BLOCK_SIZE);
     result.pushKV("curtime", pblock->GetBlockTime());
     result.pushKV("bits", strprintf("%08x", pblock->nBits));
     result.pushKV("height", int64_t(pindexPrev->nHeight) + 1);
 
     return result;
 }
 
 class submitblock_StateCatcher : public CValidationInterface {
 public:
     uint256 hash;
     bool found;
     CValidationState state;
 
     explicit submitblock_StateCatcher(const uint256 &hashIn)
         : hash(hashIn), found(false), state() {}
 
 protected:
     void BlockChecked(const CBlock &block,
                       const CValidationState &stateIn) override {
         if (block.GetHash() != hash) {
             return;
         }
 
         found = true;
         state = stateIn;
     }
 };
 
 static UniValue submitblock(const Config &config,
                             const JSONRPCRequest &request) {
     // We allow 2 arguments for compliance with BIP22. Argument 2 is ignored.
     if (request.fHelp || request.params.size() < 1 ||
         request.params.size() > 2) {
         throw std::runtime_error(
             "submitblock \"hexdata\"  ( \"dummy\" )\n"
             "\nAttempts to submit new block to network.\n"
             "See https://en.bitcoin.it/wiki/BIP_0022 for full specification.\n"
 
             "\nArguments\n"
             "1. \"hexdata\"        (string, required) the hex-encoded block "
             "data to submit\n"
             "2. \"dummy\"          (optional) dummy value, for compatibility "
             "with BIP22. This value is ignored.\n"
             "\nResult:\n"
             "\nExamples:\n" +
             HelpExampleCli("submitblock", "\"mydata\"") +
             HelpExampleRpc("submitblock", "\"mydata\""));
     }
 
     std::shared_ptr<CBlock> blockptr = std::make_shared<CBlock>();
     CBlock &block = *blockptr;
     if (!DecodeHexBlk(block, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed");
     }
 
     if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                            "Block does not start with a coinbase");
     }
 
     const BlockHash hash = block.GetHash();
     {
         LOCK(cs_main);
         const CBlockIndex *pindex = LookupBlockIndex(hash);
         if (pindex) {
             if (pindex->IsValid(BlockValidity::SCRIPTS)) {
                 return "duplicate";
             }
             if (pindex->nStatus.isInvalid()) {
                 return "duplicate-invalid";
             }
         }
     }
 
     bool new_block;
     submitblock_StateCatcher sc(block.GetHash());
     RegisterValidationInterface(&sc);
     bool accepted =
         ProcessNewBlock(config, blockptr, /* fForceProcessing */ true,
                         /* fNewBlock */ &new_block);
     UnregisterValidationInterface(&sc);
     if (!new_block && accepted) {
         return "duplicate";
     }
 
     if (!sc.found) {
         return "inconclusive";
     }
 
     return BIP22ValidationResult(config, sc.state);
 }
 
 static UniValue submitheader(const Config &config,
                              const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() != 1) {
         throw std::runtime_error("submitheader \"hexdata\"\n"
                                  "\nDecode the given hexdata as a header and "
                                  "submit it as a candidate chain tip if valid."
                                  "\nThrows when the header is invalid.\n"
                                  "\nArguments\n"
                                  "1. \"hexdata\"        (string, required) the "
                                  "hex-encoded block header data\n"
                                  "\nResult:\n"
                                  "None"
                                  "\nExamples:\n" +
                                  HelpExampleCli("submitheader", "\"aabbcc\"") +
                                  HelpExampleRpc("submitheader", "\"aabbcc\""));
     }
 
     CBlockHeader h;
     if (!DecodeHexBlockHeader(h, request.params[0].get_str())) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
                            "Block header decode failed");
     }
     {
         LOCK(cs_main);
         if (!LookupBlockIndex(h.hashPrevBlock)) {
             throw JSONRPCError(RPC_VERIFY_ERROR,
                                "Must submit previous header (" +
                                    h.hashPrevBlock.GetHex() + ") first");
         }
     }
 
     CValidationState state;
     ProcessNewBlockHeaders(config, {h}, state, /* ppindex */ nullptr,
                            /* first_invalid */ nullptr);
     if (state.IsValid()) {
         return NullUniValue;
     }
     if (state.IsError()) {
         throw JSONRPCError(RPC_VERIFY_ERROR, FormatStateMessage(state));
     }
     throw JSONRPCError(RPC_VERIFY_ERROR, state.GetRejectReason());
 }
 
 static UniValue estimatefee(const Config &config,
                             const JSONRPCRequest &request) {
     if (request.fHelp || request.params.size() > 0) {
         throw std::runtime_error(
             "estimatefee\n"
             "\nEstimates the approximate fee per kilobyte needed for a "
             "transaction\n"
             "\nResult:\n"
             "n              (numeric) estimated fee-per-kilobyte\n"
             "\nExample:\n" +
             HelpExampleCli("estimatefee", ""));
     }
 
     return ValueFromAmount(g_mempool.estimateFee().GetFeePerK());
 }
 
 // clang-format off
 static const ContextFreeRPCCommand commands[] = {
     //  category   name                     actor (function)       argNames
     //  ---------- ------------------------ ---------------------- ----------
     {"mining",     "getnetworkhashps",      getnetworkhashps,      {"nblocks", "height"}},
     {"mining",     "getmininginfo",         getmininginfo,         {}},
     {"mining",     "prioritisetransaction", prioritisetransaction, {"txid", "priority_delta", "fee_delta"}},
     {"mining",     "getblocktemplate",      getblocktemplate,      {"template_request"}},
     {"mining",     "submitblock",           submitblock,           {"hexdata", "dummy"}},
     {"mining",     "submitheader",          submitheader,          {"hexdata"}},
 
     {"generating", "generatetoaddress",     generatetoaddress,     {"nblocks", "address", "maxtries"}},
 
     {"util",       "estimatefee",           estimatefee,           {"nblocks"}},
 };
 // clang-format on
 
 void RegisterMiningRPCCommands(CRPCTable &t) {
     for (unsigned int vcidx = 0; vcidx < ARRAYLEN(commands); vcidx++)
         t.appendCommand(commands[vcidx].name, &commands[vcidx]);
 }
diff --git a/src/test/blockencodings_tests.cpp b/src/test/blockencodings_tests.cpp
index 9c90033921..858860aa20 100644
--- a/src/test/blockencodings_tests.cpp
+++ b/src/test/blockencodings_tests.cpp
@@ -1,415 +1,415 @@
 // Copyright (c) 2011-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <blockencodings.h>
 
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/merkle.h>
 #include <pow.h>
 #include <random.h>
 #include <streams.h>
 
 #include <test/test_bitcoin.h>
 
 #include <boost/test/unit_test.hpp>
 
 std::vector<std::pair<uint256, CTransactionRef>> extra_txn;
 
 struct RegtestingSetup : public TestingSetup {
     RegtestingSetup() : TestingSetup(CBaseChainParams::REGTEST) {}
 };
 
 BOOST_FIXTURE_TEST_SUITE(blockencodings_tests, RegtestingSetup)
 
 static COutPoint InsecureRandOutPoint() {
     return COutPoint(TxId(InsecureRand256()), 0);
 }
 
 static CBlock BuildBlockTestCase() {
     CBlock block;
     CMutableTransaction tx;
     tx.vin.resize(1);
     tx.vin[0].scriptSig.resize(10);
     tx.vout.resize(1);
     tx.vout[0].nValue = 42 * SATOSHI;
 
     block.vtx.resize(3);
     block.vtx[0] = MakeTransactionRef(tx);
     block.nVersion = 42;
     block.hashPrevBlock = BlockHash(InsecureRand256());
     block.nBits = 0x207fffff;
 
     tx.vin[0].prevout = InsecureRandOutPoint();
     block.vtx[1] = MakeTransactionRef(tx);
 
     tx.vin.resize(10);
     for (size_t i = 0; i < tx.vin.size(); i++) {
         tx.vin[i].prevout = InsecureRandOutPoint();
     }
     block.vtx[2] = MakeTransactionRef(tx);
 
     bool mutated;
     block.hashMerkleRoot = BlockMerkleRoot(block, &mutated);
     assert(!mutated);
 
     GlobalConfig config;
     const Consensus::Params &params = config.GetChainParams().GetConsensus();
     while (!CheckProofOfWork(block.GetHash(), block.nBits, params)) {
         ++block.nNonce;
     }
 
     return block;
 }
 
 // Number of shared use_counts we expect for a tx we haven't touched
 // (block + mempool + our copy from the GetSharedTx call)
 constexpr long SHARED_TX_OFFSET{3};
 
 BOOST_AUTO_TEST_CASE(SimpleRoundTripTest) {
     CTxMemPool pool;
     TestMemPoolEntryHelper entry;
     CBlock block(BuildBlockTestCase());
 
     LOCK2(cs_main, pool.cs);
     pool.addUnchecked(block.vtx[2]->GetId(), entry.FromTx(block.vtx[2]));
     BOOST_CHECK_EQUAL(
         pool.mapTx.find(block.vtx[2]->GetId())->GetSharedTx().use_count(),
         SHARED_TX_OFFSET + 0);
 
     // Do a simple ShortTxIDs RT
     {
         CBlockHeaderAndShortTxIDs shortIDs(block);
 
         CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
         stream << shortIDs;
 
         CBlockHeaderAndShortTxIDs shortIDs2;
         stream >> shortIDs2;
 
         PartiallyDownloadedBlock partialBlock(GetConfig(), &pool);
         BOOST_CHECK(partialBlock.InitData(shortIDs2, extra_txn) ==
                     READ_STATUS_OK);
         BOOST_CHECK(partialBlock.IsTxAvailable(0));
         BOOST_CHECK(!partialBlock.IsTxAvailable(1));
         BOOST_CHECK(partialBlock.IsTxAvailable(2));
 
         BOOST_CHECK_EQUAL(
             pool.mapTx.find(block.vtx[2]->GetId())->GetSharedTx().use_count(),
             SHARED_TX_OFFSET + 1);
 
         size_t poolSize = pool.size();
         pool.removeRecursive(*block.vtx[2]);
         BOOST_CHECK_EQUAL(pool.size(), poolSize - 1);
 
         CBlock block2;
         {
             // No transactions.
             PartiallyDownloadedBlock tmp = partialBlock;
             BOOST_CHECK(partialBlock.FillBlock(block2, {}) ==
                         READ_STATUS_INVALID);
             partialBlock = tmp;
         }
 
         // Wrong transaction
         {
             // Current implementation doesn't check txn here, but don't require
             // that.
             PartiallyDownloadedBlock tmp = partialBlock;
             partialBlock.FillBlock(block2, {block.vtx[2]});
             partialBlock = tmp;
         }
         bool mutated;
         BOOST_CHECK(block.hashMerkleRoot != BlockMerkleRoot(block2, &mutated));
 
         CBlock block3;
         BOOST_CHECK(partialBlock.FillBlock(block3, {block.vtx[1]}) ==
                     READ_STATUS_OK);
         BOOST_CHECK_EQUAL(block.GetHash().ToString(),
                           block3.GetHash().ToString());
         BOOST_CHECK_EQUAL(block.hashMerkleRoot.ToString(),
                           BlockMerkleRoot(block3, &mutated).ToString());
         BOOST_CHECK(!mutated);
     }
 }
 
 class TestHeaderAndShortIDs {
     // Utility to encode custom CBlockHeaderAndShortTxIDs
 public:
     CBlockHeader header;
     uint64_t nonce;
     std::vector<uint64_t> shorttxids;
     std::vector<PrefilledTransaction> prefilledtxn;
 
     explicit TestHeaderAndShortIDs(const CBlockHeaderAndShortTxIDs &orig) {
         CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
         stream << orig;
         stream >> *this;
     }
     explicit TestHeaderAndShortIDs(const CBlock &block)
         : TestHeaderAndShortIDs(CBlockHeaderAndShortTxIDs(block)) {}
 
     uint64_t GetShortID(const uint256 &txhash) const {
         CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
         stream << *this;
         CBlockHeaderAndShortTxIDs base;
         stream >> base;
         return base.GetShortID(txhash);
     }
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(header);
         READWRITE(nonce);
         size_t shorttxids_size = shorttxids.size();
         READWRITE(VARINT(shorttxids_size));
         shorttxids.resize(shorttxids_size);
         for (size_t i = 0; i < shorttxids.size(); i++) {
             uint32_t lsb = shorttxids[i] & 0xffffffff;
             uint16_t msb = (shorttxids[i] >> 32) & 0xffff;
             READWRITE(lsb);
             READWRITE(msb);
             shorttxids[i] = (uint64_t(msb) << 32) | uint64_t(lsb);
         }
         READWRITE(prefilledtxn);
     }
 };
 
 BOOST_AUTO_TEST_CASE(NonCoinbasePreforwardRTTest) {
     CTxMemPool pool;
     TestMemPoolEntryHelper entry;
     CBlock block(BuildBlockTestCase());
 
     LOCK2(cs_main, pool.cs);
     pool.addUnchecked(block.vtx[2]->GetId(), entry.FromTx(block.vtx[2]));
     BOOST_CHECK_EQUAL(
         pool.mapTx.find(block.vtx[2]->GetId())->GetSharedTx().use_count(),
         SHARED_TX_OFFSET + 0);
 
-    uint256 txhash;
+    TxId txid;
 
     // Test with pre-forwarding tx 1, but not coinbase
     {
         TestHeaderAndShortIDs shortIDs(block);
         shortIDs.prefilledtxn.resize(1);
         shortIDs.prefilledtxn[0] = {1, block.vtx[1]};
         shortIDs.shorttxids.resize(2);
         shortIDs.shorttxids[0] = shortIDs.GetShortID(block.vtx[0]->GetId());
         shortIDs.shorttxids[1] = shortIDs.GetShortID(block.vtx[2]->GetId());
 
         CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
         stream << shortIDs;
 
         CBlockHeaderAndShortTxIDs shortIDs2;
         stream >> shortIDs2;
 
         PartiallyDownloadedBlock partialBlock(GetConfig(), &pool);
         BOOST_CHECK(partialBlock.InitData(shortIDs2, extra_txn) ==
                     READ_STATUS_OK);
         BOOST_CHECK(!partialBlock.IsTxAvailable(0));
         BOOST_CHECK(partialBlock.IsTxAvailable(1));
         BOOST_CHECK(partialBlock.IsTxAvailable(2));
 
         // +1 because of partialBlock
         BOOST_CHECK_EQUAL(
             pool.mapTx.find(block.vtx[2]->GetId())->GetSharedTx().use_count(),
             SHARED_TX_OFFSET + 1);
 
         CBlock block2;
         {
             // No transactions.
             PartiallyDownloadedBlock tmp = partialBlock;
             BOOST_CHECK(partialBlock.FillBlock(block2, {}) ==
                         READ_STATUS_INVALID);
             partialBlock = tmp;
         }
 
         // Wrong transaction
         {
             // Current implementation doesn't check txn here, but don't require
             // that.
             PartiallyDownloadedBlock tmp = partialBlock;
             partialBlock.FillBlock(block2, {block.vtx[1]});
             partialBlock = tmp;
         }
 
         // +2 because of partialBlock and block2
         BOOST_CHECK_EQUAL(
             pool.mapTx.find(block.vtx[2]->GetId())->GetSharedTx().use_count(),
             SHARED_TX_OFFSET + 2);
         bool mutated;
         BOOST_CHECK(block.hashMerkleRoot != BlockMerkleRoot(block2, &mutated));
 
         CBlock block3;
         PartiallyDownloadedBlock partialBlockCopy = partialBlock;
         BOOST_CHECK(partialBlock.FillBlock(block3, {block.vtx[0]}) ==
                     READ_STATUS_OK);
         BOOST_CHECK_EQUAL(block.GetHash().ToString(),
                           block3.GetHash().ToString());
         BOOST_CHECK_EQUAL(block.hashMerkleRoot.ToString(),
                           BlockMerkleRoot(block3, &mutated).ToString());
         BOOST_CHECK(!mutated);
 
         // +3 because of partialBlock and block2 and block3
         BOOST_CHECK_EQUAL(
             pool.mapTx.find(block.vtx[2]->GetId())->GetSharedTx().use_count(),
             SHARED_TX_OFFSET + 3);
 
-        txhash = block.vtx[2]->GetId();
+        txid = block.vtx[2]->GetId();
         block.vtx.clear();
         block2.vtx.clear();
         block3.vtx.clear();
 
         // + 1 because of partialBlock; -1 because of block.
-        BOOST_CHECK_EQUAL(pool.mapTx.find(txhash)->GetSharedTx().use_count(),
+        BOOST_CHECK_EQUAL(pool.mapTx.find(txid)->GetSharedTx().use_count(),
                           SHARED_TX_OFFSET + 1 - 1);
     }
 
     // -1 because of block
-    BOOST_CHECK_EQUAL(pool.mapTx.find(txhash)->GetSharedTx().use_count(),
+    BOOST_CHECK_EQUAL(pool.mapTx.find(txid)->GetSharedTx().use_count(),
                       SHARED_TX_OFFSET - 1);
 }
 
 BOOST_AUTO_TEST_CASE(SufficientPreforwardRTTest) {
     CTxMemPool pool;
     TestMemPoolEntryHelper entry;
     CBlock block(BuildBlockTestCase());
 
     LOCK2(cs_main, pool.cs);
     pool.addUnchecked(block.vtx[1]->GetId(), entry.FromTx(block.vtx[1]));
     BOOST_CHECK_EQUAL(
         pool.mapTx.find(block.vtx[1]->GetId())->GetSharedTx().use_count(),
         SHARED_TX_OFFSET + 0);
 
-    uint256 txhash;
+    TxId txid;
 
     // Test with pre-forwarding coinbase + tx 2 with tx 1 in mempool
     {
         TestHeaderAndShortIDs shortIDs(block);
         shortIDs.prefilledtxn.resize(2);
         shortIDs.prefilledtxn[0] = {0, block.vtx[0]};
         // id == 1 as it is 1 after index 1
         shortIDs.prefilledtxn[1] = {1, block.vtx[2]};
         shortIDs.shorttxids.resize(1);
         shortIDs.shorttxids[0] = shortIDs.GetShortID(block.vtx[1]->GetId());
 
         CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
         stream << shortIDs;
 
         CBlockHeaderAndShortTxIDs shortIDs2;
         stream >> shortIDs2;
 
         PartiallyDownloadedBlock partialBlock(GetConfig(), &pool);
         BOOST_CHECK(partialBlock.InitData(shortIDs2, extra_txn) ==
                     READ_STATUS_OK);
         BOOST_CHECK(partialBlock.IsTxAvailable(0));
         BOOST_CHECK(partialBlock.IsTxAvailable(1));
         BOOST_CHECK(partialBlock.IsTxAvailable(2));
 
         BOOST_CHECK_EQUAL(
             pool.mapTx.find(block.vtx[1]->GetId())->GetSharedTx().use_count(),
             SHARED_TX_OFFSET + 1);
 
         CBlock block2;
         PartiallyDownloadedBlock partialBlockCopy = partialBlock;
         BOOST_CHECK(partialBlock.FillBlock(block2, {}) == READ_STATUS_OK);
         BOOST_CHECK_EQUAL(block.GetHash().ToString(),
                           block2.GetHash().ToString());
         bool mutated;
         BOOST_CHECK_EQUAL(block.hashMerkleRoot.ToString(),
                           BlockMerkleRoot(block2, &mutated).ToString());
         BOOST_CHECK(!mutated);
 
-        txhash = block.vtx[1]->GetId();
+        txid = block.vtx[1]->GetId();
         block.vtx.clear();
         block2.vtx.clear();
 
         // + 1 because of partialBlock; -1 because of block.
-        BOOST_CHECK_EQUAL(pool.mapTx.find(txhash)->GetSharedTx().use_count(),
+        BOOST_CHECK_EQUAL(pool.mapTx.find(txid)->GetSharedTx().use_count(),
                           SHARED_TX_OFFSET + 1 - 1);
     }
 
     // -1 because of block
-    BOOST_CHECK_EQUAL(pool.mapTx.find(txhash)->GetSharedTx().use_count(),
+    BOOST_CHECK_EQUAL(pool.mapTx.find(txid)->GetSharedTx().use_count(),
                       SHARED_TX_OFFSET - 1);
 }
 
 BOOST_AUTO_TEST_CASE(EmptyBlockRoundTripTest) {
     CTxMemPool pool;
     CMutableTransaction coinbase;
     coinbase.vin.resize(1);
     coinbase.vin[0].scriptSig.resize(10);
     coinbase.vout.resize(1);
     coinbase.vout[0].nValue = 42 * SATOSHI;
 
     CBlock block;
     block.vtx.resize(1);
     block.vtx[0] = MakeTransactionRef(std::move(coinbase));
     block.nVersion = 42;
     block.hashPrevBlock = BlockHash(InsecureRand256());
     block.nBits = 0x207fffff;
 
     bool mutated;
     block.hashMerkleRoot = BlockMerkleRoot(block, &mutated);
     assert(!mutated);
 
     GlobalConfig config;
     const Consensus::Params &params = config.GetChainParams().GetConsensus();
     while (!CheckProofOfWork(block.GetHash(), block.nBits, params)) {
         ++block.nNonce;
     }
 
     // Test simple header round-trip with only coinbase
     {
         CBlockHeaderAndShortTxIDs shortIDs(block);
 
         CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
         stream << shortIDs;
 
         CBlockHeaderAndShortTxIDs shortIDs2;
         stream >> shortIDs2;
 
         PartiallyDownloadedBlock partialBlock(GetConfig(), &pool);
         BOOST_CHECK(partialBlock.InitData(shortIDs2, extra_txn) ==
                     READ_STATUS_OK);
         BOOST_CHECK(partialBlock.IsTxAvailable(0));
 
         CBlock block2;
         std::vector<CTransactionRef> vtx_missing;
         BOOST_CHECK(partialBlock.FillBlock(block2, vtx_missing) ==
                     READ_STATUS_OK);
         BOOST_CHECK_EQUAL(block.GetHash().ToString(),
                           block2.GetHash().ToString());
         BOOST_CHECK_EQUAL(block.hashMerkleRoot.ToString(),
                           BlockMerkleRoot(block2, &mutated).ToString());
         BOOST_CHECK(!mutated);
     }
 }
 
 BOOST_AUTO_TEST_CASE(TransactionsRequestSerializationTest) {
     BlockTransactionsRequest req1;
     req1.blockhash = BlockHash(InsecureRand256());
     req1.indices.resize(4);
     req1.indices[0] = 0;
     req1.indices[1] = 1;
     req1.indices[2] = 3;
     req1.indices[3] = 4;
 
     CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
     stream << req1;
 
     BlockTransactionsRequest req2;
     stream >> req2;
 
     BOOST_CHECK_EQUAL(req1.blockhash.ToString(), req2.blockhash.ToString());
     BOOST_CHECK_EQUAL(req1.indices.size(), req2.indices.size());
     BOOST_CHECK_EQUAL(req1.indices[0], req2.indices[0]);
     BOOST_CHECK_EQUAL(req1.indices[1], req2.indices[1]);
     BOOST_CHECK_EQUAL(req1.indices[2], req2.indices[2]);
     BOOST_CHECK_EQUAL(req1.indices[3], req2.indices[3]);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index a83c0b1a2e..c818e6535d 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -1,1397 +1,1395 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <txmempool.h>
 
 #include <chain.h>
 #include <chainparams.h> // for GetConsensus.
 #include <clientversion.h>
 #include <config.h>
 #include <consensus/consensus.h>
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <reverse_iterator.h>
 #include <streams.h>
 #include <timedata.h>
 #include <util/moneystr.h>
 #include <util/system.h>
 #include <util/time.h>
 #include <validation.h>
 #include <version.h>
 
 #include <algorithm>
 
 CTxMemPoolEntry::CTxMemPoolEntry(const CTransactionRef &_tx, const Amount _nFee,
                                  int64_t _nTime, double _entryPriority,
                                  unsigned int _entryHeight,
                                  Amount _inChainInputValue,
                                  bool _spendsCoinbase, int64_t _sigOpsCount,
                                  LockPoints lp)
     : tx(_tx), nFee(_nFee), nTime(_nTime), entryPriority(_entryPriority),
       entryHeight(_entryHeight), inChainInputValue(_inChainInputValue),
       spendsCoinbase(_spendsCoinbase), sigOpCount(_sigOpsCount),
       lockPoints(lp) {
     nTxSize = tx->GetTotalSize();
     nModSize = tx->CalculateModifiedSize(GetTxSize());
     nUsageSize = RecursiveDynamicUsage(tx);
 
     nCountWithDescendants = 1;
     nSizeWithDescendants = GetTxSize();
     nModFeesWithDescendants = nFee;
     Amount nValueIn = tx->GetValueOut() + nFee;
     assert(inChainInputValue <= nValueIn);
 
     feeDelta = Amount::zero();
 
     nCountWithAncestors = 1;
     nSizeWithAncestors = GetTxSize();
     nModFeesWithAncestors = nFee;
     nSigOpCountWithAncestors = sigOpCount;
 }
 
 double CTxMemPoolEntry::GetPriority(unsigned int currentHeight) const {
     double deltaPriority =
         double((currentHeight - entryHeight) * (inChainInputValue / SATOSHI)) /
         nModSize;
     double dResult = entryPriority + deltaPriority;
     // This should only happen if it was called with a height below entry height
     if (dResult < 0) {
         dResult = 0;
     }
     return dResult;
 }
 
 void CTxMemPoolEntry::UpdateFeeDelta(Amount newFeeDelta) {
     nModFeesWithDescendants += newFeeDelta - feeDelta;
     nModFeesWithAncestors += newFeeDelta - feeDelta;
     feeDelta = newFeeDelta;
 }
 
 void CTxMemPoolEntry::UpdateLockPoints(const LockPoints &lp) {
     lockPoints = lp;
 }
 
 // Update the given tx for any in-mempool descendants.
 // Assumes that setMemPoolChildren is correct for the given tx and all
 // descendants.
 void CTxMemPool::UpdateForDescendants(txiter updateIt,
                                       cacheMap &cachedDescendants,
                                       const std::set<TxId> &setExclude) {
     setEntries stageEntries, setAllDescendants;
     stageEntries = GetMemPoolChildren(updateIt);
 
     while (!stageEntries.empty()) {
         const txiter cit = *stageEntries.begin();
         setAllDescendants.insert(cit);
         stageEntries.erase(cit);
         const setEntries &setChildren = GetMemPoolChildren(cit);
         for (txiter childEntry : setChildren) {
             cacheMap::iterator cacheIt = cachedDescendants.find(childEntry);
             if (cacheIt != cachedDescendants.end()) {
                 // We've already calculated this one, just add the entries for
                 // this set but don't traverse again.
                 for (txiter cacheEntry : cacheIt->second) {
                     setAllDescendants.insert(cacheEntry);
                 }
             } else if (!setAllDescendants.count(childEntry)) {
                 // Schedule for later processing
                 stageEntries.insert(childEntry);
             }
         }
     }
     // setAllDescendants now contains all in-mempool descendants of updateIt.
     // Update and add to cached descendant map
     int64_t modifySize = 0;
     int64_t modifyCount = 0;
     Amount modifyFee = Amount::zero();
     for (txiter cit : setAllDescendants) {
         if (!setExclude.count(cit->GetTx().GetId())) {
             modifySize += cit->GetTxSize();
             modifyFee += cit->GetModifiedFee();
             modifyCount++;
             cachedDescendants[updateIt].insert(cit);
             // Update ancestor state for each descendant
             mapTx.modify(cit,
                          update_ancestor_state(updateIt->GetTxSize(),
                                                updateIt->GetModifiedFee(), 1,
                                                updateIt->GetSigOpCount()));
         }
     }
     mapTx.modify(updateIt,
                  update_descendant_state(modifySize, modifyFee, modifyCount));
 }
 
 // txidsToUpdate is the set of transaction hashes from a disconnected block
 // which has been re-added to the mempool. For each entry, look for descendants
 // that are outside txidsToUpdate, and add fee/size information for such
 // descendants to the parent. For each such descendant, also update the ancestor
 // state to include the parent.
 void CTxMemPool::UpdateTransactionsFromBlock(
     const std::vector<TxId> &txidsToUpdate) {
     LOCK(cs);
     // For each entry in txidsToUpdate, store the set of in-mempool, but not
     // in-txidsToUpdate transactions, so that we don't have to recalculate
     // descendants when we come across a previously seen entry.
     cacheMap mapMemPoolDescendantsToUpdate;
 
     // Use a set for lookups into txidsToUpdate (these entries are already
     // accounted for in the state of their ancestors)
     std::set<TxId> setAlreadyIncluded(txidsToUpdate.begin(),
                                       txidsToUpdate.end());
 
     // Iterate in reverse, so that whenever we are looking at a transaction
     // we are sure that all in-mempool descendants have already been processed.
     // This maximizes the benefit of the descendant cache and guarantees that
     // setMemPoolChildren will be updated, an assumption made in
     // UpdateForDescendants.
     for (const TxId &txid : reverse_iterate(txidsToUpdate)) {
         // we cache the in-mempool children to avoid duplicate updates
         setEntries setChildren;
         // calculate children from mapNextTx
         txiter it = mapTx.find(txid);
         if (it == mapTx.end()) {
             continue;
         }
 
         auto iter = mapNextTx.lower_bound(COutPoint(txid, 0));
         // First calculate the children, and update setMemPoolChildren to
         // include them, and update their setMemPoolParents to include this tx.
         for (; iter != mapNextTx.end() && iter->first->GetTxId() == txid;
              ++iter) {
             const TxId &childTxId = iter->second->GetId();
             txiter childIter = mapTx.find(childTxId);
             assert(childIter != mapTx.end());
             // We can skip updating entries we've encountered before or that are
             // in the block (which are already accounted for).
             if (setChildren.insert(childIter).second &&
                 !setAlreadyIncluded.count(childTxId)) {
                 UpdateChild(it, childIter, true);
                 UpdateParent(childIter, it, true);
             }
         }
         UpdateForDescendants(it, mapMemPoolDescendantsToUpdate,
                              setAlreadyIncluded);
     }
 }
 
 bool CTxMemPool::CalculateMemPoolAncestors(
     const CTxMemPoolEntry &entry, setEntries &setAncestors,
     uint64_t limitAncestorCount, uint64_t limitAncestorSize,
     uint64_t limitDescendantCount, uint64_t limitDescendantSize,
     std::string &errString, bool fSearchForParents /* = true */) const {
 
     setEntries parentHashes;
     const CTransaction &tx = entry.GetTx();
 
     if (fSearchForParents) {
         // Get parents of this transaction that are in the mempool
         // GetMemPoolParents() is only valid for entries in the mempool, so we
         // iterate mapTx to find parents.
         for (const CTxIn &in : tx.vin) {
             txiter piter = mapTx.find(in.prevout.GetTxId());
             if (piter == mapTx.end()) {
                 continue;
             }
             parentHashes.insert(piter);
             if (parentHashes.size() + 1 > limitAncestorCount) {
                 errString =
                     strprintf("too many unconfirmed parents [limit: %u]",
                               limitAncestorCount);
                 return false;
             }
         }
     } else {
         // If we're not searching for parents, we require this to be an entry in
         // the mempool already.
         txiter it = mapTx.iterator_to(entry);
         parentHashes = GetMemPoolParents(it);
     }
 
     size_t totalSizeWithAncestors = entry.GetTxSize();
 
     while (!parentHashes.empty()) {
         txiter stageit = *parentHashes.begin();
 
         setAncestors.insert(stageit);
         parentHashes.erase(stageit);
         totalSizeWithAncestors += stageit->GetTxSize();
 
         if (stageit->GetSizeWithDescendants() + entry.GetTxSize() >
             limitDescendantSize) {
             errString = strprintf(
                 "exceeds descendant size limit for tx %s [limit: %u]",
                 stageit->GetTx().GetId().ToString(), limitDescendantSize);
             return false;
         }
 
         if (stageit->GetCountWithDescendants() + 1 > limitDescendantCount) {
             errString = strprintf("too many descendants for tx %s [limit: %u]",
                                   stageit->GetTx().GetId().ToString(),
                                   limitDescendantCount);
             return false;
         }
 
         if (totalSizeWithAncestors > limitAncestorSize) {
             errString = strprintf("exceeds ancestor size limit [limit: %u]",
                                   limitAncestorSize);
             return false;
         }
 
         const setEntries &setMemPoolParents = GetMemPoolParents(stageit);
         for (txiter phash : setMemPoolParents) {
             // If this is a new ancestor, add it.
             if (setAncestors.count(phash) == 0) {
                 parentHashes.insert(phash);
             }
             if (parentHashes.size() + setAncestors.size() + 1 >
                 limitAncestorCount) {
                 errString =
                     strprintf("too many unconfirmed ancestors [limit: %u]",
                               limitAncestorCount);
                 return false;
             }
         }
     }
 
     return true;
 }
 
 void CTxMemPool::UpdateAncestorsOf(bool add, txiter it,
                                    setEntries &setAncestors) {
     setEntries parentIters = GetMemPoolParents(it);
     // add or remove this tx as a child of each parent
     for (txiter piter : parentIters) {
         UpdateChild(piter, it, add);
     }
     const int64_t updateCount = (add ? 1 : -1);
     const int64_t updateSize = updateCount * it->GetTxSize();
     const Amount updateFee = updateCount * it->GetModifiedFee();
     for (txiter ancestorIt : setAncestors) {
         mapTx.modify(ancestorIt, update_descendant_state(updateSize, updateFee,
                                                          updateCount));
     }
 }
 
 void CTxMemPool::UpdateEntryForAncestors(txiter it,
                                          const setEntries &setAncestors) {
     int64_t updateCount = setAncestors.size();
     int64_t updateSize = 0;
     int64_t updateSigOpsCount = 0;
     Amount updateFee = Amount::zero();
 
     for (txiter ancestorIt : setAncestors) {
         updateSize += ancestorIt->GetTxSize();
         updateFee += ancestorIt->GetModifiedFee();
         updateSigOpsCount += ancestorIt->GetSigOpCount();
     }
     mapTx.modify(it, update_ancestor_state(updateSize, updateFee, updateCount,
                                            updateSigOpsCount));
 }
 
 void CTxMemPool::UpdateChildrenForRemoval(txiter it) {
     const setEntries &setMemPoolChildren = GetMemPoolChildren(it);
     for (txiter updateIt : setMemPoolChildren) {
         UpdateParent(updateIt, it, false);
     }
 }
 
 void CTxMemPool::UpdateForRemoveFromMempool(const setEntries &entriesToRemove,
                                             bool updateDescendants) {
     // For each entry, walk back all ancestors and decrement size associated
     // with this transaction.
     const uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
     if (updateDescendants) {
         // updateDescendants should be true whenever we're not recursively
         // removing a tx and all its descendants, eg when a transaction is
         // confirmed in a block. Here we only update statistics and not data in
         // mapLinks (which we need to preserve until we're finished with all
         // operations that need to traverse the mempool).
         for (txiter removeIt : entriesToRemove) {
             setEntries setDescendants;
             CalculateDescendants(removeIt, setDescendants);
             setDescendants.erase(removeIt); // don't update state for self
             int64_t modifySize = -int64_t(removeIt->GetTxSize());
             Amount modifyFee = -1 * removeIt->GetModifiedFee();
             int modifySigOps = -removeIt->GetSigOpCount();
             for (txiter dit : setDescendants) {
                 mapTx.modify(dit, update_ancestor_state(modifySize, modifyFee,
                                                         -1, modifySigOps));
             }
         }
     }
 
     for (txiter removeIt : entriesToRemove) {
         setEntries setAncestors;
         const CTxMemPoolEntry &entry = *removeIt;
         std::string dummy;
         // Since this is a tx that is already in the mempool, we can call CMPA
         // with fSearchForParents = false.  If the mempool is in a consistent
         // state, then using true or false should both be correct, though false
         // should be a bit faster.
         // However, if we happen to be in the middle of processing a reorg, then
         // the mempool can be in an inconsistent state. In this case, the set of
         // ancestors reachable via mapLinks will be the same as the set of
         // ancestors whose packages include this transaction, because when we
         // add a new transaction to the mempool in addUnchecked(), we assume it
         // has no children, and in the case of a reorg where that assumption is
         // false, the in-mempool children aren't linked to the in-block tx's
         // until UpdateTransactionsFromBlock() is called. So if we're being
         // called during a reorg, ie before UpdateTransactionsFromBlock() has
         // been called, then mapLinks[] will differ from the set of mempool
         // parents we'd calculate by searching, and it's important that we use
         // the mapLinks[] notion of ancestor transactions as the set of things
         // to update for removal.
         CalculateMemPoolAncestors(entry, setAncestors, nNoLimit, nNoLimit,
                                   nNoLimit, nNoLimit, dummy, false);
         // Note that UpdateAncestorsOf severs the child links that point to
         // removeIt in the entries for the parents of removeIt.
         UpdateAncestorsOf(false, removeIt, setAncestors);
     }
     // After updating all the ancestor sizes, we can now sever the link between
     // each transaction being removed and any mempool children (ie, update
     // setMemPoolParents for each direct child of a transaction being removed).
     for (txiter removeIt : entriesToRemove) {
         UpdateChildrenForRemoval(removeIt);
     }
 }
 
 void CTxMemPoolEntry::UpdateDescendantState(int64_t modifySize,
                                             Amount modifyFee,
                                             int64_t modifyCount) {
     nSizeWithDescendants += modifySize;
     assert(int64_t(nSizeWithDescendants) > 0);
     nModFeesWithDescendants += modifyFee;
     nCountWithDescendants += modifyCount;
     assert(int64_t(nCountWithDescendants) > 0);
 }
 
 void CTxMemPoolEntry::UpdateAncestorState(int64_t modifySize, Amount modifyFee,
                                           int64_t modifyCount,
                                           int modifySigOps) {
     nSizeWithAncestors += modifySize;
     assert(int64_t(nSizeWithAncestors) > 0);
     nModFeesWithAncestors += modifyFee;
     nCountWithAncestors += modifyCount;
     assert(int64_t(nCountWithAncestors) > 0);
     nSigOpCountWithAncestors += modifySigOps;
     assert(int(nSigOpCountWithAncestors) >= 0);
 }
 
 CTxMemPool::CTxMemPool() : nTransactionsUpdated(0) {
     // lock free clear
     _clear();
 
     // Sanity checks off by default for performance, because otherwise accepting
     // transactions becomes O(N^2) where N is the number of transactions in the
     // pool
     nCheckFrequency = 0;
 }
 
 CTxMemPool::~CTxMemPool() {}
 
 bool CTxMemPool::isSpent(const COutPoint &outpoint) const {
     LOCK(cs);
     return mapNextTx.count(outpoint);
 }
 
 unsigned int CTxMemPool::GetTransactionsUpdated() const {
     LOCK(cs);
     return nTransactionsUpdated;
 }
 
 void CTxMemPool::AddTransactionsUpdated(unsigned int n) {
     LOCK(cs);
     nTransactionsUpdated += n;
 }
 
 void CTxMemPool::addUnchecked(const uint256 &hash, const CTxMemPoolEntry &entry,
                               setEntries &setAncestors) {
     NotifyEntryAdded(entry.GetSharedTx());
     // Add to memory pool without checking anything.
     // Used by AcceptToMemoryPool(), which DOES do all the appropriate checks.
     indexed_transaction_set::iterator newit = mapTx.insert(entry).first;
     mapLinks.insert(make_pair(newit, TxLinks()));
 
     // Update transaction for any feeDelta created by PrioritiseTransaction
     // TODO: refactor so that the fee delta is calculated before inserting into
     // mapTx.
     std::map<uint256, TXModifier>::const_iterator pos = mapDeltas.find(hash);
     if (pos != mapDeltas.end()) {
         const TXModifier &deltas = pos->second;
         if (deltas.second != Amount::zero()) {
             mapTx.modify(newit, update_fee_delta(deltas.second));
         }
     }
 
     // Update cachedInnerUsage to include contained transaction's usage.
     // (When we update the entry for in-mempool parents, memory usage will be
     // further updated.)
     cachedInnerUsage += entry.DynamicMemoryUsage();
 
     const CTransaction &tx = newit->GetTx();
-    std::set<uint256> setParentTransactions;
+    std::set<TxId> setParentTransactions;
     for (const CTxIn &in : tx.vin) {
         mapNextTx.insert(std::make_pair(&in.prevout, &tx));
         setParentTransactions.insert(in.prevout.GetTxId());
     }
     // Don't bother worrying about child transactions of this one. Normal case
     // of a new transaction arriving is that there can't be any children,
     // because such children would be orphans. An exception to that is if a
     // transaction enters that used to be in a block. In that case, our
     // disconnect block logic will call UpdateTransactionsFromBlock to clean up
     // the mess we're leaving here.
 
