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Use replaced transactions in compact block reconstruction
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@TheBlueMatt
TheBlueMatt committed Jan 10, 2017
1 parent 1531652 commit 93380c5
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Showing 4 changed files with 41 additions and 8 deletions.
32 changes: 31 additions & 1 deletion src/blockencodings.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,7 @@ uint64_t CBlockHeaderAndShortTxIDs::GetShortID(const uint256& txhash) const {



ReadStatus PartiallyDownloadedBlock::InitData(const CBlockHeaderAndShortTxIDs& cmpctblock) {
ReadStatus PartiallyDownloadedBlock::InitData(const CBlockHeaderAndShortTxIDs& cmpctblock, std::vector<std::pair<uint256, CTransactionRef>>& extra_txn) {
if (cmpctblock.header.IsNull() || (cmpctblock.shorttxids.empty() && cmpctblock.prefilledtxn.empty()))
return READ_STATUS_INVALID;
if (cmpctblock.shorttxids.size() + cmpctblock.prefilledtxn.size() > MAX_BLOCK_BASE_SIZE / MIN_TRANSACTION_BASE_SIZE)
Expand Down Expand Up @@ -104,6 +104,7 @@ ReadStatus PartiallyDownloadedBlock::InitData(const CBlockHeaderAndShortTxIDs& c
return READ_STATUS_FAILED; // Short ID collision

std::vector<bool> have_txn(txn_available.size());
{
LOCK(pool->cs);
const std::vector<std::pair<uint256, CTxMemPool::txiter> >& vTxHashes = pool->vTxHashes;
for (size_t i = 0; i < vTxHashes.size(); i++) {
Expand All @@ -130,6 +131,35 @@ ReadStatus PartiallyDownloadedBlock::InitData(const CBlockHeaderAndShortTxIDs& c
if (mempool_count == shorttxids.size())
break;
}
}

for (size_t i = 0; i < extra_txn.size(); i++) {
uint64_t shortid = cmpctblock.GetShortID(extra_txn[i].first);
std::unordered_map<uint64_t, uint16_t>::iterator idit = shorttxids.find(shortid);
if (idit != shorttxids.end()) {
if (!have_txn[idit->second]) {
txn_available[idit->second] = extra_txn[i].second;
have_txn[idit->second] = true;
mempool_count++;
} else {
// If we find two mempool txn that match the short id, just request it.
// This should be rare enough that the extra bandwidth doesn't matter,
// but eating a round-trip due to FillBlock failure would be annoying
// Note that we dont want duplication between extra_txn and mempool to
// trigger this case, so we compare witness hashes first
if (txn_available[idit->second] &&
txn_available[idit->second]->GetWitnessHash() != extra_txn[i].second->GetWitnessHash()) {
txn_available[idit->second].reset();
mempool_count--;
}
}
}
// Though ideally we'd continue scanning for the two-txn-match-shortid case,
// the performance win of an early exit here is too good to pass up and worth
// the extra risk.
if (mempool_count == shorttxids.size())
break;
}

LogPrint("cmpctblock", "Initialized PartiallyDownloadedBlock for block %s using a cmpctblock of size %lu\n", cmpctblock.header.GetHash().ToString(), GetSerializeSize(cmpctblock, SER_NETWORK, PROTOCOL_VERSION));

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3 changes: 2 additions & 1 deletion src/blockencodings.h
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Original file line number Diff line number Diff line change
Expand Up @@ -200,7 +200,8 @@ class PartiallyDownloadedBlock {
CBlockHeader header;
PartiallyDownloadedBlock(CTxMemPool* poolIn) : pool(poolIn) {}

ReadStatus InitData(const CBlockHeaderAndShortTxIDs& cmpctblock);
// extra_txn is a list of extra transactions to look at, in <witness hash, reference> form
ReadStatus InitData(const CBlockHeaderAndShortTxIDs& cmpctblock, std::vector<std::pair<uint256, CTransactionRef>>& extra_txn);
bool IsTxAvailable(size_t index) const;
ReadStatus FillBlock(CBlock& block, const std::vector<CTransactionRef>& vtx_missing);
};
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4 changes: 2 additions & 2 deletions src/net_processing.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1879,7 +1879,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
}

