/ src / test / skiplist_tests.cpp
skiplist_tests.cpp
  1  // Copyright (c) 2014-present 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 <chain.h>
  6  #include <test/util/random.h>
  7  #include <test/util/setup_common.h>
  8  
  9  #include <vector>
 10  
 11  #include <boost/test/unit_test.hpp>
 12  
 13  #define SKIPLIST_LENGTH 300000
 14  
 15  BOOST_FIXTURE_TEST_SUITE(skiplist_tests, BasicTestingSetup)
 16  
 17  BOOST_AUTO_TEST_CASE(skiplist_test)
 18  {
 19      std::vector<CBlockIndex> vIndex(SKIPLIST_LENGTH);
 20  
 21      for (int i=0; i<SKIPLIST_LENGTH; i++) {
 22          vIndex[i].nHeight = i;
 23          vIndex[i].pprev = (i == 0) ? nullptr : &vIndex[i - 1];
 24          vIndex[i].BuildSkip();
 25      }
 26  
 27      for (int i=0; i<SKIPLIST_LENGTH; i++) {
 28          if (i > 0) {
 29              BOOST_CHECK(vIndex[i].pskip == &vIndex[vIndex[i].pskip->nHeight]);
 30              BOOST_CHECK(vIndex[i].pskip->nHeight < i);
 31          } else {
 32              BOOST_CHECK(vIndex[i].pskip == nullptr);
 33          }
 34      }
 35  
 36      for (int i=0; i < 1000; i++) {
 37          int from = m_rng.randrange(SKIPLIST_LENGTH - 1);
 38          int to = m_rng.randrange(from + 1);
 39  
 40          BOOST_CHECK(vIndex[SKIPLIST_LENGTH - 1].GetAncestor(from) == &vIndex[from]);
 41          BOOST_CHECK(vIndex[from].GetAncestor(to) == &vIndex[to]);
 42          BOOST_CHECK(vIndex[from].GetAncestor(0) == vIndex.data());
 43      }
 44  }
 45  
 46  BOOST_AUTO_TEST_CASE(getlocator_test)
 47  {
 48      // Build a main chain 100000 blocks long.
 49      std::vector<uint256> vHashMain(100000);
 50      std::vector<CBlockIndex> vBlocksMain(100000);
 51      for (unsigned int i=0; i<vBlocksMain.size(); i++) {
 52          vHashMain[i] = ArithToUint256(i); // Set the hash equal to the height, so we can quickly check the distances.
 53          vBlocksMain[i].nHeight = i;
 54          vBlocksMain[i].pprev = i ? &vBlocksMain[i - 1] : nullptr;
 55          vBlocksMain[i].phashBlock = &vHashMain[i];
 56          vBlocksMain[i].BuildSkip();
 57          BOOST_CHECK_EQUAL((int)UintToArith256(vBlocksMain[i].GetBlockHash()).GetLow64(), vBlocksMain[i].nHeight);
 58          BOOST_CHECK(vBlocksMain[i].pprev == nullptr || vBlocksMain[i].nHeight == vBlocksMain[i].pprev->nHeight + 1);
 59      }
 60  
 61      // Build a branch that splits off at block 49999, 50000 blocks long.
 62      std::vector<uint256> vHashSide(50000);
 63      std::vector<CBlockIndex> vBlocksSide(50000);
 64      for (unsigned int i=0; i<vBlocksSide.size(); i++) {
 65          vHashSide[i] = ArithToUint256(i + 50000 + (arith_uint256(1) << 128)); // Add 1<<128 to the hashes, so GetLow64() still returns the height.
 66          vBlocksSide[i].nHeight = i + 50000;
 67          vBlocksSide[i].pprev = i ? &vBlocksSide[i - 1] : (vBlocksMain.data()+49999);
 68          vBlocksSide[i].phashBlock = &vHashSide[i];
 69          vBlocksSide[i].BuildSkip();
 70          BOOST_CHECK_EQUAL((int)UintToArith256(vBlocksSide[i].GetBlockHash()).GetLow64(), vBlocksSide[i].nHeight);
 71          BOOST_CHECK(vBlocksSide[i].pprev == nullptr || vBlocksSide[i].nHeight == vBlocksSide[i].pprev->nHeight + 1);
 72      }
 73  
 74      // Build a CChain for the main branch.
 75      CChain chain;
 76      chain.SetTip(vBlocksMain.back());
 77  
 78      // Test 100 random starting points for locators.
 79      for (int n=0; n<100; n++) {
 80          int r = m_rng.randrange(150000);
 81          CBlockIndex* tip = (r < 100000) ? &vBlocksMain[r] : &vBlocksSide[r - 100000];
 82          CBlockLocator locator = GetLocator(tip);
 83  
 84          // The first result must be the block itself, the last one must be genesis.
 85          BOOST_CHECK(locator.vHave.front() == tip->GetBlockHash());
 86          BOOST_CHECK(locator.vHave.back() == vBlocksMain[0].GetBlockHash());
 87  
 88          // Entries 1 through 11 (inclusive) go back one step each.
 89          for (unsigned int i = 1; i < 12 && i < locator.vHave.size() - 1; i++) {
 90              BOOST_CHECK_EQUAL(UintToArith256(locator.vHave[i]).GetLow64(), tip->nHeight - i);
 91          }
 92  
 93          // The further ones (excluding the last one) go back with exponential steps.