     // Update ancestors with information about this tx
-    for (const uint256 &phash : setParentTransactions) {
+    for (const TxId &phash : setParentTransactions) {
         txiter pit = mapTx.find(phash);
         if (pit != mapTx.end()) {
             UpdateParent(newit, pit, true);
         }
     }
     UpdateAncestorsOf(true, newit, setAncestors);
     UpdateEntryForAncestors(newit, setAncestors);
 
     nTransactionsUpdated++;
     totalTxSize += entry.GetTxSize();
 
     vTxHashes.emplace_back(tx.GetHash(), newit);
     newit->vTxHashesIdx = vTxHashes.size() - 1;
 }
 
 void CTxMemPool::removeUnchecked(txiter it, MemPoolRemovalReason reason) {
     NotifyEntryRemoved(it->GetSharedTx(), reason);
     for (const CTxIn &txin : it->GetTx().vin) {
         mapNextTx.erase(txin.prevout);
     }
 
     if (vTxHashes.size() > 1) {
         vTxHashes[it->vTxHashesIdx] = std::move(vTxHashes.back());
         vTxHashes[it->vTxHashesIdx].second->vTxHashesIdx = it->vTxHashesIdx;
         vTxHashes.pop_back();
         if (vTxHashes.size() * 2 < vTxHashes.capacity()) {
             vTxHashes.shrink_to_fit();
         }
     } else {
         vTxHashes.clear();
     }
 
     totalTxSize -= it->GetTxSize();
     cachedInnerUsage -= it->DynamicMemoryUsage();
     cachedInnerUsage -= memusage::DynamicUsage(mapLinks[it].parents) +
                         memusage::DynamicUsage(mapLinks[it].children);
     mapLinks.erase(it);
     mapTx.erase(it);
     nTransactionsUpdated++;
 }
 
 // Calculates descendants of entry that are not already in setDescendants, and
 // adds to setDescendants. Assumes entryit is already a tx in the mempool and
 // setMemPoolChildren is correct for tx and all descendants. Also assumes that
 // if an entry is in setDescendants already, then all in-mempool descendants of
 // it are already in setDescendants as well, so that we can save time by not
 // iterating over those entries.
 void CTxMemPool::CalculateDescendants(txiter entryit,
                                       setEntries &setDescendants) const {
     setEntries stage;
     if (setDescendants.count(entryit) == 0) {
         stage.insert(entryit);
     }
     // Traverse down the children of entry, only adding children that are not
     // accounted for in setDescendants already (because those children have
     // either already been walked, or will be walked in this iteration).
     while (!stage.empty()) {
         txiter it = *stage.begin();
         setDescendants.insert(it);
         stage.erase(it);
 
         const setEntries &setChildren = GetMemPoolChildren(it);
         for (txiter childiter : setChildren) {
             if (!setDescendants.count(childiter)) {
                 stage.insert(childiter);
             }
         }
     }
 }
 
 void CTxMemPool::removeRecursive(const CTransaction &origTx,
                                  MemPoolRemovalReason reason) {
     // Remove transaction from memory pool.
     LOCK(cs);
     setEntries txToRemove;
     txiter origit = mapTx.find(origTx.GetId());
     if (origit != mapTx.end()) {
         txToRemove.insert(origit);
     } else {
         // When recursively removing but origTx isn't in the mempool be sure to
         // remove any children that are in the pool. This can happen during
         // chain re-orgs if origTx isn't re-accepted into the mempool for any
         // reason.
         for (size_t i = 0; i < origTx.vout.size(); i++) {
             auto it = mapNextTx.find(COutPoint(origTx.GetId(), i));
             if (it == mapNextTx.end()) {
                 continue;
             }
 
             txiter nextit = mapTx.find(it->second->GetId());
             assert(nextit != mapTx.end());
             txToRemove.insert(nextit);
         }
     }
 
     setEntries setAllRemoves;
     for (txiter it : txToRemove) {
         CalculateDescendants(it, setAllRemoves);
     }
 
     RemoveStaged(setAllRemoves, false, reason);
 }
 
 void CTxMemPool::removeForReorg(const Config &config,
                                 const CCoinsViewCache *pcoins,
                                 unsigned int nMemPoolHeight, int flags) {
     // Remove transactions spending a coinbase which are now immature and
     // no-longer-final transactions.
     LOCK(cs);
     setEntries txToRemove;
     for (indexed_transaction_set::const_iterator it = mapTx.begin();
          it != mapTx.end(); it++) {
         const CTransaction &tx = it->GetTx();
         LockPoints lp = it->GetLockPoints();
         bool validLP = TestLockPointValidity(&lp);
 
         CValidationState state;
         if (!ContextualCheckTransactionForCurrentBlock(
                 config.GetChainParams().GetConsensus(), tx, state, flags) ||
             !CheckSequenceLocks(*this, tx, flags, &lp, validLP)) {
             // Note if CheckSequenceLocks fails the LockPoints may still be
             // invalid. So it's critical that we remove the tx and not depend on
             // the LockPoints.
             txToRemove.insert(it);
         } else if (it->GetSpendsCoinbase()) {
             for (const CTxIn &txin : tx.vin) {
                 indexed_transaction_set::const_iterator it2 =
                     mapTx.find(txin.prevout.GetTxId());
                 if (it2 != mapTx.end()) {
                     continue;
                 }
 
                 const Coin &coin = pcoins->AccessCoin(txin.prevout);
                 if (nCheckFrequency != 0) {
                     assert(!coin.IsSpent());
                 }
 
                 if (coin.IsSpent() ||
                     (coin.IsCoinBase() &&
                      int64_t(nMemPoolHeight) - coin.GetHeight() <
                          COINBASE_MATURITY)) {
                     txToRemove.insert(it);
                     break;
                 }
             }
         }
         if (!validLP) {
             mapTx.modify(it, update_lock_points(lp));
         }
     }
     setEntries setAllRemoves;
     for (txiter it : txToRemove) {
         CalculateDescendants(it, setAllRemoves);
     }
     RemoveStaged(setAllRemoves, false, MemPoolRemovalReason::REORG);
 }
 
 void CTxMemPool::removeConflicts(const CTransaction &tx) {
     // Remove transactions which depend on inputs of tx, recursively
     AssertLockHeld(cs);
     for (const CTxIn &txin : tx.vin) {
         auto it = mapNextTx.find(txin.prevout);
         if (it != mapNextTx.end()) {
             const CTransaction &txConflict = *it->second;
             if (txConflict != tx) {
                 ClearPrioritisation(txConflict.GetId());
                 removeRecursive(txConflict, MemPoolRemovalReason::CONFLICT);
             }
         }
     }
 }
 
 /**
  * Called when a block is connected. Removes from mempool and updates the miner
  * fee estimator.
  */
 void CTxMemPool::removeForBlock(const std::vector<CTransactionRef> &vtx,
                                 unsigned int nBlockHeight) {
     LOCK(cs);
 
     DisconnectedBlockTransactions disconnectpool;
     disconnectpool.addForBlock(vtx);
 
     std::vector<const CTxMemPoolEntry *> entries;
     for (const CTransactionRef &tx :
          reverse_iterate(disconnectpool.GetQueuedTx().get<insertion_order>())) {
-        uint256 txid = tx->GetId();
+        const TxId &txid = tx->GetId();
 
         indexed_transaction_set::iterator i = mapTx.find(txid);
         if (i != mapTx.end()) {
             entries.push_back(&*i);
         }
     }
 
     for (const CTransactionRef &tx :
          reverse_iterate(disconnectpool.GetQueuedTx().get<insertion_order>())) {
         txiter it = mapTx.find(tx->GetId());
         if (it != mapTx.end()) {
             setEntries stage;
             stage.insert(it);
             RemoveStaged(stage, true, MemPoolRemovalReason::BLOCK);
         }
         removeConflicts(*tx);
         ClearPrioritisation(tx->GetId());
     }
 
     disconnectpool.clear();
 
     lastRollingFeeUpdate = GetTime();
     blockSinceLastRollingFeeBump = true;
 }
 
 void CTxMemPool::_clear() {
     mapLinks.clear();
     mapTx.clear();
     mapNextTx.clear();
     vTxHashes.clear();
     totalTxSize = 0;
     cachedInnerUsage = 0;
     lastRollingFeeUpdate = GetTime();
     blockSinceLastRollingFeeBump = false;
     rollingMinimumFeeRate = 0;
     ++nTransactionsUpdated;
 }
 
 void CTxMemPool::clear() {
     LOCK(cs);
     _clear();
 }
 
 static void CheckInputsAndUpdateCoins(const CTransaction &tx,
                                       CCoinsViewCache &mempoolDuplicate,
                                       const int64_t spendheight) {
     CValidationState state;
     Amount txfee = Amount::zero();
     bool fCheckResult =
         tx.IsCoinBase() || Consensus::CheckTxInputs(tx, state, mempoolDuplicate,
                                                     spendheight, txfee);
     assert(fCheckResult);
     UpdateCoins(mempoolDuplicate, tx, std::numeric_limits<int>::max());
 }
 
 void CTxMemPool::check(const CCoinsViewCache *pcoins) const {
     LOCK(cs);
     if (nCheckFrequency == 0) {
         return;
     }
 
     if (GetRand(std::numeric_limits<uint32_t>::max()) >= nCheckFrequency) {
         return;
     }
 
     LogPrint(BCLog::MEMPOOL,
              "Checking mempool with %u transactions and %u inputs\n",
              (unsigned int)mapTx.size(), (unsigned int)mapNextTx.size());
 
     uint64_t checkTotal = 0;
     uint64_t innerUsage = 0;
 
     CCoinsViewCache mempoolDuplicate(const_cast<CCoinsViewCache *>(pcoins));
     const int64_t spendheight = GetSpendHeight(mempoolDuplicate);
 
     std::list<const CTxMemPoolEntry *> waitingOnDependants;
     for (indexed_transaction_set::const_iterator it = mapTx.begin();
          it != mapTx.end(); it++) {
         unsigned int i = 0;
         checkTotal += it->GetTxSize();
         innerUsage += it->DynamicMemoryUsage();
         const CTransaction &tx = it->GetTx();
         txlinksMap::const_iterator linksiter = mapLinks.find(it);
         assert(linksiter != mapLinks.end());
         const TxLinks &links = linksiter->second;
         innerUsage += memusage::DynamicUsage(links.parents) +
                       memusage::DynamicUsage(links.children);
         bool fDependsWait = false;
         setEntries setParentCheck;
         for (const CTxIn &txin : tx.vin) {
             // Check that every mempool transaction's inputs refer to available
             // coins, or other mempool tx's.
             indexed_transaction_set::const_iterator it2 =
                 mapTx.find(txin.prevout.GetTxId());
             if (it2 != mapTx.end()) {
                 const CTransaction &tx2 = it2->GetTx();
                 assert(tx2.vout.size() > txin.prevout.GetN() &&
                        !tx2.vout[txin.prevout.GetN()].IsNull());
                 fDependsWait = true;
                 setParentCheck.insert(it2);
             } else {
                 assert(pcoins->HaveCoin(txin.prevout));
             }
             // Check whether its inputs are marked in mapNextTx.
             auto it3 = mapNextTx.find(txin.prevout);
             assert(it3 != mapNextTx.end());
             assert(it3->first == &txin.prevout);
             assert(it3->second == &tx);
             i++;
         }
         assert(setParentCheck == GetMemPoolParents(it));
         // Verify ancestor state is correct.
         setEntries setAncestors;
         uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
         std::string dummy;
         CalculateMemPoolAncestors(*it, setAncestors, nNoLimit, nNoLimit,
                                   nNoLimit, nNoLimit, dummy);
         uint64_t nCountCheck = setAncestors.size() + 1;
         uint64_t nSizeCheck = it->GetTxSize();
         Amount nFeesCheck = it->GetModifiedFee();
         int64_t nSigOpCheck = it->GetSigOpCount();
 
         for (txiter ancestorIt : setAncestors) {
             nSizeCheck += ancestorIt->GetTxSize();
             nFeesCheck += ancestorIt->GetModifiedFee();
             nSigOpCheck += ancestorIt->GetSigOpCount();
         }
 
         assert(it->GetCountWithAncestors() == nCountCheck);
         assert(it->GetSizeWithAncestors() == nSizeCheck);
         assert(it->GetSigOpCountWithAncestors() == nSigOpCheck);
         assert(it->GetModFeesWithAncestors() == nFeesCheck);
 
         // Check children against mapNextTx
         CTxMemPool::setEntries setChildrenCheck;
         auto iter = mapNextTx.lower_bound(COutPoint(it->GetTx().GetId(), 0));
         uint64_t child_sizes = 0;
         for (; iter != mapNextTx.end() &&
                iter->first->GetTxId() == it->GetTx().GetId();
              ++iter) {
             txiter childit = mapTx.find(iter->second->GetId());
             // mapNextTx points to in-mempool transactions
             assert(childit != mapTx.end());
             if (setChildrenCheck.insert(childit).second) {
                 child_sizes += childit->GetTxSize();
             }
         }
         assert(setChildrenCheck == GetMemPoolChildren(it));
         // Also check to make sure size is greater than sum with immediate
         // children. Just a sanity check, not definitive that this calc is
         // correct...
         assert(it->GetSizeWithDescendants() >= child_sizes + it->GetTxSize());
 
         if (fDependsWait) {
             waitingOnDependants.push_back(&(*it));
         } else {
             CheckInputsAndUpdateCoins(tx, mempoolDuplicate, spendheight);
         }
     }
 
     unsigned int stepsSinceLastRemove = 0;
     while (!waitingOnDependants.empty()) {
         const CTxMemPoolEntry *entry = waitingOnDependants.front();
         waitingOnDependants.pop_front();
         if (!mempoolDuplicate.HaveInputs(entry->GetTx())) {
             waitingOnDependants.push_back(entry);
             stepsSinceLastRemove++;
             assert(stepsSinceLastRemove < waitingOnDependants.size());
         } else {
             CheckInputsAndUpdateCoins(entry->GetTx(), mempoolDuplicate,
                                       spendheight);
             stepsSinceLastRemove = 0;
         }
     }
 
     for (auto it = mapNextTx.cbegin(); it != mapNextTx.cend(); it++) {
-        uint256 txid = it->second->GetId();
+        const TxId &txid = it->second->GetId();
         indexed_transaction_set::const_iterator it2 = mapTx.find(txid);
         const CTransaction &tx = it2->GetTx();
         assert(it2 != mapTx.end());
         assert(&tx == it->second);
     }
 
     assert(totalTxSize == checkTotal);
     assert(innerUsage == cachedInnerUsage);
 }
 
-bool CTxMemPool::CompareDepthAndScore(const uint256 &hasha,
-                                      const uint256 &hashb) {
+bool CTxMemPool::CompareDepthAndScore(const TxId &txida, const TxId &txidb) {
     LOCK(cs);
-    indexed_transaction_set::const_iterator i = mapTx.find(hasha);
+    indexed_transaction_set::const_iterator i = mapTx.find(txida);
     if (i == mapTx.end()) {
         return false;
     }
-    indexed_transaction_set::const_iterator j = mapTx.find(hashb);
+    indexed_transaction_set::const_iterator j = mapTx.find(txidb);
     if (j == mapTx.end()) {
         return true;
     }
     uint64_t counta = i->GetCountWithAncestors();
     uint64_t countb = j->GetCountWithAncestors();
     if (counta == countb) {
         return CompareTxMemPoolEntryByScore()(*i, *j);
     }
     return counta < countb;
 }
 
 namespace {
 class DepthAndScoreComparator {
 public:
     bool
     operator()(const CTxMemPool::indexed_transaction_set::const_iterator &a,
                const CTxMemPool::indexed_transaction_set::const_iterator &b) {
         uint64_t counta = a->GetCountWithAncestors();
         uint64_t countb = b->GetCountWithAncestors();
         if (counta == countb) {
             return CompareTxMemPoolEntryByScore()(*a, *b);
         }
         return counta < countb;
     }
 };
 } // namespace
 
 std::vector<CTxMemPool::indexed_transaction_set::const_iterator>
 CTxMemPool::GetSortedDepthAndScore() const {
     std::vector<indexed_transaction_set::const_iterator> iters;
     AssertLockHeld(cs);
 
     iters.reserve(mapTx.size());
     for (indexed_transaction_set::iterator mi = mapTx.begin();
          mi != mapTx.end(); ++mi) {
         iters.push_back(mi);
     }
 
     std::sort(iters.begin(), iters.end(), DepthAndScoreComparator());
     return iters;
 }
 
 void CTxMemPool::queryHashes(std::vector<uint256> &vtxid) const {
     LOCK(cs);
     auto iters = GetSortedDepthAndScore();
 
     vtxid.clear();
     vtxid.reserve(mapTx.size());
 
     for (auto it : iters) {
         vtxid.push_back(it->GetTx().GetId());
     }
 }
 
 static TxMempoolInfo
 GetInfo(CTxMemPool::indexed_transaction_set::const_iterator it) {
     return TxMempoolInfo{it->GetSharedTx(), it->GetTime(),
                          CFeeRate(it->GetFee(), it->GetTxSize()),
                          it->GetModifiedFee() - it->GetFee()};
 }
 
 std::vector<TxMempoolInfo> CTxMemPool::infoAll() const {
     LOCK(cs);
     auto iters = GetSortedDepthAndScore();
 
     std::vector<TxMempoolInfo> ret;
     ret.reserve(mapTx.size());
     for (auto it : iters) {
         ret.push_back(GetInfo(it));
     }
 
     return ret;
 }
 
-CTransactionRef CTxMemPool::get(const uint256 &txid) const {
+CTransactionRef CTxMemPool::get(const TxId &txid) const {
     LOCK(cs);
     indexed_transaction_set::const_iterator i = mapTx.find(txid);
     if (i == mapTx.end()) {
         return nullptr;
     }
 
     return i->GetSharedTx();
 }
 
-TxMempoolInfo CTxMemPool::info(const uint256 &txid) const {
+TxMempoolInfo CTxMemPool::info(const TxId &txid) const {
     LOCK(cs);
     indexed_transaction_set::const_iterator i = mapTx.find(txid);
     if (i == mapTx.end()) {
         return TxMempoolInfo();
     }
 
     return GetInfo(i);
 }
 
 CFeeRate CTxMemPool::estimateFee() const {
     LOCK(cs);
 
     uint64_t maxMempoolSize =
         gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
     // minerPolicy uses recent blocks to figure out a reasonable fee.  This
     // may disagree with the rollingMinimumFeerate under certain scenarios
     // where the mempool  increases rapidly, or blocks are being mined which
     // do not contain propagated transactions.
     return std::max(::minRelayTxFee, GetMinFee(maxMempoolSize));
 }
 
-void CTxMemPool::PrioritiseTransaction(const uint256 &hash,
-                                       double dPriorityDelta,
+void CTxMemPool::PrioritiseTransaction(const TxId &txid, double dPriorityDelta,
                                        const Amount nFeeDelta) {
     {
         LOCK(cs);
-        TXModifier &deltas = mapDeltas[hash];
+        TXModifier &deltas = mapDeltas[txid];
         deltas.first += dPriorityDelta;
         deltas.second += nFeeDelta;
-        txiter it = mapTx.find(hash);
+        txiter it = mapTx.find(txid);
         if (it != mapTx.end()) {
             mapTx.modify(it, update_fee_delta(deltas.second));
             // Now update all ancestors' modified fees with descendants
             setEntries setAncestors;
             uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
             std::string dummy;
             CalculateMemPoolAncestors(*it, setAncestors, nNoLimit, nNoLimit,
                                       nNoLimit, nNoLimit, dummy, false);
             for (txiter ancestorIt : setAncestors) {
                 mapTx.modify(ancestorIt,
                              update_descendant_state(0, nFeeDelta, 0));
             }
 
             // Now update all descendants' modified fees with ancestors
             setEntries setDescendants;
             CalculateDescendants(it, setDescendants);
             setDescendants.erase(it);
             for (txiter descendantIt : setDescendants) {
                 mapTx.modify(descendantIt,
                              update_ancestor_state(0, nFeeDelta, 0, 0));
             }
             ++nTransactionsUpdated;
         }
     }
     LogPrintf("PrioritiseTransaction: %s priority += %f, fee += %d\n",
-              hash.ToString(), dPriorityDelta, FormatMoney(nFeeDelta));
+              txid.ToString(), dPriorityDelta, FormatMoney(nFeeDelta));
 }
 
 void CTxMemPool::ApplyDeltas(const uint256 hash, double &dPriorityDelta,
                              Amount &nFeeDelta) const {
     LOCK(cs);
     std::map<uint256, TXModifier>::const_iterator pos = mapDeltas.find(hash);
     if (pos == mapDeltas.end()) {
         return;
     }
 
     const TXModifier &deltas = pos->second;
     dPriorityDelta += deltas.first;
     nFeeDelta += deltas.second;
 }
 
 void CTxMemPool::ClearPrioritisation(const uint256 hash) {
     LOCK(cs);
     mapDeltas.erase(hash);
 }
 
 bool CTxMemPool::HasNoInputsOf(const CTransaction &tx) const {
     for (const CTxIn &in : tx.vin) {
         if (exists(in.prevout.GetTxId())) {
             return false;
         }
     }
 
     return true;
 }
 
 CCoinsViewMemPool::CCoinsViewMemPool(CCoinsView *baseIn,
                                      const CTxMemPool &mempoolIn)
     : CCoinsViewBacked(baseIn), mempool(mempoolIn) {}
 
 bool CCoinsViewMemPool::GetCoin(const COutPoint &outpoint, Coin &coin) const {
     // If an entry in the mempool exists, always return that one, as it's
     // guaranteed to never conflict with the underlying cache, and it cannot
     // have pruned entries (as it contains full) transactions. First checking
     // the underlying cache risks returning a pruned entry instead.
     CTransactionRef ptx = mempool.get(outpoint.GetTxId());
     if (ptx) {
         if (outpoint.GetN() < ptx->vout.size()) {
             coin = Coin(ptx->vout[outpoint.GetN()], MEMPOOL_HEIGHT, false);
             return true;
         }
         return false;
     }
     return base->GetCoin(outpoint, coin);
 }
 
 size_t CTxMemPool::DynamicMemoryUsage() const {
     LOCK(cs);
     // Estimate the overhead of mapTx to be 12 pointers + an allocation, as no
     // exact formula for boost::multi_index_contained is implemented.
     return memusage::MallocUsage(sizeof(CTxMemPoolEntry) +
                                  12 * sizeof(void *)) *
                mapTx.size() +
            memusage::DynamicUsage(mapNextTx) +
            memusage::DynamicUsage(mapDeltas) +
            memusage::DynamicUsage(mapLinks) +
            memusage::DynamicUsage(vTxHashes) + cachedInnerUsage;
 }
 
 void CTxMemPool::RemoveStaged(setEntries &stage, bool updateDescendants,
                               MemPoolRemovalReason reason) {
     AssertLockHeld(cs);
     UpdateForRemoveFromMempool(stage, updateDescendants);
     for (txiter it : stage) {
         removeUnchecked(it, reason);
     }
 }
 
 int CTxMemPool::Expire(int64_t time) {
     LOCK(cs);
     indexed_transaction_set::index<entry_time>::type::iterator it =
         mapTx.get<entry_time>().begin();
     setEntries toremove;
     while (it != mapTx.get<entry_time>().end() && it->GetTime() < time) {
         toremove.insert(mapTx.project<0>(it));
         it++;
     }
 
     setEntries stage;
     for (txiter removeit : toremove) {
         CalculateDescendants(removeit, stage);
     }
 
     RemoveStaged(stage, false, MemPoolRemovalReason::EXPIRY);
     return stage.size();
 }
 
 void CTxMemPool::LimitSize(size_t limit, unsigned long age) {
     int expired = Expire(GetTime() - age);
     if (expired != 0) {
         LogPrint(BCLog::MEMPOOL,
                  "Expired %i transactions from the memory pool\n", expired);
     }
 
     std::vector<COutPoint> vNoSpendsRemaining;
     TrimToSize(limit, &vNoSpendsRemaining);
     for (const COutPoint &removed : vNoSpendsRemaining) {
         pcoinsTip->Uncache(removed);
     }
 }
 
 void CTxMemPool::addUnchecked(const uint256 &hash,
                               const CTxMemPoolEntry &entry) {
     setEntries setAncestors;
     uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
     std::string dummy;
     CalculateMemPoolAncestors(entry, setAncestors, nNoLimit, nNoLimit, nNoLimit,
                               nNoLimit, dummy);
     return addUnchecked(hash, entry, setAncestors);
 }
 
 void CTxMemPool::UpdateChild(txiter entry, txiter child, bool add) {
     setEntries s;
     if (add && mapLinks[entry].children.insert(child).second) {
         cachedInnerUsage += memusage::IncrementalDynamicUsage(s);
     } else if (!add && mapLinks[entry].children.erase(child)) {
         cachedInnerUsage -= memusage::IncrementalDynamicUsage(s);
     }
 }
 
 void CTxMemPool::UpdateParent(txiter entry, txiter parent, bool add) {
     setEntries s;
     if (add && mapLinks[entry].parents.insert(parent).second) {
         cachedInnerUsage += memusage::IncrementalDynamicUsage(s);
     } else if (!add && mapLinks[entry].parents.erase(parent)) {
         cachedInnerUsage -= memusage::IncrementalDynamicUsage(s);
     }
 }
 
 const CTxMemPool::setEntries &
 CTxMemPool::GetMemPoolParents(txiter entry) const {
     assert(entry != mapTx.end());
     txlinksMap::const_iterator it = mapLinks.find(entry);
     assert(it != mapLinks.end());
     return it->second.parents;
 }
 
 const CTxMemPool::setEntries &
 CTxMemPool::GetMemPoolChildren(txiter entry) const {
     assert(entry != mapTx.end());
     txlinksMap::const_iterator it = mapLinks.find(entry);
     assert(it != mapLinks.end());
     return it->second.children;
 }
 
 CFeeRate CTxMemPool::GetMinFee(size_t sizelimit) const {
     LOCK(cs);
     if (!blockSinceLastRollingFeeBump || rollingMinimumFeeRate == 0) {
         return CFeeRate(int64_t(ceill(rollingMinimumFeeRate)) * SATOSHI);
     }
 
     int64_t time = GetTime();
     if (time > lastRollingFeeUpdate + 10) {
         double halflife = ROLLING_FEE_HALFLIFE;
         if (DynamicMemoryUsage() < sizelimit / 4) {
             halflife /= 4;
         } else if (DynamicMemoryUsage() < sizelimit / 2) {
             halflife /= 2;
         }
 
         rollingMinimumFeeRate =
             rollingMinimumFeeRate /
             pow(2.0, (time - lastRollingFeeUpdate) / halflife);
         lastRollingFeeUpdate = time;
     }
     return CFeeRate(int64_t(ceill(rollingMinimumFeeRate)) * SATOSHI);
 }
 
 void CTxMemPool::trackPackageRemoved(const CFeeRate &rate) {
     AssertLockHeld(cs);
     if ((rate.GetFeePerK() / SATOSHI) > rollingMinimumFeeRate) {
         rollingMinimumFeeRate = rate.GetFeePerK() / SATOSHI;
         blockSinceLastRollingFeeBump = false;
     }
 }
 
 void CTxMemPool::TrimToSize(size_t sizelimit,
                             std::vector<COutPoint> *pvNoSpendsRemaining) {
     LOCK(cs);
 
     unsigned nTxnRemoved = 0;
     CFeeRate maxFeeRateRemoved(Amount::zero());
     while (!mapTx.empty() && DynamicMemoryUsage() > sizelimit) {
         indexed_transaction_set::index<descendant_score>::type::iterator it =
             mapTx.get<descendant_score>().begin();
 
         // We set the new mempool min fee to the feerate of the removed set,
         // plus the "minimum reasonable fee rate" (ie some value under which we
         // consider txn to have 0 fee). This way, we don't allow txn to enter
         // mempool with feerate equal to txn which were removed with no block in
         // between.
         CFeeRate removed(it->GetModFeesWithDescendants(),
                          it->GetSizeWithDescendants());
         removed += MEMPOOL_FULL_FEE_INCREMENT;
 
         trackPackageRemoved(removed);
         maxFeeRateRemoved = std::max(maxFeeRateRemoved, removed);
 
         setEntries stage;
         CalculateDescendants(mapTx.project<0>(it), stage);
         nTxnRemoved += stage.size();
 
         std::vector<CTransaction> txn;
         if (pvNoSpendsRemaining) {
             txn.reserve(stage.size());
             for (txiter iter : stage) {
                 txn.push_back(iter->GetTx());
             }
         }
         RemoveStaged(stage, false, MemPoolRemovalReason::SIZELIMIT);
         if (pvNoSpendsRemaining) {
             for (const CTransaction &tx : txn) {
                 for (const CTxIn &txin : tx.vin) {
                     if (exists(txin.prevout.GetTxId())) {
                         continue;
                     }
                     pvNoSpendsRemaining->push_back(txin.prevout);
                 }
             }
         }
     }
 
     if (maxFeeRateRemoved > CFeeRate(Amount::zero())) {
         LogPrint(BCLog::MEMPOOL,
                  "Removed %u txn, rolling minimum fee bumped to %s\n",
                  nTxnRemoved, maxFeeRateRemoved.ToString());
     }
 }
 
 uint64_t CTxMemPool::CalculateDescendantMaximum(txiter entry) const {
     // find parent with highest descendant count
     std::vector<txiter> candidates;
     setEntries counted;
     candidates.push_back(entry);
     uint64_t maximum = 0;
     while (candidates.size()) {
         txiter candidate = candidates.back();
         candidates.pop_back();
         if (!counted.insert(candidate).second) {
             continue;
         }
         const setEntries &parents = GetMemPoolParents(candidate);
         if (parents.size() == 0) {
             maximum = std::max(maximum, candidate->GetCountWithDescendants());
         } else {
             for (txiter i : parents) {
                 candidates.push_back(i);
             }
         }
     }
     return maximum;
 }
 
-void CTxMemPool::GetTransactionAncestry(const uint256 &txid, size_t &ancestors,
+void CTxMemPool::GetTransactionAncestry(const TxId &txid, size_t &ancestors,
                                         size_t &descendants) const {
     LOCK(cs);
     auto it = mapTx.find(txid);
     ancestors = descendants = 0;
     if (it != mapTx.end()) {
         ancestors = it->GetCountWithAncestors();
         descendants = CalculateDescendantMaximum(it);
     }
 }
 
 bool CTxMemPool::IsLoaded() const {
     LOCK(cs);
     return m_is_loaded;
 }
 
 void CTxMemPool::SetIsLoaded(bool loaded) {
     LOCK(cs);
     m_is_loaded = loaded;
 }
 
 SaltedTxidHasher::SaltedTxidHasher()
     : k0(GetRand(std::numeric_limits<uint64_t>::max())),
       k1(GetRand(std::numeric_limits<uint64_t>::max())) {}
 
 /** Maximum bytes for transactions to store for processing during reorg */
 static const size_t MAX_DISCONNECTED_TX_POOL_SIZE = 20 * DEFAULT_MAX_BLOCK_SIZE;
 
 void DisconnectedBlockTransactions::addForBlock(
     const std::vector<CTransactionRef> &vtx) {
     for (const auto &tx : reverse_iterate(vtx)) {
         // If we already added it, just skip.
         auto it = queuedTx.find(tx->GetId());
         if (it != queuedTx.end()) {
             continue;
         }
 
         // Insert the transaction into the pool.
         addTransaction(tx);
 
         // Fill in the set of parents.
         std::unordered_set<TxId, SaltedTxidHasher> parents;
         for (const CTxIn &in : tx->vin) {
             parents.insert(in.prevout.GetTxId());
         }
 
         // In order to make sure we keep things in topological order, we check
         // if we already know of the parent of the current transaction. If so,
         // we remove them from the set and then add them back.
         while (parents.size() > 0) {
             std::unordered_set<TxId, SaltedTxidHasher> worklist(
                 std::move(parents));
             parents.clear();
 
             for (const TxId &txid : worklist) {
                 // If we do not have that txid in the set, nothing needs to be
                 // done.
                 auto pit = queuedTx.find(txid);
                 if (pit == queuedTx.end()) {
                     continue;
                 }
 
                 // We have parent in our set, we reinsert them at the right
                 // position.
                 const CTransactionRef ptx = *pit;
                 queuedTx.erase(pit);
                 queuedTx.insert(ptx);
 
                 // And we make sure ancestors are covered.
                 for (const CTxIn &in : ptx->vin) {
                     parents.insert(in.prevout.GetTxId());
                 }
             }
         }
     }
 
     // Keep the size under control.
     while (DynamicMemoryUsage() > MAX_DISCONNECTED_TX_POOL_SIZE) {
         // Drop the earliest entry, and remove its children from the
         // mempool.
         auto it = queuedTx.get<insertion_order>().begin();
         g_mempool.removeRecursive(**it, MemPoolRemovalReason::REORG);
         removeEntry(it);
     }
 }
 
 void DisconnectedBlockTransactions::importMempool(CTxMemPool &pool) {
     // addForBlock's algorithm sorts a vector of transactions back into
     // topological order. We use it in a separate object to create a valid
     // ordering of all mempool transactions, which we then splice in front of
     // the current queuedTx. This results in a valid sequence of transactions to
     // be reprocessed in updateMempoolForReorg.
 
     // We create vtx in order of the entry_time index to facilitate for
     // addForBlocks (which iterates in reverse order), as vtx probably end in
     // the correct ordering for queuedTx.
     std::vector<CTransactionRef> vtx;
     {
         LOCK(pool.cs);
         vtx.reserve(pool.mapTx.size());
         for (const CTxMemPoolEntry &e : pool.mapTx.get<entry_time>()) {
             vtx.push_back(e.GetSharedTx());
         }
         pool.clear();
     }
 
     // Use addForBlocks to sort the transactions and then splice them in front
     // of queuedTx
     DisconnectedBlockTransactions orderedTxnPool;
     orderedTxnPool.addForBlock(vtx);
     cachedInnerUsage += orderedTxnPool.cachedInnerUsage;
     queuedTx.get<insertion_order>().splice(
         queuedTx.get<insertion_order>().begin(),
         orderedTxnPool.queuedTx.get<insertion_order>());
 
     // We limit memory usage because we can't know if more blocks will be
     // disconnected
     while (DynamicMemoryUsage() > MAX_DISCONNECTED_TX_POOL_SIZE) {
         // Drop the earliest entry which, by definition, has no children
         removeEntry(queuedTx.get<insertion_order>().begin());
     }
 }
 
 void DisconnectedBlockTransactions::updateMempoolForReorg(const Config &config,
                                                           bool fAddToMempool) {
     AssertLockHeld(cs_main);
     std::vector<TxId> txidsUpdate;
 
     // disconnectpool's insertion_order index sorts the entries from oldest to
     // newest, but the oldest entry will be the last tx from the latest mined
     // block that was disconnected.
     // Iterate disconnectpool in reverse, so that we add transactions back to
     // the mempool starting with the earliest transaction that had been
     // previously seen in a block.
     for (const CTransactionRef &tx :
          reverse_iterate(queuedTx.get<insertion_order>())) {
         // ignore validation errors in resurrected transactions
         CValidationState stateDummy;
         if (!fAddToMempool || tx->IsCoinBase() ||
             !AcceptToMemoryPool(config, g_mempool, stateDummy, tx, false,
                                 nullptr, true)) {
             // If the transaction doesn't make it in to the mempool, remove any
             // transactions that depend on it (which would now be orphans).
             g_mempool.removeRecursive(*tx, MemPoolRemovalReason::REORG);
         } else if (g_mempool.exists(tx->GetId())) {
             txidsUpdate.push_back(tx->GetId());
         }
     }
 
     queuedTx.clear();
 
     // AcceptToMemoryPool/addUnchecked all assume that new mempool entries have
     // no in-mempool children, which is generally not true when adding
     // previously-confirmed transactions back to the mempool.
     // UpdateTransactionsFromBlock finds descendants of any transactions in the
     // disconnectpool that were added back and cleans up the mempool state.
     g_mempool.UpdateTransactionsFromBlock(txidsUpdate);
 
     // We also need to remove any now-immature transactions
     g_mempool.removeForReorg(config, pcoinsTip.get(),
                              chainActive.Tip()->nHeight + 1,
                              STANDARD_LOCKTIME_VERIFY_FLAGS);
 
     // Re-limit mempool size, in case we added any transactions
     g_mempool.LimitSize(
         gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000,
         gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60);
 }
diff --git a/src/txmempool.h b/src/txmempool.h
index dc44cb4f56..e3dbb4146d 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -1,996 +1,996 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_TXMEMPOOL_H
 #define BITCOIN_TXMEMPOOL_H
 
 #include <amount.h>
 #include <coins.h>
 #include <crypto/siphash.h>
 #include <indirectmap.h>
 #include <primitives/transaction.h>
 #include <random.h>
 #include <sync.h>
 
 #include <boost/multi_index/hashed_index.hpp>
 #include <boost/multi_index/ordered_index.hpp>
 #include <boost/multi_index/sequenced_index.hpp>
 #include <boost/multi_index_container.hpp>
 #include <boost/signals2/signal.hpp>
 
 #include <map>
 #include <memory>
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
 class CBlockIndex;
 class Config;
 
 extern CCriticalSection cs_main;
 
 inline double AllowFreeThreshold() {
     return (144 * COIN) / (250 * SATOSHI);
 }
 
 inline bool AllowFree(double dPriority) {
     // Large (in bytes) low-priority (new, small-coin) transactions need a fee.
     return dPriority > AllowFreeThreshold();
 }
 
 /**
  * Fake height value used in Coins to signify they are only in the memory
  * pool(since 0.8)
  */
 static const uint32_t MEMPOOL_HEIGHT = 0x7FFFFFFF;
 
 struct LockPoints {
     // Will be set to the blockchain height and median time past values that
     // would be necessary to satisfy all relative locktime constraints (BIP68)
     // of this tx given our view of block chain history
     int height;
     int64_t time;
     // As long as the current chain descends from the highest height block
     // containing one of the inputs used in the calculation, then the cached
     // values are still valid even after a reorg.
     CBlockIndex *maxInputBlock;
 
     LockPoints() : height(0), time(0), maxInputBlock(nullptr) {}
 };
 
 class CTxMemPool;
 
 /** \class CTxMemPoolEntry
  *
  * CTxMemPoolEntry stores data about the corresponding transaction, as well as
  * data about all in-mempool transactions that depend on the transaction
  * ("descendant" transactions).
  *
  * When a new entry is added to the mempool, we update the descendant state
  * (nCountWithDescendants, nSizeWithDescendants, and nModFeesWithDescendants)
  * for all ancestors of the newly added transaction.
  */
 
 class CTxMemPoolEntry {
 private:
     CTransactionRef tx;
     //!< Cached to avoid expensive parent-transaction lookups
     Amount nFee;
     //!< ... and avoid recomputing tx size
     size_t nTxSize;
     //!< ... and modified size for priority
     size_t nModSize;
     //!< ... and total memory usage
     size_t nUsageSize;
     //!< Local time when entering the mempool
     int64_t nTime;
     //!< Priority when entering the mempool
     double entryPriority;
     //!< Chain height when entering the mempool
     unsigned int entryHeight;
     //!< Sum of all txin values that are already in blockchain
     Amount inChainInputValue;
     //!< keep track of transactions that spend a coinbase
     bool spendsCoinbase;
     //!< Total sigop plus P2SH sigops count
     int64_t sigOpCount;
     //!< Used for determining the priority of the transaction for mining in a
     //! block
     Amount feeDelta;
     //!< Track the height and time at which tx was final
     LockPoints lockPoints;
 
     // Information about descendants of this transaction that are in the
     // mempool; if we remove this transaction we must remove all of these
     // descendants as well.
     //!< number of descendant transactions
     uint64_t nCountWithDescendants;
     //!< ... and size
     uint64_t nSizeWithDescendants;
 
     //!< ... and total fees (all including us)
     Amount nModFeesWithDescendants;
 
     // Analogous statistics for ancestor transactions
     uint64_t nCountWithAncestors;
     uint64_t nSizeWithAncestors;
     Amount nModFeesWithAncestors;
     int64_t nSigOpCountWithAncestors;
 
 public:
     CTxMemPoolEntry(const CTransactionRef &_tx, const Amount _nFee,
                     int64_t _nTime, double _entryPriority,
                     unsigned int _entryHeight, Amount _inChainInputValue,
                     bool spendsCoinbase, int64_t nSigOpsCost, LockPoints lp);
 
     const CTransaction &GetTx() const { return *this->tx; }
     CTransactionRef GetSharedTx() const { return this->tx; }
     /**
      * Fast calculation of lower bound of current priority as update from entry
      * priority. Only inputs that were originally in-chain will age.
      */
     double GetPriority(unsigned int currentHeight) const;
     const Amount GetFee() const { return nFee; }
     size_t GetTxSize() const { return nTxSize; }
 
     int64_t GetTime() const { return nTime; }
     unsigned int GetHeight() const { return entryHeight; }
     int64_t GetSigOpCount() const { return sigOpCount; }
     Amount GetModifiedFee() const { return nFee + feeDelta; }
     size_t DynamicMemoryUsage() const { return nUsageSize; }
     const LockPoints &GetLockPoints() const { return lockPoints; }
 
