txorphanage: Extract GetOrphanTx

Extract orphan lookup code into GetOrphanTx function.

Author: ajtowns

src/net_processing.cpp

@@ -2104,10 +2104,9 @@ void PeerManagerImpl::ProcessOrphanTx(std::set<uint256>& orphan_work_set)
         const uint256 orphanHash = *orphan_work_set.begin();
         orphan_work_set.erase(orphan_work_set.begin());
 
-        auto orphan_it = mapOrphanTransactions.find(orphanHash);
-        if (orphan_it == mapOrphanTransactions.end()) continue;
+        const auto [porphanTx, from_peer] = GetOrphanTx(orphanHash);
+        if (porphanTx == nullptr) continue;
 
-        const CTransactionRef porphanTx = orphan_it->second.tx;
         const MempoolAcceptResult result = AcceptToMemoryPool(::ChainstateActive(), m_mempool, porphanTx, false /* bypass_limits */);
         const TxValidationState& state = result.m_state;
 
@@ -2124,10 +2123,10 @@ void PeerManagerImpl::ProcessOrphanTx(std::set<uint256>& orphan_work_set)
             if (state.IsInvalid()) {
                 LogPrint(BCLog::MEMPOOL, "   invalid orphan tx %s from peer=%d. %s\n",
                     orphanHash.ToString(),
-                    orphan_it->second.fromPeer,
+                    from_peer,
                     state.ToString());
                 // Maybe punish peer that gave us an invalid orphan tx
-                MaybePunishNodeForTx(orphan_it->second.fromPeer, state);
+                MaybePunishNodeForTx(from_peer, state);
             }
             // Has inputs but not accepted to mempool
             // Probably non-standard or insufficient fee

src/txorphanage.cpp

@@ -129,3 +129,11 @@ bool HaveOrphanTx(const GenTxid& gtxid)
     }
 }
 
+std::pair<CTransactionRef, NodeId> GetOrphanTx(const uint256& txid)
+{
+    AssertLockHeld(g_cs_orphans);
+
+    const auto it = mapOrphanTransactions.find(txid);
+    if (it == mapOrphanTransactions.end()) return {nullptr, -1};
+    return {it->second.tx, it->second.fromPeer};
+}

src/txorphanage.h

@@ -28,6 +28,7 @@ void EraseOrphansFor(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
 unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
 void AddChildrenToWorkSet(const CTransaction& tx, std::set<uint256>& orphan_work_set) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
 bool HaveOrphanTx(const GenTxid& gtxid) EXCLUSIVE_LOCKS_REQUIRED(!g_cs_orphans);
+std::pair<CTransactionRef, NodeId> GetOrphanTx(const uint256& txid) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
 
 /** Map from txid to orphan transaction record. Limited by
  *  -maxorphantx/DEFAULT_MAX_ORPHAN_TRANSACTIONS */