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authorWladimir J. van der Laan <laanwj@gmail.com>2017-05-30 18:42:22 +0200
committerWladimir J. van der Laan <laanwj@gmail.com>2017-05-30 18:43:03 +0200
commitacd9957b72a21def0445d8a414ac39d88efe5d78 (patch)
treef0d010656f37f06ad761e13010af8730ea3d1fa6 /src/txmempool.h
parent5c63d665e51ed0cd5d29275a5d63b07a64300ac8 (diff)
parentc1235e3f2dd5b01b63b020d1b8f7283e8badaf09 (diff)
Merge #9208: Improve DisconnectTip performance
c1235e3 Add RecursiveDynamicUsage overload for std::shared_ptr (Russell Yanofsky) 71f1903 Store disconnected block transactions outside mempool during reorg (Suhas Daftuar) 9decd64 [qa] Relax assumptions on mempool behavior during reorg (Suhas Daftuar) Tree-SHA512: c160ad853a5cd060d0307af7606a0c77907497ed7033c9599b95e73d83f68fdfcd4214bd8a83db1c5b7a58022722b9de1ed2e6ea2e02f38a7b6c717f079dd0c6
Diffstat (limited to 'src/txmempool.h')
-rw-r--r--src/txmempool.h99
1 files changed, 98 insertions, 1 deletions
diff --git a/src/txmempool.h b/src/txmempool.h
index a91eb5be54..671a8b596c 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -24,6 +24,7 @@
#include "boost/multi_index_container.hpp"
#include "boost/multi_index/ordered_index.hpp"
#include "boost/multi_index/hashed_index.hpp"
+#include <boost/multi_index/sequenced_index.hpp>
#include <boost/signals2/signal.hpp>
@@ -185,7 +186,7 @@ private:
const LockPoints& lp;
};
-// extracts a TxMemPoolEntry's transaction hash
+// extracts a transaction hash from CTxMempoolEntry or CTransactionRef
struct mempoolentry_txid
{
typedef uint256 result_type;
@@ -193,6 +194,11 @@ struct mempoolentry_txid
{
return entry.GetTx().GetHash();
}
+
+ result_type operator() (const CTransactionRef& tx) const
+ {
+ return tx->GetHash();
+ }
};
/** \class CompareTxMemPoolEntryByDescendantScore
@@ -662,4 +668,95 @@ public:
bool HaveCoins(const uint256 &txid) const;
};
+/**
+ * DisconnectedBlockTransactions
+
+ * During the reorg, it's desirable to re-add previously confirmed transactions
+ * to the mempool, so that anything not re-confirmed in the new chain is
+ * available to be mined. However, it's more efficient to wait until the reorg
+ * is complete and process all still-unconfirmed transactions at that time,
+ * since we expect most confirmed transactions to (typically) still be
+ * confirmed in the new chain, and re-accepting to the memory pool is expensive
+ * (and therefore better to not do in the middle of reorg-processing).
+ * Instead, store the disconnected transactions (in order!) as we go, remove any
+ * that are included in blocks in the new chain, and then process the remaining
+ * still-unconfirmed transactions at the end.
+ */
+
+// multi_index tag names
+struct txid_index {};
+struct insertion_order {};
+
+struct DisconnectedBlockTransactions {
+ typedef boost::multi_index_container<
+ CTransactionRef,
+ boost::multi_index::indexed_by<
+ // sorted by txid
+ boost::multi_index::hashed_unique<
+ boost::multi_index::tag<txid_index>,
+ mempoolentry_txid,
+ SaltedTxidHasher
+ >,
+ // sorted by order in the blockchain
+ boost::multi_index::sequenced<
+ boost::multi_index::tag<insertion_order>
+ >
+ >
+ > indexed_disconnected_transactions;
+
+ // It's almost certainly a logic bug if we don't clear out queuedTx before
+ // destruction, as we add to it while disconnecting blocks, and then we
+ // need to re-process remaining transactions to ensure mempool consistency.
+ // For now, assert() that we've emptied out this object on destruction.
+ // This assert() can always be removed if the reorg-processing code were
+ // to be refactored such that this assumption is no longer true (for
+ // instance if there was some other way we cleaned up the mempool after a
+ // reorg, besides draining this object).
+ ~DisconnectedBlockTransactions() { assert(queuedTx.empty()); }
+
+ indexed_disconnected_transactions queuedTx;
+ uint64_t cachedInnerUsage = 0;
+
+ // Estimate the overhead of queuedTx to be 6 pointers + an allocation, as
+ // no exact formula for boost::multi_index_contained is implemented.
+ size_t DynamicMemoryUsage() const {
+ return memusage::MallocUsage(sizeof(CTransactionRef) + 6 * sizeof(void*)) * queuedTx.size() + cachedInnerUsage;
+ }
+
+ void addTransaction(const CTransactionRef& tx)
+ {
+ queuedTx.insert(tx);
+ cachedInnerUsage += RecursiveDynamicUsage(tx);
+ }
+
+ // Remove entries based on txid_index, and update memory usage.
+ void removeForBlock(const std::vector<CTransactionRef>& vtx)
+ {
+ // Short-circuit in the common case of a block being added to the tip
+ if (queuedTx.empty()) {
+ return;
+ }
+ for (auto const &tx : vtx) {
+ auto it = queuedTx.find(tx->GetHash());
+ if (it != queuedTx.end()) {
+ cachedInnerUsage -= RecursiveDynamicUsage(*it);
+ queuedTx.erase(it);
+ }
+ }
+ }
+
+ // Remove an entry by insertion_order index, and update memory usage.
+ void removeEntry(indexed_disconnected_transactions::index<insertion_order>::type::iterator entry)
+ {
+ cachedInnerUsage -= RecursiveDynamicUsage(*entry);
+ queuedTx.get<insertion_order>().erase(entry);
+ }
+
+ void clear()
+ {
+ cachedInnerUsage = 0;
+ queuedTx.clear();
+ }
+};
+
#endif // BITCOIN_TXMEMPOOL_H