text: // Copyright (c) 2011-2015 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "txmempool.h"
  #include "util.h"
  
  #include "test/test_paradigm.h"
  
  #include <boost/test/unit_test.hpp>
  #include <list>
  #include <vector>
  
  BOOST_FIXTURE_TEST_SUITE(mempool_tests, TestingSetup)
  
  BOOST_AUTO_TEST_CASE(MempoolRemoveTest)
  {
      // Test CTxMemPool::remove functionality
  
      TestMemPoolEntryHelper entry;
      // Parent transaction with three children,
      // and three grand-children:
      CMutableTransaction txParent;
      txParent.vin.resize(1);
      txParent.vin[0].scriptSig = CScript() << OP_11;
      txParent.vout.resize(3);
      for (int i = 0; i < 3; i++)
      {
          txParent.vout[i].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
          txParent.vout[i].nValue = 33000LL;
      }
      CMutableTransaction txChild[3];
      for (int i = 0; i < 3; i++)
      {
          txChild[i].vin.resize(1);
          txChild[i].vin[0].scriptSig = CScript() << OP_11;
          txChild[i].vin[0].prevout.hash = txParent.GetHash();
          txChild[i].vin[0].prevout.n = i;
          txChild[i].vout.resize(1);
          txChild[i].vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
          txChild[i].vout[0].nValue = 11000LL;
      }
      CMutableTransaction txGrandChild[3];
      for (int i = 0; i < 3; i++)
      {
          txGrandChild[i].vin.resize(1);
          txGrandChild[i].vin[0].scriptSig = CScript() << OP_11;
          txGrandChild[i].vin[0].prevout.hash = txChild[i].GetHash();
          txGrandChild[i].vin[0].prevout.n = 0;
          txGrandChild[i].vout.resize(1);
          txGrandChild[i].vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
          txGrandChild[i].vout[0].nValue = 11000LL;
      }
  
  
      CTxMemPool testPool(CFeeRate(0));
      std::list<CTransaction> removed;
  
      // Nothing in pool, remove should do nothing:
      testPool.remove(txParent, removed, true);
      BOOST_CHECK_EQUAL(removed.size(), 0);
  
      // Just the parent:
      testPool.addUnchecked(txParent.GetHash(), entry.FromTx(txParent));
      testPool.remove(txParent, removed, true);
      BOOST_CHECK_EQUAL(removed.size(), 1);
      removed.clear();
      
      // Parent, children, grandchildren:
      testPool.addUnchecked(txParent.GetHash(), entry.FromTx(txParent));
      for (int i = 0; i < 3; i++)
      {
          testPool.addUnchecked(txChild[i].GetHash(), entry.FromTx(txChild[i]));
          testPool.addUnchecked(txGrandChild[i].GetHash(), entry.FromTx(txGrandChild[i]));
      }
      // Remove Child[0], GrandChild[0] should be removed:
      testPool.remove(txChild[0], removed, true);
      BOOST_CHECK_EQUAL(removed.size(), 2);
      removed.clear();
      // ... make sure grandchild and child are gone:
      testPool.remove(txGrandChild[0], removed, true);
      BOOST_CHECK_EQUAL(removed.size(), 0);
      testPool.remove(txChild[0], removed, true);
      BOOST_CHECK_EQUAL(removed.size(), 0);
      // Remove parent, all children/grandchildren should go:
      testPool.remove(txParent, removed, true);
      BOOST_CHECK_EQUAL(removed.size(), 5);
      BOOST_CHECK_EQUAL(testPool.size(), 0);
      removed.clear();
  
