No OneTemporary
Actions

Size

50 KB

Subscribers

None

View Options

	diff --git a/src/coins.h b/src/coins.h
	index 53aea809da..4b525619d5 100644
	--- a/src/coins.h
	+++ b/src/coins.h
	@@ -1,316 +1,315 @@
	// 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_COINS_H
	#define BITCOIN_COINS_H

	#include <compressor.h>
	-#include <core_memusage.h>
	#include <crypto/siphash.h>
	#include <memusage.h>
	+#include <primitives/blockhash.h>
	#include <serialize.h>
	-#include <uint256.h>

	#include <cassert>
	#include <cstdint>
	#include <unordered_map>

	/**
	* A UTXO entry.
	*
	* Serialized format:
	* - VARINT((coinbase ? 1 : 0) \| (height << 1))
	* - the non-spent CTxOut (via CTxOutCompressor)
	*/
	class Coin {
	//! Unspent transaction output.
	CTxOut out;

	//! Whether containing transaction was a coinbase and height at which the
	//! transaction was included into a block.
	uint32_t nHeightAndIsCoinBase;

	public:
	//! Empty constructor
	Coin() : nHeightAndIsCoinBase(0) {}

	//! Constructor from a CTxOut and height/coinbase information.
	Coin(CTxOut outIn, uint32_t nHeightIn, bool IsCoinbase)
	: out(std::move(outIn)),
	nHeightAndIsCoinBase((nHeightIn << 1) \| IsCoinbase) {}

	uint32_t GetHeight() const { return nHeightAndIsCoinBase >> 1; }
	bool IsCoinBase() const { return nHeightAndIsCoinBase & 0x01; }
	bool IsSpent() const { return out.IsNull(); }

	CTxOut &GetTxOut() { return out; }
	const CTxOut &GetTxOut() const { return out; }

	void Clear() {
	out.SetNull();
	nHeightAndIsCoinBase = 0;
	}

	template <typename Stream> void Serialize(Stream &s) const {
	assert(!IsSpent());
	::Serialize(s, VARINT(nHeightAndIsCoinBase));
	::Serialize(s, CTxOutCompressor(REF(out)));
	}

	template <typename Stream> void Unserialize(Stream &s) {
	::Unserialize(s, VARINT(nHeightAndIsCoinBase));
	::Unserialize(s, CTxOutCompressor(out));
	}

	size_t DynamicMemoryUsage() const {
	return memusage::DynamicUsage(out.scriptPubKey);
	}
	};

	class SaltedOutpointHasher {
	private:
	/** Salt */
	const uint64_t k0, k1;

	public:
	SaltedOutpointHasher();

	/**
	* This must return size_t. With Boost 1.46 on 32-bit systems the
	* unordered_map will behave unpredictably if the custom hasher returns a
	* uint64_t, resulting in failures when syncing the chain (#4634).
	* Note: This information above might be outdated as the unordered map
	* container type has meanwhile been switched to the C++ standard library
	* implementation.
	*/
	size_t operator()(const COutPoint &outpoint) const {
	return SipHashUint256Extra(k0, k1, outpoint.GetTxId(), outpoint.GetN());
	}
	};

	struct CCoinsCacheEntry {
	// The actual cached data.
	Coin coin;
	uint8_t flags;

	enum Flags {
	// This cache entry is potentially different from the version in the
	// parent view.
	DIRTY = (1 << 0),
	// The parent view does not have this entry (or it is pruned).
	FRESH = (1 << 1),
	/* Note that FRESH is a performance optimization with which we can erase
	coins that are fully spent if we know we do not need to flush the
	changes to the parent cache. It is always safe to not mark FRESH if
	that condition is not guaranteed. */
	};

	CCoinsCacheEntry() : flags(0) {}
	explicit CCoinsCacheEntry(Coin coinIn)
	: coin(std::move(coinIn)), flags(0) {}
	};

	typedef std::unordered_map<COutPoint, CCoinsCacheEntry, SaltedOutpointHasher>
	CCoinsMap;

	/** Cursor for iterating over CoinsView state */
	class CCoinsViewCursor {
	public:
	CCoinsViewCursor(const BlockHash &hashBlockIn) : hashBlock(hashBlockIn) {}
	virtual ~CCoinsViewCursor() {}

	virtual bool GetKey(COutPoint &key) const = 0;
	virtual bool GetValue(Coin &coin) const = 0;
	virtual unsigned int GetValueSize() const = 0;

	virtual bool Valid() const = 0;
	virtual void Next() = 0;

