Line data    Source code

       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             : #include <map>
      14             : #include <set>
      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         185 : class TxOrphanage {
      22             : public:
      23             :     /** Add a new orphan transaction */
      24             :     bool AddTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      25             : 
      26             :     /** Check if we already have an orphan transaction */
      27             :     bool HaveTx(const uint256& txid) const EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      28             : 
      29             :     /** Extract a transaction from a peer's work set
      30             :      *  Returns nullptr and sets more to false if there are no transactions
      31             :      *  to work on. Otherwise returns the transaction reference, removes
      32             :      *  the transaction from the work set, and populates its arguments with
      33             :      *  the originating peer, and whether there are more orphans for this peer
      34             :      *  to work on after this tx.
      35             :      */
      36             :     CTransactionRef GetTxToReconsider(NodeId peer, NodeId& originator, bool& more) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      37             : 
      38             :     /** Determine orphan transactions that can be candidates for reconsideration into the mempool based on block */
      39             :     void SetCandidatesByBlock(const CBlock& block) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      40             : 
      41             :     /** Erase an orphan by txid */
      42             :     int EraseTx(const uint256& txid) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      43             : 
      44             :     /** Erase all orphans announced by a peer (eg, after that peer disconnects) */
      45             :     void EraseForPeer(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      46             : 
      47             :     /** Erase all orphans included in or invalidated by a new block */
      48             :     void EraseForBlock(const CBlock& block) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      49             : 
      50             :     /** Check if there are more orphans reported by a peer to work on */
      51             :     bool HaveMoreWork(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      52             : 
      53             :     /** Limit the orphanage to the given maximum */
      54             :     void LimitOrphans(unsigned int max_orphans_size) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      55             : 
      56             :     /** Add any orphans that list a particular tx as a parent into a peer's work set */
      57             :     void AddChildrenToWorkSet(const CTransaction& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex);
      58             : 
      59             :     /** Return how many entries exist in the orphange */
      60           6 :     size_t Size() EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
      61             :     {
      62           6 :         LOCK(m_mutex);
      63           6 :         return m_orphans.size();
      64           6 :     }
      65             : 
      66             : protected:
      67             :     /** Guards orphan transactions */
      68             :     mutable Mutex m_mutex;
      69             : 
      70             :     struct OrphanTx {
      71             :         CTransactionRef tx;
      72             :         NodeId fromPeer;
      73             :         int64_t nTimeExpire;
      74             :         size_t list_pos;
      75             :         size_t nTxSize;
      76             :     };
      77             : 
      78             :     /** Map from txid to orphan transaction record. Limited by
      79             :      *  -maxorphantx/DEFAULT_MAX_ORPHAN_TRANSACTIONS */
      80             :     std::map<uint256, OrphanTx> m_orphans GUARDED_BY(m_mutex);
      81             : 
      82             :     /** Which peer provided a parent tx of orphans that need to be reconsidered */
      83             :     std::map<NodeId, std::set<uint256>> m_peer_work_set GUARDED_BY(m_mutex);
      84             : 
      85             :     using OrphanMap = decltype(m_orphans);
      86             : 
      87             :     struct IteratorComparator
      88             :     {
      89             :         template<typename I>
      90         160 :         bool operator()(const I& a, const I& b) const
      91             :         {
      92         160 :             return &(*a) < &(*b);
      93             :         }
      94             :     };
      95             : 
      96             :     /** Index from the parents' COutPoint into the m_orphans. Used
      97             :      *  to remove orphan transactions from the m_orphans */
      98             :     std::map<COutPoint, std::set<OrphanMap::iterator, IteratorComparator>> m_outpoint_to_orphan_it GUARDED_BY(m_mutex);
      99             : 
     100             :     /** Orphan transactions in vector for quick random eviction */
     101             :     std::vector<OrphanMap::iterator> m_orphan_list GUARDED_BY(m_mutex);
     102             : 
     103             :     /** Cumulative size of all transactions in the orphan map */
     104         185 :     size_t m_orphan_tx_size GUARDED_BY(m_mutex){0};
     105             : 
     106             :     /** Erase an orphan by txid */
     107             :     int _EraseTx(const uint256& txid) EXCLUSIVE_LOCKS_REQUIRED(m_mutex);
     108             : };
     109             : 
     110             : #endif // BITCOIN_TXORPHANAGE_H