      // Add children and grandchildren, but NOT the parent (simulate the parent being in a block)
      for (int i = 0; i < 3; i++)
      {
          testPool.addUnchecked(txChild[i].GetHash(), entry.FromTx(txChild[i]));
          testPool.addUnchecked(txGrandChild[i].GetHash(), entry.FromTx(txGrandChild[i]));
      }
      // Now remove the parent, as might happen if a block-re-org occurs but the parent cannot be
      // put into the mempool (maybe because it is non-standard):
      testPool.remove(txParent, removed, true);
      BOOST_CHECK_EQUAL(removed.size(), 6);
      BOOST_CHECK_EQUAL(testPool.size(), 0);
      removed.clear();
  }
  
  template<int index>
  void CheckSort(CTxMemPool &pool, std::vector<std::string> &sortedOrder)
  {
      BOOST_CHECK_EQUAL(pool.size(), sortedOrder.size());
      typename CTxMemPool::indexed_transaction_set::nth_index<index>::type::iterator it = pool.mapTx.get<index>().begin();
      int count=0;
      for (; it != pool.mapTx.get<index>().end(); ++it, ++count) {
          BOOST_CHECK_EQUAL(it->GetTx().GetHash().ToString(), sortedOrder[count]);
      }
  }
  
  BOOST_AUTO_TEST_CASE(MempoolIndexingTest)
  {
      CTxMemPool pool(CFeeRate(0));
      TestMemPoolEntryHelper entry;
      entry.hadNoDependencies = true;
  
      /* 3rd highest fee */
      CMutableTransaction tx1 = CMutableTransaction();
      tx1.vout.resize(1);
      tx1.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx1.vout[0].nValue = 10 * COIN;
      pool.addUnchecked(tx1.GetHash(), entry.Fee(10000LL).Priority(10.0).FromTx(tx1));
  
      /* highest fee */
      CMutableTransaction tx2 = CMutableTransaction();
      tx2.vout.resize(1);
      tx2.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx2.vout[0].nValue = 2 * COIN;
      pool.addUnchecked(tx2.GetHash(), entry.Fee(20000LL).Priority(9.0).FromTx(tx2));
  
      /* lowest fee */
      CMutableTransaction tx3 = CMutableTransaction();
      tx3.vout.resize(1);
      tx3.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx3.vout[0].nValue = 5 * COIN;
      pool.addUnchecked(tx3.GetHash(), entry.Fee(0LL).Priority(100.0).FromTx(tx3));
  
      /* 2nd highest fee */
      CMutableTransaction tx4 = CMutableTransaction();
      tx4.vout.resize(1);
      tx4.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx4.vout[0].nValue = 6 * COIN;
      pool.addUnchecked(tx4.GetHash(), entry.Fee(15000LL).Priority(1.0).FromTx(tx4));
  
      /* equal fee rate to tx1, but newer */
      CMutableTransaction tx5 = CMutableTransaction();
      tx5.vout.resize(1);
      tx5.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx5.vout[0].nValue = 11 * COIN;
      entry.nTime = 1;
      entry.dPriority = 10.0;
      pool.addUnchecked(tx5.GetHash(), entry.Fee(10000LL).FromTx(tx5));
      BOOST_CHECK_EQUAL(pool.size(), 5);
  
      std::vector<std::string> sortedOrder;
      sortedOrder.resize(5);
      sortedOrder[0] = tx3.GetHash().ToString(); // 0
      sortedOrder[1] = tx5.GetHash().ToString(); // 10000
      sortedOrder[2] = tx1.GetHash().ToString(); // 10000
      sortedOrder[3] = tx4.GetHash().ToString(); // 15000
      sortedOrder[4] = tx2.GetHash().ToString(); // 20000
      CheckSort<1>(pool, sortedOrder);
  
      /* low fee but with high fee child */
      /* tx6 -> tx7 -> tx8, tx9 -> tx10 */
      CMutableTransaction tx6 = CMutableTransaction();
      tx6.vout.resize(1);
      tx6.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx6.vout[0].nValue = 20 * COIN;
      pool.addUnchecked(tx6.GetHash(), entry.Fee(0LL).FromTx(tx6));
      BOOST_CHECK_EQUAL(pool.size(), 6);
      // Check that at this point, tx6 is sorted low
      sortedOrder.insert(sortedOrder.begin(), tx6.GetHash().ToString());
      CheckSort<1>(pool, sortedOrder);
  