     // Adjusts the descendant state.
     void UpdateDescendantState(int64_t modifySize, Amount modifyFee,
                                int64_t modifyCount);
     // Adjusts the ancestor state
     void UpdateAncestorState(int64_t modifySize, Amount modifyFee,
                              int64_t modifyCount, int modifySigOps);
     // Updates the fee delta used for mining priority score, and the
     // modified fees with descendants.
     void UpdateFeeDelta(Amount feeDelta);
     // Update the LockPoints after a reorg
     void UpdateLockPoints(const LockPoints &lp);
 
     uint64_t GetCountWithDescendants() const { return nCountWithDescendants; }
     uint64_t GetSizeWithDescendants() const { return nSizeWithDescendants; }
     Amount GetModFeesWithDescendants() const { return nModFeesWithDescendants; }
 
     bool GetSpendsCoinbase() const { return spendsCoinbase; }
 
     uint64_t GetCountWithAncestors() const { return nCountWithAncestors; }
     uint64_t GetSizeWithAncestors() const { return nSizeWithAncestors; }
     Amount GetModFeesWithAncestors() const { return nModFeesWithAncestors; }
     int64_t GetSigOpCountWithAncestors() const {
         return nSigOpCountWithAncestors;
     }
 
     //!< Index in mempool's vTxHashes
     mutable size_t vTxHashesIdx;
 };
 
 // Helpers for modifying CTxMemPool::mapTx, which is a boost multi_index.
 struct update_descendant_state {
     update_descendant_state(int64_t _modifySize, Amount _modifyFee,
                             int64_t _modifyCount)
         : modifySize(_modifySize), modifyFee(_modifyFee),
           modifyCount(_modifyCount) {}
 
     void operator()(CTxMemPoolEntry &e) {
         e.UpdateDescendantState(modifySize, modifyFee, modifyCount);
     }
 
 private:
     int64_t modifySize;
     Amount modifyFee;
     int64_t modifyCount;
 };
 
 struct update_ancestor_state {
     update_ancestor_state(int64_t _modifySize, Amount _modifyFee,
                           int64_t _modifyCount, int64_t _modifySigOpsCost)
         : modifySize(_modifySize), modifyFee(_modifyFee),
           modifyCount(_modifyCount), modifySigOpsCost(_modifySigOpsCost) {}
 
     void operator()(CTxMemPoolEntry &e) {
         e.UpdateAncestorState(modifySize, modifyFee, modifyCount,
                               modifySigOpsCost);
     }
 
 private:
     int64_t modifySize;
     Amount modifyFee;
     int64_t modifyCount;
     int64_t modifySigOpsCost;
 };
 
 struct update_fee_delta {
     explicit update_fee_delta(Amount _feeDelta) : feeDelta(_feeDelta) {}
 
     void operator()(CTxMemPoolEntry &e) { e.UpdateFeeDelta(feeDelta); }
 
 private:
     Amount feeDelta;
 };
 
 struct update_lock_points {
     explicit update_lock_points(const LockPoints &_lp) : lp(_lp) {}
 
     void operator()(CTxMemPoolEntry &e) { e.UpdateLockPoints(lp); }
 
 private:
     const LockPoints &lp;
 };
 
 // extracts a transaction hash from CTxMemPoolEntry or CTransactionRef
 struct mempoolentry_txid {
-    typedef uint256 result_type;
+    typedef TxId result_type;
     result_type operator()(const CTxMemPoolEntry &entry) const {
         return entry.GetTx().GetId();
     }
 
     result_type operator()(const CTransactionRef &tx) const {
         return tx->GetId();
     }
 };
 
 /** \class CompareTxMemPoolEntryByDescendantScore
  *
  *  Sort an entry by max(score/size of entry's tx, score/size with all
  * descendants).
  */
 class CompareTxMemPoolEntryByDescendantScore {
 public:
     bool operator()(const CTxMemPoolEntry &a, const CTxMemPoolEntry &b) const {
         double a_mod_fee, a_size, b_mod_fee, b_size;
 
         GetModFeeAndSize(a, a_mod_fee, a_size);
         GetModFeeAndSize(b, b_mod_fee, b_size);
 
         // Avoid division by rewriting (a/b > c/d) as (a*d > c*b).
         double f1 = a_mod_fee * b_size;
         double f2 = a_size * b_mod_fee;
 
         if (f1 == f2) {
             return a.GetTime() >= b.GetTime();
         }
         return f1 < f2;
     }
 
     // Return the fee/size we're using for sorting this entry.
     void GetModFeeAndSize(const CTxMemPoolEntry &a, double &mod_fee,
                           double &size) const {
         // Compare feerate with descendants to feerate of the transaction, and
         // return the fee/size for the max.
         double f1 = a.GetSizeWithDescendants() * (a.GetModifiedFee() / SATOSHI);
         double f2 = a.GetTxSize() * (a.GetModFeesWithDescendants() / SATOSHI);
 
         if (f2 > f1) {
             mod_fee = a.GetModFeesWithDescendants() / SATOSHI;
             size = a.GetSizeWithDescendants();
         } else {
             mod_fee = a.GetModifiedFee() / SATOSHI;
             size = a.GetTxSize();
         }
     }
 };
 
 /** \class CompareTxMemPoolEntryByScore
  *
  *  Sort by feerate of entry (fee/size) in descending order
  *  This is only used for transaction relay, so we use GetFee()
  *  instead of GetModifiedFee() to avoid leaking prioritization
  *  information via the sort order.
  */
 class CompareTxMemPoolEntryByScore {
 public:
     bool operator()(const CTxMemPoolEntry &a, const CTxMemPoolEntry &b) const {
         double f1 = b.GetTxSize() * (a.GetFee() / SATOSHI);
         double f2 = a.GetTxSize() * (b.GetFee() / SATOSHI);
         if (f1 == f2) {
             return b.GetTx().GetId() < a.GetTx().GetId();
         }
         return f1 > f2;
     }
 };
 
 class CompareTxMemPoolEntryByEntryTime {
 public:
     bool operator()(const CTxMemPoolEntry &a, const CTxMemPoolEntry &b) const {
         return a.GetTime() < b.GetTime();
     }
 };
 
 /** \class CompareTxMemPoolEntryByAncestorScore
  *
  *  Sort an entry by min(score/size of entry's tx, score/size with all
  * ancestors).
  */
 class CompareTxMemPoolEntryByAncestorFee {
 public:
     template <typename T> bool operator()(const T &a, const T &b) const {
         double a_mod_fee, a_size, b_mod_fee, b_size;
 
         GetModFeeAndSize(a, a_mod_fee, a_size);
         GetModFeeAndSize(b, b_mod_fee, b_size);
 
         // Avoid division by rewriting (a/b > c/d) as (a*d > c*b).
         double f1 = a_mod_fee * b_size;
         double f2 = a_size * b_mod_fee;
 
         if (f1 == f2) {
             return a.GetTx().GetId() < b.GetTx().GetId();
         }
         return f1 > f2;
     }
 
     // Return the fee/size we're using for sorting this entry.
     template <typename T>
     void GetModFeeAndSize(const T &a, double &mod_fee, double &size) const {
         // Compare feerate with ancestors to feerate of the transaction, and
         // return the fee/size for the min.
         double f1 = a.GetSizeWithAncestors() * (a.GetModifiedFee() / SATOSHI);
         double f2 = a.GetTxSize() * (a.GetModFeesWithAncestors() / SATOSHI);
 
         if (f1 > f2) {
             mod_fee = a.GetModFeesWithAncestors() / SATOSHI;
             size = a.GetSizeWithAncestors();
         } else {
             mod_fee = a.GetModifiedFee() / SATOSHI;
             size = a.GetTxSize();
         }
     }
 };
 
 // Multi_index tag names
 struct descendant_score {};
 struct entry_time {};
 struct ancestor_score {};
 
 /**
  * Information about a mempool transaction.
  */
 struct TxMempoolInfo {
     /** The transaction itself */
     CTransactionRef tx;
 
     /** Time the transaction entered the mempool. */
     int64_t nTime;
 
     /** Feerate of the transaction. */
     CFeeRate feeRate;
 
     /** The fee delta. */
     Amount nFeeDelta;
 };
 
 /**
  * Reason why a transaction was removed from the mempool, this is passed to the
  * notification signal.
  */
 enum class MemPoolRemovalReason {
     //!< Manually removed or unknown reason
     UNKNOWN = 0,
     //!< Expired from mempool
     EXPIRY,
     //!< Removed in size limiting
     SIZELIMIT,
     //!< Removed for reorganization
     REORG,
     //!< Removed for block
     BLOCK,
     //!< Removed for conflict with in-block transaction
     CONFLICT,
     //!< Removed for replacement
     REPLACED
 };
 
 class SaltedTxidHasher {
 private:
     /** Salt */
     const uint64_t k0, k1;
 
 public:
     SaltedTxidHasher();
 
-    size_t operator()(const uint256 &txid) const {
+    size_t operator()(const TxId &txid) const {
         return SipHashUint256(k0, k1, txid);
     }
 };
 
 typedef std::pair<double, Amount> TXModifier;
 
 /**
  * CTxMemPool stores valid-according-to-the-current-best-chain transactions that
  * may be included in the next block.
  *
  * Transactions are added when they are seen on the network (or created by the
  * local node), but not all transactions seen are added to the pool. For
  * example, the following new transactions will not be added to the mempool:
  * - a transaction which doesn't meet the minimum fee requirements.
  * - a new transaction that double-spends an input of a transaction already in
  * the pool where the new transaction does not meet the Replace-By-Fee
  * requirements as defined in BIP 125.
  * - a non-standard transaction.
  *
  * CTxMemPool::mapTx, and CTxMemPoolEntry bookkeeping:
  *
  * mapTx is a boost::multi_index that sorts the mempool on 4 criteria:
  * - transaction hash
  * - descendant feerate [we use max(feerate of tx, feerate of tx with all
  * descendants)]
  * - time in mempool
  * - ancestor feerate [we use min(feerate of tx, feerate of tx with all
  * unconfirmed ancestors)]
  *
  * Note: the term "descendant" refers to in-mempool transactions that depend on
  * this one, while "ancestor" refers to in-mempool transactions that a given
  * transaction depends on.
  *
  * In order for the feerate sort to remain correct, we must update transactions
  * in the mempool when new descendants arrive. To facilitate this, we track the
  * set of in-mempool direct parents and direct children in mapLinks. Within each
  * CTxMemPoolEntry, we track the size and fees of all descendants.
  *
  * Usually when a new transaction is added to the mempool, it has no in-mempool
  * children (because any such children would be an orphan). So in
  * addUnchecked(), we:
  * - update a new entry's setMemPoolParents to include all in-mempool parents
  * - update the new entry's direct parents to include the new tx as a child
  * - update all ancestors of the transaction to include the new tx's size/fee
  *
  * When a transaction is removed from the mempool, we must:
  * - update all in-mempool parents to not track the tx in setMemPoolChildren
  * - update all ancestors to not include the tx's size/fees in descendant state
  * - update all in-mempool children to not include it as a parent
  *
  * These happen in UpdateForRemoveFromMempool(). (Note that when removing a
  * transaction along with its descendants, we must calculate that set of
  * transactions to be removed before doing the removal, or else the mempool can
  * be in an inconsistent state where it's impossible to walk the ancestors of a
  * transaction.)
  *
  * In the event of a reorg, the assumption that a newly added tx has no
  * in-mempool children is false.  In particular, the mempool is in an
  * inconsistent state while new transactions are being added, because there may
  * be descendant transactions of a tx coming from a disconnected block that are
  * unreachable from just looking at transactions in the mempool (the linking
  * transactions may also be in the disconnected block, waiting to be added).
  * Because of this, there's not much benefit in trying to search for in-mempool
  * children in addUnchecked(). Instead, in the special case of transactions
  * being added from a disconnected block, we require the caller to clean up the
  * state, to account for in-mempool, out-of-block descendants for all the
  * in-block transactions by calling UpdateTransactionsFromBlock(). Note that
  * until this is called, the mempool state is not consistent, and in particular
  * mapLinks may not be correct (and therefore functions like
  * CalculateMemPoolAncestors() and CalculateDescendants() that rely on them to
  * walk the mempool are not generally safe to use).
  *
  * Computational limits:
  *
  * Updating all in-mempool ancestors of a newly added transaction can be slow,
  * if no bound exists on how many in-mempool ancestors there may be.
  * CalculateMemPoolAncestors() takes configurable limits that are designed to
  * prevent these calculations from being too CPU intensive.
  */
 class CTxMemPool {
 private:
     //!< Value n means that n times in 2^32 we check.
     uint32_t nCheckFrequency GUARDED_BY(cs);
     //!< Used by getblocktemplate to trigger CreateNewBlock() invocation
     unsigned int nTransactionsUpdated;
 
     //!< sum of all mempool tx's virtual sizes.
     uint64_t totalTxSize;
     //!< sum of dynamic memory usage of all the map elements (NOT the maps
     //! themselves)
     uint64_t cachedInnerUsage;
 
     mutable int64_t lastRollingFeeUpdate;
     mutable bool blockSinceLastRollingFeeBump;
     //!< minimum fee to get into the pool, decreases exponentially
     mutable double rollingMinimumFeeRate;
 
     void trackPackageRemoved(const CFeeRate &rate) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     bool m_is_loaded GUARDED_BY(cs){false};
 
 public:
     // public only for testing
     static const int ROLLING_FEE_HALFLIFE = 60 * 60 * 12;
 
     typedef boost::multi_index_container<
         CTxMemPoolEntry, boost::multi_index::indexed_by<
                              // sorted by txid
                              boost::multi_index::hashed_unique<
                                  mempoolentry_txid, SaltedTxidHasher>,
                              // sorted by fee rate
                              boost::multi_index::ordered_non_unique<
                                  boost::multi_index::tag<descendant_score>,
                                  boost::multi_index::identity<CTxMemPoolEntry>,
                                  CompareTxMemPoolEntryByDescendantScore>,
                              // sorted by entry time
                              boost::multi_index::ordered_non_unique<
                                  boost::multi_index::tag<entry_time>,
                                  boost::multi_index::identity<CTxMemPoolEntry>,
                                  CompareTxMemPoolEntryByEntryTime>,
                              // sorted by fee rate with ancestors
                              boost::multi_index::ordered_non_unique<
                                  boost::multi_index::tag<ancestor_score>,
                                  boost::multi_index::identity<CTxMemPoolEntry>,
                                  CompareTxMemPoolEntryByAncestorFee>>>
         indexed_transaction_set;
 
     /**
      * This mutex needs to be locked when accessing `mapTx` or other members
      * that are guarded by it.
      *
      * @par Consistency guarantees
      *
      * By design, it is guaranteed that:
      *
      * 1. Locking both `cs_main` and `mempool.cs` will give a view of mempool
      *    that is consistent with current chain tip (`chainActive` and
      *    `pcoinsTip`) and is fully populated. Fully populated means that if the
      *    current active chain is missing transactions that were present in a
      *    previously active chain, all the missing transactions will have been
      *    re-added to the mempool and should be present if they meet size and
      *    consistency constraints.
      *
      * 2. Locking `mempool.cs` without `cs_main` will give a view of a mempool
      *    consistent with some chain that was active since `cs_main` was last
      *    locked, and that is fully populated as described above. It is ok for
      *    code that only needs to query or remove transactions from the mempool
      *    to lock just `mempool.cs` without `cs_main`.
      *
      * To provide these guarantees, it is necessary to lock both `cs_main` and
      * `mempool.cs` whenever adding transactions to the mempool and whenever
      * changing the chain tip. It's necessary to keep both mutexes locked until
      * the mempool is consistent with the new chain tip and fully populated.
      *
      * @par Consistency bug
      *
      * The second guarantee above is not currently enforced, but
      * https://github.com/bitcoin/bitcoin/pull/14193 will fix it. No known code
      * in bitcoin currently depends on second guarantee, but it is important to
      * fix for third party code that needs be able to frequently poll the
      * mempool without locking `cs_main` and without encountering missing
      * transactions during reorgs.
      */
     mutable RecursiveMutex cs;
     indexed_transaction_set mapTx GUARDED_BY(cs);
 
     typedef indexed_transaction_set::nth_index<0>::type::iterator txiter;
     //!< All tx hashes/entries in mapTx, in random order
     std::vector<std::pair<uint256, txiter>> vTxHashes;
 
     struct CompareIteratorByHash {
         bool operator()(const txiter &a, const txiter &b) const {
             return a->GetTx().GetId() < b->GetTx().GetId();
         }
     };
     typedef std::set<txiter, CompareIteratorByHash> setEntries;
 
     const setEntries &GetMemPoolParents(txiter entry) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     const setEntries &GetMemPoolChildren(txiter entry) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     uint64_t CalculateDescendantMaximum(txiter entry) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
 private:
     typedef std::map<txiter, setEntries, CompareIteratorByHash> cacheMap;
 
     struct TxLinks {
         setEntries parents;
         setEntries children;
     };
 
     typedef std::map<txiter, TxLinks, CompareIteratorByHash> txlinksMap;
     txlinksMap mapLinks;
 
     void UpdateParent(txiter entry, txiter parent, bool add);
     void UpdateChild(txiter entry, txiter child, bool add);
 
     std::vector<indexed_transaction_set::const_iterator>
     GetSortedDepthAndScore() const EXCLUSIVE_LOCKS_REQUIRED(cs);
 
 public:
     indirectmap<COutPoint, const CTransaction *> mapNextTx GUARDED_BY(cs);
     std::map<uint256, TXModifier> mapDeltas;
 
     /**
      * Create a new CTxMemPool.
      */
     CTxMemPool();
     ~CTxMemPool();
 
     /**
      * If sanity-checking is turned on, check makes sure the pool is consistent
      * (does not contain two transactions that spend the same inputs, all inputs
      * are in the mapNextTx array). If sanity-checking is turned off, check does
      * nothing.
      */
     void check(const CCoinsViewCache *pcoins) const;
     void setSanityCheck(double dFrequency = 1.0) {
         LOCK(cs);
         nCheckFrequency = static_cast<uint32_t>(dFrequency * 4294967295.0);
     }
 
     // addUnchecked must updated state for all ancestors of a given transaction,
     // to track size/count of descendant transactions. First version of
     // addUnchecked can be used to have it call CalculateMemPoolAncestors(), and
     // then invoke the second version.
     // Note that addUnchecked is ONLY called from ATMP outside of tests
     // and any other callers may break wallet's in-mempool tracking (due to
     // lack of CValidationInterface::TransactionAddedToMempool callbacks).
     void addUnchecked(const uint256 &hash, const CTxMemPoolEntry &entry)
         EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main);
     void addUnchecked(const uint256 &hash, const CTxMemPoolEntry &entry,
                       setEntries &setAncestors)
         EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main);
 
     void removeRecursive(
         const CTransaction &tx,
         MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN);
     void removeForReorg(const Config &config, const CCoinsViewCache *pcoins,
                         unsigned int nMemPoolHeight, int flags)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void removeConflicts(const CTransaction &tx) EXCLUSIVE_LOCKS_REQUIRED(cs);
     void removeForBlock(const std::vector<CTransactionRef> &vtx,
                         unsigned int nBlockHeight);
 
     void clear();
     // lock free
     void _clear() EXCLUSIVE_LOCKS_REQUIRED(cs);
-    bool CompareDepthAndScore(const uint256 &hasha, const uint256 &hashb);
+    bool CompareDepthAndScore(const TxId &txida, const TxId &txidb);
     void queryHashes(std::vector<uint256> &vtxid) const;
     bool isSpent(const COutPoint &outpoint) const;
     unsigned int GetTransactionsUpdated() const;
     void AddTransactionsUpdated(unsigned int n);
     /**
      * Check that none of this transactions inputs are in the mempool, and thus
      * the tx is not dependent on other mempool transactions to be included in a
      * block.
      */
     bool HasNoInputsOf(const CTransaction &tx) const;
 
     /** Affect CreateNewBlock prioritisation of transactions */
-    void PrioritiseTransaction(const uint256 &hash, double dPriorityDelta,
+    void PrioritiseTransaction(const TxId &txid, double dPriorityDelta,
                                const Amount nFeeDelta);
     void ApplyDeltas(const uint256 hash, double &dPriorityDelta,
                      Amount &nFeeDelta) const;
     void ClearPrioritisation(const uint256 hash);
 
 public:
     /**
      * Remove a set of transactions from the mempool. If a transaction is in
      * this set, then all in-mempool descendants must also be in the set, unless
      * this transaction is being removed for being in a block. Set
      * updateDescendants to true when removing a tx that was in a block, so that
      * any in-mempool descendants have their ancestor state updated.
      */
     void
     RemoveStaged(setEntries &stage, bool updateDescendants,
                  MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * When adding transactions from a disconnected block back to the mempool,
      * new mempool entries may have children in the mempool (which is generally
      * not the case when otherwise adding transactions).
      * UpdateTransactionsFromBlock() will find child transactions and update the
      * descendant state for each transaction in txidsToUpdate (excluding any
      * child transactions present in txidsToUpdate, which are already accounted
      * for).
      * Note: txidsToUpdate should be the set of transactions from the
      * disconnected block that have been accepted back into the mempool.
      */
     void UpdateTransactionsFromBlock(const std::vector<TxId> &txidsToUpdate)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Try to calculate all in-mempool ancestors of entry.
      *  (these are all calculated including the tx itself)
      *  limitAncestorCount = max number of ancestors
      *  limitAncestorSize = max size of ancestors
      *  limitDescendantCount = max number of descendants any ancestor can have
      *  limitDescendantSize = max size of descendants any ancestor can have
      *  errString = populated with error reason if any limits are hit
      * fSearchForParents = whether to search a tx's vin for in-mempool parents,
      * or look up parents from mapLinks. Must be true for entries not in the
      * mempool
      */
     bool CalculateMemPoolAncestors(
         const CTxMemPoolEntry &entry, setEntries &setAncestors,
         uint64_t limitAncestorCount, uint64_t limitAncestorSize,
         uint64_t limitDescendantCount, uint64_t limitDescendantSize,
         std::string &errString, bool fSearchForParents = true) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Populate setDescendants with all in-mempool descendants of hash.
      * Assumes that setDescendants includes all in-mempool descendants of
      * anything already in it.
      */
     void CalculateDescendants(txiter it, setEntries &setDescendants) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * The minimum fee to get into the mempool, which may itself not be enough
      * for larger-sized transactions. The incrementalRelayFee policy variable is
      * used to bound the time it takes the fee rate to go back down all the way
      * to 0. When the feerate would otherwise be half of this, it is set to 0
      * instead.
      */
     CFeeRate GetMinFee(size_t sizelimit) const;
 
     /**
      * Remove transactions from the mempool until its dynamic size is <=
      * sizelimit. pvNoSpendsRemaining, if set, will be populated with the list
      * of outpoints which are not in mempool which no longer have any spends in
      * this mempool.
      */
     void TrimToSize(size_t sizelimit,
                     std::vector<COutPoint> *pvNoSpendsRemaining = nullptr);
 
     /**
      * Expire all transaction (and their dependencies) in the mempool older than
      * time. Return the number of removed transactions.
      */
     int Expire(int64_t time);
 
     /**
      * Reduce the size of the mempool by expiring and then trimming the mempool.
      */
     void LimitSize(size_t limit, unsigned long age);
 
     /**
      * Calculate the ancestor and descendant count for the given transaction.
      * The counts include the transaction itself.
      */
-    void GetTransactionAncestry(const uint256 &txid, size_t &ancestors,
+    void GetTransactionAncestry(const TxId &txid, size_t &ancestors,
                                 size_t &descendants) const;
 
     /** @returns true if the mempool is fully loaded */
     bool IsLoaded() const;
 
     /** Sets the current loaded state */
     void SetIsLoaded(bool loaded);
 
     unsigned long size() const {
         LOCK(cs);
         return mapTx.size();
     }
 
     uint64_t GetTotalTxSize() const {
         LOCK(cs);
         return totalTxSize;
     }
 
-    bool exists(uint256 hash) const {
+    bool exists(const TxId &txid) const {
         LOCK(cs);
-        return mapTx.count(hash) != 0;
+        return mapTx.count(txid) != 0;
     }
 
-    CTransactionRef get(const uint256 &hash) const;
-    TxMempoolInfo info(const uint256 &hash) const;
+    CTransactionRef get(const TxId &txid) const;
+    TxMempoolInfo info(const TxId &txid) const;
     std::vector<TxMempoolInfo> infoAll() const;
 
     CFeeRate estimateFee() const;
 
     size_t DynamicMemoryUsage() const;
 
     boost::signals2::signal<void(CTransactionRef)> NotifyEntryAdded;
     boost::signals2::signal<void(CTransactionRef, MemPoolRemovalReason)>
         NotifyEntryRemoved;
 
 private:
     /**
      * UpdateForDescendants is used by UpdateTransactionsFromBlock to update the
      * descendants for a single transaction that has been added to the mempool
      * but may have child transactions in the mempool, eg during a chain reorg.
      * setExclude is the set of descendant transactions in the mempool that must
      * not be accounted for (because any descendants in setExclude were added to
      * the mempool after the transaction being updated and hence their state is
      * already reflected in the parent state).
      *
      * cachedDescendants will be updated with the descendants of the transaction
      * being updated, so that future invocations don't need to walk the same
      * transaction again, if encountered in another transaction chain.
      */
     void UpdateForDescendants(txiter updateIt, cacheMap &cachedDescendants,
                               const std::set<TxId> &setExclude)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     /**
      * Update ancestors of hash to add/remove it as a descendant transaction.
      */
     void UpdateAncestorsOf(bool add, txiter hash, setEntries &setAncestors)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     /** Set ancestor state for an entry */
     void UpdateEntryForAncestors(txiter it, const setEntries &setAncestors)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     /**
      * For each transaction being removed, update ancestors and any direct
      * children. If updateDescendants is true, then also update in-mempool
      * descendants' ancestor state.
      */
     void UpdateForRemoveFromMempool(const setEntries &entriesToRemove,
                                     bool updateDescendants)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     /** Sever link between specified transaction and direct children. */
     void UpdateChildrenForRemoval(txiter entry) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Before calling removeUnchecked for a given transaction,
      * UpdateForRemoveFromMempool must be called on the entire (dependent) set
      * of transactions being removed at the same time. We use each
      * CTxMemPoolEntry's setMemPoolParents in order to walk ancestors of a given
      * transaction that is removed, so we can't remove intermediate transactions
      * in a chain before we've updated all the state for the removal.
      */
     void
     removeUnchecked(txiter entry,
                     MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 };
 
 /**
  * CCoinsView that brings transactions from a mempool into view.
  * It does not check for spendings by memory pool transactions.
  * Instead, it provides access to all Coins which are either unspent in the
  * base CCoinsView, or are outputs from any mempool transaction!
  * This allows transaction replacement to work as expected, as you want to
  * have all inputs "available" to check signatures, and any cycles in the
  * dependency graph are checked directly in AcceptToMemoryPool.
  * It also allows you to sign a double-spend directly in
  * signrawtransactionwithkey and signrawtransactionwithwallet, as long as the
  * conflicting transaction is not yet confirmed.
  */
 class CCoinsViewMemPool : public CCoinsViewBacked {
 protected:
     const CTxMemPool &mempool;
 
 public:
     CCoinsViewMemPool(CCoinsView *baseIn, const CTxMemPool &mempoolIn);
     bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
 };
 
 // We want to sort transactions by coin age priority
 typedef std::pair<double, CTxMemPool::txiter> TxCoinAgePriority;
 
 struct TxCoinAgePriorityCompare {
     bool operator()(const TxCoinAgePriority &a, const TxCoinAgePriority &b) {
         if (a.first == b.first) {
             // Reverse order to make sort less than
             return CompareTxMemPoolEntryByScore()(*(b.second), *(a.second));
         }
         return a.first < b.first;
     }
 };
 
 /**
  * DisconnectedBlockTransactions
  *
  * During the reorg, it's desirable to re-add previously confirmed transactions
  * to the mempool, so that anything not re-confirmed in the new chain is
  * available to be mined. However, it's more efficient to wait until the reorg
  * is complete and process all still-unconfirmed transactions at that time,
  * since we expect most confirmed transactions to (typically) still be
  * confirmed in the new chain, and re-accepting to the memory pool is expensive
  * (and therefore better to not do in the middle of reorg-processing).
  * Instead, store the disconnected transactions (in order!) as we go, remove any
  * that are included in blocks in the new chain, and then process the remaining
  * still-unconfirmed transactions at the end.
  *
  * It also enables efficient reprocessing of current mempool entries, useful
  * when (de)activating forks that result in in-mempool transactions becoming
  * invalid
  */
 // multi_index tag names
 struct txid_index {};
 struct insertion_order {};
 
 class DisconnectedBlockTransactions {
 private:
     typedef boost::multi_index_container<
         CTransactionRef, boost::multi_index::indexed_by<
                              // sorted by txid
                              boost::multi_index::hashed_unique<
                                  boost::multi_index::tag<txid_index>,
                                  mempoolentry_txid, SaltedTxidHasher>,
                              // sorted by order in the blockchain
                              boost::multi_index::sequenced<
                                  boost::multi_index::tag<insertion_order>>>>
         indexed_disconnected_transactions;
 
     indexed_disconnected_transactions queuedTx;
     uint64_t cachedInnerUsage = 0;
 
     void addTransaction(const CTransactionRef &tx) {
         queuedTx.insert(tx);
         cachedInnerUsage += RecursiveDynamicUsage(tx);
     }
 
 public:
     // It's almost certainly a logic bug if we don't clear out queuedTx before
     // destruction, as we add to it while disconnecting blocks, and then we
     // need to re-process remaining transactions to ensure mempool consistency.
     // For now, assert() that we've emptied out this object on destruction.
     // This assert() can always be removed if the reorg-processing code were
     // to be refactored such that this assumption is no longer true (for
     // instance if there was some other way we cleaned up the mempool after a
     // reorg, besides draining this object).
     ~DisconnectedBlockTransactions() { assert(queuedTx.empty()); }
 
     // Estimate the overhead of queuedTx to be 6 pointers + an allocation, as
     // no exact formula for boost::multi_index_contained is implemented.
     size_t DynamicMemoryUsage() const {
         return memusage::MallocUsage(sizeof(CTransactionRef) +
                                      6 * sizeof(void *)) *
                    queuedTx.size() +
                cachedInnerUsage;
     }
 
     const indexed_disconnected_transactions &GetQueuedTx() const {
         return queuedTx;
     }
 
     // Import mempool entries in topological order into queuedTx and clear the
     // mempool. Caller should call updateMempoolForReorg to reprocess these
     // transactions
     void importMempool(CTxMemPool &pool);
 
     // Add entries for a block while reconstructing the topological ordering so
     // they can be added back to the mempool simply.
     void addForBlock(const std::vector<CTransactionRef> &vtx);
 
     // Remove entries based on txid_index, and update memory usage.
     void removeForBlock(const std::vector<CTransactionRef> &vtx) {
         // Short-circuit in the common case of a block being added to the tip
         if (queuedTx.empty()) {
             return;
         }
         for (auto const &tx : vtx) {
             auto it = queuedTx.find(tx->GetId());
             if (it != queuedTx.end()) {
                 cachedInnerUsage -= RecursiveDynamicUsage(*it);
                 queuedTx.erase(it);
             }
         }
     }
 
     // Remove an entry by insertion_order index, and update memory usage.
     void removeEntry(indexed_disconnected_transactions::index<
                      insertion_order>::type::iterator entry) {
         cachedInnerUsage -= RecursiveDynamicUsage(*entry);
         queuedTx.get<insertion_order>().erase(entry);
     }
 
     bool isEmpty() const { return queuedTx.empty(); }
 
     void clear() {
         cachedInnerUsage = 0;
         queuedTx.clear();
     }
 
     /**
      * Make mempool consistent after a reorg, by re-adding or recursively
      * erasing disconnected block transactions from the mempool, and also
      * removing any other transactions from the mempool that are no longer valid
      * given the new tip/height.
      *
      * Note: we assume that disconnectpool only contains transactions that are
      * NOT confirmed in the current chain nor already in the mempool (otherwise,
      * in-mempool descendants of such transactions would be removed).
      *
      * Passing fAddToMempool=false will skip trying to add the transactions
      * back, and instead just erase from the mempool as needed.
      */
     void updateMempoolForReorg(const Config &config, bool fAddToMempool);
 };
 
 #endif // BITCOIN_TXMEMPOOL_H
diff --git a/src/validation.cpp b/src/validation.cpp
index 1b143ddb28..4f1a725008 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1,5790 +1,5790 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2018 The Bitcoin Core developers
 // Copyright (c) 2017-2018 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <validation.h>
 
 #include <arith_uint256.h>
 #include <blockindexworkcomparator.h>
 #include <blockvalidity.h>
 #include <chainparams.h>
 #include <checkpoints.h>
 #include <checkqueue.h>
 #include <config.h>
 #include <consensus/activation.h>
 #include <consensus/consensus.h>
 #include <consensus/merkle.h>
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <flatfile.h>
 #include <fs.h>
 #include <hash.h>
 #include <index/txindex.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <pow.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <random.h>
 #include <reverse_iterator.h>
 #include <script/script.h>
 #include <script/scriptcache.h>
 #include <script/sigcache.h>
 #include <script/standard.h>
 #include <shutdown.h>
 #include <timedata.h>
 #include <tinyformat.h>
 #include <txdb.h>
 #include <txmempool.h>
 #include <ui_interface.h>
 #include <undo.h>
 #include <util/moneystr.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 #include <validationinterface.h>
 #include <warnings.h>
 
 #include <boost/algorithm/string/replace.hpp>
 #include <boost/thread.hpp> // boost::this_thread::interruption_point() (mingw)
 
 #include <atomic>
 #include <future>
 #include <sstream>
 #include <thread>
 
 #define MICRO 0.000001
 #define MILLI 0.001
 class ConnectTrace;
 
 /**
  * CChainState stores and provides an API to update our local knowledge of the
  * current best chain and header tree.
  *
  * It generally provides access to the current block tree, as well as functions
  * to provide new data, which it will appropriately validate and incorporate in
  * its state as necessary.
  *
  * Eventually, the API here is targeted at being exposed externally as a
  * consumable libconsensus library, so any functions added must only call
  * other class member functions, pure functions in other parts of the consensus
  * library, callbacks via the validation interface, or read/write-to-disk
  * functions (eventually this will also be via callbacks).
  */
 class CChainState {
 private:
     /**
      * The set of all CBlockIndex entries with BLOCK_VALID_TRANSACTIONS (for
      * itself and all ancestors) and as good as our current tip or better.
      * Entries may be failed, though, and pruning nodes may be missing the data
      * for the block.
      */
     std::set<CBlockIndex *, CBlockIndexWorkComparator> setBlockIndexCandidates;
 
     /**
      * the ChainState CriticalSection
      * A lock that must be held when modifying this ChainState - held in
      * ActivateBestChain()
      */
     CCriticalSection m_cs_chainstate;
 
     /**
      * Every received block is assigned a unique and increasing identifier, so
      * we know which one to give priority in case of a fork.
      * Blocks loaded from disk are assigned id 0, so start the counter at 1.
      */
     std::atomic<int32_t> nBlockSequenceId{1};
     /** Decreasing counter (used by subsequent preciousblock calls). */
     int32_t nBlockReverseSequenceId = -1;
     /** chainwork for the last block that preciousblock has been applied to. */
     arith_uint256 nLastPreciousChainwork = 0;
 
     /**
      * In order to efficiently track invalidity of headers, we keep the set of
      * blocks which we tried to connect and found to be invalid here (ie which
      * were set to BLOCK_FAILED_VALID since the last restart). We can then
      * walk this set and check if a new header is a descendant of something in
      * this set, preventing us from having to walk mapBlockIndex when we try
      * to connect a bad block and fail.
      *
      * While this is more complicated than marking everything which descends
      * from an invalid block as invalid at the time we discover it to be
      * invalid, doing so would require walking all of mapBlockIndex to find all
      * descendants. Since this case should be very rare, keeping track of all
      * BLOCK_FAILED_VALID blocks in a set should be just fine and work just as
      * well.
      *
      * Because we already walk mapBlockIndex in height-order at startup, we go
      * ahead and mark descendants of invalid blocks as FAILED_CHILD at that
      * time, instead of putting things in this set.
      */
     std::set<CBlockIndex *> m_failed_blocks;
 
 public:
     CChain chainActive;
     BlockMap mapBlockIndex;
     std::multimap<CBlockIndex *, CBlockIndex *> mapBlocksUnlinked;
     CBlockIndex *pindexBestInvalid = nullptr;
     CBlockIndex *pindexBestParked = nullptr;
     CBlockIndex const *pindexFinalized = nullptr;
 
     bool LoadBlockIndex(const Config &config, CBlockTreeDB &blocktree)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool ActivateBestChain(
         const Config &config, CValidationState &state,
         std::shared_ptr<const CBlock> pblock = std::shared_ptr<const CBlock>());
 
     /**
      * If a block header hasn't already been seen, call CheckBlockHeader on it,
      * ensure that it doesn't descend from an invalid block, and then add it to
      * mapBlockIndex.
      */
     bool AcceptBlockHeader(const Config &config, const CBlockHeader &block,
                            CValidationState &state, CBlockIndex **ppindex)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     bool AcceptBlock(const Config &config,
                      const std::shared_ptr<const CBlock> &pblock,
                      CValidationState &state, bool fRequested,
                      const FlatFilePos *dbp, bool *fNewBlock)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     // Block (dis)connection on a given view:
     DisconnectResult DisconnectBlock(const CBlock &block,
                                      const CBlockIndex *pindex,
                                      CCoinsViewCache &view);
     bool ConnectBlock(const CBlock &block, CValidationState &state,
                       CBlockIndex *pindex, CCoinsViewCache &view,
                       const CChainParams &params,
                       BlockValidationOptions options, bool fJustCheck = false)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     // Block disconnection on our pcoinsTip:
     bool DisconnectTip(const Config &config, CValidationState &state,
                        DisconnectedBlockTransactions *disconnectpool)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     // Manual block validity manipulation:
     bool PreciousBlock(const Config &config, CValidationState &state,
                        CBlockIndex *pindex) LOCKS_EXCLUDED(cs_main);
     bool UnwindBlock(const Config &config, CValidationState &state,
                      CBlockIndex *pindex, bool invalidate)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void ResetBlockFailureFlags(CBlockIndex *pindex)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     template <typename F>
     void UpdateFlagsForBlock(CBlockIndex *pindexBase, CBlockIndex *pindex, F f)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     template <typename F, typename C>
     void UpdateFlags(CBlockIndex *pindex, F f, C fchild)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     template <typename F>
     void UpdateFlags(CBlockIndex *pindex, F f)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /** Remove parked status from a block and its descendants. */
     void UnparkBlockImpl(CBlockIndex *pindex, bool fClearChildren)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool ReplayBlocks(const Consensus::Params &params, CCoinsView *view);
     bool RewindBlockIndex(const Config &config);
     bool LoadGenesisBlock(const CChainParams &chainparams);
 
     void PruneBlockIndexCandidates();
 
     void UnloadBlockIndex();
 
 private:
     bool ActivateBestChainStep(const Config &config, CValidationState &state,
                                CBlockIndex *pindexMostWork,
                                const std::shared_ptr<const CBlock> &pblock,
                                bool &fInvalidFound, ConnectTrace &connectTrace)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     bool ConnectTip(const Config &config, CValidationState &state,
                     CBlockIndex *pindexNew,
                     const std::shared_ptr<const CBlock> &pblock,
                     ConnectTrace &connectTrace,
                     DisconnectedBlockTransactions &disconnectpool)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     CBlockIndex *AddToBlockIndex(const CBlockHeader &block)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /** Create a new block index entry for a given block hash */
     CBlockIndex *InsertBlockIndex(const BlockHash &hash)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /**
      * Make various assertions about the state of the block index.
      *
      * By default this only executes fully when using the Regtest chain; see:
      * fCheckBlockIndex.
      */
     void CheckBlockIndex(const Consensus::Params &consensusParams);
 
     void InvalidBlockFound(CBlockIndex *pindex, const CValidationState &state)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     CBlockIndex *FindMostWorkChain() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     bool ReceivedBlockTransactions(const CBlock &block, CValidationState &state,
                                    CBlockIndex *pindexNew,
                                    const FlatFilePos &pos)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool RollforwardBlock(const CBlockIndex *pindex, CCoinsViewCache &inputs,
                           const Consensus::Params &params)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 } g_chainstate;
 
 /**
  * Global state
  *
  * Mutex to guard access to validation specific variables, such as reading
  * or changing the chainstate.
  *
  * This may also need to be locked when updating the transaction pool, e.g. on
  * AcceptToMemoryPool. See CTxMemPool::cs comment for details.
  *
  * The transaction pool has a separate lock to allow reading from it and the
  * chainstate at the same time.
  */
 RecursiveMutex cs_main;
 
