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TheBlueMattTheBlueMatt
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Add reasonable test case for mempool trimming
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+157
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‎src/test/mempool_tests.cpp

Lines changed: 154 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -281,4 +281,158 @@ BOOST_AUTO_TEST_CASE(MempoolIndexingTest)
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CheckSort(pool, snapshotOrder);
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}
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BOOST_AUTO_TEST_CASE(MempoolSizeLimitTest)
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{
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CTxMemPool pool(CFeeRate(1000));
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CMutableTransaction tx1 = CMutableTransaction();
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tx1.vin.resize(1);
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tx1.vin[0].scriptSig = CScript() << OP_1;
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tx1.vout.resize(1);
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tx1.vout[0].scriptPubKey = CScript() << OP_1 << OP_EQUAL;
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tx1.vout[0].nValue = 10 * COIN;
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pool.addUnchecked(tx1.GetHash(), CTxMemPoolEntry(tx1, 10000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx1)));
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CMutableTransaction tx2 = CMutableTransaction();
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tx2.vin.resize(1);
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tx2.vin[0].scriptSig = CScript() << OP_2;
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tx2.vout.resize(1);
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tx2.vout[0].scriptPubKey = CScript() << OP_2 << OP_EQUAL;
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tx2.vout[0].nValue = 10 * COIN;
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pool.addUnchecked(tx2.GetHash(), CTxMemPoolEntry(tx2, 5000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx2)));
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pool.TrimToSize(pool.DynamicMemoryUsage()); // should do nothing
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BOOST_CHECK(pool.exists(tx1.GetHash()));
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BOOST_CHECK(pool.exists(tx2.GetHash()));
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pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4); // should remove the lower-feerate transaction
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BOOST_CHECK(pool.exists(tx1.GetHash()));
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BOOST_CHECK(!pool.exists(tx2.GetHash()));
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pool.addUnchecked(tx2.GetHash(), CTxMemPoolEntry(tx2, 5000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx2)));
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CMutableTransaction tx3 = CMutableTransaction();
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tx3.vin.resize(1);
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tx3.vin[0].prevout = COutPoint(tx2.GetHash(), 0);
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tx3.vin[0].scriptSig = CScript() << OP_2;
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tx3.vout.resize(1);
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tx3.vout[0].scriptPubKey = CScript() << OP_3 << OP_EQUAL;
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tx3.vout[0].nValue = 10 * COIN;
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pool.addUnchecked(tx3.GetHash(), CTxMemPoolEntry(tx3, 20000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx3)));
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pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4); // tx3 should pay for tx2 (CPFP)
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BOOST_CHECK(!pool.exists(tx1.GetHash()));
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BOOST_CHECK(pool.exists(tx2.GetHash()));
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BOOST_CHECK(pool.exists(tx3.GetHash()));
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pool.TrimToSize(::GetSerializeSize(CTransaction(tx1), SER_NETWORK, PROTOCOL_VERSION)); // mempool is limited to tx1's size in memory usage, so nothing fits
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BOOST_CHECK(!pool.exists(tx1.GetHash()));
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BOOST_CHECK(!pool.exists(tx2.GetHash()));
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BOOST_CHECK(!pool.exists(tx3.GetHash()));
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CFeeRate maxFeeRateRemoved(25000, ::GetSerializeSize(CTransaction(tx3), SER_NETWORK, PROTOCOL_VERSION) + ::GetSerializeSize(CTransaction(tx2), SER_NETWORK, PROTOCOL_VERSION));
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BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), maxFeeRateRemoved.GetFeePerK() + 1000);
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CMutableTransaction tx4 = CMutableTransaction();
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tx4.vin.resize(2);
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tx4.vin[0].prevout.SetNull();
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tx4.vin[0].scriptSig = CScript() << OP_4;
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tx4.vin[1].prevout.SetNull();
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tx4.vin[1].scriptSig = CScript() << OP_4;
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tx4.vout.resize(2);
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tx4.vout[0].scriptPubKey = CScript() << OP_4 << OP_EQUAL;
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tx4.vout[0].nValue = 10 * COIN;
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tx4.vout[1].scriptPubKey = CScript() << OP_4 << OP_EQUAL;
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tx4.vout[1].nValue = 10 * COIN;
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CMutableTransaction tx5 = CMutableTransaction();
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tx5.vin.resize(2);
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tx5.vin[0].prevout = COutPoint(tx4.GetHash(), 0);
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tx5.vin[0].scriptSig = CScript() << OP_4;
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tx5.vin[1].prevout.SetNull();
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tx5.vin[1].scriptSig = CScript() << OP_5;
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tx5.vout.resize(2);
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tx5.vout[0].scriptPubKey = CScript() << OP_5 << OP_EQUAL;
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tx5.vout[0].nValue = 10 * COIN;
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tx5.vout[1].scriptPubKey = CScript() << OP_5 << OP_EQUAL;
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tx5.vout[1].nValue = 10 * COIN;
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CMutableTransaction tx6 = CMutableTransaction();
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tx6.vin.resize(2);
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tx6.vin[0].prevout = COutPoint(tx4.GetHash(), 1);
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tx6.vin[0].scriptSig = CScript() << OP_4;
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tx6.vin[1].prevout.SetNull();
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tx6.vin[1].scriptSig = CScript() << OP_6;
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tx6.vout.resize(2);
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tx6.vout[0].scriptPubKey = CScript() << OP_6 << OP_EQUAL;
