// Test suite for ancestor feerate transaction selection.
// Implemented as an additional function, rather than a separate test case,
// to allow reusing the blockchain created in CreateNewBlock_validity.
void TestPackageSelection(const CChainParams& chainparams, CScript scriptPubKey, std::vector<CTransactionRef>& txFirst)
{
// Test the ancestor feerate transaction selection.
TestMemPoolEntryHelper entry;
// Test that a medium fee transaction will be selected after a higher fee
// rate package with a low fee rate parent.
CMutableTransaction tx;
tx.vin.resize(1);
tx.vin[0].scriptSig = CScript() << OP_1;
tx.vin[0].prevout.hash = txFirst[0]->GetHash();
tx.vin[0].prevout.n = 0;
tx.vout.resize(1);
tx.vout[0].nValue = 5000000000LL - 1000;
// This tx has a low fee: 1000 satoshis
uint256 hashParentTx = tx.GetHash(); // save this txid for later use
mempool.addUnchecked(hashParentTx, entry.Fee(1000).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
// This tx has a medium fee: 10000 satoshis
tx.vin[0].prevout.hash = txFirst[1]->GetHash();
tx.vout[0].nValue = 5000000000LL - 10000;
uint256 hashMediumFeeTx = tx.GetHash();
mempool.addUnchecked(hashMediumFeeTx, entry.Fee(10000).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
// This tx has a high fee, but depends on the first transaction
tx.vin[0].prevout.hash = hashParentTx;
tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 50k satoshi fee
uint256 hashHighFeeTx = tx.GetHash();
mempool.addUnchecked(hashHighFeeTx, entry.Fee(50000).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));
std::unique_ptr<CBlockTemplate> pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
BOOST_CHECK(pblocktemplate->block.vtx[1]->GetHash() == hashParentTx);
BOOST_CHECK(pblocktemplate->block.vtx[2]->GetHash() == hashHighFeeTx);
BOOST_CHECK(pblocktemplate->block.vtx[3]->GetHash() == hashMediumFeeTx);
// Test that a package below the block min tx fee doesn't get included
tx.vin[0].prevout.hash = hashHighFeeTx;
tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 0 fee
uint256 hashFreeTx = tx.GetHash();
mempool.addUnchecked(hashFreeTx, entry.Fee(0).FromTx(tx));
size_t freeTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
// Calculate a fee on child transaction that will put the package just
// below the block min tx fee (assuming 1 child tx of the same size).
CAmount feeToUse = blockMinFeeRate.GetFee(2*freeTxSize) - 1;
tx.vin[0].prevout.hash = hashFreeTx;
tx.vout[0].nValue = 5000000000LL - 1000 - 50000 - feeToUse;
uint256 hashLowFeeTx = tx.GetHash();
mempool.addUnchecked(hashLowFeeTx, entry.Fee(feeToUse).FromTx(tx));
pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
// Verify that the free tx and the low fee tx didn't get selected
for (size_t i=0; i<pblocktemplate->block.vtx.size(); ++i) {
BOOST_CHECK(pblocktemplate->block.vtx[i]->GetHash() != hashFreeTx);
BOOST_CHECK(pblocktemplate->block.vtx[i]->GetHash() != hashLowFeeTx);
}
// Test that packages above the min relay fee do get included, even if one
// of the transactions is below the min relay fee
// Remove the low fee transaction and replace with a higher fee transaction
mempool.removeRecursive(tx);
tx.vout[0].nValue -= 2; // Now we should be just over the min relay fee
hashLowFeeTx = tx.GetHash();
mempool.addUnchecked(hashLowFeeTx, entry.Fee(feeToUse+2).FromTx(tx));
pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
BOOST_CHECK(pblocktemplate->block.vtx[4]->GetHash() == hashFreeTx);
BOOST_CHECK(pblocktemplate->block.vtx[5]->GetHash() == hashLowFeeTx);
// Test that transaction selection properly updates ancestor fee
// calculations as ancestor transactions get included in a block.
// Add a 0-fee transaction that has 2 outputs.
tx.vin[0].prevout.hash = txFirst[2]->GetHash();
tx.vout.resize(2);
tx.vout[0].nValue = 5000000000LL - 100000000;
tx.vout[1].nValue = 100000000; // 1BTC output
uint256 hashFreeTx2 = tx.GetHash();
mempool.addUnchecked(hashFreeTx2, entry.Fee(0).SpendsCoinbase(true).FromTx(tx));
// This tx can't be mined by itself
tx.vin[0].prevout.hash = hashFreeTx2;
tx.vout.resize(1);
feeToUse = blockMinFeeRate.GetFee(freeTxSize);
tx.vout[0].nValue = 5000000000LL - 100000000 - feeToUse;
uint256 hashLowFeeTx2 = tx.GetHash();
mempool.addUnchecked(hashLowFeeTx2, entry.Fee(feeToUse).SpendsCoinbase(false).FromTx(tx));
pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
// Verify that this tx isn't selected.
for (size_t i=0; i<pblocktemplate->block.vtx.size(); ++i) {
BOOST_CHECK(pblocktemplate->block.vtx[i]->GetHash() != hashFreeTx2);
BOOST_CHECK(pblocktemplate->block.vtx[i]->GetHash() != hashLowFeeTx2);
}
// This tx will be mineable, and should cause hashLowFeeTx2 to be selected
// as well.
tx.vin[0].prevout.n = 1;
tx.vout[0].nValue = 100000000 - 10000; // 10k satoshi fee
mempool.addUnchecked(tx.GetHash(), entry.Fee(10000).FromTx(tx));
pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
BOOST_CHECK(pblocktemplate->block.vtx[8]->GetHash() == hashLowFeeTx2);
}
uint256 hashParentTx = tx.GetHash(); // save this txid for later use
mempool.addUnchecked(entry.Fee(1000).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
// This tx has a medium fee: 10000 satoshis
tx.vin[0].prevout.hash = txFirst[1]->GetHash();
tx.vout[0].nValue = 5000000000LL - 10000;
uint256 hashMediumFeeTx = tx.GetHash();
mempool.addUnchecked(entry.Fee(10000).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
// This tx has a high fee, but depends on the first transaction
tx.vin[0].prevout.hash = hashParentTx;
tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 50k satoshi fee
uint256 hashHighFeeTx = tx.GetHash();
mempool.addUnchecked(entry.Fee(50000).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));
std::unique_ptr<CBlockTemplate> pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
BOOST_CHECK(pblocktemplate->block.vtx[1]->GetHash() == hashParentTx);
BOOST_CHECK(pblocktemplate->block.vtx[2]->GetHash() == hashHighFeeTx);
BOOST_CHECK(pblocktemplate->block.vtx[3]->GetHash() == hashMediumFeeTx);
// Test that a package below the block min tx fee doesn't get included
tx.vin[0].prevout.hash = hashHighFeeTx;
tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 0 fee
uint256 hashFreeTx = tx.GetHash();
mempool.addUnchecked(entry.Fee(0).FromTx(tx));
size_t freeTxSize = ::GetSerializeSize(tx, PROTOCOL_VERSION);
// Calculate a fee on child transaction that will put the package just
// below the block min tx fee (assuming 1 child tx of the same size).
CAmount feeToUse = blockMinFeeRate.GetFee(2*freeTxSize) - 1;