diff --git a/src/test/pow_tests.cpp b/src/test/pow_tests.cpp
index bda6dca5b..356d64430 100644
--- a/src/test/pow_tests.cpp
+++ b/src/test/pow_tests.cpp
@@ -1,149 +1,190 @@
// Copyright (c) 2015 The Bitcoin Core developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "pow.h"
#include "chain.h"
#include "chainparams.h"
#include "random.h"
#include "test/test_bitcoin.h"
#include "util.h"
#include <boost/test/unit_test.hpp>
BOOST_FIXTURE_TEST_SUITE(pow_tests, BasicTestingSetup)
/* Test calculation of next difficulty target with no constraints applying */
BOOST_AUTO_TEST_CASE(get_next_work) {
SelectParams(CBaseChainParams::MAIN);
const Consensus::Params ¶ms = Params().GetConsensus();
int64_t nLastRetargetTime = 1261130161; // Block #30240
CBlockIndex pindexLast;
pindexLast.nHeight = 32255;
pindexLast.nTime = 1262152739; // Block #32255
pindexLast.nBits = 0x1d00ffff;
BOOST_CHECK_EQUAL(
CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params),
0x1d00d86a);
}
/* Test the constraint on the upper bound for next work */
BOOST_AUTO_TEST_CASE(get_next_work_pow_limit) {
SelectParams(CBaseChainParams::MAIN);
const Consensus::Params ¶ms = Params().GetConsensus();
int64_t nLastRetargetTime = 1231006505; // Block #0
CBlockIndex pindexLast;
pindexLast.nHeight = 2015;
pindexLast.nTime = 1233061996; // Block #2015
pindexLast.nBits = 0x1d00ffff;
BOOST_CHECK_EQUAL(
CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params),
0x1d00ffff);
}
/* Test the constraint on the lower bound for actual time taken */
BOOST_AUTO_TEST_CASE(get_next_work_lower_limit_actual) {
SelectParams(CBaseChainParams::MAIN);
const Consensus::Params ¶ms = Params().GetConsensus();
int64_t nLastRetargetTime = 1279008237; // Block #66528
CBlockIndex pindexLast;
pindexLast.nHeight = 68543;
pindexLast.nTime = 1279297671; // Block #68543
pindexLast.nBits = 0x1c05a3f4;
BOOST_CHECK_EQUAL(
CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params),
0x1c0168fd);
}
/* Test the constraint on the upper bound for actual time taken */
BOOST_AUTO_TEST_CASE(get_next_work_upper_limit_actual) {
SelectParams(CBaseChainParams::MAIN);
const Consensus::Params ¶ms = Params().GetConsensus();
int64_t nLastRetargetTime = 1263163443; // NOTE: Not an actual block time
CBlockIndex pindexLast;
pindexLast.nHeight = 46367;
pindexLast.nTime = 1269211443; // Block #46367
pindexLast.nBits = 0x1c387f6f;
BOOST_CHECK_EQUAL(
CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params),
0x1d00e1fd);
}
BOOST_AUTO_TEST_CASE(GetBlockProofEquivalentTime_test) {
SelectParams(CBaseChainParams::MAIN);
const Consensus::Params ¶ms = Params().GetConsensus();
std::vector<CBlockIndex> blocks(10000);
for (int i = 0; i < 10000; i++) {
blocks[i].pprev = i ? &blocks[i - 1] : nullptr;
blocks[i].nHeight = i;
blocks[i].nTime = 1269211443 + i * params.nPowTargetSpacing;
blocks[i].nBits = 0x207fffff; /* target 0x7fffff000... */
blocks[i].nChainWork =
i ? blocks[i - 1].nChainWork + GetBlockProof(blocks[i - 1])
: arith_uint256(0);
}
for (int j = 0; j < 1000; j++) {
CBlockIndex *p1 = &blocks[GetRand(10000)];
CBlockIndex *p2 = &blocks[GetRand(10000)];
CBlockIndex *p3 = &blocks[GetRand(10000)];
int64_t tdiff = GetBlockProofEquivalentTime(*p1, *p2, *p3, params);
BOOST_CHECK_EQUAL(tdiff, p1->GetBlockTime() - p2->GetBlockTime());
}
}
static CBlockIndex GetBlockIndex(CBlockIndex *pindexPrev, int64_t nTimeInterval,
uint32_t nBits) {
CBlockIndex block;
block.pprev = pindexPrev;
block.nHeight = pindexPrev->nHeight + 1;
block.nTime = pindexPrev->nTime + nTimeInterval;
block.nBits = nBits;
return block;
}
BOOST_AUTO_TEST_CASE(retargeting_test) {
SelectParams(CBaseChainParams::MAIN);
const Consensus::Params ¶ms = Params().GetConsensus();
- std::vector<CBlockIndex> blocks(1013);
+ std::vector<CBlockIndex> blocks(115);
+
+ const arith_uint256 powLimit = UintToArith256(params.powLimit);
+ arith_uint256 currentPow = powLimit >> 1;
+ uint32_t initialBits = currentPow.GetCompact();
// Genesis block?