 BlockMap &mapBlockIndex = g_chainstate.mapBlockIndex;
 CChain &chainActive = g_chainstate.chainActive;
 CBlockIndex *pindexBestHeader = nullptr;
 Mutex g_best_block_mutex;
 std::condition_variable g_best_block_cv;
 uint256 g_best_block;
 int nScriptCheckThreads = 0;
 std::atomic_bool fImporting(false);
 std::atomic_bool fReindex(false);
 bool fHavePruned = false;
 bool fPruneMode = false;
 bool fIsBareMultisigStd = DEFAULT_PERMIT_BAREMULTISIG;
 bool fRequireStandard = true;
 bool fCheckBlockIndex = false;
 bool fCheckpointsEnabled = DEFAULT_CHECKPOINTS_ENABLED;
 size_t nCoinCacheUsage = 5000 * 300;
 uint64_t nPruneTarget = 0;
 int64_t nMaxTipAge = DEFAULT_MAX_TIP_AGE;
 
 BlockHash hashAssumeValid;
 arith_uint256 nMinimumChainWork;
 
 CFeeRate minRelayTxFee = CFeeRate(DEFAULT_MIN_RELAY_TX_FEE_PER_KB);
 Amount maxTxFee = DEFAULT_TRANSACTION_MAXFEE;
 
 CTxMemPool g_mempool;
 
 /** Constant stuff for coinbase transactions we create: */
 CScript COINBASE_FLAGS;
 
 const std::string strMessageMagic = "Bitcoin Signed Message:\n";
 
 // Internal stuff
 namespace {
 CBlockIndex *&pindexBestInvalid = g_chainstate.pindexBestInvalid;
 CBlockIndex *&pindexBestParked = g_chainstate.pindexBestParked;
 
 /**
  * The best finalized block.
  * This block cannot be reorged in any way, shape or form.
  */
 CBlockIndex const *&pindexFinalized = g_chainstate.pindexFinalized;
 
 /**
  * All pairs A->B, where A (or one of its ancestors) misses transactions, but B
  * has transactions. Pruned nodes may have entries where B is missing data.
  */
 std::multimap<CBlockIndex *, CBlockIndex *> &mapBlocksUnlinked =
     g_chainstate.mapBlocksUnlinked;
 
 CCriticalSection cs_LastBlockFile;
 std::vector<CBlockFileInfo> vinfoBlockFile;
 int nLastBlockFile = 0;
 /**
  * Global flag to indicate we should check to see if there are block/undo files
  * that should be deleted. Set on startup or if we allocate more file space when
  * we're in prune mode.
  */
 bool fCheckForPruning = false;
 
 /** Dirty block index entries. */
 std::set<const CBlockIndex *> setDirtyBlockIndex;
 
 /** Dirty block file entries. */
 std::set<int> setDirtyFileInfo;
 } // namespace
 
 BlockValidationOptions::BlockValidationOptions(const Config &config)
     : excessiveBlockSize(config.GetMaxBlockSize()), checkPoW(true),
       checkMerkleRoot(true) {}
 
 CBlockIndex *FindForkInGlobalIndex(const CChain &chain,
                                    const CBlockLocator &locator) {
     AssertLockHeld(cs_main);
 
     // Find the first block the caller has in the main chain
     for (const BlockHash &hash : locator.vHave) {
         CBlockIndex *pindex = LookupBlockIndex(hash);
         if (pindex) {
             if (chain.Contains(pindex)) {
                 return pindex;
             }
             if (pindex->GetAncestor(chain.Height()) == chain.Tip()) {
                 return chain.Tip();
             }
         }
     }
     return chain.Genesis();
 }
 
 std::unique_ptr<CCoinsViewDB> pcoinsdbview;
 std::unique_ptr<CCoinsViewCache> pcoinsTip;
 std::unique_ptr<CBlockTreeDB> pblocktree;
 
 enum class FlushStateMode { NONE, IF_NEEDED, PERIODIC, ALWAYS };
 
 // See definition for documentation
 static bool FlushStateToDisk(const CChainParams &chainParams,
                              CValidationState &state, FlushStateMode mode,
                              int nManualPruneHeight = 0);
 static void FindFilesToPruneManual(std::set<int> &setFilesToPrune,
                                    int nManualPruneHeight);
 static void FindFilesToPrune(std::set<int> &setFilesToPrune,
                              uint64_t nPruneAfterHeight);
 static FILE *OpenUndoFile(const FlatFilePos &pos, bool fReadOnly = false);
 static FlatFileSeq BlockFileSeq();
 static FlatFileSeq UndoFileSeq();
 static uint32_t GetNextBlockScriptFlags(const Consensus::Params &params,
                                         const CBlockIndex *pindex);
 
 bool TestLockPointValidity(const LockPoints *lp) {
     AssertLockHeld(cs_main);
     assert(lp);
     // If there are relative lock times then the maxInputBlock will be set
     // If there are no relative lock times, the LockPoints don't depend on the
     // chain
     if (lp->maxInputBlock) {
         // Check whether chainActive is an extension of the block at which the
         // LockPoints calculation was valid. If not LockPoints are no longer
         // valid.
         if (!chainActive.Contains(lp->maxInputBlock)) {
             return false;
         }
     }
 
     // LockPoints still valid
     return true;
 }
 
 bool CheckSequenceLocks(const CTxMemPool &pool, const CTransaction &tx,
                         int flags, LockPoints *lp, bool useExistingLockPoints) {
     AssertLockHeld(cs_main);
     AssertLockHeld(pool.cs);
 
     CBlockIndex *tip = chainActive.Tip();
     assert(tip != nullptr);
 
     CBlockIndex index;
     index.pprev = tip;
     // CheckSequenceLocks() uses chainActive.Height()+1 to evaluate height based
     // locks because when SequenceLocks() is called within ConnectBlock(), the
     // height of the block *being* evaluated is what is used. Thus if we want to
     // know if a transaction can be part of the *next* block, we need to use one
     // more than chainActive.Height()
     index.nHeight = tip->nHeight + 1;
 
     std::pair<int, int64_t> lockPair;
     if (useExistingLockPoints) {
         assert(lp);
         lockPair.first = lp->height;
         lockPair.second = lp->time;
     } else {
         // pcoinsTip contains the UTXO set for chainActive.Tip()
         CCoinsViewMemPool viewMemPool(pcoinsTip.get(), pool);
         std::vector<int> prevheights;
         prevheights.resize(tx.vin.size());
         for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
             const CTxIn &txin = tx.vin[txinIndex];
             Coin coin;
             if (!viewMemPool.GetCoin(txin.prevout, coin)) {
                 return error("%s: Missing input", __func__);
             }
             if (coin.GetHeight() == MEMPOOL_HEIGHT) {
                 // Assume all mempool transaction confirm in the next block
                 prevheights[txinIndex] = tip->nHeight + 1;
             } else {
                 prevheights[txinIndex] = coin.GetHeight();
             }
         }
         lockPair = CalculateSequenceLocks(tx, flags, &prevheights, index);
         if (lp) {
             lp->height = lockPair.first;
             lp->time = lockPair.second;
             // Also store the hash of the block with the highest height of all
             // the blocks which have sequence locked prevouts. This hash needs
             // to still be on the chain for these LockPoint calculations to be
             // valid.
             // Note: It is impossible to correctly calculate a maxInputBlock if
             // any of the sequence locked inputs depend on unconfirmed txs,
             // except in the special case where the relative lock time/height is
             // 0, which is equivalent to no sequence lock. Since we assume input
             // height of tip+1 for mempool txs and test the resulting lockPair
             // from CalculateSequenceLocks against tip+1. We know
             // EvaluateSequenceLocks will fail if there was a non-zero sequence
             // lock on a mempool input, so we can use the return value of
             // CheckSequenceLocks to indicate the LockPoints validity.
             int maxInputHeight = 0;
             for (const int height : prevheights) {
                 // Can ignore mempool inputs since we'll fail if they had
                 // non-zero locks.
                 if (height != tip->nHeight + 1) {
                     maxInputHeight = std::max(maxInputHeight, height);
                 }
             }
             lp->maxInputBlock = tip->GetAncestor(maxInputHeight);
         }
     }
     return EvaluateSequenceLocks(index, lockPair);
 }
 
 /** Convert CValidationState to a human-readable message for logging */
 std::string FormatStateMessage(const CValidationState &state) {
     return strprintf(
         "%s%s (code %i)", state.GetRejectReason(),
         state.GetDebugMessage().empty() ? "" : ", " + state.GetDebugMessage(),
         state.GetRejectCode());
 }
 
 static bool
 IsMagneticAnomalyEnabledForCurrentBlock(const Consensus::Params &params)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     return IsMagneticAnomalyEnabled(params, chainActive.Tip());
 }
 
 static bool IsGravitonEnabledForCurrentBlock(const Consensus::Params &params)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     return IsGravitonEnabled(params, chainActive.Tip());
 }
 
 // Command-line argument "-replayprotectionactivationtime=<timestamp>" will
 // cause the node to switch to replay protected SigHash ForkID value when the
 // median timestamp of the previous 11 blocks is greater than or equal to
 // <timestamp>. Defaults to the pre-defined timestamp when not set.
 static bool IsReplayProtectionEnabled(const Consensus::Params &params,
                                       int64_t nMedianTimePast) {
     return nMedianTimePast >= gArgs.GetArg("-replayprotectionactivationtime",
                                            params.phononActivationTime);
 }
 
 static bool IsReplayProtectionEnabled(const Consensus::Params &params,
                                       const CBlockIndex *pindexPrev) {
     if (pindexPrev == nullptr) {
         return false;
     }
 
     return IsReplayProtectionEnabled(params, pindexPrev->GetMedianTimePast());
 }
 
 static bool
 IsReplayProtectionEnabledForCurrentBlock(const Consensus::Params &params)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     return IsReplayProtectionEnabled(params, chainActive.Tip());
 }
 
 // Used to avoid mempool polluting consensus critical paths if CCoinsViewMempool
 // were somehow broken and returning the wrong scriptPubKeys
 static bool CheckInputsFromMempoolAndCache(
     const CTransaction &tx, CValidationState &state,
     const CCoinsViewCache &view, const CTxMemPool &pool, const uint32_t flags,
     bool cacheSigStore, PrecomputedTransactionData &txdata)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
 
     // pool.cs should be locked already, but go ahead and re-take the lock here
     // to enforce that mempool doesn't change between when we check the view and
     // when we actually call through to CheckInputs
     LOCK(pool.cs);
 
     assert(!tx.IsCoinBase());
     for (const CTxIn &txin : tx.vin) {
         const Coin &coin = view.AccessCoin(txin.prevout);
 
         // At this point we haven't actually checked if the coins are all
         // available (or shouldn't assume we have, since CheckInputs does). So
         // we just return failure if the inputs are not available here, and then
         // only have to check equivalence for available inputs.
         if (coin.IsSpent()) {
             return false;
         }
 
         const CTransactionRef &txFrom = pool.get(txin.prevout.GetTxId());
         if (txFrom) {
             assert(txFrom->GetId() == txin.prevout.GetTxId());
             assert(txFrom->vout.size() > txin.prevout.GetN());
             assert(txFrom->vout[txin.prevout.GetN()] == coin.GetTxOut());
         } else {
             const Coin &coinFromDisk = pcoinsTip->AccessCoin(txin.prevout);
             assert(!coinFromDisk.IsSpent());
             assert(coinFromDisk.GetTxOut() == coin.GetTxOut());
         }
     }
 
     return CheckInputs(tx, state, view, true, flags, cacheSigStore, true,
                        txdata);
 }
 
 static bool AcceptToMemoryPoolWorker(
     const Config &config, CTxMemPool &pool, CValidationState &state,
     const CTransactionRef &ptx, bool fLimitFree, bool *pfMissingInputs,
     int64_t nAcceptTime, bool fOverrideMempoolLimit, const Amount nAbsurdFee,
     std::vector<COutPoint> &coins_to_uncache, bool test_accept)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
 
     const Consensus::Params &consensusParams =
         config.GetChainParams().GetConsensus();
 
     const CTransaction &tx = *ptx;
     const TxId txid = tx.GetId();
 
     // mempool "read lock" (held through
     // GetMainSignals().TransactionAddedToMempool())
     LOCK(pool.cs);
     if (pfMissingInputs) {
         *pfMissingInputs = false;
     }
 
     // Coinbase is only valid in a block, not as a loose transaction.
     if (!CheckRegularTransaction(tx, state)) {
         // state filled in by CheckRegularTransaction.
         return false;
     }
 
     // Rather not work on nonstandard transactions (unless -testnet/-regtest)
     std::string reason;
     if (fRequireStandard && !IsStandardTx(tx, reason)) {
         return state.DoS(0, false, REJECT_NONSTANDARD, reason);
     }
 
     // Only accept nLockTime-using transactions that can be mined in the next
     // block; we don't want our mempool filled up with transactions that can't
     // be mined yet.
     CValidationState ctxState;
     if (!ContextualCheckTransactionForCurrentBlock(
             consensusParams, tx, ctxState, STANDARD_LOCKTIME_VERIFY_FLAGS)) {
         // We copy the state from a dummy to ensure we don't increase the
         // ban score of peer for transaction that could be valid in the future.
         return state.DoS(
             0, false, REJECT_NONSTANDARD, ctxState.GetRejectReason(),
             ctxState.CorruptionPossible(), ctxState.GetDebugMessage());
     }
 
     // Is it already in the memory pool?
     if (pool.exists(txid)) {
         return state.Invalid(false, REJECT_DUPLICATE, "txn-already-in-mempool");
     }
 
     // Check for conflicts with in-memory transactions
     for (const CTxIn &txin : tx.vin) {
         auto itConflicting = pool.mapNextTx.find(txin.prevout);
         if (itConflicting != pool.mapNextTx.end()) {
             // Disable replacement feature for good
             return state.Invalid(false, REJECT_DUPLICATE,
                                  "txn-mempool-conflict");
         }
     }
 
     {
         CCoinsView dummy;
         CCoinsViewCache view(&dummy);
 
         LockPoints lp;
         CCoinsViewMemPool viewMemPool(pcoinsTip.get(), pool);
         view.SetBackend(viewMemPool);
 
         // Do all inputs exist?
         for (const CTxIn &txin : tx.vin) {
             if (!pcoinsTip->HaveCoinInCache(txin.prevout)) {
                 coins_to_uncache.push_back(txin.prevout);
             }
 
             if (!view.HaveCoin(txin.prevout)) {
                 // Are inputs missing because we already have the tx?
                 for (size_t out = 0; out < tx.vout.size(); out++) {
                     // Optimistically just do efficient check of cache for
                     // outputs.
                     if (pcoinsTip->HaveCoinInCache(COutPoint(txid, out))) {
                         return state.Invalid(false, REJECT_DUPLICATE,
                                              "txn-already-known");
                     }
                 }
 
                 // Otherwise assume this might be an orphan tx for which we just
                 // haven't seen parents yet.
                 if (pfMissingInputs) {
                     *pfMissingInputs = true;
                 }
 
                 // fMissingInputs and !state.IsInvalid() is used to detect this
                 // condition, don't set state.Invalid()
                 return false;
             }
         }
 
         // Are the actual inputs available?
         if (!view.HaveInputs(tx)) {
             return state.Invalid(false, REJECT_DUPLICATE,
                                  "bad-txns-inputs-spent");
         }
 
         // Bring the best block into scope.
         view.GetBestBlock();
 
         // We have all inputs cached now, so switch back to dummy, so we don't
         // need to keep lock on mempool.
         view.SetBackend(dummy);
 
         // Only accept BIP68 sequence locked transactions that can be mined in
         // the next block; we don't want our mempool filled up with transactions
         // that can't be mined yet. Must keep pool.cs for this unless we change
         // CheckSequenceLocks to take a CoinsViewCache instead of create its
         // own.
         if (!CheckSequenceLocks(pool, tx, STANDARD_LOCKTIME_VERIFY_FLAGS,
                                 &lp)) {
             return state.DoS(0, false, REJECT_NONSTANDARD, "non-BIP68-final");
         }
 
         Amount nFees = Amount::zero();
         if (!Consensus::CheckTxInputs(tx, state, view, GetSpendHeight(view),
                                       nFees)) {
             return error("%s: Consensus::CheckTxInputs: %s, %s", __func__,
                          tx.GetId().ToString(), FormatStateMessage(state));
         }
 
         // Check for non-standard pay-to-script-hash in inputs
         if (fRequireStandard && !AreInputsStandard(tx, view)) {
             return state.Invalid(false, REJECT_NONSTANDARD,
                                  "bad-txns-nonstandard-inputs");
         }
 
         int64_t nSigOpsCount =
             GetTransactionSigOpCount(tx, view, STANDARD_SCRIPT_VERIFY_FLAGS);
 
         // nModifiedFees includes any fee deltas from PrioritiseTransaction
         Amount nModifiedFees = nFees;
         double nPriorityDummy = 0;
         pool.ApplyDeltas(txid, nPriorityDummy, nModifiedFees);
 
         Amount inChainInputValue;
         double dPriority =
             view.GetPriority(tx, chainActive.Height(), inChainInputValue);
 
         // Keep track of transactions that spend a coinbase, which we re-scan
         // during reorgs to ensure COINBASE_MATURITY is still met.
         bool fSpendsCoinbase = false;
         for (const CTxIn &txin : tx.vin) {
             const Coin &coin = view.AccessCoin(txin.prevout);
             if (coin.IsCoinBase()) {
                 fSpendsCoinbase = true;
                 break;
             }
         }
 
         CTxMemPoolEntry entry(ptx, nFees, nAcceptTime, dPriority,
                               chainActive.Height(), inChainInputValue,
                               fSpendsCoinbase, nSigOpsCount, lp);
         unsigned int nSize = entry.GetTxSize();
 
         // Check that the transaction doesn't have an excessive number of
         // sigops, making it impossible to mine. Since the coinbase transaction
         // itself can contain sigops MAX_STANDARD_TX_SIGOPS is less than
         // MAX_BLOCK_SIGOPS_PER_MB; we still consider this an invalid rather
         // than merely non-standard transaction.
         if (nSigOpsCount > MAX_STANDARD_TX_SIGOPS) {
             return state.DoS(0, false, REJECT_NONSTANDARD,
                              "bad-txns-too-many-sigops", false,
                              strprintf("%d", nSigOpsCount));
         }
 
         Amount mempoolRejectFee =
             pool.GetMinFee(
                     gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) *
                     1000000)
                 .GetFee(nSize);
         if (mempoolRejectFee > Amount::zero() &&
             nModifiedFees < mempoolRejectFee) {
             return state.DoS(
                 0, false, REJECT_INSUFFICIENTFEE, "mempool min fee not met",
                 false, strprintf("%d < %d", nModifiedFees, mempoolRejectFee));
         }
 
         if (gArgs.GetBoolArg("-relaypriority", DEFAULT_RELAYPRIORITY) &&
             nModifiedFees < minRelayTxFee.GetFee(nSize) &&
             !AllowFree(entry.GetPriority(chainActive.Height() + 1))) {
             // Require that free transactions have sufficient priority to be
             // mined in the next block.
             return state.DoS(0, false, REJECT_INSUFFICIENTFEE,
                              "insufficient priority");
         }
 
         // Continuously rate-limit free (really, very-low-fee) transactions.
         // This mitigates 'penny-flooding' -- sending thousands of free
         // transactions just to be annoying or make others' transactions take
         // longer to confirm.
         if (fLimitFree && nModifiedFees < minRelayTxFee.GetFee(nSize)) {
             static CCriticalSection csFreeLimiter;
             static double dFreeCount;
             static int64_t nLastTime;
             int64_t nNow = GetTime();
 
             LOCK(csFreeLimiter);
 
             // Use an exponentially decaying ~10-minute window:
             dFreeCount *= pow(1.0 - 1.0 / 600.0, double(nNow - nLastTime));
             nLastTime = nNow;
             // -limitfreerelay unit is thousand-bytes-per-minute
             // At default rate it would take over a month to fill 1GB
 
             // NOTE: Use the actual size here, and not the fee size since this
             // is counting real size for the rate limiter.
             if (dFreeCount + nSize >=
                 gArgs.GetArg("-limitfreerelay", DEFAULT_LIMITFREERELAY) * 10 *
                     1000) {
                 return state.DoS(0, false, REJECT_INSUFFICIENTFEE,
                                  "rate limited free transaction");
             }
 
             LogPrint(BCLog::MEMPOOL, "Rate limit dFreeCount: %g => %g\n",
                      dFreeCount, dFreeCount + nSize);
             dFreeCount += nSize;
         }
 
         if (nAbsurdFee != Amount::zero() && nFees > nAbsurdFee) {
             return state.Invalid(false, REJECT_HIGHFEE, "absurdly-high-fee",
                                  strprintf("%d > %d", nFees, nAbsurdFee));
         }
 
         // Calculate in-mempool ancestors, up to a limit.
         CTxMemPool::setEntries setAncestors;
         size_t nLimitAncestors =
             gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT);
         size_t nLimitAncestorSize =
             gArgs.GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT) *
             1000;
         size_t nLimitDescendants =
             gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT);
         size_t nLimitDescendantSize =
             gArgs.GetArg("-limitdescendantsize",
                          DEFAULT_DESCENDANT_SIZE_LIMIT) *
             1000;
         std::string errString;
         if (!pool.CalculateMemPoolAncestors(
                 entry, setAncestors, nLimitAncestors, nLimitAncestorSize,
                 nLimitDescendants, nLimitDescendantSize, errString)) {
             return state.DoS(0, false, REJECT_NONSTANDARD,
                              "too-long-mempool-chain", false, errString);
         }
 
         // Set extraFlags as a set of flags that needs to be activated.
         uint32_t extraFlags = SCRIPT_VERIFY_NONE;
         if (IsReplayProtectionEnabledForCurrentBlock(consensusParams)) {
             extraFlags |= SCRIPT_ENABLE_REPLAY_PROTECTION;
         }
 
         if (IsMagneticAnomalyEnabledForCurrentBlock(consensusParams)) {
             extraFlags |= SCRIPT_VERIFY_CHECKDATASIG_SIGOPS;
         }
 
         if (IsGravitonEnabledForCurrentBlock(consensusParams)) {
             extraFlags |= SCRIPT_ENABLE_SCHNORR_MULTISIG;
             extraFlags |= SCRIPT_VERIFY_MINIMALDATA;
         }
 
         // Make sure whatever we need to activate is actually activated.
         const uint32_t scriptVerifyFlags =
             STANDARD_SCRIPT_VERIFY_FLAGS | extraFlags;
 
         // Check against previous transactions. This is done last to help
         // prevent CPU exhaustion denial-of-service attacks.
         PrecomputedTransactionData txdata(tx);
         if (!CheckInputs(tx, state, view, true, scriptVerifyFlags, true, false,
                          txdata)) {
             // State filled in by CheckInputs.
             return false;
         }
 
         // Check again against the next block's script verification flags
         // to cache our script execution flags.
         //
         // This is also useful in case of bugs in the standard flags that cause
         // transactions to pass as valid when they're actually invalid. For
         // instance the STRICTENC flag was incorrectly allowing certain CHECKSIG
         // NOT scripts to pass, even though they were invalid.
         //
         // There is a similar check in CreateNewBlock() to prevent creating
         // invalid blocks (using TestBlockValidity), however allowing such
         // transactions into the mempool can be exploited as a DoS attack.
         uint32_t nextBlockScriptVerifyFlags =
             GetNextBlockScriptFlags(consensusParams, chainActive.Tip());
 
         if (!CheckInputsFromMempoolAndCache(tx, state, view, pool,
                                             nextBlockScriptVerifyFlags, true,
                                             txdata)) {
             return error("%s: BUG! PLEASE REPORT THIS! CheckInputs failed "
                          "against next-block but not STANDARD flags %s, %s",
                          __func__, txid.ToString(), FormatStateMessage(state));
         }
 
         if (test_accept) {
             // Tx was accepted, but not added
             return true;
         }
 
         // Store transaction in memory.
         pool.addUnchecked(txid, entry, setAncestors);
 
         // Trim mempool and check if tx was trimmed.
         if (!fOverrideMempoolLimit) {
             pool.LimitSize(
                 gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000,
                 gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 *
                     60);
             if (!pool.exists(txid)) {
                 return state.DoS(0, false, REJECT_INSUFFICIENTFEE,
                                  "mempool full");
             }
         }
     }
 
     GetMainSignals().TransactionAddedToMempool(ptx);
     return true;
 }
 
 /**
  * (try to) add transaction to memory pool with a specified acceptance time.
  */
 static bool AcceptToMemoryPoolWithTime(
     const Config &config, CTxMemPool &pool, CValidationState &state,
     const CTransactionRef &tx, bool fLimitFree, bool *pfMissingInputs,
     int64_t nAcceptTime, bool fOverrideMempoolLimit, const Amount nAbsurdFee,
     bool test_accept) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     std::vector<COutPoint> coins_to_uncache;
     bool res = AcceptToMemoryPoolWorker(
         config, pool, state, tx, fLimitFree, pfMissingInputs, nAcceptTime,
         fOverrideMempoolLimit, nAbsurdFee, coins_to_uncache, test_accept);
     if (!res) {
         for (const COutPoint &outpoint : coins_to_uncache) {
             pcoinsTip->Uncache(outpoint);
         }
     }
 
     // After we've (potentially) uncached entries, ensure our coins cache is
     // still within its size limits
     CValidationState stateDummy;
     FlushStateToDisk(config.GetChainParams(), stateDummy,
                      FlushStateMode::PERIODIC);
     return res;
 }
 
 bool AcceptToMemoryPool(const Config &config, CTxMemPool &pool,
                         CValidationState &state, const CTransactionRef &tx,
                         bool fLimitFree, bool *pfMissingInputs,
                         bool fOverrideMempoolLimit, const Amount nAbsurdFee,
                         bool test_accept) {
     return AcceptToMemoryPoolWithTime(
         config, pool, state, tx, fLimitFree, pfMissingInputs, GetTime(),
         fOverrideMempoolLimit, nAbsurdFee, test_accept);
 }
 
 /**
  * Return transaction in txOut, and if it was found inside a block, its hash is
  * placed in hashBlock. If blockIndex is provided, the transaction is fetched
  * from the corresponding block.
  */
 bool GetTransaction(const Consensus::Params &params, const TxId &txid,
                     CTransactionRef &txOut, uint256 &hashBlock, bool fAllowSlow,
                     CBlockIndex *blockIndex) {
     CBlockIndex *pindexSlow = blockIndex;
 
     LOCK(cs_main);
 
     if (!blockIndex) {
         CTransactionRef ptx = g_mempool.get(txid);
         if (ptx) {
             txOut = ptx;
             return true;
         }
 
         if (g_txindex) {
             return g_txindex->FindTx(txid, hashBlock, txOut);
         }
 
         // use coin database to locate block that contains transaction, and scan
         // it
         if (fAllowSlow) {
             const Coin &coin = AccessByTxid(*pcoinsTip, txid);
             if (!coin.IsSpent()) {
                 pindexSlow = chainActive[coin.GetHeight()];
             }
         }
     }
 
     if (pindexSlow) {
         CBlock block;
         if (ReadBlockFromDisk(block, pindexSlow, params)) {
             for (const auto &tx : block.vtx) {
                 if (tx->GetId() == txid) {
                     txOut = tx;
                     hashBlock = pindexSlow->GetBlockHash();
                     return true;
                 }
             }
         }
     }
 
     return false;
 }
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // CBlock and CBlockIndex
 //
 
 static bool WriteBlockToDisk(const CBlock &block, FlatFilePos &pos,
                              const CMessageHeader::MessageMagic &messageStart) {
     // Open history file to append
     CAutoFile fileout(OpenBlockFile(pos), SER_DISK, CLIENT_VERSION);
     if (fileout.IsNull()) {
         return error("WriteBlockToDisk: OpenBlockFile failed");
     }
 
     // Write index header
     unsigned int nSize = GetSerializeSize(block, fileout.GetVersion());
     fileout << messageStart << nSize;
 
     // Write block
     long fileOutPos = ftell(fileout.Get());
     if (fileOutPos < 0) {
         return error("WriteBlockToDisk: ftell failed");
     }
 
     pos.nPos = (unsigned int)fileOutPos;
     fileout << block;
 
     return true;
 }
 
 bool ReadBlockFromDisk(CBlock &block, const FlatFilePos &pos,
                        const Consensus::Params &params) {
     block.SetNull();
 
     // Open history file to read
     CAutoFile filein(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION);
     if (filein.IsNull()) {
         return error("ReadBlockFromDisk: OpenBlockFile failed for %s",
                      pos.ToString());
     }
 
     // Read block
     try {
         filein >> block;
     } catch (const std::exception &e) {
         return error("%s: Deserialize or I/O error - %s at %s", __func__,
                      e.what(), pos.ToString());
     }
 
     // Check the header
     if (!CheckProofOfWork(block.GetHash(), block.nBits, params)) {
         return error("ReadBlockFromDisk: Errors in block header at %s",
                      pos.ToString());
     }
 
     return true;
 }
 
 bool ReadBlockFromDisk(CBlock &block, const CBlockIndex *pindex,
                        const Consensus::Params &params) {
     FlatFilePos blockPos;
     {
         LOCK(cs_main);
         blockPos = pindex->GetBlockPos();
     }
 
     if (!ReadBlockFromDisk(block, blockPos, params)) {
         return false;
     }
 
     if (block.GetHash() != pindex->GetBlockHash()) {
         return error("ReadBlockFromDisk(CBlock&, CBlockIndex*): GetHash() "
                      "doesn't match index for %s at %s",
                      pindex->ToString(), pindex->GetBlockPos().ToString());
     }
 
     return true;
 }
 
 Amount GetBlockSubsidy(int nHeight, const Consensus::Params &consensusParams) {
     int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
     // Force block reward to zero when right shift is undefined.
     if (halvings >= 64) {
         return Amount::zero();
     }
 
     Amount nSubsidy = 50 * COIN;
     // Subsidy is cut in half every 210,000 blocks which will occur
     // approximately every 4 years.
     return ((nSubsidy / SATOSHI) >> halvings) * SATOSHI;
 }
 
 bool IsInitialBlockDownload() {
     // Once this function has returned false, it must remain false.
     static std::atomic<bool> latchToFalse{false};
     // Optimization: pre-test latch before taking the lock.
     if (latchToFalse.load(std::memory_order_relaxed)) {
         return false;
     }
 
     LOCK(cs_main);
     if (latchToFalse.load(std::memory_order_relaxed)) {
         return false;
     }
     if (fImporting || fReindex) {
         return true;
     }
     if (chainActive.Tip() == nullptr) {
         return true;
     }
     if (chainActive.Tip()->nChainWork < nMinimumChainWork) {
         return true;
     }
     if (chainActive.Tip()->GetBlockTime() < (GetTime() - nMaxTipAge)) {
         return true;
     }
     LogPrintf("Leaving InitialBlockDownload (latching to false)\n");
     latchToFalse.store(true, std::memory_order_relaxed);
     return false;
 }
 
 CBlockIndex const *pindexBestForkTip = nullptr;
 CBlockIndex const *pindexBestForkBase = nullptr;
 
 static void AlertNotify(const std::string &strMessage) {
     uiInterface.NotifyAlertChanged();
     std::string strCmd = gArgs.GetArg("-alertnotify", "");
     if (strCmd.empty()) {
         return;
     }
 
     // Alert text should be plain ascii coming from a trusted source, but to be
     // safe we first strip anything not in safeChars, then add single quotes
     // around the whole string before passing it to the shell:
     std::string singleQuote("'");
     std::string safeStatus = SanitizeString(strMessage);
     safeStatus = singleQuote + safeStatus + singleQuote;
     boost::replace_all(strCmd, "%s", safeStatus);
 
     std::thread t(runCommand, strCmd);
     // thread runs free
     t.detach();
 }
 
 static void CheckForkWarningConditions() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     // Before we get past initial download, we cannot reliably alert about forks
     // (we assume we don't get stuck on a fork before finishing our initial
     // sync)
     if (IsInitialBlockDownload()) {
         return;
     }
 
     // If our best fork is no longer within 72 blocks (+/- 12 hours if no one
     // mines it) of our head, drop it
     if (pindexBestForkTip &&
         chainActive.Height() - pindexBestForkTip->nHeight >= 72) {
         pindexBestForkTip = nullptr;
     }
 
     if (pindexBestForkTip ||
         (pindexBestInvalid &&
          pindexBestInvalid->nChainWork >
              chainActive.Tip()->nChainWork +
                  (GetBlockProof(*chainActive.Tip()) * 6))) {
         if (!GetfLargeWorkForkFound() && pindexBestForkBase) {
             std::string warning =
                 std::string("'Warning: Large-work fork detected, forking after "
                             "block ") +
                 pindexBestForkBase->phashBlock->ToString() + std::string("'");
             AlertNotify(warning);
         }
 
         if (pindexBestForkTip && pindexBestForkBase) {
             LogPrintf("%s: Warning: Large fork found\n  forking the "
                       "chain at height %d (%s)\n  lasting to height %d "
                       "(%s).\nChain state database corruption likely.\n",
                       __func__, pindexBestForkBase->nHeight,
                       pindexBestForkBase->phashBlock->ToString(),
                       pindexBestForkTip->nHeight,
                       pindexBestForkTip->phashBlock->ToString());
             SetfLargeWorkForkFound(true);
         } else {
             LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks "
                       "longer than our best chain.\nChain state database "
                       "corruption likely.\n",
                       __func__);
             SetfLargeWorkInvalidChainFound(true);
         }
     } else {
         SetfLargeWorkForkFound(false);
         SetfLargeWorkInvalidChainFound(false);
     }
 }
 
 static void CheckForkWarningConditionsOnNewFork(CBlockIndex *pindexNewForkTip)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     // If we are on a fork that is sufficiently large, set a warning flag.
     const CBlockIndex *pfork = chainActive.FindFork(pindexNewForkTip);
 
     // We define a condition where we should warn the user about as a fork of at
     // least 7 blocks with a tip within 72 blocks (+/- 12 hours if no one mines
     // it) of ours. We use 7 blocks rather arbitrarily as it represents just
     // under 10% of sustained network hash rate operating on the fork, or a
     // chain that is entirely longer than ours and invalid (note that this
     // should be detected by both). We define it this way because it allows us
     // to only store the highest fork tip (+ base) which meets the 7-block
     // condition and from this always have the most-likely-to-cause-warning fork
     if (pfork &&
         (!pindexBestForkTip ||
          pindexNewForkTip->nHeight > pindexBestForkTip->nHeight) &&
         pindexNewForkTip->nChainWork - pfork->nChainWork >
             (GetBlockProof(*pfork) * 7) &&
         chainActive.Height() - pindexNewForkTip->nHeight < 72) {
         pindexBestForkTip = pindexNewForkTip;
         pindexBestForkBase = pfork;
     }
 
     CheckForkWarningConditions();
 }
 
 static void InvalidChainFound(CBlockIndex *pindexNew)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     if (!pindexBestInvalid ||
         pindexNew->nChainWork > pindexBestInvalid->nChainWork) {
         pindexBestInvalid = pindexNew;
     }
 
     // If the invalid chain found is supposed to be finalized, we need to move
     // back the finalization point.
     if (IsBlockFinalized(pindexNew)) {
         pindexFinalized = pindexNew->pprev;
     }
 
     LogPrintf("%s: invalid block=%s  height=%d  log2_work=%.8g  date=%s\n",
               __func__, pindexNew->GetBlockHash().ToString(),
               pindexNew->nHeight,
               log(pindexNew->nChainWork.getdouble()) / log(2.0),
               FormatISO8601DateTime(pindexNew->GetBlockTime()));
     CBlockIndex *tip = chainActive.Tip();
     assert(tip);
     LogPrintf("%s:  current best=%s  height=%d  log2_work=%.8g  date=%s\n",
               __func__, tip->GetBlockHash().ToString(), chainActive.Height(),
               log(tip->nChainWork.getdouble()) / log(2.0),
               FormatISO8601DateTime(tip->GetBlockTime()));
 }
 
 void CChainState::InvalidBlockFound(CBlockIndex *pindex,
                                     const CValidationState &state) {
     if (!state.CorruptionPossible()) {
         pindex->nStatus = pindex->nStatus.withFailed();
         m_failed_blocks.insert(pindex);
         setDirtyBlockIndex.insert(pindex);
         InvalidChainFound(pindex);
     }
 }
 
 void SpendCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                 int nHeight) {
     // Mark inputs spent.
     if (tx.IsCoinBase()) {
         return;
     }
 
     txundo.vprevout.reserve(tx.vin.size());
     for (const CTxIn &txin : tx.vin) {
         txundo.vprevout.emplace_back();
         bool is_spent = view.SpendCoin(txin.prevout, &txundo.vprevout.back());
         assert(is_spent);
     }
 }
 
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                  int nHeight) {
     SpendCoins(view, tx, txundo, nHeight);
     AddCoins(view, tx, nHeight);
 }
 
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, int nHeight) {
     // Mark inputs spent.
     if (!tx.IsCoinBase()) {
         for (const CTxIn &txin : tx.vin) {
             bool is_spent = view.SpendCoin(txin.prevout);
             assert(is_spent);
         }
     }
 
     // Add outputs.
     AddCoins(view, tx, nHeight);
 }
 
 bool CScriptCheck::operator()() {
     const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
     return VerifyScript(scriptSig, scriptPubKey, nFlags,
                         CachingTransactionSignatureChecker(ptxTo, nIn, amount,
                                                            cacheStore, txdata),
                         &error);
 }
 
 int GetSpendHeight(const CCoinsViewCache &inputs) {
     LOCK(cs_main);
     CBlockIndex *pindexPrev = LookupBlockIndex(inputs.GetBestBlock());
     return pindexPrev->nHeight + 1;
 }
 
 bool CheckInputs(const CTransaction &tx, CValidationState &state,
                  const CCoinsViewCache &inputs, bool fScriptChecks,
                  const uint32_t flags, bool sigCacheStore,
                  bool scriptCacheStore,
                  const PrecomputedTransactionData &txdata,
                  std::vector<CScriptCheck> *pvChecks) {
     AssertLockHeld(cs_main);
     assert(!tx.IsCoinBase());
 
     if (pvChecks) {
         pvChecks->reserve(tx.vin.size());
     }
 
     // Skip script verification when connecting blocks under the assumevalid
     // block. Assuming the assumevalid block is valid this is safe because
     // block merkle hashes are still computed and checked, of course, if an
     // assumed valid block is invalid due to false scriptSigs this optimization
     // would allow an invalid chain to be accepted.
     if (!fScriptChecks) {
         return true;
     }
 
     // First check if script executions have been cached with the same flags.
     // Note that this assumes that the inputs provided are correct (ie that the
     // transaction hash which is in tx's prevouts properly commits to the
     // scriptPubKey in the inputs view of that transaction).
     uint256 hashCacheEntry = GetScriptCacheKey(tx, flags);
     if (IsKeyInScriptCache(hashCacheEntry, !scriptCacheStore)) {
         return true;
     }
 
     for (size_t i = 0; i < tx.vin.size(); i++) {
         const COutPoint &prevout = tx.vin[i].prevout;
         const Coin &coin = inputs.AccessCoin(prevout);
         assert(!coin.IsSpent());
 
         // We very carefully only pass in things to CScriptCheck which are
         // clearly committed to by tx's hash. This provides a sanity
         // check that our caching is not introducing consensus failures through
         // additional data in, eg, the coins being spent being checked as a part
         // of CScriptCheck.
         const CScript &scriptPubKey = coin.GetTxOut().scriptPubKey;
         const Amount amount = coin.GetTxOut().nValue;
 
         // Verify signature
         CScriptCheck check(scriptPubKey, amount, tx, i, flags, sigCacheStore,
                            txdata);
         if (pvChecks) {
             pvChecks->push_back(std::move(check));
         } else if (!check()) {
             ScriptError scriptError = check.GetScriptError();
             // Compute flags without the optional standardness flags.
             // This differs from MANDATORY_SCRIPT_VERIFY_FLAGS as it contains
             // additional upgrade flags (see AcceptToMemoryPoolWorker variable
             // extraFlags).
             uint32_t mandatoryFlags =
                 flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS;
             if (flags != mandatoryFlags) {
                 // Check whether the failure was caused by a non-mandatory
                 // script verification check. If so, don't trigger DoS
                 // protection to avoid splitting the network on the basis of
                 // relay policy disagreements.
                 CScriptCheck check2(scriptPubKey, amount, tx, i, mandatoryFlags,
                                     sigCacheStore, txdata);
                 if (check2()) {
                     return state.Invalid(
                         false, REJECT_NONSTANDARD,
                         strprintf("non-mandatory-script-verify-flag (%s)",
                                   ScriptErrorString(scriptError)));
                 }
                 // update the error message to reflect the mandatory violation.
                 scriptError = check2.GetScriptError();
             }
 