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tx6.vout[0].nValue = 10 * COIN;
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tx6.vout[1].scriptPubKey = CScript() << OP_6 << OP_EQUAL;
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tx6.vout[1].nValue = 10 * COIN;
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CMutableTransaction tx7 = CMutableTransaction();
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tx7.vin.resize(2);
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tx7.vin[0].prevout = COutPoint(tx5.GetHash(), 0);
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tx7.vin[0].scriptSig = CScript() << OP_5;
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tx7.vin[1].prevout = COutPoint(tx6.GetHash(), 0);
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tx7.vin[1].scriptSig = CScript() << OP_6;
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tx7.vout.resize(2);
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tx7.vout[0].scriptPubKey = CScript() << OP_7 << OP_EQUAL;
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tx7.vout[0].nValue = 10 * COIN;
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tx7.vout[0].scriptPubKey = CScript() << OP_7 << OP_EQUAL;
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tx7.vout[0].nValue = 10 * COIN;
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pool.addUnchecked(tx4.GetHash(), CTxMemPoolEntry(tx4, 7000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx4)));
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pool.addUnchecked(tx5.GetHash(), CTxMemPoolEntry(tx5, 1000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx5)));
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pool.addUnchecked(tx6.GetHash(), CTxMemPoolEntry(tx6, 1100LL, 0, 10.0, 1, pool.HasNoInputsOf(tx6)));
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pool.addUnchecked(tx7.GetHash(), CTxMemPoolEntry(tx7, 9000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx7)));
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// we only require this remove, at max, 2 txn, because its not clear what we're really optimizing for aside from that
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pool.TrimToSize(pool.DynamicMemoryUsage() - 1);
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BOOST_CHECK(pool.exists(tx4.GetHash()));
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BOOST_CHECK(pool.exists(tx6.GetHash()));
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BOOST_CHECK(!pool.exists(tx7.GetHash()));
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if (!pool.exists(tx5.GetHash()))
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pool.addUnchecked(tx5.GetHash(), CTxMemPoolEntry(tx5, 1000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx5)));
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pool.addUnchecked(tx7.GetHash(), CTxMemPoolEntry(tx7, 9000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx7)));
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pool.TrimToSize(pool.DynamicMemoryUsage() / 2); // should maximize mempool size by only removing 5/7
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BOOST_CHECK(pool.exists(tx4.GetHash()));
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BOOST_CHECK(!pool.exists(tx5.GetHash()));
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BOOST_CHECK(pool.exists(tx6.GetHash()));
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BOOST_CHECK(!pool.exists(tx7.GetHash()));
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pool.addUnchecked(tx5.GetHash(), CTxMemPoolEntry(tx5, 1000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx5)));
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pool.addUnchecked(tx7.GetHash(), CTxMemPoolEntry(tx7, 9000LL, 0, 10.0, 1, pool.HasNoInputsOf(tx7)));
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std::vector<CTransaction> vtx;
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std::list<CTransaction> conflicts;
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SetMockTime(42);
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SetMockTime(42 + CTxMemPool::ROLLING_FEE_HALFLIFE);
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BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), maxFeeRateRemoved.GetFeePerK() + 1000);
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// ... we should keep the same min fee until we get a block
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pool.removeForBlock(vtx, 1, conflicts);
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SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE);
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BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), (maxFeeRateRemoved.GetFeePerK() + 1000)/2);
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// ... then feerate should drop 1/2 each halflife
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SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2);
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BOOST_CHECK_EQUAL(pool.GetMinFee(pool.DynamicMemoryUsage() * 5 / 2).GetFeePerK(), (maxFeeRateRemoved.GetFeePerK() + 1000)/4);
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// ... with a 1/2 halflife when mempool is < 1/2 its target size
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SetMockTime(42 + 2*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
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BOOST_CHECK_EQUAL(pool.GetMinFee(pool.DynamicMemoryUsage() * 9 / 2).GetFeePerK(), (maxFeeRateRemoved.GetFeePerK() + 1000)/8);
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// ... with a 1/4 halflife when mempool is < 1/4 its target size
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SetMockTime(42 + 7*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
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BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), 1000);
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// ... but feerate should never drop below 1000
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SetMockTime(42 + 8*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
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pool.GetMinFee(1);
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BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), 0);
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// ... unless it has gone all the way to 0 (after getting past 1000/2)
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SetMockTime(0);
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}
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BOOST_AUTO_TEST_SUITE_END()

‎src/txmempool.h

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -290,11 +290,13 @@ class CTxMemPool
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mutable int64_t lastRollingFeeUpdate;
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mutable bool blockSinceLastRollingFeeBump;
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mutable double rollingMinimumFeeRate; //! minimum fee to get into the pool, decreases exponentially
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static const int ROLLING_FEE_HALFLIFE = 60 * 60 * 12;
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void trackPackageRemoved(const CFeeRate& rate);
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public:
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static const int ROLLING_FEE_HALFLIFE = 60 * 60 * 12; // public only for testing
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typedef boost::multi_index_container<
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CTxMemPoolEntry,
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boost::multi_index::indexed_by<

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