	//! Get best block at the time this cursor was created
	const BlockHash &GetBestBlock() const { return hashBlock; }

	private:
	BlockHash hashBlock;
	};

	/** Abstract view on the open txout dataset. */
	class CCoinsView {
	public:
	/**
	* Retrieve the Coin (unspent transaction output) for a given outpoint.
	* Returns true only when an unspent coin was found, which is returned in
	* coin. When false is returned, coin's value is unspecified.
	*/
	virtual bool GetCoin(const COutPoint &outpoint, Coin &coin) const;

	//! Just check whether a given outpoint is unspent.
	virtual bool HaveCoin(const COutPoint &outpoint) const;

	//! Retrieve the block hash whose state this CCoinsView currently represents
	virtual BlockHash GetBestBlock() const;

	//! Retrieve the range of blocks that may have been only partially written.
	//! If the database is in a consistent state, the result is the empty
	//! vector.
	//! Otherwise, a two-element vector is returned consisting of the new and
	//! the old block hash, in that order.
	virtual std::vector<BlockHash> GetHeadBlocks() const;

	//! Do a bulk modification (multiple Coin changes + BestBlock change).
	//! The passed mapCoins can be modified.
	virtual bool BatchWrite(CCoinsMap &mapCoins, const BlockHash &hashBlock);

	//! Get a cursor to iterate over the whole state
	virtual CCoinsViewCursor *Cursor() const;

	//! As we use CCoinsViews polymorphically, have a virtual destructor
	virtual ~CCoinsView() {}

	//! Estimate database size (0 if not implemented)
	virtual size_t EstimateSize() const { return 0; }
	};

	/** CCoinsView backed by another CCoinsView */
	class CCoinsViewBacked : public CCoinsView {
	protected:
	CCoinsView *base;

	public:
	CCoinsViewBacked(CCoinsView *viewIn);
	bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
	bool HaveCoin(const COutPoint &outpoint) const override;
	BlockHash GetBestBlock() const override;
	std::vector<BlockHash> GetHeadBlocks() const override;
	void SetBackend(CCoinsView &viewIn);
	bool BatchWrite(CCoinsMap &mapCoins, const BlockHash &hashBlock) override;
	CCoinsViewCursor *Cursor() const override;
	size_t EstimateSize() const override;
	};

	/**
	* CCoinsView that adds a memory cache for transactions to another CCoinsView
	*/
	class CCoinsViewCache : public CCoinsViewBacked {
	protected:
	/**
	* Make mutable so that we can "fill the cache" even from Get-methods
	* declared as "const".
	*/
	mutable BlockHash hashBlock;
	mutable CCoinsMap cacheCoins;

	/* Cached dynamic memory usage for the inner Coin objects. */
	mutable size_t cachedCoinsUsage;

	public:
	CCoinsViewCache(CCoinsView *baseIn);

	/**
	* By deleting the copy constructor, we prevent accidentally using it when
	* one intends to create a cache on top of a base cache.
	*/
	CCoinsViewCache(const CCoinsViewCache &) = delete;

	// Standard CCoinsView methods
	bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
	bool HaveCoin(const COutPoint &outpoint) const override;
	BlockHash GetBestBlock() const override;
	void SetBestBlock(const BlockHash &hashBlock);
	bool BatchWrite(CCoinsMap &mapCoins, const BlockHash &hashBlock) override;
	CCoinsViewCursor *Cursor() const override {
	throw std::logic_error(
	"CCoinsViewCache cursor iteration not supported.");
	}

	/**
	* Check if we have the given utxo already loaded in this cache.
	* The semantics are the same as HaveCoin(), but no calls to the backing
	* CCoinsView are made.
	*/
	bool HaveCoinInCache(const COutPoint &outpoint) const;

	/**
	* Return a reference to Coin in the cache, or a pruned one if not found.
	* This is more efficient than GetCoin.
	*
	* Generally, do not hold the reference returned for more than a short
	* scope. While the current implementation allows for modifications to the
	* contents of the cache while holding the reference, this behavior should
	* not be relied on! To be safe, best to not hold the returned reference
	* through any other calls to this cache.
	*/
	const Coin &AccessCoin(const COutPoint &output) const;

	/**
	* Add a coin. Set potential_overwrite to true if a non-pruned version may
	* already exist.
	*/
	void AddCoin(const COutPoint &outpoint, Coin coin,
	bool potential_overwrite);

	/**
	* Spend a coin. Pass moveto in order to get the deleted data.
	* If no unspent output exists for the passed outpoint, this call has no
	* effect.
	*/
	bool SpendCoin(const COutPoint &outpoint, Coin *moveto = nullptr);