PartiallyDownloadedBlock& partialBlock = *(*queuedBlockIt)->partialBlock;
ReadStatus status = partialBlock.InitData(cmpctblock);
ReadStatus status = partialBlock.InitData(cmpctblock, vExtraTxnForCompact);
if (status == READ_STATUS_INVALID) {
MarkBlockAsReceived(pindex->GetBlockHash()); // Reset in-flight state in case of whitelist
Misbehaving(pfrom->GetId(), 100);
Expand Down Expand Up @@ -1921,7 +1921,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
// Optimistically try to reconstruct anyway since we might be
// able to without any round trips.
PartiallyDownloadedBlock tempBlock(&mempool);
ReadStatus status = tempBlock.InitData(cmpctblock);
ReadStatus status = tempBlock.InitData(cmpctblock, vExtraTxnForCompact);
if (status != READ_STATUS_OK) {
// TODO: don't ignore failures
return true;
Expand Down
10 changes: 6 additions & 4 deletions src/test/blockencodings_tests.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,8 @@

#include <boost/test/unit_test.hpp>

std::vector<std::pair<uint256, CTransactionRef>> extra_txn;

struct RegtestingSetup : public TestingSetup {
RegtestingSetup() : TestingSetup(CBaseChainParams::REGTEST) {}
};
Expand Down Expand Up @@ -73,7 +75,7 @@ BOOST_AUTO_TEST_CASE(SimpleRoundTripTest)
stream >> shortIDs2;

PartiallyDownloadedBlock partialBlock(&pool);
BOOST_CHECK(partialBlock.InitData(shortIDs2) == READ_STATUS_OK);
BOOST_CHECK(partialBlock.InitData(shortIDs2, extra_txn) == READ_STATUS_OK);
BOOST_CHECK( partialBlock.IsTxAvailable(0));
BOOST_CHECK(!partialBlock.IsTxAvailable(1));
BOOST_CHECK( partialBlock.IsTxAvailable(2));
Expand Down Expand Up @@ -179,7 +181,7 @@ BOOST_AUTO_TEST_CASE(NonCoinbasePreforwardRTTest)
stream >> shortIDs2;

PartiallyDownloadedBlock partialBlock(&pool);
BOOST_CHECK(partialBlock.InitData(shortIDs2) == READ_STATUS_OK);
BOOST_CHECK(partialBlock.InitData(shortIDs2, extra_txn) == READ_STATUS_OK);
BOOST_CHECK(!partialBlock.IsTxAvailable(0));
BOOST_CHECK( partialBlock.IsTxAvailable(1));
BOOST_CHECK( partialBlock.IsTxAvailable(2));
Expand Down Expand Up @@ -245,7 +247,7 @@ BOOST_AUTO_TEST_CASE(SufficientPreforwardRTTest)
stream >> shortIDs2;

PartiallyDownloadedBlock partialBlock(&pool);
BOOST_CHECK(partialBlock.InitData(shortIDs2) == READ_STATUS_OK);
BOOST_CHECK(partialBlock.InitData(shortIDs2, extra_txn) == READ_STATUS_OK);
BOOST_CHECK( partialBlock.IsTxAvailable(0));
BOOST_CHECK( partialBlock.IsTxAvailable(1));
BOOST_CHECK( partialBlock.IsTxAvailable(2));
Expand Down Expand Up @@ -300,7 +302,7 @@ BOOST_AUTO_TEST_CASE(EmptyBlockRoundTripTest)
stream >> shortIDs2;

PartiallyDownloadedBlock partialBlock(&pool);
BOOST_CHECK(partialBlock.InitData(shortIDs2) == READ_STATUS_OK);
BOOST_CHECK(partialBlock.InitData(shortIDs2, extra_txn) == READ_STATUS_OK);
BOOST_CHECK(partialBlock.IsTxAvailable(0));

CBlock block2;
Expand Down

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