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// 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 &params = 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 &params = 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 &params = 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 &params = 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 &params = 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])
: 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;
block.nChainWork = pindexPrev->nChainWork + GetBlockProof(block);
return block;
}
BOOST_AUTO_TEST_CASE(retargeting_test) {
SelectParams(CBaseChainParams::MAIN);
const Consensus::Params &params = Params().GetConsensus();
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 = initialBits;
blocks[0].nChainWork = GetBlockProof(blocks[0]);
// Pile up some blocks.
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 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),
initialBits);
}
// Now we expect the difficulty to decrease.
blocks[110] = GetBlockIndex(&blocks[109], 2 * 3600, initialBits);
currentPow.SetCompact(currentPow.GetCompact());
currentPow += (currentPow >> 2);
BOOST_CHECK_EQUAL(
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_CASE(cash_difficulty_test) {
SelectParams(CBaseChainParams::MAIN);
const Consensus::Params &params = Params().GetConsensus();
std::vector<CBlockIndex> blocks(3000);
const arith_uint256 powLimit = UintToArith256(params.powLimit);
uint32_t powLimitBits = powLimit.GetCompact();
arith_uint256 currentPow = powLimit >> 4;
uint32_t initialBits = currentPow.GetCompact();
// Genesis block.
blocks[0] = CBlockIndex();
blocks[0].nHeight = 0;
blocks[0].nTime = 1269211443;
blocks[0].nBits = initialBits;
blocks[0].nChainWork = GetBlockProof(blocks[0]);
// Block counter.
size_t i;
// Pile up some blocks every 10 mins to establish some history.
for (i = 1; i < 2050; i++) {
blocks[i] = GetBlockIndex(&blocks[i - 1], 600, initialBits);
}
CBlockHeader blkHeaderDummy;
uint32_t nBits =
GetNextCashWorkRequired(&blocks[2049], &blkHeaderDummy, params);
// Difficulty stays the same as long as we produce a block every 10 mins.
for (size_t j = 0; j < 10; i++, j++) {
blocks[i] = GetBlockIndex(&blocks[i - 1], 600, nBits);
BOOST_CHECK_EQUAL(
GetNextCashWorkRequired(&blocks[i], &blkHeaderDummy, params),
nBits);
}
// Make sure we skip over blocks that are out of wack. To do so, we produce
// a block that is far in the future, and then produce a block with the
// expected timestamp.
blocks[i] = GetBlockIndex(&blocks[i - 1], 6000, nBits);
BOOST_CHECK_EQUAL(
GetNextCashWorkRequired(&blocks[i++], &blkHeaderDummy, params), nBits);
blocks[i] = GetBlockIndex(&blocks[i - 1], 2 * 600 - 6000, nBits);
BOOST_CHECK_EQUAL(
GetNextCashWorkRequired(&blocks[i++], &blkHeaderDummy, params), nBits);
// The system should continue unaffected by the block with a bogous
// timestamps.
for (size_t j = 0; j < 20; i++, j++) {
blocks[i] = GetBlockIndex(&blocks[i - 1], 600, nBits);
BOOST_CHECK_EQUAL(
GetNextCashWorkRequired(&blocks[i], &blkHeaderDummy, params),
nBits);
}
// We start emitting blocks slightly faster. The first block has no impact.
blocks[i] = GetBlockIndex(&blocks[i - 1], 550, nBits);
BOOST_CHECK_EQUAL(
GetNextCashWorkRequired(&blocks[i++], &blkHeaderDummy, params), nBits);
// Now we should see difficulty increase slowly.
for (size_t j = 0; j < 10; i++, j++) {
blocks[i] = GetBlockIndex(&blocks[i - 1], 550, nBits);
const uint32_t nextBits =
GetNextCashWorkRequired(&blocks[i], &blkHeaderDummy, params);
arith_uint256 currentTarget;
currentTarget.SetCompact(nBits);
arith_uint256 nextTarget;
nextTarget.SetCompact(nextBits);
// Make sure that difficulty increases very slowly.
