Line data    Source code

       1             : // Copyright (c) 2017-2020 The Bitcoin Core developers
       2             : // Distributed under the MIT software license, see the accompanying
       3             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       4             : 
       5             : #include <boost/test/unit_test.hpp>
       6             : 
       7             : #include <stdlib.h>
       8             : 
       9             : #include <chain.h>
      10             : #include <rpc/blockchain.h>
      11             : #include <test/util/setup_common.h>
      12             : #include <util/string.h>
      13             : 
      14             : /* Equality between doubles is imprecise. Comparison should be done
      15             :  * with a small threshold of tolerance, rather than exact equality.
      16             :  */
      17           5 : static bool DoubleEquals(double a, double b, double epsilon)
      18             : {
      19           5 :     return std::abs(a - b) < epsilon;
      20             : }
      21             : 
      22           5 : static CBlockIndex* CreateBlockIndexWithNbits(uint32_t nbits)
      23             : {
      24           5 :     CBlockIndex* block_index = new CBlockIndex();
      25           5 :     block_index->nHeight = 46367;
      26           5 :     block_index->nTime = 1269211443;
      27           5 :     block_index->nBits = nbits;
      28           5 :     return block_index;
      29           0 : }
      30             : 
      31           5 : static void RejectDifficultyMismatch(double difficulty, double expected_difficulty) {
      32           5 :      BOOST_CHECK_MESSAGE(
      33             :         DoubleEquals(difficulty, expected_difficulty, 0.00001),
      34             :         "Difficulty was " + ToString(difficulty)
      35             :             + " but was expected to be " + ToString(expected_difficulty));
      36           5 : }
      37             : 
      38             : /* Given a BlockIndex with the provided nbits,
      39             :  * verify that the expected difficulty results.
      40             :  */
      41           5 : static void TestDifficulty(uint32_t nbits, double expected_difficulty)
      42             : {
      43           5 :     CBlockIndex* block_index = CreateBlockIndexWithNbits(nbits);
      44           5 :     double difficulty = GetDifficulty(block_index);
      45           5 :     delete block_index;
      46             : 
      47           5 :     RejectDifficultyMismatch(difficulty, expected_difficulty);
      48           5 : }
      49             : 
      50          89 : BOOST_FIXTURE_TEST_SUITE(blockchain_tests, BasicTestingSetup)
      51             : 
      52          95 : BOOST_AUTO_TEST_CASE(get_difficulty_for_very_low_target)
      53             : {
      54           1 :     TestDifficulty(0x1f111111, 0.000001);
      55           1 : }
      56             : 
      57          95 : BOOST_AUTO_TEST_CASE(get_difficulty_for_low_target)
      58             : {
      59           1 :     TestDifficulty(0x1ef88f6f, 0.000016);
      60           1 : }
      61             : 
      62          95 : BOOST_AUTO_TEST_CASE(get_difficulty_for_mid_target)
      63             : {
      64           1 :     TestDifficulty(0x1df88f6f, 0.004023);
      65           1 : }
      66             : 
      67          95 : BOOST_AUTO_TEST_CASE(get_difficulty_for_high_target)
      68             : {
      69           1 :     TestDifficulty(0x1cf88f6f, 1.029916);
      70           1 : }
      71             : 
      72          95 : BOOST_AUTO_TEST_CASE(get_difficulty_for_very_high_target)
      73             : {
      74           1 :     TestDifficulty(0x12345678, 5913134931067755359633408.0);
      75           1 : }
      76             : 
      77          89 : BOOST_AUTO_TEST_SUITE_END()