 94          unsigned int dist = 2;
 95          for (unsigned int i = 12; i < locator.vHave.size() - 1; i++) {
 96              BOOST_CHECK_EQUAL(UintToArith256(locator.vHave[i - 1]).GetLow64() - UintToArith256(locator.vHave[i]).GetLow64(), dist);
 97              dist *= 2;
 98          }
 99      }
100  }
101  
102  BOOST_AUTO_TEST_CASE(findearliestatleast_test)
103  {
104      std::vector<uint256> vHashMain(100000);
105      std::vector<CBlockIndex> vBlocksMain(100000);
106      for (unsigned int i=0; i<vBlocksMain.size(); i++) {
107          vHashMain[i] = ArithToUint256(i); // Set the hash equal to the height
108          vBlocksMain[i].nHeight = i;
109          vBlocksMain[i].pprev = i ? &vBlocksMain[i - 1] : nullptr;
110          vBlocksMain[i].phashBlock = &vHashMain[i];
111          vBlocksMain[i].BuildSkip();
112          if (i < 10) {
113              vBlocksMain[i].nTime = i;
114              vBlocksMain[i].nTimeMax = i;
115          } else {
116              // randomly choose something in the range [MTP, MTP*2]
117              int64_t medianTimePast = vBlocksMain[i].GetMedianTimePast();
118              int r{int(m_rng.randrange(medianTimePast))};
119              vBlocksMain[i].nTime = uint32_t(r + medianTimePast);
120              vBlocksMain[i].nTimeMax = std::max(vBlocksMain[i].nTime, vBlocksMain[i-1].nTimeMax);
121          }
122      }
123      // Check that we set nTimeMax up correctly.
124      unsigned int curTimeMax = 0;
125      for (unsigned int i=0; i<vBlocksMain.size(); ++i) {
126          curTimeMax = std::max(curTimeMax, vBlocksMain[i].nTime);
127          BOOST_CHECK(curTimeMax == vBlocksMain[i].nTimeMax);
128      }
129  
130      // Build a CChain for the main branch.
131      CChain chain;
132      chain.SetTip(vBlocksMain.back());
133  
134      // Verify that FindEarliestAtLeast is correct.
135      for (unsigned int i=0; i<10000; ++i) {
136          // Pick a random element in vBlocksMain.
137          int r = m_rng.randrange(vBlocksMain.size());
138          int64_t test_time = vBlocksMain[r].nTime;
139          CBlockIndex* ret = chain.FindEarliestAtLeast(test_time, 0);
140          BOOST_CHECK(ret->nTimeMax >= test_time);
141          BOOST_CHECK((ret->pprev==nullptr) || ret->pprev->nTimeMax < test_time);
142          BOOST_CHECK(vBlocksMain[r].GetAncestor(ret->nHeight) == ret);
143      }
144  }
145  
146  BOOST_AUTO_TEST_CASE(findearliestatleast_edge_test)
147  {
148      std::list<CBlockIndex> blocks;
149      for (const unsigned int timeMax : {100, 100, 100, 200, 200, 200, 300, 300, 300}) {
150          CBlockIndex* prev = blocks.empty() ? nullptr : &blocks.back();
151          blocks.emplace_back();
152          blocks.back().nHeight = prev ? prev->nHeight + 1 : 0;
153          blocks.back().pprev = prev;
154          blocks.back().BuildSkip();
155          blocks.back().nTimeMax = timeMax;
156      }
157  
158      CChain chain;
159      chain.SetTip(blocks.back());
160  
161      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(50, 0)->nHeight, 0);
162      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(100, 0)->nHeight, 0);
163      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(150, 0)->nHeight, 3);
164      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(200, 0)->nHeight, 3);
165      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(250, 0)->nHeight, 6);
166      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(300, 0)->nHeight, 6);
167      BOOST_CHECK(!chain.FindEarliestAtLeast(350, 0));
168  
169      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, 0)->nHeight, 0);
170      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(-1, 0)->nHeight, 0);
171  
172      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(std::numeric_limits<int64_t>::min(), 0)->nHeight, 0);
173      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(-int64_t(std::numeric_limits<unsigned int>::max()) - 1, 0)->nHeight, 0);
174      BOOST_CHECK(!chain.FindEarliestAtLeast(std::numeric_limits<int64_t>::max(), 0));
175      BOOST_CHECK(!chain.FindEarliestAtLeast(std::numeric_limits<unsigned int>::max(), 0));
176      BOOST_CHECK(!chain.FindEarliestAtLeast(int64_t(std::numeric_limits<unsigned int>::max()) + 1, 0));
177  
178      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, -1)->nHeight, 0);
179      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, 0)->nHeight, 0);
180      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, 3)->nHeight, 3);
181      BOOST_CHECK_EQUAL(chain.FindEarliestAtLeast(0, 8)->nHeight, 8);
182      BOOST_CHECK(!chain.FindEarliestAtLeast(0, 9));
183  
184      CBlockIndex* ret1 = chain.FindEarliestAtLeast(100, 2);
185      BOOST_CHECK(ret1->nTimeMax >= 100 && ret1->nHeight == 2);
186      BOOST_CHECK(!chain.FindEarliestAtLeast(300, 9));
187      CBlockIndex* ret2 = chain.FindEarliestAtLeast(200, 4);
188      BOOST_CHECK(ret2->nTimeMax >= 200 && ret2->nHeight == 4);
189  }
190  
191  BOOST_AUTO_TEST_SUITE_END()