blocks[0] = CBlockIndex();
blocks[0].nHeight = 0;
blocks[0].nTime = 1269211443;
- blocks[0].nBits = 0x207fffff;
+ blocks[0].nBits = initialBits;
// Pile up some blocks.
- for (size_t i = 1; i < 1000; i++) {
- blocks[i] =
- GetBlockIndex(&blocks[i - 1], params.nPowTargetSpacing, 0x207fffff);
+ for (size_t i = 1; i < 100; i++) {
+ blocks[i] = GetBlockIndex(&blocks[i - 1], params.nPowTargetSpacing,
+ initialBits);
}
CBlockHeader blkHeaderDummy;
// We start getting 2h blocks time. For the first 5 blocks, it doesn't
// matter as the MTP is not affected. For the next 5 block, MTP difference
- // increases but stays bellow 12h.
- for (size_t i = 1000; i < 1010; i++) {
- blocks[i] = GetBlockIndex(&blocks[i - 1], 2 * 3600, 0x207fffff);
+ // increases but stays below 12h.
+ for (size_t i = 100; i < 110; i++) {
+ blocks[i] = GetBlockIndex(&blocks[i - 1], 2 * 3600, initialBits);
BOOST_CHECK_EQUAL(
GetNextWorkRequired(&blocks[i], &blkHeaderDummy, params),
- 0x207fffff);
+ initialBits);
}
// Now we expect the difficulty to decrease.
- blocks[1010] = GetBlockIndex(&blocks[1009], 2 * 3600, 0x207fffff);
+ blocks[110] = GetBlockIndex(&blocks[109], 2 * 3600, initialBits);
+ currentPow.SetCompact(currentPow.GetCompact());
+ currentPow += (currentPow >> 2);
BOOST_CHECK_EQUAL(
- GetNextWorkRequired(&blocks[1010], &blkHeaderDummy, params),
- 0x1d00ffff);
+ GetNextWorkRequired(&blocks[110], &blkHeaderDummy, params),
+ currentPow.GetCompact());
+
+ // As we continue with 2h blocks, difficulty continue to decrease.
+ blocks[111] =
+ GetBlockIndex(&blocks[110], 2 * 3600, currentPow.GetCompact());
+ currentPow.SetCompact(currentPow.GetCompact());
+ currentPow += (currentPow >> 2);
+ BOOST_CHECK_EQUAL(
+ GetNextWorkRequired(&blocks[111], &blkHeaderDummy, params),
+ currentPow.GetCompact());
+
+ // We decrease again.
+ blocks[112] =
+ GetBlockIndex(&blocks[111], 2 * 3600, currentPow.GetCompact());
+ currentPow.SetCompact(currentPow.GetCompact());
+ currentPow += (currentPow >> 2);
+ BOOST_CHECK_EQUAL(
+ GetNextWorkRequired(&blocks[112], &blkHeaderDummy, params),
+ currentPow.GetCompact());
+
+ // We check that we do not go below the minimal difficulty.
+ blocks[113] =
+ GetBlockIndex(&blocks[112], 2 * 3600, currentPow.GetCompact());
+ currentPow.SetCompact(currentPow.GetCompact());
+ currentPow += (currentPow >> 2);
+ BOOST_CHECK(powLimit.GetCompact() != currentPow.GetCompact());
+ BOOST_CHECK_EQUAL(
+ GetNextWorkRequired(&blocks[113], &blkHeaderDummy, params),
+ powLimit.GetCompact());
+
+ // Once we reached the minimal difficulty, we stick with it.
+ blocks[114] = GetBlockIndex(&blocks[113], 2 * 3600, powLimit.GetCompact());
+ BOOST_CHECK(powLimit.GetCompact() != currentPow.GetCompact());
+ BOOST_CHECK_EQUAL(
+ GetNextWorkRequired(&blocks[114], &blkHeaderDummy, params),
+ powLimit.GetCompact());
}
BOOST_AUTO_TEST_SUITE_END()