             // Failures of other flags indicate a transaction that is invalid in
             // new blocks, e.g. a invalid P2SH. We DoS ban such nodes as they
             // are not following the protocol. That said during an upgrade
             // careful thought should be taken as to the correct behavior - we
             // may want to continue peering with non-upgraded nodes even after
             // soft-fork super-majority signaling has occurred.
             return state.DoS(
                 100, false, REJECT_INVALID,
                 strprintf("mandatory-script-verify-flag-failed (%s)",
                           ScriptErrorString(scriptError)));
         }
     }
 
     if (scriptCacheStore && !pvChecks) {
         // We executed all of the provided scripts, and were told to cache the
         // result. Do so now.
         AddKeyInScriptCache(hashCacheEntry);
     }
 
     return true;
 }
 
 namespace {
 
 bool UndoWriteToDisk(const CBlockUndo &blockundo, FlatFilePos &pos,
                      const uint256 &hashBlock,
                      const CMessageHeader::MessageMagic &messageStart) {
     // Open history file to append
     CAutoFile fileout(OpenUndoFile(pos), SER_DISK, CLIENT_VERSION);
     if (fileout.IsNull()) {
         return error("%s: OpenUndoFile failed", __func__);
     }
 
     // Write index header
     unsigned int nSize = GetSerializeSize(blockundo, fileout.GetVersion());
     fileout << messageStart << nSize;
 
     // Write undo data
     long fileOutPos = ftell(fileout.Get());
     if (fileOutPos < 0) {
         return error("%s: ftell failed", __func__);
     }
     pos.nPos = (unsigned int)fileOutPos;
     fileout << blockundo;
 
     // calculate & write checksum
     CHashWriter hasher(SER_GETHASH, PROTOCOL_VERSION);
     hasher << hashBlock;
     hasher << blockundo;
     fileout << hasher.GetHash();
 
     return true;
 }
 
 static bool UndoReadFromDisk(CBlockUndo &blockundo, const CBlockIndex *pindex) {
     FlatFilePos pos = pindex->GetUndoPos();
     if (pos.IsNull()) {
         return error("%s: no undo data available", __func__);
     }
 
     // Open history file to read
     CAutoFile filein(OpenUndoFile(pos, true), SER_DISK, CLIENT_VERSION);
     if (filein.IsNull()) {
         return error("%s: OpenUndoFile failed", __func__);
     }
 
     // Read block
     uint256 hashChecksum;
     // We need a CHashVerifier as reserializing may lose data
     CHashVerifier<CAutoFile> verifier(&filein);
     try {
         verifier << pindex->pprev->GetBlockHash();
         verifier >> blockundo;
         filein >> hashChecksum;
     } catch (const std::exception &e) {
         return error("%s: Deserialize or I/O error - %s", __func__, e.what());
     }
 
     // Verify checksum
     if (hashChecksum != verifier.GetHash()) {
         return error("%s: Checksum mismatch", __func__);
     }
 
     return true;
 }
 
 /** Abort with a message */
 static bool AbortNode(const std::string &strMessage,
                       const std::string &userMessage = "") {
     SetMiscWarning(strMessage);
     LogPrintf("*** %s\n", strMessage);
     uiInterface.ThreadSafeMessageBox(
         userMessage.empty() ? _("Error: A fatal internal error occurred, see "
                                 "debug.log for details")
                             : userMessage,
         "", CClientUIInterface::MSG_ERROR);
     StartShutdown();
     return false;
 }
 
 static bool AbortNode(CValidationState &state, const std::string &strMessage,
                       const std::string &userMessage = "") {
     AbortNode(strMessage, userMessage);
     return state.Error(strMessage);
 }
 
 } // namespace
 
 /** Restore the UTXO in a Coin at a given COutPoint. */
 DisconnectResult UndoCoinSpend(const Coin &undo, CCoinsViewCache &view,
                                const COutPoint &out) {
     bool fClean = true;
 
     if (view.HaveCoin(out)) {
         // Overwriting transaction output.
         fClean = false;
     }
 
     if (undo.GetHeight() == 0) {
         // Missing undo metadata (height and coinbase). Older versions included
         // this information only in undo records for the last spend of a
         // transactions' outputs. This implies that it must be present for some
         // other output of the same tx.
         const Coin &alternate = AccessByTxid(view, out.GetTxId());
         if (alternate.IsSpent()) {
             // Adding output for transaction without known metadata
             return DISCONNECT_FAILED;
         }
 
         // This is somewhat ugly, but hopefully utility is limited. This is only
         // useful when working from legacy on disck data. In any case, putting
         // the correct information in there doesn't hurt.
         const_cast<Coin &>(undo) = Coin(undo.GetTxOut(), alternate.GetHeight(),
                                         alternate.IsCoinBase());
     }
 
     // The potential_overwrite parameter to AddCoin is only allowed to be false
     // if we know for sure that the coin did not already exist in the cache. As
     // we have queried for that above using HaveCoin, we don't need to guess.
     // When fClean is false, a coin already existed and it is an overwrite.
     view.AddCoin(out, std::move(undo), !fClean);
 
     return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
 }
 
 /**
  * Undo the effects of this block (with given index) on the UTXO set represented
  * by coins. When FAILED is returned, view is left in an indeterminate state.
  */
 DisconnectResult CChainState::DisconnectBlock(const CBlock &block,
                                               const CBlockIndex *pindex,
                                               CCoinsViewCache &view) {
     CBlockUndo blockUndo;
     if (!UndoReadFromDisk(blockUndo, pindex)) {
         error("DisconnectBlock(): failure reading undo data");
         return DISCONNECT_FAILED;
     }
 
     return ApplyBlockUndo(blockUndo, block, pindex, view);
 }
 
 DisconnectResult ApplyBlockUndo(const CBlockUndo &blockUndo,
                                 const CBlock &block, const CBlockIndex *pindex,
                                 CCoinsViewCache &view) {
     bool fClean = true;
 
     if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) {
         error("DisconnectBlock(): block and undo data inconsistent");
         return DISCONNECT_FAILED;
     }
 
     // First, restore inputs.
     for (size_t i = 1; i < block.vtx.size(); i++) {
         const CTransaction &tx = *(block.vtx[i]);
         const CTxUndo &txundo = blockUndo.vtxundo[i - 1];
         if (txundo.vprevout.size() != tx.vin.size()) {
             error("DisconnectBlock(): transaction and undo data inconsistent");
             return DISCONNECT_FAILED;
         }
 
         for (size_t j = 0; j < tx.vin.size(); j++) {
             const COutPoint &out = tx.vin[j].prevout;
             const Coin &undo = txundo.vprevout[j];
             DisconnectResult res = UndoCoinSpend(undo, view, out);
             if (res == DISCONNECT_FAILED) {
                 return DISCONNECT_FAILED;
             }
             fClean = fClean && res != DISCONNECT_UNCLEAN;
         }
     }
 
     // Second, revert created outputs.
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         const TxId &txid = tx.GetId();
         const bool is_coinbase = tx.IsCoinBase();
 
         // Check that all outputs are available and match the outputs in the
         // block itself exactly.
         for (size_t o = 0; o < tx.vout.size(); o++) {
             if (tx.vout[o].scriptPubKey.IsUnspendable()) {
                 continue;
             }
 
             COutPoint out(txid, o);
             Coin coin;
             bool is_spent = view.SpendCoin(out, &coin);
             if (!is_spent || tx.vout[o] != coin.GetTxOut() ||
                 uint32_t(pindex->nHeight) != coin.GetHeight() ||
                 is_coinbase != coin.IsCoinBase()) {
                 // transaction output mismatch
                 fClean = false;
             }
         }
     }
 
     // Move best block pointer to previous block.
     view.SetBestBlock(block.hashPrevBlock);
 
     return fClean ? DISCONNECT_OK : DISCONNECT_UNCLEAN;
 }
 
 static void FlushBlockFile(bool fFinalize = false) {
     LOCK(cs_LastBlockFile);
 
     FlatFilePos block_pos_old(nLastBlockFile,
                               vinfoBlockFile[nLastBlockFile].nSize);
     FlatFilePos undo_pos_old(nLastBlockFile,
                              vinfoBlockFile[nLastBlockFile].nUndoSize);
 
     bool status = true;
     status &= BlockFileSeq().Flush(block_pos_old, fFinalize);
     status &= UndoFileSeq().Flush(undo_pos_old, fFinalize);
     if (!status) {
         AbortNode("Flushing block file to disk failed. This is likely the "
                   "result of an I/O error.");
     }
 }
 
 static bool FindUndoPos(CValidationState &state, int nFile, FlatFilePos &pos,
                         unsigned int nAddSize);
 
 static bool WriteUndoDataForBlock(const CBlockUndo &blockundo,
                                   CValidationState &state, CBlockIndex *pindex,
                                   const CChainParams &chainparams) {
     // Write undo information to disk
     if (pindex->GetUndoPos().IsNull()) {
         FlatFilePos _pos;
         if (!FindUndoPos(state, pindex->nFile, _pos,
                          ::GetSerializeSize(blockundo, CLIENT_VERSION) + 40)) {
             return error("ConnectBlock(): FindUndoPos failed");
         }
         if (!UndoWriteToDisk(blockundo, _pos, pindex->pprev->GetBlockHash(),
                              chainparams.DiskMagic())) {
             return AbortNode(state, "Failed to write undo data");
         }
 
         // update nUndoPos in block index
         pindex->nUndoPos = _pos.nPos;
         pindex->nStatus = pindex->nStatus.withUndo();
         setDirtyBlockIndex.insert(pindex);
     }
 
     return true;
 }
 
 static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
 
 void ThreadScriptCheck() {
     RenameThread("bitcoin-scriptch");
     scriptcheckqueue.Thread();
 }
 
 int32_t ComputeBlockVersion(const CBlockIndex *pindexPrev,
                             const Consensus::Params &params) {
     int32_t nVersion = VERSIONBITS_TOP_BITS;
     return nVersion;
 }
 
 // Returns the script flags which should be checked for the block after
 // the given block.
 static uint32_t GetNextBlockScriptFlags(const Consensus::Params &params,
                                         const CBlockIndex *pindex) {
     uint32_t flags = SCRIPT_VERIFY_NONE;
 
     // Start enforcing P2SH (BIP16)
     if ((pindex->nHeight + 1) >= params.BIP16Height) {
         flags |= SCRIPT_VERIFY_P2SH;
     }
 
     // Start enforcing the DERSIG (BIP66) rule.
     if ((pindex->nHeight + 1) >= params.BIP66Height) {
         flags |= SCRIPT_VERIFY_DERSIG;
     }
 
     // Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule.
     if ((pindex->nHeight + 1) >= params.BIP65Height) {
         flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
     }
 
     // Start enforcing CSV (BIP68, BIP112 and BIP113) rule.
     if ((pindex->nHeight + 1) >= params.CSVHeight) {
         flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
     }
 
     // If the UAHF is enabled, we start accepting replay protected txns
     if (IsUAHFenabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_STRICTENC;
         flags |= SCRIPT_ENABLE_SIGHASH_FORKID;
     }
 
     // If the DAA HF is enabled, we start rejecting transaction that use a high
     // s in their signature. We also make sure that signature that are supposed
     // to fail (for instance in multisig or other forms of smart contracts) are
     // null.
     if (IsDAAEnabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_LOW_S;
         flags |= SCRIPT_VERIFY_NULLFAIL;
     }
 
     // When the magnetic anomaly fork is enabled, we start accepting
     // transactions using the OP_CHECKDATASIG opcode and it's verify
     // alternative. We also start enforcing push only signatures and
     // clean stack.
     if (IsMagneticAnomalyEnabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_CHECKDATASIG_SIGOPS;
         flags |= SCRIPT_VERIFY_SIGPUSHONLY;
         flags |= SCRIPT_VERIFY_CLEANSTACK;
     }
 
     if (IsGravitonEnabled(params, pindex)) {
         flags |= SCRIPT_ENABLE_SCHNORR_MULTISIG;
         flags |= SCRIPT_VERIFY_MINIMALDATA;
     }
 
     // We make sure this node will have replay protection during the next hard
     // fork.
     if (IsReplayProtectionEnabled(params, pindex)) {
         flags |= SCRIPT_ENABLE_REPLAY_PROTECTION;
     }
 
     return flags;
 }
 
 static int64_t nTimeCheck = 0;
 static int64_t nTimeForks = 0;
 static int64_t nTimeVerify = 0;
 static int64_t nTimeConnect = 0;
 static int64_t nTimeIndex = 0;
 static int64_t nTimeCallbacks = 0;
 static int64_t nTimeTotal = 0;
 static int64_t nBlocksTotal = 0;
 
 /**
  * Apply the effects of this block (with given index) on the UTXO set
  * represented by coins. Validity checks that depend on the UTXO set are also
  * done; ConnectBlock() can fail if those validity checks fail (among other
  * reasons).
  */
 bool CChainState::ConnectBlock(const CBlock &block, CValidationState &state,
                                CBlockIndex *pindex, CCoinsViewCache &view,
                                const CChainParams &params,
                                BlockValidationOptions options,
                                bool fJustCheck) {
     AssertLockHeld(cs_main);
     assert(pindex);
     assert(*pindex->phashBlock == block.GetHash());
     int64_t nTimeStart = GetTimeMicros();
 
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     // Check it again in case a previous version let a bad block in
     // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
     // ContextualCheckBlockHeader() here. This means that if we add a new
     // consensus rule that is enforced in one of those two functions, then we
     // may have let in a block that violates the rule prior to updating the
     // software, and we would NOT be enforcing the rule here. Fully solving
     // upgrade from one software version to the next after a consensus rule
     // change is potentially tricky and issue-specific (see RewindBlockIndex()
     // for one general approach that was used for BIP 141 deployment).
     // Also, currently the rule against blocks more than 2 hours in the future
     // is enforced in ContextualCheckBlockHeader(); we wouldn't want to
     // re-enforce that rule here (at least until we make it impossible for
     // GetAdjustedTime() to go backward).
     if (!CheckBlock(block, state, consensusParams,
                     options.withCheckPoW(!fJustCheck)
                         .withCheckMerkleRoot(!fJustCheck))) {
         if (state.CorruptionPossible()) {
             // We don't write down blocks to disk if they may have been
             // corrupted, so this should be impossible unless we're having
             // hardware problems.
             return AbortNode(state, "Corrupt block found indicating potential "
                                     "hardware failure; shutting down");
         }
         return error("%s: Consensus::CheckBlock: %s", __func__,
                      FormatStateMessage(state));
     }
 
     // Verify that the view's current state corresponds to the previous block
     BlockHash hashPrevBlock =
         pindex->pprev == nullptr ? BlockHash() : pindex->pprev->GetBlockHash();
     assert(hashPrevBlock == view.GetBestBlock());
 
     // Special case for the genesis block, skipping connection of its
     // transactions (its coinbase is unspendable)
     if (block.GetHash() == consensusParams.hashGenesisBlock) {
         if (!fJustCheck) {
             view.SetBestBlock(pindex->GetBlockHash());
         }
 
         return true;
     }
 
     nBlocksTotal++;
 
     bool fScriptChecks = true;
     if (!hashAssumeValid.IsNull()) {
         // We've been configured with the hash of a block which has been
         // externally verified to have a valid history. A suitable default value
         // is included with the software and updated from time to time. Because
         // validity relative to a piece of software is an objective fact these
         // defaults can be easily reviewed. This setting doesn't force the
         // selection of any particular chain but makes validating some faster by
         // effectively caching the result of part of the verification.
         BlockMap::const_iterator it = mapBlockIndex.find(hashAssumeValid);
         if (it != mapBlockIndex.end()) {
             if (it->second->GetAncestor(pindex->nHeight) == pindex &&
                 pindexBestHeader->GetAncestor(pindex->nHeight) == pindex &&
                 pindexBestHeader->nChainWork >= nMinimumChainWork) {
                 // This block is a member of the assumed verified chain and an
                 // ancestor of the best header. The equivalent time check
                 // discourages hash power from extorting the network via DOS
                 // attack into accepting an invalid block through telling users
                 // they must manually set assumevalid. Requiring a software
                 // change or burying the invalid block, regardless of the
                 // setting, makes it hard to hide the implication of the demand.
                 // This also avoids having release candidates that are hardly
                 // doing any signature verification at all in testing without
                 // having to artificially set the default assumed verified block
                 // further back. The test against nMinimumChainWork prevents the
                 // skipping when denied access to any chain at least as good as
                 // the expected chain.
                 fScriptChecks =
                     (GetBlockProofEquivalentTime(
                          *pindexBestHeader, *pindex, *pindexBestHeader,
                          consensusParams) <= 60 * 60 * 24 * 7 * 2);
             }
         }
     }
 
     int64_t nTime1 = GetTimeMicros();
     nTimeCheck += nTime1 - nTimeStart;
     LogPrint(BCLog::BENCH, "    - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime1 - nTimeStart), nTimeCheck * MICRO,
              nTimeCheck * MILLI / nBlocksTotal);
 
     // Do not allow blocks that contain transactions which 'overwrite' older
     // transactions, unless those are already completely spent. If such
     // overwrites are allowed, coinbases and transactions depending upon those
     // can be duplicated to remove the ability to spend the first instance --
     // even after being sent to another address. See BIP30 and
     // http://r6.ca/blog/20120206T005236Z.html for more information. This logic
     // is not necessary for memory pool transactions, as AcceptToMemoryPool
     // already refuses previously-known transaction ids entirely. This rule was
     // originally applied to all blocks with a timestamp after March 15, 2012,
     // 0:00 UTC. Now that the whole chain is irreversibly beyond that time it is
     // applied to all blocks except the two in the chain that violate it. This
     // prevents exploiting the issue against nodes during their initial block
     // download.
     bool fEnforceBIP30 = !((pindex->nHeight == 91842 &&
                             pindex->GetBlockHash() ==
                                 uint256S("0x00000000000a4d0a398161ffc163c503763"
                                          "b1f4360639393e0e4c8e300e0caec")) ||
                            (pindex->nHeight == 91880 &&
                             pindex->GetBlockHash() ==
                                 uint256S("0x00000000000743f190a18c5577a3c2d2a1f"
                                          "610ae9601ac046a38084ccb7cd721")));
 
     // Once BIP34 activated it was not possible to create new duplicate
     // coinbases and thus other than starting with the 2 existing duplicate
     // coinbase pairs, not possible to create overwriting txs. But by the time
     // BIP34 activated, in each of the existing pairs the duplicate coinbase had
     // overwritten the first before the first had been spent. Since those
     // coinbases are sufficiently buried it's no longer possible to create
     // further duplicate transactions descending from the known pairs either. If
     // we're on the known chain at height greater than where BIP34 activated, we
     // can save the db accesses needed for the BIP30 check.
     assert(pindex->pprev);
     CBlockIndex *pindexBIP34height =
         pindex->pprev->GetAncestor(consensusParams.BIP34Height);
     // Only continue to enforce if we're below BIP34 activation height or the
     // block hash at that height doesn't correspond.
     fEnforceBIP30 =
         fEnforceBIP30 &&
         (!pindexBIP34height ||
          !(pindexBIP34height->GetBlockHash() == consensusParams.BIP34Hash));
 
     if (fEnforceBIP30) {
         for (const auto &tx : block.vtx) {
             for (size_t o = 0; o < tx->vout.size(); o++) {
                 if (view.HaveCoin(COutPoint(tx->GetId(), o))) {
                     return state.DoS(
                         100,
                         error("ConnectBlock(): tried to overwrite transaction"),
                         REJECT_INVALID, "bad-txns-BIP30");
                 }
             }
         }
     }
 
     // Start enforcing BIP68 (sequence locks).
     int nLockTimeFlags = 0;
     if (pindex->nHeight >= consensusParams.CSVHeight) {
         nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
     }
 
     const uint32_t flags =
         GetNextBlockScriptFlags(consensusParams, pindex->pprev);
 
     int64_t nTime2 = GetTimeMicros();
     nTimeForks += nTime2 - nTime1;
     LogPrint(BCLog::BENCH, "    - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime2 - nTime1), nTimeForks * MICRO,
              nTimeForks * MILLI / nBlocksTotal);
 
     CBlockUndo blockundo;
 
     CCheckQueueControl<CScriptCheck> control(fScriptChecks ? &scriptcheckqueue
                                                            : nullptr);
 
     std::vector<int> prevheights;
     Amount nFees = Amount::zero();
     int nInputs = 0;
 
     // Sigops counting. We need to do it again because of P2SH.
     uint64_t nSigOpsCount = 0;
     const uint64_t currentBlockSize =
         ::GetSerializeSize(block, PROTOCOL_VERSION);
     const uint64_t nMaxSigOpsCount = GetMaxBlockSigOpsCount(currentBlockSize);
 
     blockundo.vtxundo.reserve(block.vtx.size() - 1);
 
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
 
         nInputs += tx.vin.size();
 
         if (tx.IsCoinBase()) {
             // We've already checked for sigops count before P2SH in CheckBlock.
             nSigOpsCount += GetSigOpCountWithoutP2SH(tx, flags);
         }
 
         // We do not need to throw when a transaction is duplicated. If they are
         // in the same block, CheckBlock will catch it, and if they are in a
         // different block, it'll register as a double spend or BIP30 violation.
         // In both cases, we get a more meaningful feedback out of it.
         AddCoins(view, tx, pindex->nHeight, true);
     }
 
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         if (tx.IsCoinBase()) {
             continue;
         }
 
         Amount txfee = Amount::zero();
         if (!Consensus::CheckTxInputs(tx, state, view, pindex->nHeight,
                                       txfee)) {
             return error("%s: Consensus::CheckTxInputs: %s, %s", __func__,
                          tx.GetId().ToString(), FormatStateMessage(state));
         }
         nFees += txfee;
         if (!MoneyRange(nFees)) {
             return state.DoS(
                 100,
                 error("%s: accumulated fee in the block out of range.",
                       __func__),
                 REJECT_INVALID, "bad-txns-accumulated-fee-outofrange");
         }
 
         // Check that transaction is BIP68 final BIP68 lock checks (as
         // opposed to nLockTime checks) must be in ConnectBlock because they
         // require the UTXO set.
         prevheights.resize(tx.vin.size());
         for (size_t j = 0; j < tx.vin.size(); j++) {
             prevheights[j] = view.AccessCoin(tx.vin[j].prevout).GetHeight();
         }
 
         if (!SequenceLocks(tx, nLockTimeFlags, &prevheights, *pindex)) {
             return state.DoS(
                 100,
                 error("%s: contains a non-BIP68-final transaction", __func__),
                 REJECT_INVALID, "bad-txns-nonfinal");
         }
 
         // GetTransactionSigOpCount counts 2 types of sigops:
         // * legacy (always)
         // * p2sh (when P2SH enabled in flags and excludes coinbase)
         auto txSigOpsCount = GetTransactionSigOpCount(tx, view, flags);
         if (txSigOpsCount > MAX_TX_SIGOPS_COUNT) {
             return state.DoS(100, false, REJECT_INVALID, "bad-txn-sigops");
         }
 
         nSigOpsCount += txSigOpsCount;
         if (nSigOpsCount > nMaxSigOpsCount) {
             return state.DoS(100, error("ConnectBlock(): too many sigops"),
                              REJECT_INVALID, "bad-blk-sigops");
         }
 
         // Don't cache results if we're actually connecting blocks (still
         // consult the cache, though).
         bool fCacheResults = fJustCheck;
 
         std::vector<CScriptCheck> vChecks;
         if (!CheckInputs(tx, state, view, fScriptChecks, flags, fCacheResults,
                          fCacheResults, PrecomputedTransactionData(tx),
                          &vChecks)) {
             return error("ConnectBlock(): CheckInputs on %s failed with %s",
                          tx.GetId().ToString(), FormatStateMessage(state));
         }
 
         control.Add(vChecks);
 
         blockundo.vtxundo.push_back(CTxUndo());
         SpendCoins(view, tx, blockundo.vtxundo.back(), pindex->nHeight);
     }
 
     int64_t nTime3 = GetTimeMicros();
     nTimeConnect += nTime3 - nTime2;
     LogPrint(BCLog::BENCH,
              "      - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) "
              "[%.2fs (%.2fms/blk)]\n",
              (unsigned)block.vtx.size(), MILLI * (nTime3 - nTime2),
              MILLI * (nTime3 - nTime2) / block.vtx.size(),
              nInputs <= 1 ? 0 : MILLI * (nTime3 - nTime2) / (nInputs - 1),
              nTimeConnect * MICRO, nTimeConnect * MILLI / nBlocksTotal);
 
     Amount blockReward =
         nFees + GetBlockSubsidy(pindex->nHeight, consensusParams);
     if (block.vtx[0]->GetValueOut() > blockReward) {
         return state.DoS(100,
                          error("ConnectBlock(): coinbase pays too much "
                                "(actual=%d vs limit=%d)",
                                block.vtx[0]->GetValueOut(), blockReward),
                          REJECT_INVALID, "bad-cb-amount");
     }
 
     if (!control.Wait()) {
         return state.DoS(100, false, REJECT_INVALID, "blk-bad-inputs", false,
                          "parallel script check failed");
     }
 
     int64_t nTime4 = GetTimeMicros();
     nTimeVerify += nTime4 - nTime2;
     LogPrint(
         BCLog::BENCH,
         "    - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n",
         nInputs - 1, MILLI * (nTime4 - nTime2),
         nInputs <= 1 ? 0 : MILLI * (nTime4 - nTime2) / (nInputs - 1),
         nTimeVerify * MICRO, nTimeVerify * MILLI / nBlocksTotal);
 
     if (fJustCheck) {
         return true;
     }
 
     if (!WriteUndoDataForBlock(blockundo, state, pindex, params)) {
         return false;
     }
 
     if (!pindex->IsValid(BlockValidity::SCRIPTS)) {
         pindex->RaiseValidity(BlockValidity::SCRIPTS);
         setDirtyBlockIndex.insert(pindex);
     }
 
     assert(pindex->phashBlock);
     // add this block to the view's block chain
     view.SetBestBlock(pindex->GetBlockHash());
 
     int64_t nTime5 = GetTimeMicros();
     nTimeIndex += nTime5 - nTime4;
     LogPrint(BCLog::BENCH, "    - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime5 - nTime4), nTimeIndex * MICRO,
              nTimeIndex * MILLI / nBlocksTotal);
 
     int64_t nTime6 = GetTimeMicros();
     nTimeCallbacks += nTime6 - nTime5;
     LogPrint(BCLog::BENCH, "    - Callbacks: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime6 - nTime5), nTimeCallbacks * MICRO,
              nTimeCallbacks * MILLI / nBlocksTotal);
 
     return true;
 }
 
 /**
  * Update the on-disk chain state.
  * The caches and indexes are flushed depending on the mode we're called with if
  * they're too large, if it's been a while since the last write, or always and
  * in all cases if we're in prune mode and are deleting files.
  *
  * If FlushStateMode::NONE is used, then FlushStateToDisk(...) won't do anything
  * besides checking if we need to prune.
  */
 static bool FlushStateToDisk(const CChainParams &chainparams,
                              CValidationState &state, FlushStateMode mode,
                              int nManualPruneHeight) {
     int64_t nMempoolUsage = g_mempool.DynamicMemoryUsage();
     LOCK(cs_main);
     static int64_t nLastWrite = 0;
     static int64_t nLastFlush = 0;
     std::set<int> setFilesToPrune;
     bool full_flush_completed = false;
     try {
         {
             bool fFlushForPrune = false;
             bool fDoFullFlush = false;
             LOCK(cs_LastBlockFile);
             if (fPruneMode && (fCheckForPruning || nManualPruneHeight > 0) &&
                 !fReindex) {
                 if (nManualPruneHeight > 0) {
                     FindFilesToPruneManual(setFilesToPrune, nManualPruneHeight);
                 } else {
                     FindFilesToPrune(setFilesToPrune,
                                      chainparams.PruneAfterHeight());
                     fCheckForPruning = false;
                 }
                 if (!setFilesToPrune.empty()) {
                     fFlushForPrune = true;
                     if (!fHavePruned) {
                         pblocktree->WriteFlag("prunedblockfiles", true);
                         fHavePruned = true;
                     }
                 }
             }
             int64_t nNow = GetTimeMicros();
             // Avoid writing/flushing immediately after startup.
             if (nLastWrite == 0) {
                 nLastWrite = nNow;
             }
             if (nLastFlush == 0) {
                 nLastFlush = nNow;
             }
             int64_t nMempoolSizeMax =
                 gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000;
             int64_t cacheSize = pcoinsTip->DynamicMemoryUsage();
             int64_t nTotalSpace =
                 nCoinCacheUsage +
                 std::max<int64_t>(nMempoolSizeMax - nMempoolUsage, 0);
             // The cache is large and we're within 10% and 10 MiB of the limit,
             // but we have time now (not in the middle of a block processing).
             bool fCacheLarge =
                 mode == FlushStateMode::PERIODIC &&
                 cacheSize > std::max((9 * nTotalSpace) / 10,
                                      nTotalSpace -
                                          MAX_BLOCK_COINSDB_USAGE * 1024 * 1024);
             // The cache is over the limit, we have to write now.
             bool fCacheCritical =
                 mode == FlushStateMode::IF_NEEDED && cacheSize > nTotalSpace;
             // It's been a while since we wrote the block index to disk. Do this
             // frequently, so we don't need to redownload after a crash.
             bool fPeriodicWrite =
                 mode == FlushStateMode::PERIODIC &&
                 nNow > nLastWrite + (int64_t)DATABASE_WRITE_INTERVAL * 1000000;
             // It's been very long since we flushed the cache. Do this
             // infrequently, to optimize cache usage.
             bool fPeriodicFlush =
                 mode == FlushStateMode::PERIODIC &&
                 nNow > nLastFlush + (int64_t)DATABASE_FLUSH_INTERVAL * 1000000;
             // Combine all conditions that result in a full cache flush.
             fDoFullFlush = (mode == FlushStateMode::ALWAYS) || fCacheLarge ||
                            fCacheCritical || fPeriodicFlush || fFlushForPrune;
             // Write blocks and block index to disk.
             if (fDoFullFlush || fPeriodicWrite) {
                 // Depend on nMinDiskSpace to ensure we can write block index
                 if (!CheckDiskSpace(GetBlocksDir())) {
                     return AbortNode(state, "Disk space is low!",
                                      _("Error: Disk space is low!"));
                 }
 
                 // First make sure all block and undo data is flushed to disk.
                 FlushBlockFile();
                 // Then update all block file information (which may refer to
                 // block and undo files).
                 {
                     std::vector<std::pair<int, const CBlockFileInfo *>> vFiles;
                     vFiles.reserve(setDirtyFileInfo.size());
                     for (int i : setDirtyFileInfo) {
                         vFiles.push_back(std::make_pair(i, &vinfoBlockFile[i]));
                     }
 
                     setDirtyFileInfo.clear();
 
                     std::vector<const CBlockIndex *> vBlocks;
                     vBlocks.reserve(setDirtyBlockIndex.size());
                     for (const CBlockIndex *cbi : setDirtyBlockIndex) {
                         vBlocks.push_back(cbi);
                     }
 
                     setDirtyBlockIndex.clear();
 
                     if (!pblocktree->WriteBatchSync(vFiles, nLastBlockFile,
                                                     vBlocks)) {
                         return AbortNode(
                             state, "Failed to write to block index database");
                     }
                 }
 
                 // Finally remove any pruned files
                 if (fFlushForPrune) {
                     UnlinkPrunedFiles(setFilesToPrune);
                 }
                 nLastWrite = nNow;
             }
             // Flush best chain related state. This can only be done if the
             // blocks / block index write was also done.
             if (fDoFullFlush && !pcoinsTip->GetBestBlock().IsNull()) {
                 // Typical Coin structures on disk are around 48 bytes in size.
                 // Pushing a new one to the database can cause it to be written
                 // twice (once in the log, and once in the tables). This is
                 // already an overestimation, as most will delete an existing
                 // entry or overwrite one. Still, use a conservative safety
                 // factor of 2.
                 if (!CheckDiskSpace(GetDataDir(),
                                     48 * 2 * 2 * pcoinsTip->GetCacheSize())) {
                     return AbortNode(state, "Disk space is low!",
                                      _("Error: Disk space is low!"));
                 }
 
                 // Flush the chainstate (which may refer to block index
                 // entries).
                 if (!pcoinsTip->Flush()) {
                     return AbortNode(state, "Failed to write to coin database");
                 }
                 nLastFlush = nNow;
                 full_flush_completed = true;
             }
         }
 
         if (full_flush_completed) {
             // Update best block in wallet (so we can detect restored wallets).
             GetMainSignals().ChainStateFlushed(chainActive.GetLocator());
         }
     } catch (const std::runtime_error &e) {
         return AbortNode(state, std::string("System error while flushing: ") +
                                     e.what());
     }
     return true;
 }
 
 void FlushStateToDisk() {
     CValidationState state;
     const CChainParams &chainparams = Params();
     if (!FlushStateToDisk(chainparams, state, FlushStateMode::ALWAYS)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   FormatStateMessage(state));
     }
 }
 
 void PruneAndFlush() {
     CValidationState state;
     fCheckForPruning = true;
     const CChainParams &chainparams = Params();
     if (!FlushStateToDisk(chainparams, state, FlushStateMode::NONE)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   FormatStateMessage(state));
     }
 }
 
 /** Check warning conditions and do some notifications on new chain tip set. */
 static void UpdateTip(const Config &config, CBlockIndex *pindexNew) {
     // New best block
     g_mempool.AddTransactionsUpdated(1);
 
     {
         LOCK(g_best_block_mutex);
         g_best_block = pindexNew->GetBlockHash();
         g_best_block_cv.notify_all();
     }
 
     LogPrintf(
         "%s: new best=%s height=%d version=0x%08x log2_work=%.8g tx=%lu "
         "date='%s' progress=%f cache=%.1fMiB(%utxo)\n",
         __func__, pindexNew->GetBlockHash().ToString(), pindexNew->nHeight,
         pindexNew->nVersion, log(pindexNew->nChainWork.getdouble()) / log(2.0),
         (unsigned long)pindexNew->nChainTx,
         FormatISO8601DateTime(pindexNew->GetBlockTime()),
         GuessVerificationProgress(config.GetChainParams().TxData(), pindexNew),
         pcoinsTip->DynamicMemoryUsage() * (1.0 / (1 << 20)),
         pcoinsTip->GetCacheSize());
 }
 
 /**
  * Disconnect chainActive's tip.
  * After calling, the mempool will be in an inconsistent state, with
  * transactions from disconnected blocks being added to disconnectpool. You
  * should make the mempool consistent again by calling updateMempoolForReorg.
  * with cs_main held.
  *
  * If disconnectpool is nullptr, then no disconnected transactions are added to
  * disconnectpool (note that the caller is responsible for mempool consistency
  * in any case).
  */
 bool CChainState::DisconnectTip(const Config &config, CValidationState &state,
                                 DisconnectedBlockTransactions *disconnectpool) {
     AssertLockHeld(cs_main);
     CBlockIndex *pindexDelete = chainActive.Tip();
     const Consensus::Params &consensusParams =
         config.GetChainParams().GetConsensus();
 
     assert(pindexDelete);
 
     // Read block from disk.
     std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
     CBlock &block = *pblock;
     if (!ReadBlockFromDisk(block, pindexDelete, consensusParams)) {
         return AbortNode(state, "Failed to read block");
     }
 
     // Apply the block atomically to the chain state.
     int64_t nStart = GetTimeMicros();
     {
         CCoinsViewCache view(pcoinsTip.get());
         assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
         if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK) {
             return error("DisconnectTip(): DisconnectBlock %s failed",
                          pindexDelete->GetBlockHash().ToString());
         }
 
         bool flushed = view.Flush();
         assert(flushed);
     }
 
     LogPrint(BCLog::BENCH, "- Disconnect block: %.2fms\n",
              (GetTimeMicros() - nStart) * MILLI);
 
     // Write the chain state to disk, if necessary.
     if (!FlushStateToDisk(config.GetChainParams(), state,
                           FlushStateMode::IF_NEEDED)) {
         return false;
     }
 
     // If this block is deactivating a fork, we move all mempool transactions
     // in front of disconnectpool for reprocessing in a future
     // updateMempoolForReorg call
     if (pindexDelete->pprev != nullptr &&
         GetNextBlockScriptFlags(consensusParams, pindexDelete) !=
             GetNextBlockScriptFlags(consensusParams, pindexDelete->pprev)) {
         LogPrint(BCLog::MEMPOOL,
                  "Disconnecting mempool due to rewind of upgrade block\n");
         if (disconnectpool) {
             disconnectpool->importMempool(g_mempool);
         }
         g_mempool.clear();
     }
 
     if (disconnectpool) {
         disconnectpool->addForBlock(block.vtx);
     }
 
     // If the tip is finalized, then undo it.
     if (pindexFinalized == pindexDelete) {
         pindexFinalized = pindexDelete->pprev;
     }
 
     chainActive.SetTip(pindexDelete->pprev);
 
     // Update chainActive and related variables.
     UpdateTip(config, pindexDelete->pprev);
     // Let wallets know transactions went from 1-confirmed to
     // 0-confirmed or conflicted:
     GetMainSignals().BlockDisconnected(pblock);
     return true;
 }
 
 static int64_t nTimeReadFromDisk = 0;
 static int64_t nTimeConnectTotal = 0;
 static int64_t nTimeFlush = 0;
 static int64_t nTimeChainState = 0;
 static int64_t nTimePostConnect = 0;
 
 struct PerBlockConnectTrace {
     CBlockIndex *pindex = nullptr;
     std::shared_ptr<const CBlock> pblock;
     std::shared_ptr<std::vector<CTransactionRef>> conflictedTxs;
     PerBlockConnectTrace()
         : conflictedTxs(std::make_shared<std::vector<CTransactionRef>>()) {}
 };
 
 /**
  * Used to track blocks whose transactions were applied to the UTXO state as a
  * part of a single ActivateBestChainStep call.
  *
  * This class also tracks transactions that are removed from the mempool as
  * conflicts (per block) and can be used to pass all those transactions through
  * SyncTransaction.
  *
  * This class assumes (and asserts) that the conflicted transactions for a given
  * block are added via mempool callbacks prior to the BlockConnected()
  * associated with those transactions. If any transactions are marked
  * conflicted, it is assumed that an associated block will always be added.
  *
  * This class is single-use, once you call GetBlocksConnected() you have to
  * throw it away and make a new one.
  */
 class ConnectTrace {
 private:
     std::vector<PerBlockConnectTrace> blocksConnected;
     CTxMemPool &pool;
     boost::signals2::scoped_connection m_connNotifyEntryRemoved;
 
 public:
     explicit ConnectTrace(CTxMemPool &_pool) : blocksConnected(1), pool(_pool) {
         m_connNotifyEntryRemoved = pool.NotifyEntryRemoved.connect(
             std::bind(&ConnectTrace::NotifyEntryRemoved, this,
                       std::placeholders::_1, std::placeholders::_2));
     }
 
     void BlockConnected(CBlockIndex *pindex,
                         std::shared_ptr<const CBlock> pblock) {
         assert(!blocksConnected.back().pindex);
         assert(pindex);
         assert(pblock);
         blocksConnected.back().pindex = pindex;
         blocksConnected.back().pblock = std::move(pblock);
         blocksConnected.emplace_back();
     }
 
     std::vector<PerBlockConnectTrace> &GetBlocksConnected() {
         // We always keep one extra block at the end of our list because blocks
         // are added after all the conflicted transactions have been filled in.
         // Thus, the last entry should always be an empty one waiting for the
         // transactions from the next block. We pop the last entry here to make
         // sure the list we return is sane.
         assert(!blocksConnected.back().pindex);
         assert(blocksConnected.back().conflictedTxs->empty());
         blocksConnected.pop_back();
         return blocksConnected;
     }
 
     void NotifyEntryRemoved(CTransactionRef txRemoved,
                             MemPoolRemovalReason reason) {
         assert(!blocksConnected.back().pindex);
         if (reason == MemPoolRemovalReason::CONFLICT) {
             blocksConnected.back().conflictedTxs->emplace_back(
                 std::move(txRemoved));
         }
     }
 };
 
 static bool FinalizeBlockInternal(const Config &config, CValidationState &state,
                                   const CBlockIndex *pindex)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
     if (pindex->nStatus.isInvalid()) {
         // We try to finalize an invalid block.
         return state.DoS(100,
                          error("%s: Trying to finalize invalid block %s",
                                __func__, pindex->GetBlockHash().ToString()),
                          REJECT_INVALID, "finalize-invalid-block");
     }
 
     // Check that the request is consistent with current finalization.
     if (pindexFinalized && !AreOnTheSameFork(pindex, pindexFinalized)) {
         return state.DoS(
             20,
             error("%s: Trying to finalize block %s which conflicts "
                   "with already finalized block",
                   __func__, pindex->GetBlockHash().ToString()),
             REJECT_AGAINST_FINALIZED, "bad-fork-prior-finalized");
     }
 
     if (IsBlockFinalized(pindex)) {
         // The block is already finalized.
         return true;
     }
 