BOOST_CHECK(nextTarget < currentTarget);
BOOST_CHECK((currentTarget - nextTarget) < (currentTarget >> 10));
nBits = nextBits;
}
// Check the actual value.
BOOST_CHECK_EQUAL(nBits, 0x1c0fe7b1);
// If we dramatically shorten block production, difficulty increases faster.
for (size_t j = 0; j < 20; i++, j++) {
blocks[i] = GetBlockIndex(&blocks[i - 1], 10, nBits);
const uint32_t nextBits =
GetNextCashWorkRequired(&blocks[i], &blkHeaderDummy, params);
arith_uint256 currentTarget;
currentTarget.SetCompact(nBits);
arith_uint256 nextTarget;
nextTarget.SetCompact(nextBits);
// Make sure that difficulty increases faster.
BOOST_CHECK(nextTarget < currentTarget);
BOOST_CHECK((currentTarget - nextTarget) < (currentTarget >> 4));
nBits = nextBits;
}
// Check the actual value.
BOOST_CHECK_EQUAL(nBits, 0x1c0db19f);
// We start to emit blocks significantly slower. The first block has no
// impact.
blocks[i] = GetBlockIndex(&blocks[i - 1], 6000, nBits);
nBits = GetNextCashWorkRequired(&blocks[i++], &blkHeaderDummy, params);
// Check the actual value.
BOOST_CHECK_EQUAL(nBits, 0x1c0d9222);
// If we dramatically slow down block production, difficulty decreases.
for (size_t j = 0; j < 93; i++, j++) {
blocks[i] = GetBlockIndex(&blocks[i - 1], 6000, nBits);
const uint32_t nextBits =
GetNextCashWorkRequired(&blocks[i], &blkHeaderDummy, params);
arith_uint256 currentTarget;
currentTarget.SetCompact(nBits);
arith_uint256 nextTarget;
nextTarget.SetCompact(nextBits);
// Check the difficulty decreases.
BOOST_CHECK(nextTarget <= powLimit);
BOOST_CHECK(nextTarget > currentTarget);
BOOST_CHECK((nextTarget - currentTarget) < (currentTarget >> 3));
nBits = nextBits;
}
// Check the actual value.
BOOST_CHECK_EQUAL(nBits, 0x1c2f13b9);
// Due to the window of time being bounded, next block's difficulty actually
// gets harder.
blocks[i] = GetBlockIndex(&blocks[i - 1], 6000, nBits);
nBits = GetNextCashWorkRequired(&blocks[i++], &blkHeaderDummy, params);
BOOST_CHECK_EQUAL(nBits, 0x1c2ee9bf);
// And goes down again. It takes a while due to the window being bounded and
// the skewed block causes 2 blocks to get out of the window.
for (size_t j = 0; j < 192; i++, j++) {
blocks[i] = GetBlockIndex(&blocks[i - 1], 6000, nBits);
const uint32_t nextBits =
GetNextCashWorkRequired(&blocks[i], &blkHeaderDummy, params);
arith_uint256 currentTarget;
currentTarget.SetCompact(nBits);
arith_uint256 nextTarget;
nextTarget.SetCompact(nextBits);
// Check the difficulty decreases.
BOOST_CHECK(nextTarget <= powLimit);
BOOST_CHECK(nextTarget > currentTarget);
BOOST_CHECK((nextTarget - currentTarget) < (currentTarget >> 3));
nBits = nextBits;
}
// Check the actual value.
BOOST_CHECK_EQUAL(nBits, 0x1d00ffff);
// Once the difficulty reached the minimum allowed level, it doesn't get any
// easier.
for (size_t j = 0; j < 5; i++, j++) {
blocks[i] = GetBlockIndex(&blocks[i - 1], 6000, nBits);
const uint32_t nextBits =
GetNextCashWorkRequired(&blocks[i], &blkHeaderDummy, params);
// Check the difficulty stays constant.
BOOST_CHECK_EQUAL(nextBits, powLimitBits);
nBits = nextBits;
}
}
BOOST_AUTO_TEST_SUITE_END()