      CTxMemPool::setEntries setAncestors;
      setAncestors.insert(pool.mapTx.find(tx6.GetHash()));
      CMutableTransaction tx7 = CMutableTransaction();
      tx7.vin.resize(1);
      tx7.vin[0].prevout = COutPoint(tx6.GetHash(), 0);
      tx7.vin[0].scriptSig = CScript() << OP_11;
      tx7.vout.resize(2);
      tx7.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx7.vout[0].nValue = 10 * COIN;
      tx7.vout[1].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx7.vout[1].nValue = 1 * COIN;
  
      CTxMemPool::setEntries setAncestorsCalculated;
      std::string dummy;
      BOOST_CHECK_EQUAL(pool.CalculateMemPoolAncestors(entry.Fee(2000000LL).FromTx(tx7), setAncestorsCalculated, 100, 1000000, 1000, 1000000, dummy), true);
      BOOST_CHECK(setAncestorsCalculated == setAncestors);
  
      pool.addUnchecked(tx7.GetHash(), entry.FromTx(tx7), setAncestors);
      BOOST_CHECK_EQUAL(pool.size(), 7);
  
      // Now tx6 should be sorted higher (high fee child): tx7, tx6, tx2, ...
      sortedOrder.erase(sortedOrder.begin());
      sortedOrder.push_back(tx6.GetHash().ToString());
      sortedOrder.push_back(tx7.GetHash().ToString());
      CheckSort<1>(pool, sortedOrder);
  
      /* low fee child of tx7 */
      CMutableTransaction tx8 = CMutableTransaction();
      tx8.vin.resize(1);
      tx8.vin[0].prevout = COutPoint(tx7.GetHash(), 0);
      tx8.vin[0].scriptSig = CScript() << OP_11;
      tx8.vout.resize(1);
      tx8.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx8.vout[0].nValue = 10 * COIN;
      setAncestors.insert(pool.mapTx.find(tx7.GetHash()));
      pool.addUnchecked(tx8.GetHash(), entry.Fee(0LL).Time(2).FromTx(tx8), setAncestors);
  
      // Now tx8 should be sorted low, but tx6/tx both high
      sortedOrder.insert(sortedOrder.begin(), tx8.GetHash().ToString());
      CheckSort<1>(pool, sortedOrder);
  
      /* low fee child of tx7 */
      CMutableTransaction tx9 = CMutableTransaction();
      tx9.vin.resize(1);
      tx9.vin[0].prevout = COutPoint(tx7.GetHash(), 1);
      tx9.vin[0].scriptSig = CScript() << OP_11;
      tx9.vout.resize(1);
      tx9.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx9.vout[0].nValue = 1 * COIN;
      pool.addUnchecked(tx9.GetHash(), entry.Fee(0LL).Time(3).FromTx(tx9), setAncestors);
  
      // tx9 should be sorted low
      BOOST_CHECK_EQUAL(pool.size(), 9);
      sortedOrder.insert(sortedOrder.begin(), tx9.GetHash().ToString());
      CheckSort<1>(pool, sortedOrder);
  
      std::vector<std::string> snapshotOrder = sortedOrder;
  
      setAncestors.insert(pool.mapTx.find(tx8.GetHash()));
      setAncestors.insert(pool.mapTx.find(tx9.GetHash()));
      /* tx10 depends on tx8 and tx9 and has a high fee*/
      CMutableTransaction tx10 = CMutableTransaction();
      tx10.vin.resize(2);
      tx10.vin[0].prevout = COutPoint(tx8.GetHash(), 0);
      tx10.vin[0].scriptSig = CScript() << OP_11;
      tx10.vin[1].prevout = COutPoint(tx9.GetHash(), 0);
      tx10.vin[1].scriptSig = CScript() << OP_11;
      tx10.vout.resize(1);
      tx10.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
      tx10.vout[0].nValue = 10 * COIN;
  
      setAncestorsCalculated.clear();
      BOOST_CHECK_EQUAL(pool.CalculateMemPoolAncestors(entry.Fee(200000LL).Time(4).FromTx(tx10), setAncestorsCalculated, 100, 1000000, 1000, 1000000, dummy), true);
      BOOST_CHECK(setAncestorsCalculated == setAncestors);
  
      pool.addUnchecked(tx10.GetHash(), entry.FromTx(tx10), setAncestors);
  
