1 // Copyright (c) 2021 The Bitcoin Core developers 2 // Distributed under the MIT software license, see the accompanying 3 // file COPYING or http://www.opensource.org/licenses/mit-license.php. 4 5 #ifndef BITCOIN_TXORPHANAGE_H 6 #define BITCOIN_TXORPHANAGE_H 7 8 #include <net.h> 9 #include <primitives/block.h> 10 #include <primitives/transaction.h> 11 #include <sync.h> 12 13 /** Guards orphan transactions and extra txs for compact blocks */ 14 extern RecursiveMutex g_cs_orphans; 15 16 /** A class to track orphan transactions (failed on TX_MISSING_INPUTS) 17 * Since we cannot distinguish orphans from bad transactions with 18 * non-existent inputs, we heavily limit the number of orphans 19 * we keep and the duration we keep them for. 20 */ 21 class TxOrphanage { 22 public: 23 /** Add a new orphan transaction */ 24 bool AddTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans); 25 26 /** Check if we already have an orphan transaction (by txid or wtxid) */ 27 bool HaveTx(const GenTxid& gtxid) const LOCKS_EXCLUDED(::g_cs_orphans); 28 29 /** Get an orphan transaction and its originating peer 30 * (Transaction ref will be nullptr if not found) 31 */ 32 std::pair<CTransactionRef, NodeId> GetTx(const uint256& txid) const EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans); 33 34 /** Erase an orphan by txid */ 35 int EraseTx(const uint256& txid) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans); 36 37 /** Erase all orphans announced by a peer (eg, after that peer disconnects) */ 38 void EraseForPeer(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans); 39 40 /** Erase all orphans included in or invalidated by a new block */ 41 void EraseForBlock(const CBlock& block) LOCKS_EXCLUDED(::g_cs_orphans); 42 43 /** Limit the orphanage to the given maximum */ 44 unsigned int LimitOrphans(unsigned int max_orphans) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans); 45 46 /** Add any orphans that list a particular tx as a parent into a peer's work set 47 * (ie orphans that may have found their final missing parent, and so should be reconsidered for the mempool) */ 48 void AddChildrenToWorkSet(const CTransaction& tx, std::set<uint256>& orphan_work_set) const EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans); 49 50 protected: 51 struct OrphanTx { 52 CTransactionRef tx; 53 NodeId fromPeer; 54 int64_t nTimeExpire; 55 size_t list_pos; 56 }; 57 58 /** Map from txid to orphan transaction record. Limited by 59 * -maxorphantx/DEFAULT_MAX_ORPHAN_TRANSACTIONS */ 60 std::map<uint256, OrphanTx> m_orphans GUARDED_BY(g_cs_orphans); 61 62 using OrphanMap = decltype(m_orphans); 63 64 struct IteratorComparator 65 { 66 template<typename I> operatorIteratorComparator67 bool operator()(const I& a, const I& b) const 68 { 69 return &(*a) < &(*b); 70 } 71 }; 72 73 /** Index from the parents' COutPoint into the m_orphans. Used 74 * to remove orphan transactions from the m_orphans */ 75 std::map<COutPoint, std::set<OrphanMap::iterator, IteratorComparator>> m_outpoint_to_orphan_it GUARDED_BY(g_cs_orphans); 76 77 /** Orphan transactions in vector for quick random eviction */ 78 std::vector<OrphanMap::iterator> m_orphan_list GUARDED_BY(g_cs_orphans); 79 80 /** Index from wtxid into the m_orphans to lookup orphan 81 * transactions using their witness ids. */ 82 std::map<uint256, OrphanMap::iterator> m_wtxid_to_orphan_it GUARDED_BY(g_cs_orphans); 83 }; 84 85 #endif // BITCOIN_TXORPHANAGE_H 86