From 9805f4af7ecb6becf8a146bd845fb131ffa625c9 Mon Sep 17 00:00:00 2001 From: Kaz Wesley Date: Sat, 30 Apr 2016 21:45:26 -0700 Subject: mapNextTx: use pointer as key, simplify value Saves about 10% of application memory usage once the mempool warms up. Since the mempool is DynamicUsage-regulated, this will translate to a larger mempool in the same amount of space. Map value type: eliminate the vin index; no users of the map need to know which input of the transaction is spending the prevout. Map key type: replace the COutPoint with a pointer to a COutPoint. A COutPoint is 36 bytes, but each COutPoint is accessible from the same map entry's value. A trivial DereferencingComparator functor allows indirect map keys, but the resulting syntax is misleading: `map.find(&outpoint)`. Implement an indirectmap that acts as a wrapper to a map that uses a DereferencingComparator, supporting a syntax that accurately reflect the container's semantics: inserts and iterators use pointers since they store pointers and need them to remain constant and dereferenceable, but lookup functions take const references. --- src/txmempool.cpp | 46 ++++++++++++++++++++++------------------------ 1 file changed, 22 insertions(+), 24 deletions(-) (limited to 'src/txmempool.cpp') diff --git a/src/txmempool.cpp b/src/txmempool.cpp index 52c7793118..d7fb77661b 100644 --- a/src/txmempool.cpp +++ b/src/txmempool.cpp @@ -147,11 +147,11 @@ void CTxMemPool::UpdateTransactionsFromBlock(const std::vector &vHashes if (it == mapTx.end()) { continue; } - std::map::iterator iter = mapNextTx.lower_bound(COutPoint(hash, 0)); + auto iter = mapNextTx.lower_bound(COutPoint(hash, 0)); // First calculate the children, and update setMemPoolChildren to // include them, and update their setMemPoolParents to include this tx. - for (; iter != mapNextTx.end() && iter->first.hash == hash; ++iter) { - const uint256 &childHash = iter->second.ptx->GetHash(); + for (; iter != mapNextTx.end() && iter->first->hash == hash; ++iter) { + const uint256 &childHash = iter->second->GetHash(); txiter childIter = mapTx.find(childHash); assert(childIter != mapTx.end()); // We can skip updating entries we've encountered before or that @@ -365,11 +365,11 @@ void CTxMemPool::pruneSpent(const uint256 &hashTx, CCoins &coins) { LOCK(cs); - std::map::iterator it = mapNextTx.lower_bound(COutPoint(hashTx, 0)); + auto it = mapNextTx.lower_bound(COutPoint(hashTx, 0)); // iterate over all COutPoints in mapNextTx whose hash equals the provided hashTx - while (it != mapNextTx.end() && it->first.hash == hashTx) { - coins.Spend(it->first.n); // and remove those outputs from coins + while (it != mapNextTx.end() && it->first->hash == hashTx) { + coins.Spend(it->first->n); // and remove those outputs from coins it++; } } @@ -414,7 +414,7 @@ bool CTxMemPool::addUnchecked(const uint256& hash, const CTxMemPoolEntry &entry, const CTransaction& tx = newit->GetTx(); std::set setParentTransactions; for (unsigned int i = 0; i < tx.vin.size(); i++) { - mapNextTx[tx.vin[i].prevout] = CInPoint(&tx, i); + mapNextTx.insert(std::make_pair(&tx.vin[i].prevout, &tx)); setParentTransactions.insert(tx.vin[i].prevout.hash); } // Don't bother worrying about child transactions of this one. @@ -500,10 +500,10 @@ void CTxMemPool::removeRecursive(const CTransaction &origTx, std::list::iterator it = mapNextTx.find(COutPoint(origTx.GetHash(), i)); + auto it = mapNextTx.find(COutPoint(origTx.GetHash(), i)); if (it == mapNextTx.end()) continue; - txiter nextit = mapTx.find(it->second.ptx->GetHash()); + txiter nextit = mapTx.find(it->second->GetHash()); assert(nextit != mapTx.end()); txToRemove.insert(nextit); } @@ -561,9 +561,9 @@ void CTxMemPool::removeConflicts(const CTransaction &tx, std::list list result; LOCK(cs); BOOST_FOREACH(const CTxIn &txin, tx.vin) { - std::map::iterator it = mapNextTx.find(txin.prevout); + auto it = mapNextTx.find(txin.prevout); if (it != mapNextTx.end()) { - const CTransaction &txConflict = *it->second.ptx; + const CTransaction &txConflict = *it->second; if (txConflict != tx) { removeRecursive(txConflict, removed); @@ -671,10 +671,10 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const assert(coins && coins->IsAvailable(txin.prevout.n)); } // Check whether its inputs are marked in mapNextTx. - std::map::const_iterator it3 = mapNextTx.find(txin.prevout); + auto it3 = mapNextTx.find(txin.prevout); assert(it3 != mapNextTx.end()); - assert(it3->second.ptx == &tx); - assert(it3->second.n == i); + assert(it3->first == &txin.prevout); + assert(it3->second == &tx); i++; } assert(setParentCheck == GetMemPoolParents(it)); @@ -701,10 +701,10 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const // Check children against mapNextTx CTxMemPool::setEntries setChildrenCheck; - std::map::const_iterator iter = mapNextTx.lower_bound(COutPoint(it->GetTx().GetHash(), 0)); + auto iter = mapNextTx.lower_bound(COutPoint(it->GetTx().GetHash(), 0)); int64_t childSizes = 0; - for (; iter != mapNextTx.end() && iter->first.hash == it->GetTx().GetHash(); ++iter) { - txiter childit = mapTx.find(iter->second.ptx->GetHash()); + for (; iter != mapNextTx.end() && iter->first->hash == it->GetTx().GetHash(); ++iter) { + txiter childit = mapTx.find(iter->second->GetHash()); assert(childit != mapTx.end()); // mapNextTx points to in-mempool transactions if (setChildrenCheck.insert(childit).second) { childSizes += childit->GetTxSize(); @@ -738,14 +738,12 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const stepsSinceLastRemove = 0; } } - for (std::map::const_iterator it = mapNextTx.begin(); it != mapNextTx.end(); it++) { - uint256 hash = it->second.ptx->GetHash(); + for (auto it = mapNextTx.cbegin(); it != mapNextTx.cend(); it++) { + uint256 hash = it->second->GetHash(); indexed_transaction_set::const_iterator it2 = mapTx.find(hash); const CTransaction& tx = it2->GetTx(); assert(it2 != mapTx.end()); - assert(&tx == it->second.ptx); - assert(tx.vin.size() > it->second.n); - assert(it->first == it->second.ptx->vin[it->second.n].prevout); + assert(&tx == it->second); } assert(totalTxSize == checkTotal); @@ -1044,8 +1042,8 @@ void CTxMemPool::TrimToSize(size_t sizelimit, std::vector* pvNoSpendsRe BOOST_FOREACH(const CTxIn& txin, tx.vin) { if (exists(txin.prevout.hash)) continue; - std::map::iterator it = mapNextTx.lower_bound(COutPoint(txin.prevout.hash, 0)); - if (it == mapNextTx.end() || it->first.hash != txin.prevout.hash) + auto it = mapNextTx.lower_bound(COutPoint(txin.prevout.hash, 0)); + if (it == mapNextTx.end() || it->first->hash != txin.prevout.hash) pvNoSpendsRemaining->push_back(txin.prevout.hash); } } -- cgit v1.2.3