      /**
       *  tx8 and tx9 should both now be sorted higher
       *  Final order after tx10 is added:
       *
       *  tx3 = 0 (1)
       *  tx5 = 10000 (1)
       *  tx1 = 10000 (1)
       *  tx4 = 15000 (1)
       *  tx2 = 20000 (1)
       *  tx9 = 200k (2 txs)
       *  tx8 = 200k (2 txs)
       *  tx10 = 200k (1 tx)
       *  tx6 = 2.2M (5 txs)
       *  tx7 = 2.2M (4 txs)
       */
      sortedOrder.erase(sortedOrder.begin(), sortedOrder.begin()+2); // take out tx9, tx8 from the beginning
      sortedOrder.insert(sortedOrder.begin()+5, tx9.GetHash().ToString());
      sortedOrder.insert(sortedOrder.begin()+6, tx8.GetHash().ToString());
      sortedOrder.insert(sortedOrder.begin()+7, tx10.GetHash().ToString()); // tx10 is just before tx6
      CheckSort<1>(pool, sortedOrder);
  
      // there should be 10 transactions in the mempool
      BOOST_CHECK_EQUAL(pool.size(), 10);
  
      // Now try removing tx10 and verify the sort order returns to normal
      std::list<CTransaction> removed;
      pool.remove(pool.mapTx.find(tx10.GetHash())->GetTx(), removed, true);
      CheckSort<1>(pool, snapshotOrder);
  
      pool.remove(pool.mapTx.find(tx9.GetHash())->GetTx(), removed, true);
      pool.remove(pool.mapTx.find(tx8.GetHash())->GetTx(), removed, true);
      /* Now check the sort on the mining score index.
       * Final order should be:
       *
       * tx7 (2M)
       * tx2 (20k)
       * tx4 (15000)
       * tx1/tx5 (10000)
       * tx3/6 (0)
       * (Ties resolved by hash)
       */
      sortedOrder.clear();
      sortedOrder.push_back(tx7.GetHash().ToString());
      sortedOrder.push_back(tx2.GetHash().ToString());
      sortedOrder.push_back(tx4.GetHash().ToString());
      if (tx1.GetHash() < tx5.GetHash()) {
          sortedOrder.push_back(tx5.GetHash().ToString());
          sortedOrder.push_back(tx1.GetHash().ToString());
      } else {
          sortedOrder.push_back(tx1.GetHash().ToString());
          sortedOrder.push_back(tx5.GetHash().ToString());
      }
      if (tx3.GetHash() < tx6.GetHash()) {
          sortedOrder.push_back(tx6.GetHash().ToString());
          sortedOrder.push_back(tx3.GetHash().ToString());
      } else {
          sortedOrder.push_back(tx3.GetHash().ToString());
          sortedOrder.push_back(tx6.GetHash().ToString());
      }
      CheckSort<3>(pool, sortedOrder);
  }
  
  
  BOOST_AUTO_TEST_CASE(MempoolSizeLimitTest)
  {
      CTxMemPool pool(CFeeRate(1000));
      TestMemPoolEntryHelper entry;
      entry.dPriority = 10.0;
  
      CMutableTransaction tx1 = CMutableTransaction();
      tx1.vin.resize(1);
      tx1.vin[0].scriptSig = CScript() << OP_1;
      tx1.vout.resize(1);
      tx1.vout[0].scriptPubKey = CScript() << OP_1 << OP_EQUAL;
      tx1.vout[0].nValue = 10 * COIN;
      pool.addUnchecked(tx1.GetHash(), entry.Fee(10000LL).FromTx(tx1, &pool));
  