     // We have a new block to finalize.
     pindexFinalized = pindex;
     return true;
 }
 
 static const CBlockIndex *FindBlockToFinalize(const Config &config,
                                               CBlockIndex *pindexNew)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     AssertLockHeld(cs_main);
 
     const int32_t maxreorgdepth =
         gArgs.GetArg("-maxreorgdepth", DEFAULT_MAX_REORG_DEPTH);
 
     const int64_t finalizationdelay =
         gArgs.GetArg("-finalizationdelay", DEFAULT_MIN_FINALIZATION_DELAY);
 
     // Find our candidate.
     // If maxreorgdepth is < 0 pindex will be null and auto finalization
     // disabled
     const CBlockIndex *pindex =
         pindexNew->GetAncestor(pindexNew->nHeight - maxreorgdepth);
 
     int64_t now = GetTime();
 
     // If the finalization delay is not expired since the startup time,
     // finalization should be avoided. Header receive time is not saved to disk
     // and so cannot be anterior to startup time.
     if (now < (GetStartupTime() + finalizationdelay)) {
         return nullptr;
     }
 
     // While our candidate is not eligible (finalization delay not expired), try
     // the previous one.
     while (pindex && (pindex != pindexFinalized)) {
         // Check that the block to finalize is known for a long enough time.
         // This test will ensure that an attacker could not cause a block to
         // finalize by forking the chain with a depth > maxreorgdepth.
         // If the block is loaded from disk, header receive time is 0 and the
         // block will be finalized. This is safe because the delay since the
         // node startup is already expired.
         auto headerReceivedTime = pindex->GetHeaderReceivedTime();
 
         // If finalization delay is <= 0, finalization always occurs immediately
         if (now >= (headerReceivedTime + finalizationdelay)) {
             return pindex;
         }
 
         pindex = pindex->pprev;
     }
 
     return nullptr;
 }
 
 /**
  * Connect a new block to chainActive. pblock is either nullptr or a pointer to
  * a CBlock corresponding to pindexNew, to bypass loading it again from disk.
  *
  * The block is always added to connectTrace (either after loading from disk or
  * by copying pblock) - if that is not intended, care must be taken to remove
  * the last entry in blocksConnected in case of failure.
  */
 bool CChainState::ConnectTip(const Config &config, CValidationState &state,
                              CBlockIndex *pindexNew,
                              const std::shared_ptr<const CBlock> &pblock,
                              ConnectTrace &connectTrace,
                              DisconnectedBlockTransactions &disconnectpool) {
     AssertLockHeld(cs_main);
 
     const CChainParams &params = config.GetChainParams();
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     assert(pindexNew->pprev == chainActive.Tip());
     // Read block from disk.
     int64_t nTime1 = GetTimeMicros();
     std::shared_ptr<const CBlock> pthisBlock;
     if (!pblock) {
         std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
         if (!ReadBlockFromDisk(*pblockNew, pindexNew, consensusParams)) {
             return AbortNode(state, "Failed to read block");
         }
         pthisBlock = pblockNew;
     } else {
         pthisBlock = pblock;
     }
 
     const CBlock &blockConnecting = *pthisBlock;
 
     // Apply the block atomically to the chain state.
     int64_t nTime2 = GetTimeMicros();
     nTimeReadFromDisk += nTime2 - nTime1;
     int64_t nTime3;
     LogPrint(BCLog::BENCH, "  - Load block from disk: %.2fms [%.2fs]\n",
              (nTime2 - nTime1) * MILLI, nTimeReadFromDisk * MICRO);
     {
         CCoinsViewCache view(pcoinsTip.get());
         bool rv = ConnectBlock(blockConnecting, state, pindexNew, view, params,
                                BlockValidationOptions(config));
         GetMainSignals().BlockChecked(blockConnecting, state);
         if (!rv) {
             if (state.IsInvalid()) {
                 InvalidBlockFound(pindexNew, state);
             }
 
             return error("ConnectTip(): ConnectBlock %s failed (%s)",
                          pindexNew->GetBlockHash().ToString(),
                          FormatStateMessage(state));
         }
 
         // Update the finalized block.
         const CBlockIndex *pindexToFinalize =
             FindBlockToFinalize(config, pindexNew);
         if (pindexToFinalize &&
             !FinalizeBlockInternal(config, state, pindexToFinalize)) {
             state.SetCorruptionPossible();
             return error("ConnectTip(): FinalizeBlock %s failed (%s)",
                          pindexNew->GetBlockHash().ToString(),
                          FormatStateMessage(state));
         }
 
         nTime3 = GetTimeMicros();
         nTimeConnectTotal += nTime3 - nTime2;
         LogPrint(BCLog::BENCH,
                  "  - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n",
                  (nTime3 - nTime2) * MILLI, nTimeConnectTotal * MICRO,
                  nTimeConnectTotal * MILLI / nBlocksTotal);
         bool flushed = view.Flush();
         assert(flushed);
     }
 
     int64_t nTime4 = GetTimeMicros();
     nTimeFlush += nTime4 - nTime3;
     LogPrint(BCLog::BENCH, "  - Flush: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime4 - nTime3) * MILLI, nTimeFlush * MICRO,
              nTimeFlush * MILLI / nBlocksTotal);
 
     // Write the chain state to disk, if necessary.
     if (!FlushStateToDisk(config.GetChainParams(), state,
                           FlushStateMode::IF_NEEDED)) {
         return false;
     }
 
     int64_t nTime5 = GetTimeMicros();
     nTimeChainState += nTime5 - nTime4;
     LogPrint(BCLog::BENCH,
              "  - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime5 - nTime4) * MILLI, nTimeChainState * MICRO,
              nTimeChainState * MILLI / nBlocksTotal);
 
     // Remove conflicting transactions from the mempool.;
     g_mempool.removeForBlock(blockConnecting.vtx, pindexNew->nHeight);
     disconnectpool.removeForBlock(blockConnecting.vtx);
 
     // If this block is activating a fork, we move all mempool transactions
     // in front of disconnectpool for reprocessing in a future
     // updateMempoolForReorg call
     if (pindexNew->pprev != nullptr &&
         GetNextBlockScriptFlags(consensusParams, pindexNew) !=
             GetNextBlockScriptFlags(consensusParams, pindexNew->pprev)) {
         LogPrint(BCLog::MEMPOOL,
                  "Disconnecting mempool due to acceptance of upgrade block\n");
         disconnectpool.importMempool(g_mempool);
     }
 
     // Update chainActive & related variables.
     chainActive.SetTip(pindexNew);
     UpdateTip(config, pindexNew);
 
     int64_t nTime6 = GetTimeMicros();
     nTimePostConnect += nTime6 - nTime5;
     nTimeTotal += nTime6 - nTime1;
     LogPrint(BCLog::BENCH,
              "  - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime6 - nTime5) * MILLI, nTimePostConnect * MICRO,
              nTimePostConnect * MILLI / nBlocksTotal);
     LogPrint(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime6 - nTime1) * MILLI, nTimeTotal * MICRO,
              nTimeTotal * MILLI / nBlocksTotal);
 
     connectTrace.BlockConnected(pindexNew, std::move(pthisBlock));
     return true;
 }
 
 /**
  * Return the tip of the chain with the most work in it, that isn't known to be
  * invalid (it's however far from certain to be valid).
  */
 CBlockIndex *CChainState::FindMostWorkChain() {
     AssertLockHeld(cs_main);
     do {
         CBlockIndex *pindexNew = nullptr;
 
         // Find the best candidate header.
         {
             std::set<CBlockIndex *, CBlockIndexWorkComparator>::reverse_iterator
                 it = setBlockIndexCandidates.rbegin();
             if (it == setBlockIndexCandidates.rend()) {
                 return nullptr;
             }
             pindexNew = *it;
         }
 
         // If this block will cause a finalized block to be reorged, then we
         // mark it as invalid.
         if (pindexFinalized && !AreOnTheSameFork(pindexNew, pindexFinalized)) {
             LogPrintf("Mark block %s invalid because it forks prior to the "
                       "finalization point %d.\n",
                       pindexNew->GetBlockHash().ToString(),
                       pindexFinalized->nHeight);
             pindexNew->nStatus = pindexNew->nStatus.withFailed();
             InvalidChainFound(pindexNew);
         }
 
         const CBlockIndex *pindexFork = chainActive.FindFork(pindexNew);
 
         // Check whether all blocks on the path between the currently active
         // chain and the candidate are valid. Just going until the active chain
         // is an optimization, as we know all blocks in it are valid already.
         CBlockIndex *pindexTest = pindexNew;
         bool hasValidAncestor = true;
         while (hasValidAncestor && pindexTest && pindexTest != pindexFork) {
             assert(pindexTest->nChainTx || pindexTest->nHeight == 0);
 
             // If this is a parked chain, but it has enough PoW, clear the park
             // state.
             bool fParkedChain = pindexTest->nStatus.isOnParkedChain();
             if (fParkedChain && gArgs.GetBoolArg("-parkdeepreorg", true)) {
                 const CBlockIndex *pindexTip = chainActive.Tip();
 
                 // During initialization, pindexTip and/or pindexFork may be
                 // null. In this case, we just ignore the fact that the chain is
                 // parked.
                 if (!pindexTip || !pindexFork) {
                     UnparkBlock(pindexTest);
                     continue;
                 }
 
                 // A parked chain can be unparked if it has twice as much PoW
                 // accumulated as the main chain has since the fork block.
                 CBlockIndex const *pindexExtraPow = pindexTip;
                 arith_uint256 requiredWork = pindexTip->nChainWork;
                 switch (pindexTip->nHeight - pindexFork->nHeight) {
                     // Limit the penality for depth 1, 2 and 3 to half a block
                     // worth of work to ensure we don't fork accidentally.
                     case 3:
                     case 2:
                         pindexExtraPow = pindexExtraPow->pprev;
                     // FALLTHROUGH
                     case 1: {
                         const arith_uint256 deltaWork =
                             pindexExtraPow->nChainWork - pindexFork->nChainWork;
                         requiredWork += (deltaWork >> 1);
                         break;
                     }
                     default:
                         requiredWork +=
                             pindexExtraPow->nChainWork - pindexFork->nChainWork;
                         break;
                 }
 
                 if (pindexNew->nChainWork > requiredWork) {
                     // We have enough, clear the parked state.
                     LogPrintf("Unpark block %s as its chain has accumulated "
                               "enough PoW.\n",
                               pindexTest->GetBlockHash().ToString());
                     fParkedChain = false;
                     UnparkBlock(pindexTest);
                 }
             }
 
             // Pruned nodes may have entries in setBlockIndexCandidates for
             // which block files have been deleted. Remove those as candidates
             // for the most work chain if we come across them; we can't switch
             // to a chain unless we have all the non-active-chain parent blocks.
             bool fInvalidChain = pindexTest->nStatus.isInvalid();
             bool fMissingData = !pindexTest->nStatus.hasData();
             if (!(fInvalidChain || fParkedChain || fMissingData)) {
                 // The current block is acceptable, move to the parent, up to
                 // the fork point.
                 pindexTest = pindexTest->pprev;
                 continue;
             }
 
             // Candidate chain is not usable (either invalid or missing data)
             hasValidAncestor = false;
             setBlockIndexCandidates.erase(pindexTest);
 
             if (fInvalidChain &&
                 (pindexBestInvalid == nullptr ||
                  pindexNew->nChainWork > pindexBestInvalid->nChainWork)) {
                 pindexBestInvalid = pindexNew;
             }
 
             if (fParkedChain &&
                 (pindexBestParked == nullptr ||
                  pindexNew->nChainWork > pindexBestParked->nChainWork)) {
                 pindexBestParked = pindexNew;
             }
 
             CBlockIndex *pindexFailed = pindexNew;
             // Remove the entire chain from the set.
             while (pindexTest != pindexFailed) {
                 if (fInvalidChain || fParkedChain) {
                     pindexFailed->nStatus =
                         pindexFailed->nStatus.withFailedParent(fInvalidChain)
                             .withParkedParent(fParkedChain);
                 } else if (fMissingData) {
                     // If we're missing data, then add back to
                     // mapBlocksUnlinked, so that if the block arrives in the
                     // future we can try adding to setBlockIndexCandidates
                     // again.
                     mapBlocksUnlinked.insert(
                         std::make_pair(pindexFailed->pprev, pindexFailed));
                 }
                 setBlockIndexCandidates.erase(pindexFailed);
                 pindexFailed = pindexFailed->pprev;
             }
 
             if (fInvalidChain || fParkedChain) {
                 // We discovered a new chain tip that is either parked or
                 // invalid, we may want to warn.
                 CheckForkWarningConditionsOnNewFork(pindexNew);
             }
         }
 
         // We found a candidate that has valid ancestors. This is our guy.
         if (hasValidAncestor) {
             return pindexNew;
         }
     } while (true);
 }
 
 /**
  * Delete all entries in setBlockIndexCandidates that are worse than the current
  * tip.
  */
 void CChainState::PruneBlockIndexCandidates() {
     // Note that we can't delete the current block itself, as we may need to
     // return to it later in case a reorganization to a better block fails.
     auto it = setBlockIndexCandidates.begin();
     while (it != setBlockIndexCandidates.end() &&
            setBlockIndexCandidates.value_comp()(*it, chainActive.Tip())) {
         setBlockIndexCandidates.erase(it++);
     }
 
     // Either the current tip or a successor of it we're working towards is left
     // in setBlockIndexCandidates.
     assert(!setBlockIndexCandidates.empty());
 }
 
 /**
  * Try to make some progress towards making pindexMostWork the active block.
  * pblock is either nullptr or a pointer to a CBlock corresponding to
  * pindexMostWork.
  */
 bool CChainState::ActivateBestChainStep(
     const Config &config, CValidationState &state, CBlockIndex *pindexMostWork,
     const std::shared_ptr<const CBlock> &pblock, bool &fInvalidFound,
     ConnectTrace &connectTrace) {
     AssertLockHeld(cs_main);
 
     const CBlockIndex *pindexOldTip = chainActive.Tip();
     const CBlockIndex *pindexFork = chainActive.FindFork(pindexMostWork);
 
     // Disconnect active blocks which are no longer in the best chain.
     bool fBlocksDisconnected = false;
     DisconnectedBlockTransactions disconnectpool;
     while (chainActive.Tip() && chainActive.Tip() != pindexFork) {
         if (!DisconnectTip(config, state, &disconnectpool)) {
             // This is likely a fatal error, but keep the mempool consistent,
             // just in case. Only remove from the mempool in this case.
             disconnectpool.updateMempoolForReorg(config, false);
             return false;
         }
 
         fBlocksDisconnected = true;
     }
 
     // Build list of new blocks to connect.
     std::vector<CBlockIndex *> vpindexToConnect;
     bool fContinue = true;
     int nHeight = pindexFork ? pindexFork->nHeight : -1;
     while (fContinue && nHeight != pindexMostWork->nHeight) {
         // Don't iterate the entire list of potential improvements toward the
         // best tip, as we likely only need a few blocks along the way.
         int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight);
         vpindexToConnect.clear();
         vpindexToConnect.reserve(nTargetHeight - nHeight);
         CBlockIndex *pindexIter = pindexMostWork->GetAncestor(nTargetHeight);
         while (pindexIter && pindexIter->nHeight != nHeight) {
             vpindexToConnect.push_back(pindexIter);
             pindexIter = pindexIter->pprev;
         }
 
         nHeight = nTargetHeight;
 
         // Connect new blocks.
         for (CBlockIndex *pindexConnect : reverse_iterate(vpindexToConnect)) {
             if (!ConnectTip(config, state, pindexConnect,
                             pindexConnect == pindexMostWork
                                 ? pblock
                                 : std::shared_ptr<const CBlock>(),
                             connectTrace, disconnectpool)) {
                 if (state.IsInvalid()) {
                     // The block violates a consensus rule.
                     if (!state.CorruptionPossible()) {
                         InvalidChainFound(vpindexToConnect.back());
                     }
 
                     state = CValidationState();
                     fInvalidFound = true;
                     fContinue = false;
                     break;
                 }
 
                 // A system error occurred (disk space, database error, ...).
                 // Make the mempool consistent with the current tip, just in
                 // case any observers try to use it before shutdown.
                 disconnectpool.updateMempoolForReorg(config, false);
                 return false;
             } else {
                 PruneBlockIndexCandidates();
                 if (!pindexOldTip ||
                     chainActive.Tip()->nChainWork > pindexOldTip->nChainWork) {
                     // We're in a better position than we were. Return
                     // temporarily to release the lock.
                     fContinue = false;
                     break;
                 }
             }
         }
     }
 
     if (fBlocksDisconnected || !disconnectpool.isEmpty()) {
         // If any blocks were disconnected, we need to update the mempool even
         // if disconnectpool is empty. The disconnectpool may also be non-empty
         // if the mempool was imported due to new validation rules being in
         // effect.
         LogPrint(BCLog::MEMPOOL, "Updating mempool due to reorganization or "
                                  "rules upgrade/downgrade\n");
         disconnectpool.updateMempoolForReorg(config, true);
     }
 
     g_mempool.check(pcoinsTip.get());
 
     // Callbacks/notifications for a new best chain.
     if (fInvalidFound) {
         CheckForkWarningConditionsOnNewFork(pindexMostWork);
     } else {
         CheckForkWarningConditions();
     }
 
     return true;
 }
 
 static void NotifyHeaderTip() LOCKS_EXCLUDED(cs_main) {
     bool fNotify = false;
     bool fInitialBlockDownload = false;
     static CBlockIndex *pindexHeaderOld = nullptr;
     CBlockIndex *pindexHeader = nullptr;
     {
         LOCK(cs_main);
         pindexHeader = pindexBestHeader;
 
         if (pindexHeader != pindexHeaderOld) {
             fNotify = true;
             fInitialBlockDownload = IsInitialBlockDownload();
             pindexHeaderOld = pindexHeader;
         }
     }
 
     // Send block tip changed notifications without cs_main
     if (fNotify) {
         uiInterface.NotifyHeaderTip(fInitialBlockDownload, pindexHeader);
     }
 }
 
 /**
  * Make the best chain active, in multiple steps. The result is either failure
  * or an activated best chain. pblock is either nullptr or a pointer to a block
  * that is already loaded (to avoid loading it again from disk).
  *
  * ActivateBestChain is split into steps (see ActivateBestChainStep) so that
  * we avoid holding cs_main for an extended period of time; the length of this
  * call may be quite long during reindexing or a substantial reorg.
  */
 bool CChainState::ActivateBestChain(const Config &config,
                                     CValidationState &state,
                                     std::shared_ptr<const CBlock> pblock) {
     // Note that while we're often called here from ProcessNewBlock, this is
     // far from a guarantee. Things in the P2P/RPC will often end up calling
     // us in the middle of ProcessNewBlock - do not assume pblock is set
     // sanely for performance or correctness!
     AssertLockNotHeld(cs_main);
 
     // ABC maintains a fair degree of expensive-to-calculate internal state
     // because this function periodically releases cs_main so that it does not
     // lock up other threads for too long during large connects - and to allow
     // for e.g. the callback queue to drain we use m_cs_chainstate to enforce
     // mutual exclusion so that only one caller may execute this function at a
     // time
     LOCK(m_cs_chainstate);
 
     CBlockIndex *pindexMostWork = nullptr;
     CBlockIndex *pindexNewTip = nullptr;
     int nStopAtHeight = gArgs.GetArg("-stopatheight", DEFAULT_STOPATHEIGHT);
     do {
         boost::this_thread::interruption_point();
 
         if (GetMainSignals().CallbacksPending() > 10) {
             // Block until the validation queue drains. This should largely
             // never happen in normal operation, however may happen during
             // reindex, causing memory blowup if we run too far ahead.
             // Note that if a validationinterface callback ends up calling
             // ActivateBestChain this may lead to a deadlock! We should
             // probably have a DEBUG_LOCKORDER test for this in the future.
             SyncWithValidationInterfaceQueue();
         }
 
         {
             LOCK(cs_main);
             CBlockIndex *starting_tip = chainActive.Tip();
             bool blocks_connected = false;
             do {
                 // We absolutely may not unlock cs_main until we've made forward
                 // progress (with the exception of shutdown due to hardware
                 // issues, low disk space, etc).
 
                 // Destructed before cs_main is unlocked
                 ConnectTrace connectTrace(g_mempool);
 
                 if (pindexMostWork == nullptr) {
                     pindexMostWork = FindMostWorkChain();
                 }
 
                 // Whether we have anything to do at all.
                 if (pindexMostWork == nullptr ||
                     pindexMostWork == chainActive.Tip()) {
                     break;
                 }
 
                 bool fInvalidFound = false;
                 std::shared_ptr<const CBlock> nullBlockPtr;
                 if (!ActivateBestChainStep(
                         config, state, pindexMostWork,
                         pblock && pblock->GetHash() ==
                                       pindexMostWork->GetBlockHash()
                             ? pblock
                             : nullBlockPtr,
                         fInvalidFound, connectTrace)) {
                     return false;
                 }
                 blocks_connected = true;
 
                 if (fInvalidFound) {
                     // Wipe cache, we may need another branch now.
                     pindexMostWork = nullptr;
                 }
 
                 pindexNewTip = chainActive.Tip();
                 for (const PerBlockConnectTrace &trace :
                      connectTrace.GetBlocksConnected()) {
                     assert(trace.pblock && trace.pindex);
                     GetMainSignals().BlockConnected(trace.pblock, trace.pindex,
                                                     trace.conflictedTxs);
                 }
             } while (!chainActive.Tip() ||
                      (starting_tip && CBlockIndexWorkComparator()(
                                           chainActive.Tip(), starting_tip)));
 
             if (!blocks_connected) {
                 return true;
             }
 
             const CBlockIndex *pindexFork = chainActive.FindFork(starting_tip);
             bool fInitialDownload = IsInitialBlockDownload();
 
             // Notify external listeners about the new tip.
             // Enqueue while holding cs_main to ensure that UpdatedBlockTip is
             // called in the order in which blocks are connected
             if (pindexFork != pindexNewTip) {
                 // Notify ValidationInterface subscribers
                 GetMainSignals().UpdatedBlockTip(pindexNewTip, pindexFork,
                                                  fInitialDownload);
 
                 // Always notify the UI if a new block tip was connected
                 uiInterface.NotifyBlockTip(fInitialDownload, pindexNewTip);
             }
         }
         // When we reach this point, we switched to a new tip (stored in
         // pindexNewTip).
 
         if (nStopAtHeight && pindexNewTip &&
             pindexNewTip->nHeight >= nStopAtHeight) {
             StartShutdown();
         }
 
         // We check shutdown only after giving ActivateBestChainStep a chance to
         // run once so that we never shutdown before connecting the genesis
         // block during LoadChainTip(). Previously this caused an assert()
         // failure during shutdown in such cases as the UTXO DB flushing checks
         // that the best block hash is non-null.
         if (ShutdownRequested()) {
             break;
         }
     } while (pindexNewTip != pindexMostWork);
 
     const CChainParams &params = config.GetChainParams();
     CheckBlockIndex(params.GetConsensus());
 
     // Write changes periodically to disk, after relay.
     if (!FlushStateToDisk(params, state, FlushStateMode::PERIODIC)) {
         return false;
     }
 
     return true;
 }
 
 bool ActivateBestChain(const Config &config, CValidationState &state,
                        std::shared_ptr<const CBlock> pblock) {
     return g_chainstate.ActivateBestChain(config, state, std::move(pblock));
 }
 
 bool CChainState::PreciousBlock(const Config &config, CValidationState &state,
                                 CBlockIndex *pindex) {
     {
         LOCK(cs_main);
         if (pindex->nChainWork < chainActive.Tip()->nChainWork) {
             // Nothing to do, this block is not at the tip.
             return true;
         }
 
         if (chainActive.Tip()->nChainWork > nLastPreciousChainwork) {
             // The chain has been extended since the last call, reset the
             // counter.
             nBlockReverseSequenceId = -1;
         }
 
         nLastPreciousChainwork = chainActive.Tip()->nChainWork;
         setBlockIndexCandidates.erase(pindex);
         pindex->nSequenceId = nBlockReverseSequenceId;
         if (nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) {
             // We can't keep reducing the counter if somebody really wants to
             // call preciousblock 2**31-1 times on the same set of tips...
             nBlockReverseSequenceId--;
         }
 
         // In case this was parked, unpark it.
         UnparkBlock(pindex);
 
         // Make sure it is added to the candidate list if appropriate.
         if (pindex->IsValid(BlockValidity::TRANSACTIONS) && pindex->nChainTx) {
             setBlockIndexCandidates.insert(pindex);
             PruneBlockIndexCandidates();
         }
     }
 
     return ActivateBestChain(config, state);
 }
 
 bool PreciousBlock(const Config &config, CValidationState &state,
                    CBlockIndex *pindex) {
     return g_chainstate.PreciousBlock(config, state, pindex);
 }
 
 bool CChainState::UnwindBlock(const Config &config, CValidationState &state,
                               CBlockIndex *pindex, bool invalidate) {
     AssertLockHeld(cs_main);
 
     // We first disconnect backwards and then mark the blocks as invalid.
     // This prevents a case where pruned nodes may fail to invalidateblock
     // and be left unable to start as they have no tip candidates (as there
     // are no blocks that meet the "have data and are not invalid per
     // nStatus" criteria for inclusion in setBlockIndexCandidates).
 
     bool pindex_was_in_chain = false;
     CBlockIndex *invalid_walk_tip = chainActive.Tip();
 
     DisconnectedBlockTransactions disconnectpool;
     while (chainActive.Contains(pindex)) {
         pindex_was_in_chain = true;
         // ActivateBestChain considers blocks already in chainActive
         // unconditionally valid already, so force disconnect away from it.
         if (!DisconnectTip(config, state, &disconnectpool)) {
             // It's probably hopeless to try to make the mempool consistent
             // here if DisconnectTip failed, but we can try.
             disconnectpool.updateMempoolForReorg(config, false);
             return false;
         }
     }
 
     // Now mark the blocks we just disconnected as descendants invalid
     // (note this may not be all descendants).
     while (pindex_was_in_chain && invalid_walk_tip != pindex) {
         invalid_walk_tip->nStatus =
             invalidate ? invalid_walk_tip->nStatus.withFailedParent()
                        : invalid_walk_tip->nStatus.withParkedParent();
         setDirtyBlockIndex.insert(invalid_walk_tip);
         invalid_walk_tip = invalid_walk_tip->pprev;
     }
 
     // Mark the block as either invalid or parked.
     pindex->nStatus = invalidate ? pindex->nStatus.withFailed()
                                  : pindex->nStatus.withParked();
     setDirtyBlockIndex.insert(pindex);
     if (invalidate) {
         m_failed_blocks.insert(pindex);
     }
 
     // DisconnectTip will add transactions to disconnectpool; try to add these
     // back to the mempool.
     disconnectpool.updateMempoolForReorg(config, true);
 
     // The resulting new best tip may not be in setBlockIndexCandidates anymore,
     // so add it again.
     for (const std::pair<const BlockHash, CBlockIndex *> &it : mapBlockIndex) {
         CBlockIndex *i = it.second;
         if (i->IsValid(BlockValidity::TRANSACTIONS) && i->nChainTx &&
             !setBlockIndexCandidates.value_comp()(i, chainActive.Tip())) {
             setBlockIndexCandidates.insert(i);
         }
     }
 
     if (invalidate) {
         InvalidChainFound(pindex);
     }
 
     // Only notify about a new block tip if the active chain was modified.
     if (pindex_was_in_chain) {
         uiInterface.NotifyBlockTip(IsInitialBlockDownload(), pindex->pprev);
     }
     return true;
 }
 
 bool FinalizeBlockAndInvalidate(const Config &config, CValidationState &state,
                                 CBlockIndex *pindex) {
     AssertLockHeld(cs_main);
     if (!FinalizeBlockInternal(config, state, pindex)) {
         // state is set by FinalizeBlockInternal.
         return false;
     }
 
     // We have a valid candidate, make sure it is not parked.
     if (pindex->nStatus.isOnParkedChain()) {
         UnparkBlock(pindex);
     }
 
     // If the finalized block is not on the active chain, we need to rewind.
     if (!AreOnTheSameFork(pindex, chainActive.Tip())) {
         const CBlockIndex *pindexFork = chainActive.FindFork(pindex);
         CBlockIndex *pindexToInvalidate =
             chainActive.Tip()->GetAncestor(pindexFork->nHeight + 1);
         return InvalidateBlock(config, state, pindexToInvalidate);
     }
 
     return true;
 }
 
 bool InvalidateBlock(const Config &config, CValidationState &state,
                      CBlockIndex *pindex) {
     return g_chainstate.UnwindBlock(config, state, pindex, true);
 }
 
 bool ParkBlock(const Config &config, CValidationState &state,
                CBlockIndex *pindex) {
     return g_chainstate.UnwindBlock(config, state, pindex, false);
 }
 
 template <typename F>
 void CChainState::UpdateFlagsForBlock(CBlockIndex *pindexBase,
                                       CBlockIndex *pindex, F f) {
     BlockStatus newStatus = f(pindex->nStatus);
     if (pindex->nStatus != newStatus &&
         pindex->GetAncestor(pindexBase->nHeight) == pindexBase) {
         pindex->nStatus = newStatus;
         setDirtyBlockIndex.insert(pindex);
         if (newStatus.isValid()) {
             m_failed_blocks.erase(pindex);
         }
 
         if (pindex->IsValid(BlockValidity::TRANSACTIONS) && pindex->nChainTx &&
             setBlockIndexCandidates.value_comp()(chainActive.Tip(), pindex)) {
             setBlockIndexCandidates.insert(pindex);
         }
     }
 }
 
 template <typename F, typename C>
 void CChainState::UpdateFlags(CBlockIndex *pindex, F f, C fchild) {
     AssertLockHeld(cs_main);
 
     // Update the current block.
     UpdateFlagsForBlock(pindex, pindex, f);
 
     // Update the flags from this block and all its descendants.
     BlockMap::iterator it = mapBlockIndex.begin();
     while (it != mapBlockIndex.end()) {
         UpdateFlagsForBlock(pindex, it->second, fchild);
         it++;
     }
 
     // Update the flags from all ancestors too.
     while (pindex != nullptr) {
         BlockStatus newStatus = f(pindex->nStatus);
         if (pindex->nStatus != newStatus) {
             pindex->nStatus = newStatus;
             setDirtyBlockIndex.insert(pindex);
             if (newStatus.isValid()) {
                 m_failed_blocks.erase(pindex);
             }
         }
         pindex = pindex->pprev;
     }
 }
 
 template <typename F> void CChainState::UpdateFlags(CBlockIndex *pindex, F f) {
     // Handy shorthand.
     UpdateFlags(pindex, f, f);
 }
 
 void CChainState::ResetBlockFailureFlags(CBlockIndex *pindex) {
     AssertLockHeld(cs_main);
 
     if (pindexBestInvalid &&
         (pindexBestInvalid->GetAncestor(pindex->nHeight) == pindex ||
          pindex->GetAncestor(pindexBestInvalid->nHeight) ==
              pindexBestInvalid)) {
         // Reset the invalid block marker if it is about to be cleared.
         pindexBestInvalid = nullptr;
     }
 
     // In case we are reconsidering something before the finalization point,
     // move the finalization point to the last common ancestor.
     if (pindexFinalized) {
         pindexFinalized = LastCommonAncestor(pindex, pindexFinalized);
     }
 
     UpdateFlags(pindex, [](const BlockStatus status) {
         return status.withClearedFailureFlags();
     });
 }
 
 void ResetBlockFailureFlags(CBlockIndex *pindex) {
     return g_chainstate.ResetBlockFailureFlags(pindex);
 }
 
 void CChainState::UnparkBlockImpl(CBlockIndex *pindex, bool fClearChildren) {
     AssertLockHeld(cs_main);
 
     if (pindexBestParked &&
         (pindexBestParked->GetAncestor(pindex->nHeight) == pindex ||
          pindex->GetAncestor(pindexBestParked->nHeight) == pindexBestParked)) {
         // Reset the parked block marker if it is about to be cleared.
         pindexBestParked = nullptr;
     }
 
     UpdateFlags(
         pindex,
         [](const BlockStatus status) {
             return status.withClearedParkedFlags();
         },
         [fClearChildren](const BlockStatus status) {
             return fClearChildren ? status.withClearedParkedFlags()
                                   : status.withParkedParent(false);
         });
 }
 
 void UnparkBlockAndChildren(CBlockIndex *pindex) {
     return g_chainstate.UnparkBlockImpl(pindex, true);
 }
 
 void UnparkBlock(CBlockIndex *pindex) {
     return g_chainstate.UnparkBlockImpl(pindex, false);
 }
 
 const CBlockIndex *GetFinalizedBlock() {
     AssertLockHeld(cs_main);
     return pindexFinalized;
 }
 
 bool IsBlockFinalized(const CBlockIndex *pindex) {
     AssertLockHeld(cs_main);
     return pindexFinalized &&
            pindexFinalized->GetAncestor(pindex->nHeight) == pindex;
 }
 
 CBlockIndex *CChainState::AddToBlockIndex(const CBlockHeader &block) {
     AssertLockHeld(cs_main);
 
     // Check for duplicate
     BlockHash hash = block.GetHash();
     BlockMap::iterator it = mapBlockIndex.find(hash);
     if (it != mapBlockIndex.end()) {
         return it->second;
     }
 
     // Construct new block index object
     CBlockIndex *pindexNew = new CBlockIndex(block);
     // We assign the sequence id to blocks only when the full data is available,
     // to avoid miners withholding blocks but broadcasting headers, to get a
     // competitive advantage.
     pindexNew->nSequenceId = 0;
     BlockMap::iterator mi =
         mapBlockIndex.insert(std::make_pair(hash, pindexNew)).first;
     pindexNew->phashBlock = &((*mi).first);
     BlockMap::iterator miPrev = mapBlockIndex.find(block.hashPrevBlock);
     if (miPrev != mapBlockIndex.end()) {
         pindexNew->pprev = (*miPrev).second;
         pindexNew->nHeight = pindexNew->pprev->nHeight + 1;
         pindexNew->BuildSkip();
     }
     pindexNew->nTimeReceived = GetTime();
     pindexNew->nTimeMax =
         (pindexNew->pprev
              ? std::max(pindexNew->pprev->nTimeMax, pindexNew->nTime)
              : pindexNew->nTime);
     pindexNew->nChainWork =
         (pindexNew->pprev ? pindexNew->pprev->nChainWork : 0) +
         GetBlockProof(*pindexNew);
     pindexNew->RaiseValidity(BlockValidity::TREE);
     if (pindexBestHeader == nullptr ||
         pindexBestHeader->nChainWork < pindexNew->nChainWork) {
         pindexBestHeader = pindexNew;
     }
 
     setDirtyBlockIndex.insert(pindexNew);
     return pindexNew;
 }
 
 /**
  * Mark a block as having its data received and checked (up to
  * BLOCK_VALID_TRANSACTIONS).
  */
 bool CChainState::ReceivedBlockTransactions(const CBlock &block,
                                             CValidationState &state,
                                             CBlockIndex *pindexNew,
                                             const FlatFilePos &pos) {
     pindexNew->nTx = block.vtx.size();
     pindexNew->nChainTx = 0;
     pindexNew->nFile = pos.nFile;
     pindexNew->nDataPos = pos.nPos;
     pindexNew->nUndoPos = 0;
     pindexNew->nStatus = pindexNew->nStatus.withData();
     pindexNew->RaiseValidity(BlockValidity::TRANSACTIONS);
     setDirtyBlockIndex.insert(pindexNew);
 
     if (pindexNew->pprev == nullptr || pindexNew->pprev->nChainTx) {
         // If pindexNew is the genesis block or all parents are
         // BLOCK_VALID_TRANSACTIONS.
         std::deque<CBlockIndex *> queue;
         queue.push_back(pindexNew);
 
         // Recursively process any descendant blocks that now may be eligible to
         // be connected.
         while (!queue.empty()) {
             CBlockIndex *pindex = queue.front();
             queue.pop_front();
             pindex->nChainTx =
                 (pindex->pprev ? pindex->pprev->nChainTx : 0) + pindex->nTx;
             if (pindex->nSequenceId == 0) {
                 // We assign a sequence is when transaction are received to
                 // prevent a miner from being able to broadcast a block but not
                 // its content. However, a sequence id may have been set
                 // manually, for instance via PreciousBlock, in which case, we
                 // don't need to assign one.
                 pindex->nSequenceId = nBlockSequenceId++;
             }
 
             if (chainActive.Tip() == nullptr ||
                 !setBlockIndexCandidates.value_comp()(pindex,
                                                       chainActive.Tip())) {
                 setBlockIndexCandidates.insert(pindex);
             }
 
             std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                       std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
                 range = mapBlocksUnlinked.equal_range(pindex);
             while (range.first != range.second) {
                 std::multimap<CBlockIndex *, CBlockIndex *>::iterator it =
                     range.first;
                 queue.push_back(it->second);
                 range.first++;
                 mapBlocksUnlinked.erase(it);
             }
         }
     } else if (pindexNew->pprev &&
                pindexNew->pprev->IsValid(BlockValidity::TREE)) {
         mapBlocksUnlinked.insert(std::make_pair(pindexNew->pprev, pindexNew));
     }
 
     return true;
 }
 
 static bool FindBlockPos(FlatFilePos &pos, unsigned int nAddSize,
                          unsigned int nHeight, uint64_t nTime,
                          bool fKnown = false) {
     LOCK(cs_LastBlockFile);
 
     unsigned int nFile = fKnown ? pos.nFile : nLastBlockFile;
     if (vinfoBlockFile.size() <= nFile) {
         vinfoBlockFile.resize(nFile + 1);
     }
 
     if (!fKnown) {
         while (vinfoBlockFile[nFile].nSize + nAddSize >= MAX_BLOCKFILE_SIZE) {
             nFile++;
             if (vinfoBlockFile.size() <= nFile) {
                 vinfoBlockFile.resize(nFile + 1);
             }
         }
         pos.nFile = nFile;
         pos.nPos = vinfoBlockFile[nFile].nSize;
     }
 
     if ((int)nFile != nLastBlockFile) {
         if (!fKnown) {
             LogPrintf("Leaving block file %i: %s\n", nLastBlockFile,
                       vinfoBlockFile[nLastBlockFile].ToString());
         }
         FlushBlockFile(!fKnown);
         nLastBlockFile = nFile;
     }
 
     vinfoBlockFile[nFile].AddBlock(nHeight, nTime);
     if (fKnown) {
         vinfoBlockFile[nFile].nSize =
             std::max(pos.nPos + nAddSize, vinfoBlockFile[nFile].nSize);
     } else {
         vinfoBlockFile[nFile].nSize += nAddSize;
     }
 
     if (!fKnown) {
         bool out_of_space;
         size_t bytes_allocated =
             BlockFileSeq().Allocate(pos, nAddSize, out_of_space);
         if (out_of_space) {
             return AbortNode("Disk space is low!",
                              _("Error: Disk space is low!"));
         }
         if (bytes_allocated != 0 && fPruneMode) {
             fCheckForPruning = true;
         }
     }
 
     setDirtyFileInfo.insert(nFile);
     return true;
 }
 
 static bool FindUndoPos(CValidationState &state, int nFile, FlatFilePos &pos,
                         unsigned int nAddSize) {
     pos.nFile = nFile;
 
     LOCK(cs_LastBlockFile);
 
     pos.nPos = vinfoBlockFile[nFile].nUndoSize;
     vinfoBlockFile[nFile].nUndoSize += nAddSize;
     setDirtyFileInfo.insert(nFile);
 
     bool out_of_space;
     size_t bytes_allocated =
         UndoFileSeq().Allocate(pos, nAddSize, out_of_space);
     if (out_of_space) {
         return AbortNode(state, "Disk space is low!",
                          _("Error: Disk space is low!"));
     }
     if (bytes_allocated != 0 && fPruneMode) {
         fCheckForPruning = true;
     }
 
     return true;
 }
 
 /**
  * Return true if the provided block header is valid.
  * Only verify PoW if blockValidationOptions is configured to do so.
  * This allows validation of headers on which the PoW hasn't been done.
  * For example: to validate template handed to mining software.
  * Do not call this for any check that depends on the context.
  * For context-dependent calls, see ContextualCheckBlockHeader.
  */
 static bool CheckBlockHeader(const CBlockHeader &block, CValidationState &state,
                              const Consensus::Params &params,
                              BlockValidationOptions validationOptions) {
     // Check proof of work matches claimed amount
     if (validationOptions.shouldValidatePoW() &&
         !CheckProofOfWork(block.GetHash(), block.nBits, params)) {
         return state.DoS(50, false, REJECT_INVALID, "high-hash", false,
                          "proof of work failed");
     }
 
     return true;
 }
 
 bool CheckBlock(const CBlock &block, CValidationState &state,
                 const Consensus::Params &params,
                 BlockValidationOptions validationOptions) {
     // These are checks that are independent of context.
     if (block.fChecked) {
         return true;
     }
 
     // Check that the header is valid (particularly PoW).  This is mostly
     // redundant with the call in AcceptBlockHeader.
     if (!CheckBlockHeader(block, state, params, validationOptions)) {
         return false;
     }
 
     // Check the merkle root.
     if (validationOptions.shouldValidateMerkleRoot()) {
         bool mutated;
         uint256 hashMerkleRoot2 = BlockMerkleRoot(block, &mutated);
         if (block.hashMerkleRoot != hashMerkleRoot2) {
             return state.DoS(100, false, REJECT_INVALID, "bad-txnmrklroot",
                              true, "hashMerkleRoot mismatch");
         }
 
         // Check for merkle tree malleability (CVE-2012-2459): repeating
         // sequences of transactions in a block without affecting the merkle
         // root of a block, while still invalidating it.
         if (mutated) {
             return state.DoS(100, false, REJECT_INVALID, "bad-txns-duplicate",
                              true, "duplicate transaction");
         }
     }
 
     // All potential-corruption validation must be done before we do any
     // transaction validation, as otherwise we may mark the header as invalid
     // because we receive the wrong transactions for it.
 