	/**
	* Push the modifications applied to this cache to its base.
	* Failure to call this method before destruction will cause the changes to
	* be forgotten. If false is returned, the state of this cache (and its
	* backing view) will be undefined.
	*/
	bool Flush();

	/**
	* Removes the UTXO with the given outpoint from the cache, if it is not
	* modified.
	*/
	void Uncache(const COutPoint &outpoint);

	//! Calculate the size of the cache (in number of transaction outputs)
	unsigned int GetCacheSize() const;

	//! Calculate the size of the cache (in bytes)
	size_t DynamicMemoryUsage() const;

	/**
	* Amount of bitcoins coming in to a transaction
	* Note that lightweight clients may not know anything besides the hash of
	* previous transactions, so may not be able to calculate this.
	*
	* @param[in] tx transaction for which we are checking input total
	* @return Sum of value of all inputs (scriptSigs)
	*/
	Amount GetValueIn(const CTransaction &tx) const;

	//! Check whether all prevouts of the transaction are present in the UTXO
	//! set represented by this view
	bool HaveInputs(const CTransaction &tx) const;

	const CTxOut &GetOutputFor(const CTxIn &input) const;

	private:
	CCoinsMap::iterator FetchCoin(const COutPoint &outpoint) const;
	};

	//! Utility function to add all of a transaction's outputs to a cache.
	// When check is false, this assumes that overwrites are only possible for
	// coinbase transactions.
	// When check is true, the underlying view may be queried to determine whether
	// an addition is an overwrite.
	// TODO: pass in a boolean to limit these possible overwrites to known
	// (pre-BIP34) cases.
	void AddCoins(CCoinsViewCache &cache, const CTransaction &tx, int nHeight,
	bool check = false);

	//! Utility function to find any unspent output with a given txid.
	// This function can be quite expensive because in the event of a transaction
	// which is not found in the cache, it can cause up to MAX_OUTPUTS_PER_BLOCK
	// lookups to database, so it should be used with care.
	const Coin &AccessByTxid(const CCoinsViewCache &cache, const TxId &txid);

	#endif // BITCOIN_COINS_H
	diff --git a/src/txmempool.h b/src/txmempool.h
	index 6e78ab7fca..ba013a1e05 100644
	--- a/src/txmempool.h
	+++ b/src/txmempool.h
	@@ -1,988 +1,989 @@
	// 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 <core_memusage.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 <set>
	#include <string>
	#include <utility>
	#include <vector>

	class CBlockIndex;
	class Config;

	extern RecursiveMutex cs_main;

	/**
	* 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:
	const CTransactionRef tx;
	//! Cached to avoid expensive parent-transaction lookups
	const Amount nFee;
	//! ... and avoid recomputing tx size
	const size_t nTxSize;
	//! ... and total memory usage
	const size_t nUsageSize;
	//! Local time when entering the mempool
	const int64_t nTime;
	//! Chain height when entering the mempool
	const unsigned int entryHeight;
	//! keep track of transactions that spend a coinbase
	const bool spendsCoinbase;
	/**
	* Total sigop plus P2SH sigops count.
	* After the sigchecks activation we repurpose the 'sigops' tracking in
	* mempool/mining to actually track sigchecks instead. (Proper SigOps will
	* not need to be counted any more since it's getting deactivated.)
	*/
	const 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;
	//! ... and sigop count
	int64_t nSigOpCountWithDescendants;

	// 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, unsigned int _entryHeight,
	bool spendsCoinbase, int64_t _nSigOpCount, LockPoints lp);

	const CTransaction &GetTx() const { return *this->tx; }
	CTransactionRef GetSharedTx() const { return this->tx; }
	const Amount GetFee() const { return nFee; }
	size_t GetTxSize() const { return nTxSize; }
	size_t GetTxVirtualSize() const;