      CMutableTransaction tx2 = CMutableTransaction();
      tx2.vin.resize(1);
      tx2.vin[0].scriptSig = CScript() << OP_2;
      tx2.vout.resize(1);
      tx2.vout[0].scriptPubKey = CScript() << OP_2 << OP_EQUAL;
      tx2.vout[0].nValue = 10 * COIN;
      pool.addUnchecked(tx2.GetHash(), entry.Fee(5000LL).FromTx(tx2, &pool));
  
      pool.TrimToSize(pool.DynamicMemoryUsage()); // should do nothing
      BOOST_CHECK(pool.exists(tx1.GetHash()));
      BOOST_CHECK(pool.exists(tx2.GetHash()));
  
      pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4); // should remove the lower-feerate transaction
      BOOST_CHECK(pool.exists(tx1.GetHash()));
      BOOST_CHECK(!pool.exists(tx2.GetHash()));
  
      pool.addUnchecked(tx2.GetHash(), entry.FromTx(tx2, &pool));
      CMutableTransaction tx3 = CMutableTransaction();
      tx3.vin.resize(1);
      tx3.vin[0].prevout = COutPoint(tx2.GetHash(), 0);
      tx3.vin[0].scriptSig = CScript() << OP_2;
      tx3.vout.resize(1);
      tx3.vout[0].scriptPubKey = CScript() << OP_3 << OP_EQUAL;
      tx3.vout[0].nValue = 10 * COIN;
      pool.addUnchecked(tx3.GetHash(), entry.Fee(20000LL).FromTx(tx3, &pool));
  
      pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4); // tx3 should pay for tx2 (CPFP)
      BOOST_CHECK(!pool.exists(tx1.GetHash()));
      BOOST_CHECK(pool.exists(tx2.GetHash()));
      BOOST_CHECK(pool.exists(tx3.GetHash()));
  
      pool.TrimToSize(::GetSerializeSize(CTransaction(tx1), SER_NETWORK, PROTOCOL_VERSION)); // mempool is limited to tx1's size in memory usage, so nothing fits
      BOOST_CHECK(!pool.exists(tx1.GetHash()));
      BOOST_CHECK(!pool.exists(tx2.GetHash()));
      BOOST_CHECK(!pool.exists(tx3.GetHash()));
  
      CFeeRate maxFeeRateRemoved(25000, ::GetSerializeSize(CTransaction(tx3), SER_NETWORK, PROTOCOL_VERSION) + ::GetSerializeSize(CTransaction(tx2), SER_NETWORK, PROTOCOL_VERSION));
      BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), maxFeeRateRemoved.GetFeePerK() + 1000);
  
      CMutableTransaction tx4 = CMutableTransaction();
      tx4.vin.resize(2);
      tx4.vin[0].prevout.SetNull();
      tx4.vin[0].scriptSig = CScript() << OP_4;
      tx4.vin[1].prevout.SetNull();
      tx4.vin[1].scriptSig = CScript() << OP_4;
      tx4.vout.resize(2);
      tx4.vout[0].scriptPubKey = CScript() << OP_4 << OP_EQUAL;
      tx4.vout[0].nValue = 10 * COIN;
      tx4.vout[1].scriptPubKey = CScript() << OP_4 << OP_EQUAL;
      tx4.vout[1].nValue = 10 * COIN;
  
      CMutableTransaction tx5 = CMutableTransaction();
      tx5.vin.resize(2);
      tx5.vin[0].prevout = COutPoint(tx4.GetHash(), 0);
      tx5.vin[0].scriptSig = CScript() << OP_4;
      tx5.vin[1].prevout.SetNull();
      tx5.vin[1].scriptSig = CScript() << OP_5;
      tx5.vout.resize(2);
      tx5.vout[0].scriptPubKey = CScript() << OP_5 << OP_EQUAL;
      tx5.vout[0].nValue = 10 * COIN;
      tx5.vout[1].scriptPubKey = CScript() << OP_5 << OP_EQUAL;
      tx5.vout[1].nValue = 10 * COIN;
  
      CMutableTransaction tx6 = CMutableTransaction();
      tx6.vin.resize(2);
      tx6.vin[0].prevout = COutPoint(tx4.GetHash(), 1);
      tx6.vin[0].scriptSig = CScript() << OP_4;
      tx6.vin[1].prevout.SetNull();
      tx6.vin[1].scriptSig = CScript() << OP_6;
      tx6.vout.resize(2);
      tx6.vout[0].scriptPubKey = CScript() << OP_6 << OP_EQUAL;
      tx6.vout[0].nValue = 10 * COIN;
      tx6.vout[1].scriptPubKey = CScript() << OP_6 << OP_EQUAL;
      tx6.vout[1].nValue = 10 * COIN;
  