     // First transaction must be coinbase.
     if (block.vtx.empty()) {
         return state.DoS(100, false, REJECT_INVALID, "bad-cb-missing", false,
                          "first tx is not coinbase");
     }
 
     // Size limits.
     auto nMaxBlockSize = validationOptions.getExcessiveBlockSize();
 
     // Bail early if there is no way this block is of reasonable size.
     if ((block.vtx.size() * MIN_TRANSACTION_SIZE) > nMaxBlockSize) {
         return state.DoS(100, false, REJECT_INVALID, "bad-blk-length", false,
                          "size limits failed");
     }
 
     auto currentBlockSize = ::GetSerializeSize(block, PROTOCOL_VERSION);
     if (currentBlockSize > nMaxBlockSize) {
         return state.DoS(100, false, REJECT_INVALID, "bad-blk-length", false,
                          "size limits failed");
     }
 
     // And a valid coinbase.
     if (!CheckCoinbase(*block.vtx[0], state)) {
         return state.Invalid(false, state.GetRejectCode(),
                              state.GetRejectReason(),
                              strprintf("Coinbase check failed (txid %s) %s",
                                        block.vtx[0]->GetId().ToString(),
                                        state.GetDebugMessage()));
     }
 
     // Keep track of the sigops count.
     uint64_t nSigOps = 0;
     auto nMaxSigOpsCount = GetMaxBlockSigOpsCount(currentBlockSize);
 
     // Check transactions
     auto txCount = block.vtx.size();
     auto *tx = block.vtx[0].get();
 
     size_t i = 0;
     while (true) {
         // Count the sigops for the current transaction. If the total sigops
         // count is too high, the the block is invalid.
         nSigOps += GetSigOpCountWithoutP2SH(*tx, STANDARD_SCRIPT_VERIFY_FLAGS);
         if (nSigOps > nMaxSigOpsCount) {
             return state.DoS(100, false, REJECT_INVALID, "bad-blk-sigops",
                              false, "out-of-bounds SigOpCount");
         }
 
         // Go to the next transaction.
         i++;
 
         // We reached the end of the block, success.
         if (i >= txCount) {
             break;
         }
 
         // Check that the transaction is valid. Because this check differs for
         // the coinbase, the loop is arranged such as this only runs after at
         // least one increment.
         tx = block.vtx[i].get();
         if (!CheckRegularTransaction(*tx, state)) {
             return state.Invalid(
                 false, state.GetRejectCode(), state.GetRejectReason(),
                 strprintf("Transaction check failed (txid %s) %s",
                           tx->GetId().ToString(), state.GetDebugMessage()));
         }
     }
 
     if (validationOptions.shouldValidatePoW() &&
         validationOptions.shouldValidateMerkleRoot()) {
         block.fChecked = true;
     }
 
     return true;
 }
 
 /**
  * Context-dependent validity checks.
  * By "context", we mean only the previous block headers, but not the UTXO
  * set; UTXO-related validity checks are done in ConnectBlock().
  * NOTE: This function is not currently invoked by ConnectBlock(), so we
  * should consider upgrade issues if we change which consensus rules are
  * enforced in this function (eg by adding a new consensus rule). See comment
  * in ConnectBlock().
  * Note that -reindex-chainstate skips the validation that happens here!
  */
 static bool ContextualCheckBlockHeader(const CChainParams &params,
                                        const CBlockHeader &block,
                                        CValidationState &state,
                                        const CBlockIndex *pindexPrev,
                                        int64_t nAdjustedTime) {
     assert(pindexPrev != nullptr);
     const int nHeight = pindexPrev->nHeight + 1;
 
     // Check proof of work
     const Consensus::Params &consensusParams = params.GetConsensus();
     if (block.nBits !=
         GetNextWorkRequired(pindexPrev, &block, consensusParams)) {
         LogPrintf("bad bits after height: %d\n", pindexPrev->nHeight);
         return state.DoS(100, false, REJECT_INVALID, "bad-diffbits", false,
                          "incorrect proof of work");
     }
 
     // Check against checkpoints
     if (fCheckpointsEnabled) {
         const CCheckpointData &checkpoints = params.Checkpoints();
 
         // Check that the block chain matches the known block chain up to a
         // checkpoint.
         if (!Checkpoints::CheckBlock(checkpoints, nHeight, block.GetHash())) {
             return state.DoS(100,
                              error("%s: rejected by checkpoint lock-in at %d",
                                    __func__, nHeight),
                              REJECT_CHECKPOINT, "checkpoint mismatch");
         }
 
         // Don't accept any forks from the main chain prior to last checkpoint.
         // GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's
         // in our MapBlockIndex.
         CBlockIndex *pcheckpoint = Checkpoints::GetLastCheckpoint(checkpoints);
         if (pcheckpoint && nHeight < pcheckpoint->nHeight) {
             return state.DoS(
                 100,
                 error("%s: forked chain older than last checkpoint (height %d)",
                       __func__, nHeight),
                 REJECT_CHECKPOINT, "bad-fork-prior-to-checkpoint");
         }
     }
 
     // Check timestamp against prev
     if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast()) {
         return state.Invalid(false, REJECT_INVALID, "time-too-old",
                              "block's timestamp is too early");
     }
 
     // Check timestamp
     if (block.GetBlockTime() > nAdjustedTime + MAX_FUTURE_BLOCK_TIME) {
         return state.Invalid(false, REJECT_INVALID, "time-too-new",
                              "block timestamp too far in the future");
     }
 
     // Reject outdated version blocks when 95% (75% on testnet) of the network
     // has upgraded:
     // check for version 2, 3 and 4 upgrades
     if ((block.nVersion < 2 && nHeight >= consensusParams.BIP34Height) ||
         (block.nVersion < 3 && nHeight >= consensusParams.BIP66Height) ||
         (block.nVersion < 4 && nHeight >= consensusParams.BIP65Height)) {
         return state.Invalid(
             false, REJECT_OBSOLETE,
             strprintf("bad-version(0x%08x)", block.nVersion),
             strprintf("rejected nVersion=0x%08x block", block.nVersion));
     }
 
     return true;
 }
 
 bool ContextualCheckTransactionForCurrentBlock(const Consensus::Params &params,
                                                const CTransaction &tx,
                                                CValidationState &state,
                                                int flags) {
     AssertLockHeld(cs_main);
 
     // By convention a negative value for flags indicates that the current
     // network-enforced consensus rules should be used. In a future soft-fork
     // scenario that would mean checking which rules would be enforced for the
     // next block and setting the appropriate flags. At the present time no
     // soft-forks are scheduled, so no flags are set.
     flags = std::max(flags, 0);
 
     // ContextualCheckTransactionForCurrentBlock() uses chainActive.Height()+1
     // to evaluate nLockTime because when IsFinalTx() is called within
     // CBlock::AcceptBlock(), the height of the block *being* evaluated is what
     // is used. Thus if we want to know if a transaction can be part of the
     // *next* block, we need to call ContextualCheckTransaction() with one more
     // than chainActive.Height().
     const int nBlockHeight = chainActive.Height() + 1;
 
     // BIP113 will require that time-locked transactions have nLockTime set to
     // less than the median time of the previous block they're contained in.
     // When the next block is created its previous block will be the current
     // chain tip, so we use that to calculate the median time passed to
     // ContextualCheckTransaction() if LOCKTIME_MEDIAN_TIME_PAST is set.
     const int64_t nMedianTimePast =
         chainActive.Tip() == nullptr ? 0
                                      : chainActive.Tip()->GetMedianTimePast();
     const int64_t nLockTimeCutoff = (flags & LOCKTIME_MEDIAN_TIME_PAST)
                                         ? nMedianTimePast
                                         : GetAdjustedTime();
 
     return ContextualCheckTransaction(params, tx, state, nBlockHeight,
                                       nLockTimeCutoff, nMedianTimePast);
 }
 
 /**
  * NOTE: This function is not currently invoked by ConnectBlock(), so we
  * should consider upgrade issues if we change which consensus rules are
  * enforced in this function (eg by adding a new consensus rule). See comment
  * in ConnectBlock().
  * Note that -reindex-chainstate skips the validation that happens here!
  */
 static bool ContextualCheckBlock(const CBlock &block, CValidationState &state,
                                  const Consensus::Params &params,
                                  const CBlockIndex *pindexPrev) {
     const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
 
     // Start enforcing BIP113 (Median Time Past).
     int nLockTimeFlags = 0;
     if (nHeight >= params.CSVHeight) {
         assert(pindexPrev != nullptr);
         nLockTimeFlags |= LOCKTIME_MEDIAN_TIME_PAST;
     }
 
     const int64_t nMedianTimePast =
         pindexPrev == nullptr ? 0 : pindexPrev->GetMedianTimePast();
 
     const int64_t nLockTimeCutoff = (nLockTimeFlags & LOCKTIME_MEDIAN_TIME_PAST)
                                         ? nMedianTimePast
                                         : block.GetBlockTime();
 
     const bool fIsMagneticAnomalyEnabled =
         IsMagneticAnomalyEnabled(params, pindexPrev);
 
     // Check that all transactions are finalized
     const CTransaction *prevTx = nullptr;
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         if (fIsMagneticAnomalyEnabled) {
             if (prevTx && (tx.GetId() <= prevTx->GetId())) {
                 if (tx.GetId() == prevTx->GetId()) {
                     return state.DoS(100, false, REJECT_INVALID, "tx-duplicate",
                                      false,
                                      strprintf("Duplicated transaction %s",
                                                tx.GetId().ToString()));
                 }
 
                 return state.DoS(
                     100, false, REJECT_INVALID, "tx-ordering", false,
                     strprintf("Transaction order is invalid (%s < %s)",
                               tx.GetId().ToString(),
                               prevTx->GetId().ToString()));
             }
 
             if (prevTx || !tx.IsCoinBase()) {
                 prevTx = &tx;
             }
         }
 
         if (!ContextualCheckTransaction(params, tx, state, nHeight,
                                         nLockTimeCutoff, nMedianTimePast)) {
             // state set by ContextualCheckTransaction.
             return false;
         }
     }
 
     // Enforce rule that the coinbase starts with serialized block height
     if (nHeight >= params.BIP34Height) {
         CScript expect = CScript() << nHeight;
         if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() ||
             !std::equal(expect.begin(), expect.end(),
                         block.vtx[0]->vin[0].scriptSig.begin())) {
             return state.DoS(100, false, REJECT_INVALID, "bad-cb-height", false,
                              "block height mismatch in coinbase");
         }
     }
 
     return true;
 }
 
 /**
  * If the provided block header is valid, add it to the block index.
  *
  * Returns true if the block is successfully added to the block index.
  */
 bool CChainState::AcceptBlockHeader(const Config &config,
                                     const CBlockHeader &block,
                                     CValidationState &state,
                                     CBlockIndex **ppindex) {
     AssertLockHeld(cs_main);
     const CChainParams &chainparams = config.GetChainParams();
 
     // Check for duplicate
     BlockHash hash = block.GetHash();
     BlockMap::iterator miSelf = mapBlockIndex.find(hash);
     CBlockIndex *pindex = nullptr;
     if (hash != chainparams.GetConsensus().hashGenesisBlock) {
         if (miSelf != mapBlockIndex.end()) {
             // Block header is already known.
             pindex = miSelf->second;
             if (ppindex) {
                 *ppindex = pindex;
             }
 
             if (pindex->nStatus.isInvalid()) {
                 return state.Invalid(error("%s: block %s is marked invalid",
                                            __func__, hash.ToString()),
                                      0, "duplicate");
             }
 
             return true;
         }
 
         if (!CheckBlockHeader(block, state, chainparams.GetConsensus(),
                               BlockValidationOptions(config))) {
             return error("%s: Consensus::CheckBlockHeader: %s, %s", __func__,
                          hash.ToString(), FormatStateMessage(state));
         }
 
         // Get prev block index
         BlockMap::iterator mi = mapBlockIndex.find(block.hashPrevBlock);
         if (mi == mapBlockIndex.end()) {
             return state.DoS(10, error("%s: prev block not found", __func__), 0,
                              "prev-blk-not-found");
         }
 
         CBlockIndex *pindexPrev = (*mi).second;
         assert(pindexPrev);
         if (pindexPrev->nStatus.isInvalid()) {
             return state.DoS(100, error("%s: prev block invalid", __func__),
                              REJECT_INVALID, "bad-prevblk");
         }
 
         if (!ContextualCheckBlockHeader(chainparams, block, state, pindexPrev,
                                         GetAdjustedTime())) {
             return error("%s: Consensus::ContextualCheckBlockHeader: %s, %s",
                          __func__, hash.ToString(), FormatStateMessage(state));
         }
 
         /* Determine if this block descends from any block which has been found
          * invalid (m_failed_blocks), then mark pindexPrev and any blocks
          * between them as failed. For example:
          *
          *                D3
          *              /
          *      B2 - C2
          *    /         \
          *  A             D2 - E2 - F2
          *    \
          *      B1 - C1 - D1 - E1
          *
          * In the case that we attempted to reorg from E1 to F2, only to find
          * C2 to be invalid, we would mark D2, E2, and F2 as BLOCK_FAILED_CHILD
          * but NOT D3 (it was not in any of our candidate sets at the time).
          *
          * In any case D3 will also be marked as BLOCK_FAILED_CHILD at restart
          * in LoadBlockIndex.
          */
         if (!pindexPrev->IsValid(BlockValidity::SCRIPTS)) {
             // The above does not mean "invalid": it checks if the previous
             // block hasn't been validated up to BLOCK_VALID_SCRIPTS. This is a
             // performance optimization, in the common case of adding a new
             // block to the tip, we don't need to iterate over the failed blocks
             // list.
             for (const CBlockIndex *failedit : m_failed_blocks) {
                 if (pindexPrev->GetAncestor(failedit->nHeight) == failedit) {
                     assert(failedit->nStatus.hasFailed());
                     CBlockIndex *invalid_walk = pindexPrev;
                     while (invalid_walk != failedit) {
                         invalid_walk->nStatus =
                             invalid_walk->nStatus.withFailedParent();
                         setDirtyBlockIndex.insert(invalid_walk);
                         invalid_walk = invalid_walk->pprev;
                     }
                     return state.DoS(100,
                                      error("%s: prev block invalid", __func__),
                                      REJECT_INVALID, "bad-prevblk");
                 }
             }
         }
     }
 
     if (pindex == nullptr) {
         pindex = AddToBlockIndex(block);
     }
 
     if (ppindex) {
         *ppindex = pindex;
     }
 
     CheckBlockIndex(chainparams.GetConsensus());
     return true;
 }
 
 // Exposed wrapper for AcceptBlockHeader
 bool ProcessNewBlockHeaders(const Config &config,
                             const std::vector<CBlockHeader> &headers,
                             CValidationState &state,
                             const CBlockIndex **ppindex,
                             CBlockHeader *first_invalid) {
     if (first_invalid != nullptr) {
         first_invalid->SetNull();
     }
 
     {
         LOCK(cs_main);
         for (const CBlockHeader &header : headers) {
             // Use a temp pindex instead of ppindex to avoid a const_cast
             CBlockIndex *pindex = nullptr;
             if (!g_chainstate.AcceptBlockHeader(config, header, state,
                                                 &pindex)) {
                 if (first_invalid) {
                     *first_invalid = header;
                 }
                 return false;
             }
 
             if (ppindex) {
                 *ppindex = pindex;
             }
         }
     }
 
     NotifyHeaderTip();
     return true;
 }
 
 /**
  * Store block on disk. If dbp is non-nullptr, the file is known to already
  * reside on disk.
  */
 static FlatFilePos SaveBlockToDisk(const CBlock &block, int nHeight,
                                    const CChainParams &chainparams,
                                    const FlatFilePos *dbp) {
     unsigned int nBlockSize = ::GetSerializeSize(block, CLIENT_VERSION);
     FlatFilePos blockPos;
     if (dbp != nullptr) {
         blockPos = *dbp;
     }
     if (!FindBlockPos(blockPos, nBlockSize + 8, nHeight, block.GetBlockTime(),
                       dbp != nullptr)) {
         error("%s: FindBlockPos failed", __func__);
         return FlatFilePos();
     }
     if (dbp == nullptr) {
         if (!WriteBlockToDisk(block, blockPos, chainparams.DiskMagic())) {
             AbortNode("Failed to write block");
             return FlatFilePos();
         }
     }
     return blockPos;
 }
 
 /**
  * Store a block on disk.
  *
  * @param[in]     config     The global config.
  * @param[in-out] pblock     The block we want to accept.
  * @param[in]     fRequested A boolean to indicate if this block was requested
  *                           from our peers.
  * @param[in]     dbp        If non-null, the disk position of the block.
  * @param[in-out] fNewBlock  True if block was first received via this call.
  * @return True if the block is accepted as a valid block and written to disk.
  */
 bool CChainState::AcceptBlock(const Config &config,
                               const std::shared_ptr<const CBlock> &pblock,
                               CValidationState &state, bool fRequested,
                               const FlatFilePos *dbp, bool *fNewBlock) {
     AssertLockHeld(cs_main);
 
     const CBlock &block = *pblock;
     if (fNewBlock) {
         *fNewBlock = false;
     }
 
     CBlockIndex *pindex = nullptr;
     if (!AcceptBlockHeader(config, block, state, &pindex)) {
         return false;
     }
 
     // Try to process all requested blocks that we don't have, but only
     // process an unrequested block if it's new and has enough work to
     // advance our tip, and isn't too many blocks ahead.
     bool fAlreadyHave = pindex->nStatus.hasData();
 
     // TODO: deal better with return value and error conditions for duplicate
     // and unrequested blocks.
     if (fAlreadyHave) {
         return true;
     }
 
     // Compare block header timestamps and received times of the block and the
     // chaintip.  If they have the same chain height, use these diffs as a
     // tie-breaker, attempting to pick the more honestly-mined block.
     int64_t newBlockTimeDiff = std::llabs(pindex->GetReceivedTimeDiff());
     int64_t chainTipTimeDiff =
         chainActive.Tip() ? std::llabs(chainActive.Tip()->GetReceivedTimeDiff())
                           : 0;
 
     bool isSameHeight = chainActive.Tip() &&
                         (pindex->nChainWork == chainActive.Tip()->nChainWork);
     if (isSameHeight) {
         LogPrintf("Chain tip timestamp-to-received-time difference: hash=%s, "
                   "diff=%d\n",
                   chainActive.Tip()->GetBlockHash().ToString(),
                   chainTipTimeDiff);
         LogPrintf("New block timestamp-to-received-time difference: hash=%s, "
                   "diff=%d\n",
                   pindex->GetBlockHash().ToString(), newBlockTimeDiff);
     }
 
     bool fHasMoreOrSameWork =
         (chainActive.Tip() ? pindex->nChainWork >= chainActive.Tip()->nChainWork
                            : true);
 
     // Blocks that are too out-of-order needlessly limit the effectiveness of
     // pruning, because pruning will not delete block files that contain any
     // blocks which are too close in height to the tip.  Apply this test
     // regardless of whether pruning is enabled; it should generally be safe to
     // not process unrequested blocks.
     bool fTooFarAhead =
         (pindex->nHeight > int(chainActive.Height() + MIN_BLOCKS_TO_KEEP));
 
     // TODO: Decouple this function from the block download logic by removing
     // fRequested
     // This requires some new chain data structure to efficiently look up if a
     // block is in a chain leading to a candidate for best tip, despite not
     // being such a candidate itself.
 
     // If we didn't ask for it:
     if (!fRequested) {
         // This is a previously-processed block that was pruned.
         if (pindex->nTx != 0) {
             return true;
         }
 
         // Don't process less-work chains.
         if (!fHasMoreOrSameWork) {
             return true;
         }
 
         // Block height is too high.
         if (fTooFarAhead) {
             return true;
         }
 
         // Protect against DoS attacks from low-work chains.
         // If our tip is behind, a peer could try to send us
         // low-work blocks on a fake chain that we would never
         // request; don't process these.
         if (pindex->nChainWork < nMinimumChainWork) {
             return true;
         }
     }
 
     const CChainParams &chainparams = config.GetChainParams();
 
     if (!CheckBlock(block, state, chainparams.GetConsensus(),
                     BlockValidationOptions(config)) ||
         !ContextualCheckBlock(block, state, chainparams.GetConsensus(),
                               pindex->pprev)) {
         if (state.IsInvalid() && !state.CorruptionPossible()) {
             pindex->nStatus = pindex->nStatus.withFailed();
             setDirtyBlockIndex.insert(pindex);
         }
 
         return error("%s: %s (block %s)", __func__, FormatStateMessage(state),
                      block.GetHash().ToString());
     }
 
     // If this is a deep reorg (a regorg of more than one block), preemptively
     // mark the chain as parked. If it has enough work, it'll unpark
     // automatically. We mark the block as parked at the very last minute so we
     // can make sure everything is ready to be reorged if needed.
     if (gArgs.GetBoolArg("-parkdeepreorg", true)) {
         const CBlockIndex *pindexFork = chainActive.FindFork(pindex);
         if (pindexFork && pindexFork->nHeight + 1 < pindex->nHeight) {
             LogPrintf("Park block %s as it would cause a deep reorg.\n",
                       pindex->GetBlockHash().ToString());
             pindex->nStatus = pindex->nStatus.withParked();
             setDirtyBlockIndex.insert(pindex);
         }
     }
 
     // Header is valid/has work and the merkle tree is good.
     // Relay now, but if it does not build on our best tip, let the
     // SendMessages loop relay it.
     if (!IsInitialBlockDownload() && chainActive.Tip() == pindex->pprev) {
         GetMainSignals().NewPoWValidBlock(pindex, pblock);
     }
 
     // Write block to history file
     if (fNewBlock) {
         *fNewBlock = true;
     }
     try {
         FlatFilePos blockPos =
             SaveBlockToDisk(block, pindex->nHeight, chainparams, dbp);
         if (blockPos.IsNull()) {
             state.Error(strprintf(
                 "%s: Failed to find position to write new block to disk",
                 __func__));
             return false;
         }
         if (!ReceivedBlockTransactions(block, state, pindex, blockPos)) {
             return error("AcceptBlock(): ReceivedBlockTransactions failed");
         }
     } catch (const std::runtime_error &e) {
         return AbortNode(state, std::string("System error: ") + e.what());
     }
 
     FlushStateToDisk(config.GetChainParams(), state, FlushStateMode::NONE);
 
     CheckBlockIndex(chainparams.GetConsensus());
 
     return true;
 }
 
 bool ProcessNewBlock(const Config &config,
                      const std::shared_ptr<const CBlock> pblock,
                      bool fForceProcessing, bool *fNewBlock) {
     AssertLockNotHeld(cs_main);
 
     {
         if (fNewBlock) {
             *fNewBlock = false;
         }
 
         CValidationState state;
 
         // CheckBlock() does not support multi-threaded block validation
         // because CBlock::fChecked can cause data race.
         // Therefore, the following critical section must include the
         // CheckBlock() call as well.
         LOCK(cs_main);
 
         // Ensure that CheckBlock() passes before calling AcceptBlock, as
         // belt-and-suspenders.
         bool ret =
             CheckBlock(*pblock, state, config.GetChainParams().GetConsensus(),
                        BlockValidationOptions(config));
         if (ret) {
             // Store to disk
             ret = g_chainstate.AcceptBlock(
                 config, pblock, state, fForceProcessing, nullptr, fNewBlock);
         }
 
         if (!ret) {
             GetMainSignals().BlockChecked(*pblock, state);
             return error("%s: AcceptBlock FAILED (%s)", __func__,
                          FormatStateMessage(state));
         }
     }
 
     NotifyHeaderTip();
 
     // Only used to report errors, not invalidity - ignore it
     CValidationState state;
     if (!g_chainstate.ActivateBestChain(config, state, pblock)) {
         return error("%s: ActivateBestChain failed (%s)", __func__,
                      FormatStateMessage(state));
     }
 
     return true;
 }
 
 bool TestBlockValidity(CValidationState &state, const CChainParams &params,
                        const CBlock &block, CBlockIndex *pindexPrev,
                        BlockValidationOptions validationOptions) {
     AssertLockHeld(cs_main);
     assert(pindexPrev && pindexPrev == chainActive.Tip());
     CCoinsViewCache viewNew(pcoinsTip.get());
     BlockHash block_hash(block.GetHash());
     CBlockIndex indexDummy(block);
     indexDummy.pprev = pindexPrev;
     indexDummy.nHeight = pindexPrev->nHeight + 1;
     indexDummy.phashBlock = &block_hash;
 
     // NOTE: CheckBlockHeader is called by CheckBlock
     if (!ContextualCheckBlockHeader(params, block, state, pindexPrev,
                                     GetAdjustedTime())) {
         return error("%s: Consensus::ContextualCheckBlockHeader: %s", __func__,
                      FormatStateMessage(state));
     }
 
     if (!CheckBlock(block, state, params.GetConsensus(), validationOptions)) {
         return error("%s: Consensus::CheckBlock: %s", __func__,
                      FormatStateMessage(state));
     }
 
     if (!ContextualCheckBlock(block, state, params.GetConsensus(),
                               pindexPrev)) {
         return error("%s: Consensus::ContextualCheckBlock: %s", __func__,
                      FormatStateMessage(state));
     }
 
     if (!g_chainstate.ConnectBlock(block, state, &indexDummy, viewNew, params,
                                    validationOptions, true)) {
         return false;
     }
 
     assert(state.IsValid());
     return true;
 }
 
 /**
  * BLOCK PRUNING CODE
  */
 
 /**
  * Calculate the amount of disk space the block & undo files currently use.
  */
 uint64_t CalculateCurrentUsage() {
     LOCK(cs_LastBlockFile);
 
     uint64_t retval = 0;
     for (const CBlockFileInfo &file : vinfoBlockFile) {
         retval += file.nSize + file.nUndoSize;
     }
 
     return retval;
 }
 
 /**
  * Prune a block file (modify associated database entries)
  */
 void PruneOneBlockFile(const int fileNumber) {
     LOCK(cs_LastBlockFile);
 
     for (const auto &entry : mapBlockIndex) {
         CBlockIndex *pindex = entry.second;
         if (pindex->nFile == fileNumber) {
             pindex->nStatus = pindex->nStatus.withData(false).withUndo(false);
             pindex->nFile = 0;
             pindex->nDataPos = 0;
             pindex->nUndoPos = 0;
             setDirtyBlockIndex.insert(pindex);
 
             // Prune from mapBlocksUnlinked -- any block we prune would have
             // to be downloaded again in order to consider its chain, at which
             // point it would be considered as a candidate for
             // mapBlocksUnlinked or setBlockIndexCandidates.
             std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                       std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
                 range = mapBlocksUnlinked.equal_range(pindex->pprev);
             while (range.first != range.second) {
                 std::multimap<CBlockIndex *, CBlockIndex *>::iterator _it =
                     range.first;
                 range.first++;
                 if (_it->second == pindex) {
                     mapBlocksUnlinked.erase(_it);
                 }
             }
         }
     }
 
     vinfoBlockFile[fileNumber].SetNull();
     setDirtyFileInfo.insert(fileNumber);
 }
 
 void UnlinkPrunedFiles(const std::set<int> &setFilesToPrune) {
     for (const int i : setFilesToPrune) {
         FlatFilePos pos(i, 0);
         fs::remove(BlockFileSeq().FileName(pos));
         fs::remove(UndoFileSeq().FileName(pos));
         LogPrintf("Prune: %s deleted blk/rev (%05u)\n", __func__, i);
     }
 }
 
 /**
  * Calculate the block/rev files to delete based on height specified by user
  * with RPC command pruneblockchain
  */
 static void FindFilesToPruneManual(std::set<int> &setFilesToPrune,
                                    int nManualPruneHeight) {
     assert(fPruneMode && nManualPruneHeight > 0);
 
     LOCK2(cs_main, cs_LastBlockFile);
     if (chainActive.Tip() == nullptr) {
         return;
     }
 
     // last block to prune is the lesser of (user-specified height,
     // MIN_BLOCKS_TO_KEEP from the tip)
     unsigned int nLastBlockWeCanPrune =
         std::min((unsigned)nManualPruneHeight,
                  chainActive.Tip()->nHeight - MIN_BLOCKS_TO_KEEP);
     int count = 0;
     for (int fileNumber = 0; fileNumber < nLastBlockFile; fileNumber++) {
         if (vinfoBlockFile[fileNumber].nSize == 0 ||
             vinfoBlockFile[fileNumber].nHeightLast > nLastBlockWeCanPrune) {
             continue;
         }
         PruneOneBlockFile(fileNumber);
         setFilesToPrune.insert(fileNumber);
         count++;
     }
     LogPrintf("Prune (Manual): prune_height=%d removed %d blk/rev pairs\n",
               nLastBlockWeCanPrune, count);
 }
 
 /* This function is called from the RPC code for pruneblockchain */
 void PruneBlockFilesManual(int nManualPruneHeight) {
     CValidationState state;
     const CChainParams &chainparams = Params();
     if (!FlushStateToDisk(chainparams, state, FlushStateMode::NONE,
                           nManualPruneHeight)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   FormatStateMessage(state));
     }
 }
 
 /**
  * Prune block and undo files (blk???.dat and undo???.dat) so that the disk
  * space used is less than a user-defined target. The user sets the target (in
  * MB) on the command line or in config file.  This will be run on startup and
  * whenever new space is allocated in a block or undo file, staying below the
  * target. Changing back to unpruned requires a reindex (which in this case
  * means the blockchain must be re-downloaded.)
  *
  * Pruning functions are called from FlushStateToDisk when the global
  * fCheckForPruning flag has been set. Block and undo files are deleted in
  * lock-step (when blk00003.dat is deleted, so is rev00003.dat.). Pruning cannot
  * take place until the longest chain is at least a certain length (100000 on
  * mainnet, 1000 on testnet, 1000 on regtest). Pruning will never delete a block
  * within a defined distance (currently 288) from the active chain's tip. The
  * block index is updated by unsetting HAVE_DATA and HAVE_UNDO for any blocks
  * that were stored in the deleted files. A db flag records the fact that at
  * least some block files have been pruned.
  *
  * @param[out]   setFilesToPrune   The set of file indices that can be unlinked
  * will be returned
  */
 static void FindFilesToPrune(std::set<int> &setFilesToPrune,
                              uint64_t nPruneAfterHeight) {
     LOCK2(cs_main, cs_LastBlockFile);
     if (chainActive.Tip() == nullptr || nPruneTarget == 0) {
         return;
     }
     if (uint64_t(chainActive.Tip()->nHeight) <= nPruneAfterHeight) {
         return;
     }
 
     unsigned int nLastBlockWeCanPrune =
         chainActive.Tip()->nHeight - MIN_BLOCKS_TO_KEEP;
     uint64_t nCurrentUsage = CalculateCurrentUsage();
     // We don't check to prune until after we've allocated new space for files,
     // so we should leave a buffer under our target to account for another
     // allocation before the next pruning.
     uint64_t nBuffer = BLOCKFILE_CHUNK_SIZE + UNDOFILE_CHUNK_SIZE;
     uint64_t nBytesToPrune;
     int count = 0;
 
     if (nCurrentUsage + nBuffer >= nPruneTarget) {
         // On a prune event, the chainstate DB is flushed.
         // To avoid excessive prune events negating the benefit of high dbcache
         // values, we should not prune too rapidly.
         // So when pruning in IBD, increase the buffer a bit to avoid a re-prune
         // too soon.
         if (IsInitialBlockDownload()) {
             // Since this is only relevant during IBD, we use a fixed 10%
             nBuffer += nPruneTarget / 10;
         }
 
         for (int fileNumber = 0; fileNumber < nLastBlockFile; fileNumber++) {
             nBytesToPrune = vinfoBlockFile[fileNumber].nSize +
                             vinfoBlockFile[fileNumber].nUndoSize;
 
             if (vinfoBlockFile[fileNumber].nSize == 0) {
                 continue;
             }
 
             // are we below our target?
             if (nCurrentUsage + nBuffer < nPruneTarget) {
                 break;
             }
 
             // don't prune files that could have a block within
             // MIN_BLOCKS_TO_KEEP of the main chain's tip but keep scanning
             if (vinfoBlockFile[fileNumber].nHeightLast > nLastBlockWeCanPrune) {
                 continue;
             }
 
             PruneOneBlockFile(fileNumber);
             // Queue up the files for removal
             setFilesToPrune.insert(fileNumber);
             nCurrentUsage -= nBytesToPrune;
             count++;
         }
     }
 
     LogPrint(BCLog::PRUNE,
              "Prune: target=%dMiB actual=%dMiB diff=%dMiB "
              "max_prune_height=%d removed %d blk/rev pairs\n",
              nPruneTarget / 1024 / 1024, nCurrentUsage / 1024 / 1024,
              ((int64_t)nPruneTarget - (int64_t)nCurrentUsage) / 1024 / 1024,
              nLastBlockWeCanPrune, count);
 }
 
 static FlatFileSeq BlockFileSeq() {
     return FlatFileSeq(GetBlocksDir(), "blk", BLOCKFILE_CHUNK_SIZE);
 }
 
 static FlatFileSeq UndoFileSeq() {
     return FlatFileSeq(GetBlocksDir(), "rev", UNDOFILE_CHUNK_SIZE);
 }
 
 FILE *OpenBlockFile(const FlatFilePos &pos, bool fReadOnly) {
     return BlockFileSeq().Open(pos, fReadOnly);
 }
 
 /** Open an undo file (rev?????.dat) */
 static FILE *OpenUndoFile(const FlatFilePos &pos, bool fReadOnly) {
     return UndoFileSeq().Open(pos, fReadOnly);
 }
 
 fs::path GetBlockPosFilename(const FlatFilePos &pos) {
     return BlockFileSeq().FileName(pos);
 }
 
 CBlockIndex *CChainState::InsertBlockIndex(const BlockHash &hash) {
     AssertLockHeld(cs_main);
 
     if (hash.IsNull()) {
         return nullptr;
     }
 
     // Return existing
     BlockMap::iterator mi = mapBlockIndex.find(hash);
     if (mi != mapBlockIndex.end()) {
         return (*mi).second;
     }
 
     // Create new
     CBlockIndex *pindexNew = new CBlockIndex();
     mi = mapBlockIndex.insert(std::make_pair(hash, pindexNew)).first;
     pindexNew->phashBlock = &((*mi).first);
 
     return pindexNew;
 }
 
 bool CChainState::LoadBlockIndex(const Config &config,
                                  CBlockTreeDB &blocktree) {
     AssertLockHeld(cs_main);
     if (!blocktree.LoadBlockIndexGuts(
             config.GetChainParams().GetConsensus(),
             [this](const BlockHash &hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
                 return this->InsertBlockIndex(hash);
             })) {
         return false;
     }
 
     // Calculate nChainWork
     std::vector<std::pair<int, CBlockIndex *>> vSortedByHeight;
     vSortedByHeight.reserve(mapBlockIndex.size());
     for (const std::pair<const BlockHash, CBlockIndex *> &item :
          mapBlockIndex) {
         CBlockIndex *pindex = item.second;
         vSortedByHeight.push_back(std::make_pair(pindex->nHeight, pindex));
     }
 
     sort(vSortedByHeight.begin(), vSortedByHeight.end());
     for (const std::pair<int, CBlockIndex *> &item : vSortedByHeight) {
         CBlockIndex *pindex = item.second;
         pindex->nChainWork = (pindex->pprev ? pindex->pprev->nChainWork : 0) +
                              GetBlockProof(*pindex);
         pindex->nTimeMax =
             (pindex->pprev ? std::max(pindex->pprev->nTimeMax, pindex->nTime)
                            : pindex->nTime);
         // We can link the chain of blocks for which we've received transactions
         // at some point. Pruned nodes may have deleted the block.
         if (pindex->nTx > 0) {
             if (pindex->pprev) {
                 if (pindex->pprev->nChainTx) {
                     pindex->nChainTx = pindex->pprev->nChainTx + pindex->nTx;
                 } else {
                     pindex->nChainTx = 0;
                     mapBlocksUnlinked.insert(
                         std::make_pair(pindex->pprev, pindex));
                 }
             } else {
                 pindex->nChainTx = pindex->nTx;
             }
         }
 
         if (!pindex->nStatus.hasFailed() && pindex->pprev &&
             pindex->pprev->nStatus.hasFailed()) {
             pindex->nStatus = pindex->nStatus.withFailedParent();
             setDirtyBlockIndex.insert(pindex);
         }
         if (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
             (pindex->nChainTx || pindex->pprev == nullptr)) {
             setBlockIndexCandidates.insert(pindex);
         }
 
         if (pindex->nStatus.isInvalid() &&
             (!pindexBestInvalid ||
              pindex->nChainWork > pindexBestInvalid->nChainWork)) {
             pindexBestInvalid = pindex;
         }
 
         if (pindex->nStatus.isOnParkedChain() &&
             (!pindexBestParked ||
              pindex->nChainWork > pindexBestParked->nChainWork)) {
             pindexBestParked = pindex;
         }
 
         if (pindex->pprev) {
             pindex->BuildSkip();
         }
 
         if (pindex->IsValid(BlockValidity::TREE) &&
             (pindexBestHeader == nullptr ||
              CBlockIndexWorkComparator()(pindexBestHeader, pindex))) {
             pindexBestHeader = pindex;
         }
     }
 
     return true;
 }
 
 static bool LoadBlockIndexDB(const Config &config)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     if (!g_chainstate.LoadBlockIndex(config, *pblocktree)) {
         return false;
     }
 
     // Load block file info
     pblocktree->ReadLastBlockFile(nLastBlockFile);
     vinfoBlockFile.resize(nLastBlockFile + 1);
     LogPrintf("%s: last block file = %i\n", __func__, nLastBlockFile);
     for (int nFile = 0; nFile <= nLastBlockFile; nFile++) {
         pblocktree->ReadBlockFileInfo(nFile, vinfoBlockFile[nFile]);
     }
 
     LogPrintf("%s: last block file info: %s\n", __func__,
               vinfoBlockFile[nLastBlockFile].ToString());
 
     for (int nFile = nLastBlockFile + 1; true; nFile++) {
         CBlockFileInfo info;
         if (pblocktree->ReadBlockFileInfo(nFile, info)) {
             vinfoBlockFile.push_back(info);
         } else {
             break;
         }
     }
 
     // Check presence of blk files
     LogPrintf("Checking all blk files are present...\n");
     std::set<int> setBlkDataFiles;
     for (const std::pair<const BlockHash, CBlockIndex *> &item :
          mapBlockIndex) {
         CBlockIndex *pindex = item.second;
         if (pindex->nStatus.hasData()) {
             setBlkDataFiles.insert(pindex->nFile);
         }
     }
 
     for (const int i : setBlkDataFiles) {
         FlatFilePos pos(i, 0);
         if (CAutoFile(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION)
                 .IsNull()) {
             return false;
         }
     }
 
     // Check whether we have ever pruned block & undo files
     pblocktree->ReadFlag("prunedblockfiles", fHavePruned);
     if (fHavePruned) {
         LogPrintf(
             "LoadBlockIndexDB(): Block files have previously been pruned\n");
     }
 
     // Check whether we need to continue reindexing
     bool fReindexing = false;
     pblocktree->ReadReindexing(fReindexing);
     if (fReindexing) {
         fReindex = true;
     }
 
     return true;
 }
 
 bool LoadChainTip(const Config &config) {
     AssertLockHeld(cs_main);
 
     if (chainActive.Tip() &&
         chainActive.Tip()->GetBlockHash() == pcoinsTip->GetBestBlock()) {
         return true;
     }
 
     if (pcoinsTip->GetBestBlock().IsNull() && mapBlockIndex.size() == 1) {
         // In case we just added the genesis block, connect it now, so
         // that we always have a chainActive.Tip() when we return.
         LogPrintf("%s: Connecting genesis block...\n", __func__);
         CValidationState state;
         if (!ActivateBestChain(config, state)) {
             LogPrintf("%s: failed to activate chain (%s)\n", __func__,
                       FormatStateMessage(state));
             return false;
         }
     }
 
