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Add unit tests for next difficulty calculations

Split GetNextWorkRequired() into two functions to allow the difficulty calculations to
be tested without requiring a full blockchain.
Add unit tests to cover basic difficulty calculation, plus each of the min/max actual
time, and maximum difficulty target conditions.
tags/v0.15.1
Ross Nicoll 6 years ago
parent
commit
34e5015cd2
No account linked to committer's email address
4 changed files with 74 additions and 1 deletions
  1. 1
    0
      src/Makefile.test.include
  2. 6
    1
      src/pow.cpp
  3. 1
    0
      src/pow.h
  4. 66
    0
      src/test/pow_tests.cpp

+ 1
- 0
src/Makefile.test.include View File

@@ -55,6 +55,7 @@ BITCOIN_TESTS =\
test/multisig_tests.cpp \
test/netbase_tests.cpp \
test/pmt_tests.cpp \
test/pow_tests.cpp \
test/rpc_tests.cpp \
test/sanity_tests.cpp \
test/script_P2SH_tests.cpp \

+ 6
- 1
src/pow.cpp View File

@@ -48,8 +48,13 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
pindexFirst = pindexFirst->pprev;
assert(pindexFirst);

return CalculateNextWorkRequired(pindexLast, pindexFirst->GetBlockTime());
}

unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime)
{
// Limit adjustment step
int64_t nActualTimespan = pindexLast->GetBlockTime() - pindexFirst->GetBlockTime();
int64_t nActualTimespan = pindexLast->GetBlockTime() - nFirstBlockTime;
LogPrintf(" nActualTimespan = %d before bounds\n", nActualTimespan);
if (nActualTimespan < Params().TargetTimespan()/4)
nActualTimespan = Params().TargetTimespan()/4;

+ 1
- 0
src/pow.h View File

@@ -14,6 +14,7 @@ class uint256;
class arith_uint256;

unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock);
unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime);

/** Check whether a block hash satisfies the proof-of-work requirement specified by nBits */
bool CheckProofOfWork(uint256 hash, unsigned int nBits);

+ 66
- 0
src/test/pow_tests.cpp View File

@@ -0,0 +1,66 @@
// 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 "main.h"
#include "pow.h"
#include "util.h"

#include <boost/test/unit_test.hpp>

using namespace std;

BOOST_AUTO_TEST_SUITE(pow_tests)

/* Test calculation of next difficulty target with no constraints applying */
BOOST_AUTO_TEST_CASE(get_next_work)
{
SelectParams(CBaseChainParams::MAIN);

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), 0x1d00d86a);
}

/* Test the constraint on the upper bound for next work */
BOOST_AUTO_TEST_CASE(get_next_work_pow_limit)
{
SelectParams(CBaseChainParams::MAIN);

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), 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);

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), 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);
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), 0x1d00e1fd);
}

BOOST_AUTO_TEST_SUITE_END()

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