      CMutableTransaction tx7 = CMutableTransaction();
      tx7.vin.resize(2);
      tx7.vin[0].prevout = COutPoint(tx5.GetHash(), 0);
      tx7.vin[0].scriptSig = CScript() << OP_5;
      tx7.vin[1].prevout = COutPoint(tx6.GetHash(), 0);
      tx7.vin[1].scriptSig = CScript() << OP_6;
      tx7.vout.resize(2);
      tx7.vout[0].scriptPubKey = CScript() << OP_7 << OP_EQUAL;
      tx7.vout[0].nValue = 10 * COIN;
      tx7.vout[1].scriptPubKey = CScript() << OP_7 << OP_EQUAL;
      tx7.vout[1].nValue = 10 * COIN;
  
      pool.addUnchecked(tx4.GetHash(), entry.Fee(7000LL).FromTx(tx4, &pool));
      pool.addUnchecked(tx5.GetHash(), entry.Fee(1000LL).FromTx(tx5, &pool));
      pool.addUnchecked(tx6.GetHash(), entry.Fee(1100LL).FromTx(tx6, &pool));
      pool.addUnchecked(tx7.GetHash(), entry.Fee(9000LL).FromTx(tx7, &pool));
  
      // we only require this remove, at max, 2 txn, because its not clear what we're really optimizing for aside from that
      pool.TrimToSize(pool.DynamicMemoryUsage() - 1);
      BOOST_CHECK(pool.exists(tx4.GetHash()));
      BOOST_CHECK(pool.exists(tx6.GetHash()));
      BOOST_CHECK(!pool.exists(tx7.GetHash()));
  
      if (!pool.exists(tx5.GetHash()))
          pool.addUnchecked(tx5.GetHash(), entry.Fee(1000LL).FromTx(tx5, &pool));
      pool.addUnchecked(tx7.GetHash(), entry.Fee(9000LL).FromTx(tx7, &pool));
  
      pool.TrimToSize(pool.DynamicMemoryUsage() / 2); // should maximize mempool size by only removing 5/7
      BOOST_CHECK(pool.exists(tx4.GetHash()));
      BOOST_CHECK(!pool.exists(tx5.GetHash()));
      BOOST_CHECK(pool.exists(tx6.GetHash()));
      BOOST_CHECK(!pool.exists(tx7.GetHash()));
  
      pool.addUnchecked(tx5.GetHash(), entry.Fee(1000LL).FromTx(tx5, &pool));
      pool.addUnchecked(tx7.GetHash(), entry.Fee(9000LL).FromTx(tx7, &pool));
  
      std::vector<CTransaction> vtx;
      std::list<CTransaction> conflicts;
      SetMockTime(42);
      SetMockTime(42 + CTxMemPool::ROLLING_FEE_HALFLIFE);
      BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), maxFeeRateRemoved.GetFeePerK() + 1000);
      // ... we should keep the same min fee until we get a block
      pool.removeForBlock(vtx, 1, conflicts);
      SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE);
      BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), (maxFeeRateRemoved.GetFeePerK() + 1000)/2);
      // ... then feerate should drop 1/2 each halflife
  
      SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2);
      BOOST_CHECK_EQUAL(pool.GetMinFee(pool.DynamicMemoryUsage() * 5 / 2).GetFeePerK(), (maxFeeRateRemoved.GetFeePerK() + 1000)/4);
      // ... with a 1/2 halflife when mempool is < 1/2 its target size
  
      SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
      BOOST_CHECK_EQUAL(pool.GetMinFee(pool.DynamicMemoryUsage() * 9 / 2).GetFeePerK(), (maxFeeRateRemoved.GetFeePerK() + 1000)/8);
      // ... with a 1/4 halflife when mempool is < 1/4 its target size
  
      SetMockTime(42 + 7*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
      BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), 1000);
      // ... but feerate should never drop below 1000
  
      SetMockTime(42 + 8*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
      BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), 0);
      // ... unless it has gone all the way to 0 (after getting past 1000/2)
  
      SetMockTime(0);
  }
  
  BOOST_AUTO_TEST_SUITE_END()
  