	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, int64_t modifySigOpCount);
	// Adjusts the ancestor state
	void UpdateAncestorState(int64_t modifySize, Amount modifyFee,
	int64_t modifyCount, int64_t 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; }
	uint64_t GetVirtualSizeWithDescendants() const;
	Amount GetModFeesWithDescendants() const { return nModFeesWithDescendants; }
	int64_t GetSigOpCountWithDescendants() const {
	return nSigOpCountWithDescendants;
	}

	bool GetSpendsCoinbase() const { return spendsCoinbase; }

	uint64_t GetCountWithAncestors() const { return nCountWithAncestors; }
	uint64_t GetSizeWithAncestors() const { return nSizeWithAncestors; }
	uint64_t GetVirtualSizeWithAncestors() const;
	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, int64_t _modifySigOpCount)
	: modifySize(_modifySize), modifyFee(_modifyFee),
	modifyCount(_modifyCount), modifySigOpCount(_modifySigOpCount) {}

	void operator()(CTxMemPoolEntry &e) {
	e.UpdateDescendantState(modifySize, modifyFee, modifyCount,
	modifySigOpCount);
	}

	private:
	int64_t modifySize;
	Amount modifyFee;
	int64_t modifyCount;
	int64_t modifySigOpCount;
	};

	struct update_ancestor_state {
	update_ancestor_state(int64_t _modifySize, Amount _modifyFee,
	int64_t _modifyCount, int64_t _modifySigOpCount)
	: modifySize(_modifySize), modifyFee(_modifyFee),
	modifyCount(_modifyCount), modifySigOpCount(_modifySigOpCount) {}

	void operator()(CTxMemPoolEntry &e) {
	e.UpdateAncestorState(modifySize, modifyFee, modifyCount,
	modifySigOpCount);
	}

	private:
	int64_t modifySize;
	Amount modifyFee;
	int64_t modifyCount;
	int64_t modifySigOpCount;
	};

	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 id from CTxMemPoolEntry or CTransactionRef
	struct mempoolentry_txid {
	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 (ad > cb).
	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.GetVirtualSizeWithDescendants() * (a.GetModifiedFee() / SATOSHI);
	double f2 =
	a.GetTxVirtualSize() * (a.GetModFeesWithDescendants() / SATOSHI);

	if (f2 > f1) {
	mod_fee = a.GetModFeesWithDescendants() / SATOSHI;
	size = a.GetVirtualSizeWithDescendants();
	} else {
	mod_fee = a.GetModifiedFee() / SATOSHI;
	size = a.GetTxVirtualSize();
	}
	}
	};

	/** \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 (ad > cb).
	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.GetVirtualSizeWithAncestors() * (a.GetModifiedFee() / SATOSHI);
	double f2 =
	a.GetTxVirtualSize() * (a.GetModFeesWithAncestors() / SATOSHI);

	if (f1 > f2) {
	mod_fee = a.GetModFeesWithAncestors() / SATOSHI;
	size = a.GetVirtualSizeWithAncestors();
	} else {
	mod_fee = a.GetModifiedFee() / SATOSHI;
	size = a.GetTxVirtualSize();
	}
	}
	};

	// 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 TxId &txid) const {
	return SipHashUint256(k0, k1, txid);
	}
	};

	/**
	* 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 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<TxHash, txiter>> vTxHashes;

	struct CompareIteratorById {
	bool operator()(const txiter &a, const txiter &b) const {
	return a->GetTx().GetId() < b->GetTx().GetId();
	}
	};
	typedef std::set<txiter, CompareIteratorById> 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, CompareIteratorById> cacheMap;

	struct TxLinks {
	setEntries parents;
	setEntries children;
	};

	typedef std::map<txiter, TxLinks, CompareIteratorById> 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<TxId, Amount> 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 CTxMemPoolEntry &entry)
	EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main);
	void addUnchecked(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 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 TxId &txid, const Amount nFeeDelta);
	void ApplyDelta(const TxId &txid, Amount &nFeeDelta) const;
	void ClearPrioritisation(const TxId &txid);

	/** Get the transaction in the pool that spends the same prevout */
	const CTransaction *GetConflictTx(const COutPoint &prevout) const
	EXCLUSIVE_LOCKS_REQUIRED(cs);

	/** Returns an iterator to the given txid, if found */
	boost::optional<txiter> GetIter(const TxId &txid) const
	EXCLUSIVE_LOCKS_REQUIRED(cs);

	/**
	* Translate a set of txids into a set of pool iterators to avoid repeated
	* lookups.
	*/
	setEntries GetIterSet(const std::set<TxId> &txids) const
	EXCLUSIVE_LOCKS_REQUIRED(cs);

	/**
	* 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 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(const TxId &txid) const {
	LOCK(cs);
	return mapTx.count(txid) != 0;
	}

	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;
	};

	/**
	* 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

File Metadata

Mime Type: text/x-diff
Expires: Sun, Mar 2, 12:58 (21 h, 45 m)
Storage Engine: blob
Storage Format: Raw Data
Storage Handle: 5187927
Default Alt Text: (50 KB)

No OneTemporaryActions

View Options

File Metadata

Event Timeline

No OneTemporary
Actions