     // Load pointer to end of best chain
     CBlockIndex *pindex = LookupBlockIndex(pcoinsTip->GetBestBlock());
     if (!pindex) {
         return false;
     }
     chainActive.SetTip(pindex);
 
     g_chainstate.PruneBlockIndexCandidates();
 
     LogPrintf(
         "Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
         chainActive.Tip()->GetBlockHash().ToString(), chainActive.Height(),
         FormatISO8601DateTime(chainActive.Tip()->GetBlockTime()),
         GuessVerificationProgress(config.GetChainParams().TxData(),
                                   chainActive.Tip()));
     return true;
 }
 
 CVerifyDB::CVerifyDB() {
     uiInterface.ShowProgress(_("Verifying blocks..."), 0, false);
 }
 
 CVerifyDB::~CVerifyDB() {
     uiInterface.ShowProgress("", 100, false);
 }
 
 bool CVerifyDB::VerifyDB(const Config &config, CCoinsView *coinsview,
                          int nCheckLevel, int nCheckDepth) {
     LOCK(cs_main);
 
     const CChainParams &params = config.GetChainParams();
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     if (chainActive.Tip() == nullptr || chainActive.Tip()->pprev == nullptr) {
         return true;
     }
 
     // Verify blocks in the best chain
     if (nCheckDepth <= 0 || nCheckDepth > chainActive.Height()) {
         nCheckDepth = chainActive.Height();
     }
 
     nCheckLevel = std::max(0, std::min(4, nCheckLevel));
     LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth,
               nCheckLevel);
 
     CCoinsViewCache coins(coinsview);
     CBlockIndex *pindex;
     CBlockIndex *pindexFailure = nullptr;
     int nGoodTransactions = 0;
     CValidationState state;
     int reportDone = 0;
     LogPrintfToBeContinued("[0%%]...");
     for (pindex = chainActive.Tip(); pindex && pindex->pprev;
          pindex = pindex->pprev) {
         boost::this_thread::interruption_point();
         int percentageDone = std::max(
             1, std::min(
                    99,
                    (int)(((double)(chainActive.Height() - pindex->nHeight)) /
                          (double)nCheckDepth * (nCheckLevel >= 4 ? 50 : 100))));
 
         if (reportDone < percentageDone / 10) {
             // report every 10% step
             LogPrintfToBeContinued("[%d%%]...", percentageDone);
             reportDone = percentageDone / 10;
         }
 
         uiInterface.ShowProgress(_("Verifying blocks..."), percentageDone,
                                  false);
         if (pindex->nHeight <= chainActive.Height() - nCheckDepth) {
             break;
         }
 
         if (fPruneMode && !pindex->nStatus.hasData()) {
             // If pruning, only go back as far as we have data.
             LogPrintf("VerifyDB(): block verification stopping at height %d "
                       "(pruning, no data)\n",
                       pindex->nHeight);
             break;
         }
 
         CBlock block;
 
         // check level 0: read from disk
         if (!ReadBlockFromDisk(block, pindex, consensusParams)) {
             return error(
                 "VerifyDB(): *** ReadBlockFromDisk failed at %d, hash=%s",
                 pindex->nHeight, pindex->GetBlockHash().ToString());
         }
 
         // check level 1: verify block validity
         if (nCheckLevel >= 1 && !CheckBlock(block, state, consensusParams,
                                             BlockValidationOptions(config))) {
             return error("%s: *** found bad block at %d, hash=%s (%s)\n",
                          __func__, pindex->nHeight,
                          pindex->GetBlockHash().ToString(),
                          FormatStateMessage(state));
         }
 
         // check level 2: verify undo validity
         if (nCheckLevel >= 2 && pindex) {
             CBlockUndo undo;
             if (!pindex->GetUndoPos().IsNull()) {
                 if (!UndoReadFromDisk(undo, pindex)) {
                     return error(
                         "VerifyDB(): *** found bad undo data at %d, hash=%s\n",
                         pindex->nHeight, pindex->GetBlockHash().ToString());
                 }
             }
         }
 
         // check level 3: check for inconsistencies during memory-only
         // disconnect of tip blocks
         if (nCheckLevel >= 3 &&
             (coins.DynamicMemoryUsage() + pcoinsTip->DynamicMemoryUsage()) <=
                 nCoinCacheUsage) {
             assert(coins.GetBestBlock() == pindex->GetBlockHash());
             DisconnectResult res =
                 g_chainstate.DisconnectBlock(block, pindex, coins);
             if (res == DISCONNECT_FAILED) {
                 return error("VerifyDB(): *** irrecoverable inconsistency in "
                              "block data at %d, hash=%s",
                              pindex->nHeight,
                              pindex->GetBlockHash().ToString());
             }
 
             if (res == DISCONNECT_UNCLEAN) {
                 nGoodTransactions = 0;
                 pindexFailure = pindex;
             } else {
                 nGoodTransactions += block.vtx.size();
             }
         }
 
         if (ShutdownRequested()) {
             return true;
         }
     }
 
     if (pindexFailure) {
         return error("VerifyDB(): *** coin database inconsistencies found "
                      "(last %i blocks, %i good transactions before that)\n",
                      chainActive.Height() - pindexFailure->nHeight + 1,
                      nGoodTransactions);
     }
 
     // store block count as we move pindex at check level >= 4
     int block_count = chainActive.Height() - pindex->nHeight;
 
     // check level 4: try reconnecting blocks
     if (nCheckLevel >= 4) {
         while (pindex != chainActive.Tip()) {
             boost::this_thread::interruption_point();
             uiInterface.ShowProgress(
                 _("Verifying blocks..."),
                 std::max(
                     1, std::min(99, 100 - (int)(((double)(chainActive.Height() -
                                                           pindex->nHeight)) /
                                                 (double)nCheckDepth * 50))),
                 false);
             pindex = chainActive.Next(pindex);
             CBlock block;
             if (!ReadBlockFromDisk(block, pindex, consensusParams)) {
                 return error(
                     "VerifyDB(): *** ReadBlockFromDisk failed at %d, hash=%s",
                     pindex->nHeight, pindex->GetBlockHash().ToString());
             }
             if (!g_chainstate.ConnectBlock(block, state, pindex, coins, params,
                                            BlockValidationOptions(config))) {
                 return error("VerifyDB(): *** found unconnectable block at %d, "
                              "hash=%s (%s)",
                              pindex->nHeight, pindex->GetBlockHash().ToString(),
                              FormatStateMessage(state));
             }
         }
     }
 
     LogPrintf("[DONE].\n");
     LogPrintf("No coin database inconsistencies in last %i blocks (%i "
               "transactions)\n",
               block_count, nGoodTransactions);
 
     return true;
 }
 
 /**
  * Apply the effects of a block on the utxo cache, ignoring that it may already
  * have been applied.
  */
 bool CChainState::RollforwardBlock(const CBlockIndex *pindex,
                                    CCoinsViewCache &view,
                                    const Consensus::Params &params) {
     // TODO: merge with ConnectBlock
     CBlock block;
     if (!ReadBlockFromDisk(block, pindex, params)) {
         return error("ReplayBlock(): ReadBlockFromDisk failed at %d, hash=%s",
                      pindex->nHeight, pindex->GetBlockHash().ToString());
     }
 
     for (const CTransactionRef &tx : block.vtx) {
         // Pass check = true as every addition may be an overwrite.
         AddCoins(view, *tx, pindex->nHeight, true);
     }
 
     for (const CTransactionRef &tx : block.vtx) {
         if (tx->IsCoinBase()) {
             continue;
         }
 
         for (const CTxIn &txin : tx->vin) {
             view.SpendCoin(txin.prevout);
         }
     }
 
     return true;
 }
 
 bool CChainState::ReplayBlocks(const Consensus::Params &params,
                                CCoinsView *view) {
     LOCK(cs_main);
 
     CCoinsViewCache cache(view);
 
     std::vector<BlockHash> hashHeads = view->GetHeadBlocks();
     if (hashHeads.empty()) {
         // We're already in a consistent state.
         return true;
     }
 
     if (hashHeads.size() != 2) {
         return error("ReplayBlocks(): unknown inconsistent state");
     }
 
     uiInterface.ShowProgress(_("Replaying blocks..."), 0, false);
     LogPrintf("Replaying blocks\n");
 
     // Old tip during the interrupted flush.
     const CBlockIndex *pindexOld = nullptr;
     // New tip during the interrupted flush.
     const CBlockIndex *pindexNew;
     // Latest block common to both the old and the new tip.
     const CBlockIndex *pindexFork = nullptr;
 
     if (mapBlockIndex.count(hashHeads[0]) == 0) {
         return error(
             "ReplayBlocks(): reorganization to unknown block requested");
     }
 
     pindexNew = mapBlockIndex[hashHeads[0]];
 
     if (!hashHeads[1].IsNull()) {
         // The old tip is allowed to be 0, indicating it's the first flush.
         if (mapBlockIndex.count(hashHeads[1]) == 0) {
             return error(
                 "ReplayBlocks(): reorganization from unknown block requested");
         }
 
         pindexOld = mapBlockIndex[hashHeads[1]];
         pindexFork = LastCommonAncestor(pindexOld, pindexNew);
         assert(pindexFork != nullptr);
     }
 
     // Rollback along the old branch.
     while (pindexOld != pindexFork) {
         if (pindexOld->nHeight > 0) {
             // Never disconnect the genesis block.
             CBlock block;
             if (!ReadBlockFromDisk(block, pindexOld, params)) {
                 return error("RollbackBlock(): ReadBlockFromDisk() failed at "
                              "%d, hash=%s",
                              pindexOld->nHeight,
                              pindexOld->GetBlockHash().ToString());
             }
 
             LogPrintf("Rolling back %s (%i)\n",
                       pindexOld->GetBlockHash().ToString(), pindexOld->nHeight);
             DisconnectResult res = DisconnectBlock(block, pindexOld, cache);
             if (res == DISCONNECT_FAILED) {
                 return error(
                     "RollbackBlock(): DisconnectBlock failed at %d, hash=%s",
                     pindexOld->nHeight, pindexOld->GetBlockHash().ToString());
             }
 
             // If DISCONNECT_UNCLEAN is returned, it means a non-existing UTXO
             // was deleted, or an existing UTXO was overwritten. It corresponds
             // to cases where the block-to-be-disconnect never had all its
             // operations applied to the UTXO set. However, as both writing a
             // UTXO and deleting a UTXO are idempotent operations, the result is
             // still a version of the UTXO set with the effects of that block
             // undone.
         }
         pindexOld = pindexOld->pprev;
     }
 
     // Roll forward from the forking point to the new tip.
     int nForkHeight = pindexFork ? pindexFork->nHeight : 0;
     for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight;
          ++nHeight) {
         const CBlockIndex *pindex = pindexNew->GetAncestor(nHeight);
         LogPrintf("Rolling forward %s (%i)\n",
                   pindex->GetBlockHash().ToString(), nHeight);
         if (!RollforwardBlock(pindex, cache, params)) {
             return false;
         }
     }
 
     cache.SetBestBlock(pindexNew->GetBlockHash());
     cache.Flush();
     uiInterface.ShowProgress("", 100, false);
     return true;
 }
 
 bool ReplayBlocks(const Consensus::Params &params, CCoinsView *view) {
     return g_chainstate.ReplayBlocks(params, view);
 }
 
 bool CChainState::RewindBlockIndex(const Config &config) {
     LOCK(cs_main);
 
     const CChainParams &params = config.GetChainParams();
     int nHeight = chainActive.Height() + 1;
 
     // nHeight is now the height of the first insufficiently-validated block, or
     // tipheight + 1
     CValidationState state;
     CBlockIndex *pindex = chainActive.Tip();
     while (chainActive.Height() >= nHeight) {
         if (fPruneMode && !chainActive.Tip()->nStatus.hasData()) {
             // If pruning, don't try rewinding past the HAVE_DATA point; since
             // older blocks can't be served anyway, there's no need to walk
             // further, and trying to DisconnectTip() will fail (and require a
             // needless reindex/redownload of the blockchain).
             break;
         }
 
         if (!DisconnectTip(config, state, nullptr)) {
             return error("RewindBlockIndex: unable to disconnect block at "
                          "height %i (%s)",
                          pindex->nHeight, FormatStateMessage(state));
         }
 
         // Occasionally flush state to disk.
         if (!FlushStateToDisk(params, state, FlushStateMode::PERIODIC)) {
             LogPrintf("RewindBlockIndex: unable to flush state to disk (%s)\n",
                       FormatStateMessage(state));
             return false;
         }
     }
 
     // Reduce validity flag and have-data flags.
     // We do this after actual disconnecting, otherwise we'll end up writing the
     // lack of data to disk before writing the chainstate, resulting in a
     // failure to continue if interrupted.
     for (const auto &entry : mapBlockIndex) {
         CBlockIndex *pindexIter = entry.second;
         if (pindexIter->IsValid(BlockValidity::TRANSACTIONS) &&
             pindexIter->nChainTx) {
             setBlockIndexCandidates.insert(pindexIter);
         }
     }
 
     if (chainActive.Tip() != nullptr) {
         // We can't prune block index candidates based on our tip if we have
         // no tip due to chainActive being empty!
         PruneBlockIndexCandidates();
 
         CheckBlockIndex(params.GetConsensus());
     }
 
     return true;
 }
 
 bool RewindBlockIndex(const Config &config) {
     if (!g_chainstate.RewindBlockIndex(config)) {
         return false;
     }
 
     if (chainActive.Tip() != nullptr) {
         // FlushStateToDisk can possibly read chainActive. Be conservative
         // and skip it here, we're about to -reindex-chainstate anyway, so
         // it'll get called a bunch real soon.
         CValidationState state;
         if (!FlushStateToDisk(config.GetChainParams(), state,
                               FlushStateMode::ALWAYS)) {
             LogPrintf("RewindBlockIndex: unable to flush state to disk (%s)\n",
                       FormatStateMessage(state));
             return false;
         }
     }
 
     return true;
 }
 
 // May NOT be used after any connections are up as much of the peer-processing
 // logic assumes a consistent block index state
 void CChainState::UnloadBlockIndex() {
     nBlockSequenceId = 1;
     m_failed_blocks.clear();
     setBlockIndexCandidates.clear();
 }
 
 // May NOT be used after any connections are up as much
 // of the peer-processing logic assumes a consistent
 // block index state
 void UnloadBlockIndex() {
     LOCK(cs_main);
     chainActive.SetTip(nullptr);
     pindexFinalized = nullptr;
     pindexBestInvalid = nullptr;
     pindexBestParked = nullptr;
     pindexBestHeader = nullptr;
     pindexBestForkTip = nullptr;
     pindexBestForkBase = nullptr;
     g_mempool.clear();
     mapBlocksUnlinked.clear();
     vinfoBlockFile.clear();
     nLastBlockFile = 0;
     setDirtyBlockIndex.clear();
     setDirtyFileInfo.clear();
 
     for (const BlockMap::value_type &entry : mapBlockIndex) {
         delete entry.second;
     }
 
     mapBlockIndex.clear();
     fHavePruned = false;
 
     g_chainstate.UnloadBlockIndex();
 }
 
 bool LoadBlockIndex(const Config &config) {
     // Load block index from databases
     bool needs_init = fReindex;
     if (!fReindex) {
         bool ret = LoadBlockIndexDB(config);
         if (!ret) {
             return false;
         }
 
         needs_init = mapBlockIndex.empty();
     }
 
     if (needs_init) {
         // Everything here is for *new* reindex/DBs. Thus, though
         // LoadBlockIndexDB may have set fReindex if we shut down
         // mid-reindex previously, we don't check fReindex and
         // instead only check it prior to LoadBlockIndexDB to set
         // needs_init.
 
         LogPrintf("Initializing databases...\n");
     }
     return true;
 }
 
 bool CChainState::LoadGenesisBlock(const CChainParams &chainparams) {
     LOCK(cs_main);
 
     // Check whether we're already initialized by checking for genesis in
     // mapBlockIndex. Note that we can't use chainActive here, since it is
     // set based on the coins db, not the block index db, which is the only
     // thing loaded at this point.
     if (mapBlockIndex.count(chainparams.GenesisBlock().GetHash())) {
         return true;
     }
 
     try {
         const CBlock &block = chainparams.GenesisBlock();
         FlatFilePos blockPos = SaveBlockToDisk(block, 0, chainparams, nullptr);
         if (blockPos.IsNull()) {
             return error("%s: writing genesis block to disk failed", __func__);
         }
         CBlockIndex *pindex = AddToBlockIndex(block);
         CValidationState state;
         if (!ReceivedBlockTransactions(block, state, pindex, blockPos)) {
             return error("%s: genesis block not accepted (%s)", __func__,
                          FormatStateMessage(state));
         }
     } catch (const std::runtime_error &e) {
         return error("%s: failed to write genesis block: %s", __func__,
                      e.what());
     }
 
     return true;
 }
 
 bool LoadGenesisBlock(const CChainParams &chainparams) {
     return g_chainstate.LoadGenesisBlock(chainparams);
 }
 
 bool LoadExternalBlockFile(const Config &config, FILE *fileIn,
                            FlatFilePos *dbp) {
     // Map of disk positions for blocks with unknown parent (only used for
     // reindex)
     static std::multimap<uint256, FlatFilePos> mapBlocksUnknownParent;
     int64_t nStart = GetTimeMillis();
 
     const CChainParams &chainparams = config.GetChainParams();
 
     int nLoaded = 0;
     try {
         // This takes over fileIn and calls fclose() on it in the CBufferedFile
         // destructor. Make sure we have at least 2*MAX_TX_SIZE space in there
         // so any transaction can fit in the buffer.
         CBufferedFile blkdat(fileIn, 2 * MAX_TX_SIZE, MAX_TX_SIZE + 8, SER_DISK,
                              CLIENT_VERSION);
         uint64_t nRewind = blkdat.GetPos();
         while (!blkdat.eof()) {
             boost::this_thread::interruption_point();
 
             blkdat.SetPos(nRewind);
             // Start one byte further next time, in case of failure.
             nRewind++;
             // Remove former limit.
             blkdat.SetLimit();
             unsigned int nSize = 0;
             try {
                 // Locate a header.
                 uint8_t buf[CMessageHeader::MESSAGE_START_SIZE];
                 blkdat.FindByte(chainparams.DiskMagic()[0]);
                 nRewind = blkdat.GetPos() + 1;
                 blkdat >> buf;
                 if (memcmp(buf, chainparams.DiskMagic().data(),
                            CMessageHeader::MESSAGE_START_SIZE)) {
                     continue;
                 }
 
                 // Read size.
                 blkdat >> nSize;
                 if (nSize < 80) {
                     continue;
                 }
             } catch (const std::exception &) {
                 // No valid block header found; don't complain.
                 break;
             }
 
             try {
                 // read block
                 uint64_t nBlockPos = blkdat.GetPos();
                 if (dbp) {
                     dbp->nPos = nBlockPos;
                 }
                 blkdat.SetLimit(nBlockPos + nSize);
                 blkdat.SetPos(nBlockPos);
                 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
                 CBlock &block = *pblock;
                 blkdat >> block;
                 nRewind = blkdat.GetPos();
 
                 const BlockHash hash = block.GetHash();
                 {
                     LOCK(cs_main);
                     // detect out of order blocks, and store them for later
                     if (hash != chainparams.GetConsensus().hashGenesisBlock &&
                         !LookupBlockIndex(block.hashPrevBlock)) {
                         LogPrint(
                             BCLog::REINDEX,
                             "%s: Out of order block %s, parent %s not known\n",
                             __func__, hash.ToString(),
                             block.hashPrevBlock.ToString());
                         if (dbp) {
                             mapBlocksUnknownParent.insert(
                                 std::make_pair(block.hashPrevBlock, *dbp));
                         }
                         continue;
                     }
 
                     // process in case the block isn't known yet
                     CBlockIndex *pindex = LookupBlockIndex(hash);
                     if (!pindex || !pindex->nStatus.hasData()) {
                         CValidationState state;
                         if (g_chainstate.AcceptBlock(config, pblock, state,
                                                      true, dbp, nullptr)) {
                             nLoaded++;
                         }
                         if (state.IsError()) {
                             break;
                         }
                     } else if (hash != chainparams.GetConsensus()
                                            .hashGenesisBlock &&
                                pindex->nHeight % 1000 == 0) {
                         LogPrint(
                             BCLog::REINDEX,
                             "Block Import: already had block %s at height %d\n",
                             hash.ToString(), pindex->nHeight);
                     }
                 }
 
                 // Activate the genesis block so normal node progress can
                 // continue
                 if (hash == chainparams.GetConsensus().hashGenesisBlock) {
                     CValidationState state;
                     if (!ActivateBestChain(config, state)) {
                         break;
                     }
                 }
 
                 NotifyHeaderTip();
 
                 // Recursively process earlier encountered successors of this
                 // block
                 std::deque<uint256> queue;
                 queue.push_back(hash);
                 while (!queue.empty()) {
                     uint256 head = queue.front();
                     queue.pop_front();
                     std::pair<std::multimap<uint256, FlatFilePos>::iterator,
                               std::multimap<uint256, FlatFilePos>::iterator>
                         range = mapBlocksUnknownParent.equal_range(head);
                     while (range.first != range.second) {
                         std::multimap<uint256, FlatFilePos>::iterator it =
                             range.first;
                         std::shared_ptr<CBlock> pblockrecursive =
                             std::make_shared<CBlock>();
                         if (ReadBlockFromDisk(*pblockrecursive, it->second,
                                               chainparams.GetConsensus())) {
                             LogPrint(
                                 BCLog::REINDEX,
                                 "%s: Processing out of order child %s of %s\n",
                                 __func__, pblockrecursive->GetHash().ToString(),
                                 head.ToString());
                             LOCK(cs_main);
                             CValidationState dummy;
                             if (g_chainstate.AcceptBlock(
                                     config, pblockrecursive, dummy, true,
                                     &it->second, nullptr)) {
                                 nLoaded++;
                                 queue.push_back(pblockrecursive->GetHash());
                             }
                         }
                         range.first++;
                         mapBlocksUnknownParent.erase(it);
                         NotifyHeaderTip();
                     }
                 }
             } catch (const std::exception &e) {
                 LogPrintf("%s: Deserialize or I/O error - %s\n", __func__,
                           e.what());
             }
         }
     } catch (const std::runtime_error &e) {
         AbortNode(std::string("System error: ") + e.what());
     }
 
     if (nLoaded > 0) {
         LogPrintf("Loaded %i blocks from external file in %dms\n", nLoaded,
                   GetTimeMillis() - nStart);
     }
 
     return nLoaded > 0;
 }
 
 void CChainState::CheckBlockIndex(const Consensus::Params &consensusParams) {
     if (!fCheckBlockIndex) {
         return;
     }
 
     LOCK(cs_main);
 
     // During a reindex, we read the genesis block and call CheckBlockIndex
     // before ActivateBestChain, so we have the genesis block in mapBlockIndex
     // but no active chain. (A few of the tests when iterating the block tree
     // require that chainActive has been initialized.)
     if (chainActive.Height() < 0) {
         assert(mapBlockIndex.size() <= 1);
         return;
     }
 
     // Build forward-pointing map of the entire block tree.
     std::multimap<CBlockIndex *, CBlockIndex *> forward;
     for (const auto &entry : mapBlockIndex) {
         forward.emplace(entry.second->pprev, entry.second);
     }
 
     assert(forward.size() == mapBlockIndex.size());
 
     std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
               std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
         rangeGenesis = forward.equal_range(nullptr);
     CBlockIndex *pindex = rangeGenesis.first->second;
     rangeGenesis.first++;
     // There is only one index entry with parent nullptr.
     assert(rangeGenesis.first == rangeGenesis.second);
 
     // Iterate over the entire block tree, using depth-first search.
     // Along the way, remember whether there are blocks on the path from genesis
     // block being explored which are the first to have certain properties.
     size_t nNodes = 0;
     int nHeight = 0;
     // Oldest ancestor of pindex which is invalid.
     CBlockIndex *pindexFirstInvalid = nullptr;
     // Oldest ancestor of pindex which is parked.
     CBlockIndex *pindexFirstParked = nullptr;
     // Oldest ancestor of pindex which does not have data available.
     CBlockIndex *pindexFirstMissing = nullptr;
     // Oldest ancestor of pindex for which nTx == 0.
     CBlockIndex *pindexFirstNeverProcessed = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotTreeValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_TRANSACTIONS
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotTransactionsValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_CHAIN
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotChainValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_SCRIPTS
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotScriptsValid = nullptr;
     while (pindex != nullptr) {
         nNodes++;
         if (pindexFirstInvalid == nullptr && pindex->nStatus.hasFailed()) {
             pindexFirstInvalid = pindex;
         }
         if (pindexFirstParked == nullptr && pindex->nStatus.isParked()) {
             pindexFirstParked = pindex;
         }
         if (pindexFirstMissing == nullptr && !pindex->nStatus.hasData()) {
             pindexFirstMissing = pindex;
         }
         if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) {
             pindexFirstNeverProcessed = pindex;
         }
         if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::TREE) {
             pindexFirstNotTreeValid = pindex;
         }
         if (pindex->pprev != nullptr &&
             pindexFirstNotTransactionsValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::TRANSACTIONS) {
             pindexFirstNotTransactionsValid = pindex;
         }
         if (pindex->pprev != nullptr && pindexFirstNotChainValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::CHAIN) {
             pindexFirstNotChainValid = pindex;
         }
         if (pindex->pprev != nullptr && pindexFirstNotScriptsValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::SCRIPTS) {
             pindexFirstNotScriptsValid = pindex;
         }
 
         // Begin: actual consistency checks.
         if (pindex->pprev == nullptr) {
             // Genesis block checks.
             // Genesis block's hash must match.
             assert(pindex->GetBlockHash() == consensusParams.hashGenesisBlock);
             // The current active chain's genesis block must be this block.
             assert(pindex == chainActive.Genesis());
         }
         if (pindex->nChainTx == 0) {
             // nSequenceId can't be set positive for blocks that aren't linked
             // (negative is used for preciousblock)
             assert(pindex->nSequenceId <= 0);
         }
         // VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or
         // not pruning has occurred). HAVE_DATA is only equivalent to nTx > 0
         // (or VALID_TRANSACTIONS) if no pruning has occurred.
         if (!fHavePruned) {
             // If we've never pruned, then HAVE_DATA should be equivalent to nTx
             // > 0
             assert(pindex->nStatus.hasData() == (pindex->nTx > 0));
             assert(pindexFirstMissing == pindexFirstNeverProcessed);
         } else if (pindex->nStatus.hasData()) {
             // If we have pruned, then we can only say that HAVE_DATA implies
             // nTx > 0
             assert(pindex->nTx > 0);
         }
         if (pindex->nStatus.hasUndo()) {
             assert(pindex->nStatus.hasData());
         }
         // This is pruning-independent.
         assert((pindex->nStatus.getValidity() >= BlockValidity::TRANSACTIONS) ==
                (pindex->nTx > 0));
         // All parents having had data (at some point) is equivalent to all
         // parents being VALID_TRANSACTIONS, which is equivalent to nChainTx
         // being set.
         // nChainTx != 0 is used to signal that all parent blocks have been
         // processed (but may have been pruned).
         assert((pindexFirstNeverProcessed != nullptr) ==
                (pindex->nChainTx == 0));
         assert((pindexFirstNotTransactionsValid != nullptr) ==
                (pindex->nChainTx == 0));
         // nHeight must be consistent.
         assert(pindex->nHeight == nHeight);
         // For every block except the genesis block, the chainwork must be
         // larger than the parent's.
         assert(pindex->pprev == nullptr ||
                pindex->nChainWork >= pindex->pprev->nChainWork);
         // The pskip pointer must point back for all but the first 2 blocks.
         assert(nHeight < 2 ||
                (pindex->pskip && (pindex->pskip->nHeight < nHeight)));
         // All mapBlockIndex entries must at least be TREE valid
         assert(pindexFirstNotTreeValid == nullptr);
         if (pindex->nStatus.getValidity() >= BlockValidity::TREE) {
             // TREE valid implies all parents are TREE valid
             assert(pindexFirstNotTreeValid == nullptr);
         }
         if (pindex->nStatus.getValidity() >= BlockValidity::CHAIN) {
             // CHAIN valid implies all parents are CHAIN valid
             assert(pindexFirstNotChainValid == nullptr);
         }
         if (pindex->nStatus.getValidity() >= BlockValidity::SCRIPTS) {
             // SCRIPTS valid implies all parents are SCRIPTS valid
             assert(pindexFirstNotScriptsValid == nullptr);
         }
         if (pindexFirstInvalid == nullptr) {
             // Checks for not-invalid blocks.
             // The failed mask cannot be set for blocks without invalid parents.
             assert(!pindex->nStatus.isInvalid());
         }
         if (pindexFirstParked == nullptr) {
             // Checks for not-invalid blocks.
             // The failed mask cannot be set for blocks without invalid parents.
             assert(!pindex->nStatus.isOnParkedChain());
         }
         if (!CBlockIndexWorkComparator()(pindex, chainActive.Tip()) &&
             pindexFirstNeverProcessed == nullptr) {
             if (pindexFirstInvalid == nullptr) {
                 // If this block sorts at least as good as the current tip and
                 // is valid and we have all data for its parents, it must be in
                 // setBlockIndexCandidates or be parked.
                 if (pindexFirstMissing == nullptr) {
                     assert(pindex->nStatus.isOnParkedChain() ||
                            setBlockIndexCandidates.count(pindex));
                 }
                 // chainActive.Tip() must also be there even if some data has
                 // been pruned.
                 if (pindex == chainActive.Tip()) {
                     assert(setBlockIndexCandidates.count(pindex));
                 }
                 // If some parent is missing, then it could be that this block
                 // was in setBlockIndexCandidates but had to be removed because
                 // of the missing data. In this case it must be in
                 // mapBlocksUnlinked -- see test below.
             }
         } else {
             // If this block sorts worse than the current tip or some ancestor's
             // block has never been seen, it cannot be in
             // setBlockIndexCandidates.
             assert(setBlockIndexCandidates.count(pindex) == 0);
         }
         // Check whether this block is in mapBlocksUnlinked.
         std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                   std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
             rangeUnlinked = mapBlocksUnlinked.equal_range(pindex->pprev);
         bool foundInUnlinked = false;
         while (rangeUnlinked.first != rangeUnlinked.second) {
             assert(rangeUnlinked.first->first == pindex->pprev);
             if (rangeUnlinked.first->second == pindex) {
                 foundInUnlinked = true;
                 break;
             }
             rangeUnlinked.first++;
         }
         if (pindex->pprev && pindex->nStatus.hasData() &&
             pindexFirstNeverProcessed != nullptr &&
             pindexFirstInvalid == nullptr) {
             // If this block has block data available, some parent was never
             // received, and has no invalid parents, it must be in
             // mapBlocksUnlinked.
             assert(foundInUnlinked);
         }
         if (!pindex->nStatus.hasData()) {
             // Can't be in mapBlocksUnlinked if we don't HAVE_DATA
             assert(!foundInUnlinked);
         }
         if (pindexFirstMissing == nullptr) {
             // We aren't missing data for any parent -- cannot be in
             // mapBlocksUnlinked.
             assert(!foundInUnlinked);
         }
         if (pindex->pprev && pindex->nStatus.hasData() &&
             pindexFirstNeverProcessed == nullptr &&
             pindexFirstMissing != nullptr) {
             // We HAVE_DATA for this block, have received data for all parents
             // at some point, but we're currently missing data for some parent.
             // We must have pruned.
             assert(fHavePruned);
             // This block may have entered mapBlocksUnlinked if:
             //  - it has a descendant that at some point had more work than the
             //    tip, and
             //  - we tried switching to that descendant but were missing
             //    data for some intermediate block between chainActive and the
             //    tip.
             // So if this block is itself better than chainActive.Tip() and it
             // wasn't in
             // setBlockIndexCandidates, then it must be in mapBlocksUnlinked.
             if (!CBlockIndexWorkComparator()(pindex, chainActive.Tip()) &&
                 setBlockIndexCandidates.count(pindex) == 0) {
                 if (pindexFirstInvalid == nullptr) {
                     assert(foundInUnlinked);
                 }
             }
         }
         // Perhaps too slow
         // assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash());
         // End: actual consistency checks.
 
         // Try descending into the first subnode.
         std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                   std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
             range = forward.equal_range(pindex);
         if (range.first != range.second) {
             // A subnode was found.
             pindex = range.first->second;
             nHeight++;
             continue;
         }
         // This is a leaf node. Move upwards until we reach a node of which we
         // have not yet visited the last child.
         while (pindex) {
             // We are going to either move to a parent or a sibling of pindex.
             // If pindex was the first with a certain property, unset the
             // corresponding variable.
             if (pindex == pindexFirstInvalid) {
                 pindexFirstInvalid = nullptr;
             }
             if (pindex == pindexFirstParked) {
                 pindexFirstParked = nullptr;
             }
             if (pindex == pindexFirstMissing) {
                 pindexFirstMissing = nullptr;
             }
             if (pindex == pindexFirstNeverProcessed) {
                 pindexFirstNeverProcessed = nullptr;
             }
             if (pindex == pindexFirstNotTreeValid) {
                 pindexFirstNotTreeValid = nullptr;
             }
             if (pindex == pindexFirstNotTransactionsValid) {
                 pindexFirstNotTransactionsValid = nullptr;
             }
             if (pindex == pindexFirstNotChainValid) {
                 pindexFirstNotChainValid = nullptr;
             }
             if (pindex == pindexFirstNotScriptsValid) {
                 pindexFirstNotScriptsValid = nullptr;
             }
             // Find our parent.
             CBlockIndex *pindexPar = pindex->pprev;
             // Find which child we just visited.
             std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                       std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
                 rangePar = forward.equal_range(pindexPar);
             while (rangePar.first->second != pindex) {
                 // Our parent must have at least the node we're coming from as
                 // child.
                 assert(rangePar.first != rangePar.second);
                 rangePar.first++;
             }
             // Proceed to the next one.
             rangePar.first++;
             if (rangePar.first != rangePar.second) {
                 // Move to the sibling.
                 pindex = rangePar.first->second;
                 break;
             } else {
                 // Move up further.
                 pindex = pindexPar;
                 nHeight--;
                 continue;
             }
         }
     }
 
     // Check that we actually traversed the entire map.
     assert(nNodes == forward.size());
 }
 
 std::string CBlockFileInfo::ToString() const {
     return strprintf(
         "CBlockFileInfo(blocks=%u, size=%u, heights=%u...%u, time=%s...%s)",
         nBlocks, nSize, nHeightFirst, nHeightLast,
         FormatISO8601DateTime(nTimeFirst), FormatISO8601DateTime(nTimeLast));
 }
 
 CBlockFileInfo *GetBlockFileInfo(size_t n) {
     LOCK(cs_LastBlockFile);
 
     return &vinfoBlockFile.at(n);
 }
 
 static const uint64_t MEMPOOL_DUMP_VERSION = 1;
 
 bool LoadMempool(const Config &config, CTxMemPool &pool) {
     int64_t nExpiryTimeout =
         gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60;
     FILE *filestr = fsbridge::fopen(GetDataDir() / "mempool.dat", "rb");
     CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
     if (file.IsNull()) {
         LogPrintf(
             "Failed to open mempool file from disk. Continuing anyway.\n");
         return false;
     }
 
     int64_t count = 0;
     int64_t expired = 0;
     int64_t failed = 0;
     int64_t already_there = 0;
     int64_t nNow = GetTime();
 
     try {
         uint64_t version;
         file >> version;
         if (version != MEMPOOL_DUMP_VERSION) {
             return false;
         }
 
         uint64_t num;
         file >> num;
         double prioritydummy = 0;
         while (num--) {
             CTransactionRef tx;
             int64_t nTime;
             int64_t nFeeDelta;
             file >> tx;
             file >> nTime;
             file >> nFeeDelta;
 
             Amount amountdelta = nFeeDelta * SATOSHI;
             if (amountdelta != Amount::zero()) {
                 pool.PrioritiseTransaction(tx->GetId(), prioritydummy,
                                            amountdelta);
             }
             CValidationState state;
             if (nTime + nExpiryTimeout > nNow) {
                 LOCK(cs_main);
                 AcceptToMemoryPoolWithTime(
                     config, pool, state, tx, true /* fLimitFree */,
                     nullptr /* pfMissingInputs */, nTime,
                     false /* fOverrideMempoolLimit */,
                     Amount::zero() /* nAbsurdFee */, false /* test_accept */);
                 if (state.IsValid()) {
                     ++count;
                 } else {
                     // mempool may contain the transaction already, e.g. from
                     // wallet(s) having loaded it while we were processing
                     // mempool transactions; consider these as valid, instead of
                     // failed, but mark them as 'already there'
-                    if (pool.exists(tx->GetHash())) {
+                    if (pool.exists(tx->GetId())) {
                         ++already_there;
                     } else {
                         ++failed;
                     }
                 }
             } else {
                 ++expired;
             }
 
             if (ShutdownRequested()) {
                 return false;
             }
         }
-        std::map<uint256, Amount> mapDeltas;
+        std::map<TxId, Amount> mapDeltas;
         file >> mapDeltas;
 
         for (const auto &i : mapDeltas) {
             pool.PrioritiseTransaction(i.first, prioritydummy, i.second);
         }
     } catch (const std::exception &e) {
         LogPrintf("Failed to deserialize mempool data on disk: %s. Continuing "
                   "anyway.\n",
                   e.what());
         return false;
     }
 
     LogPrintf("Imported mempool transactions from disk: %i succeeded, %i "
               "failed, %i expired, %i already there\n",
               count, failed, expired, already_there);
     return true;
 }
 
 bool DumpMempool(const CTxMemPool &pool) {
     int64_t start = GetTimeMicros();
 
     std::map<uint256, Amount> mapDeltas;
     std::vector<TxMempoolInfo> vinfo;
 
     static Mutex dump_mutex;
     LOCK(dump_mutex);
 
     {
         LOCK(pool.cs);
         for (const auto &i : pool.mapDeltas) {
             mapDeltas[i.first] = i.second.second;
         }
 
         vinfo = pool.infoAll();
     }
 
     int64_t mid = GetTimeMicros();
 
     try {
         FILE *filestr = fsbridge::fopen(GetDataDir() / "mempool.dat.new", "wb");
         if (!filestr) {
             return false;
         }
 
         CAutoFile file(filestr, SER_DISK, CLIENT_VERSION);
 
         uint64_t version = MEMPOOL_DUMP_VERSION;
         file << version;
 
         file << uint64_t(vinfo.size());
         for (const auto &i : vinfo) {
             file << *(i.tx);
             file << int64_t(i.nTime);
             file << i.nFeeDelta;
             mapDeltas.erase(i.tx->GetId());
         }
 
         file << mapDeltas;
         if (!FileCommit(file.Get())) {
             throw std::runtime_error("FileCommit failed");
         }
         file.fclose();
         RenameOver(GetDataDir() / "mempool.dat.new",
                    GetDataDir() / "mempool.dat");
         int64_t last = GetTimeMicros();
         LogPrintf("Dumped mempool: %gs to copy, %gs to dump\n",
                   (mid - start) * MICRO, (last - mid) * MICRO);
     } catch (const std::exception &e) {
         LogPrintf("Failed to dump mempool: %s. Continuing anyway.\n", e.what());
         return false;
     }
     return true;
 }
 
 //! Guess how far we are in the verification process at the given block index
 //! require cs_main if pindex has not been validated yet (because nChainTx might
 //! be unset)
 //! This conditional lock requirement might be confusing, see:
 //! https://github.com/bitcoin/bitcoin/issues/15994
 double GuessVerificationProgress(const ChainTxData &data,
                                  const CBlockIndex *pindex) {
     if (pindex == nullptr) {
         return 0.0;
     }
 
     int64_t nNow = time(nullptr);
 
     double fTxTotal;
     if (pindex->nChainTx <= data.nTxCount) {
         fTxTotal = data.nTxCount + (nNow - data.nTime) * data.dTxRate;
     } else {
         fTxTotal =
             pindex->nChainTx + (nNow - pindex->GetBlockTime()) * data.dTxRate;
     }
 
     return pindex->nChainTx / fTxTotal;
 }
 
 class CMainCleanup {
 public:
     CMainCleanup() {}
     ~CMainCleanup() {
         // block headers
         for (const std::pair<const BlockHash, CBlockIndex *> &it :
              mapBlockIndex) {
             delete it.second;
         }
         mapBlockIndex.clear();
     }
 } instance_of_cmaincleanup;