move-only: Add txorphanage module

This module captures orphan tracking code for tx relay.

Can be reviewed with --color-moved=dimmed-zebra

1 files changed, 54 insertions, 0 deletions

diff --git a/src/txorphanage.h b/src/txorphanage.h
new file mode 100644
index 0000000000..d97b4b1f43
--- /dev/null
+++ b/src/txorphanage.h
@@ -0,0 +1,54 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_TXORPHANAGE_H
+#define BITCOIN_TXORPHANAGE_H
+
+#include <net.h>
+#include <primitives/transaction.h>
+#include <sync.h>
+
+/** Expiration time for orphan transactions in seconds */
+static constexpr int64_t ORPHAN_TX_EXPIRE_TIME = 20 * 60;
+
+/** Guards orphan transactions and extra txs for compact blocks */
+extern RecursiveMutex g_cs_orphans;
+
+struct COrphanTx {
+    // When modifying, adapt the copy of this definition in tests/DoS_tests.
+    CTransactionRef tx;
+    NodeId fromPeer;
+    int64_t nTimeExpire;
+    size_t list_pos;
+};
+
+int EraseOrphanTx(uint256 hash) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
+void EraseOrphansFor(NodeId peer);
+unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans);
+
+/** Map from txid to orphan transaction record. Limited by
+ *  -maxorphantx/DEFAULT_MAX_ORPHAN_TRANSACTIONS */
+extern std::map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(g_cs_orphans);
+
+/** Index from wtxid into the mapOrphanTransactions to lookup orphan
+ *  transactions using their witness ids. */
+extern std::map<uint256, std::map<uint256, COrphanTx>::iterator> g_orphans_by_wtxid GUARDED_BY(g_cs_orphans);
+
+    struct IteratorComparator
+    {
+        template<typename I>
+        bool operator()(const I& a, const I& b) const
+        {
+            return &(*a) < &(*b);
+        }
+    };
+
+    /** Index from the parents' COutPoint into the mapOrphanTransactions. Used
+     *  to remove orphan transactions from the mapOrphanTransactions */
+    extern std::map<COutPoint, std::set<std::map<uint256, COrphanTx>::iterator, IteratorComparator>> mapOrphanTransactionsByPrev GUARDED_BY(g_cs_orphans);
+
+    /** Orphan transactions in vector for quick random eviction */
+    extern std::vector<std::map<uint256, COrphanTx>::iterator> g_orphan_list GUARDED_BY(g_cs_orphans);
+
+#endif // BITCOIN_TXORPHANAGE_H