From 6bd4963c069bfd0af420e8a3fb724c3b693a1e76 Mon Sep 17 00:00:00 2001
From: Anthony Towns <aj@erisian.com.au>
Date: Sun, 31 Jan 2021 23:42:00 +1000
Subject: txorphanage: Move functions and data into class

Collects all the orphan handling globals into a single member var in
net_processing, and ensures access is encapuslated into the interface
functions. Also adds doxygen comments for methods.
---
 src/txorphanage.h | 69 ++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 46 insertions(+), 23 deletions(-)

(limited to 'src/txorphanage.h')

diff --git a/src/txorphanage.h b/src/txorphanage.h
index f2ffbf3d67..6b9837815b 100644
--- a/src/txorphanage.h
+++ b/src/txorphanage.h
@@ -13,30 +13,48 @@
 /** 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;
-};
+/** Data structure to keep track of orphan transactions
+ */
+class TxOrphanage {
+public:
+    /** Add a new orphan transaction */
+    bool AddTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
+
+    /** Check if we already have an orphan transaction (by txid or wtxid) */
+    bool HaveTx(const GenTxid& gtxid) const EXCLUSIVE_LOCKS_REQUIRED(!g_cs_orphans);
+
+    /** Get the details of an orphan transaction (returns nullptr if not found) */
+    std::pair<CTransactionRef, NodeId> GetTx(const uint256& txid) const EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
 
-int EraseOrphanTx(const uint256& txid) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
-void EraseOrphansFor(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
-void EraseOrphansForBlock(const CBlock& block) 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);
-bool OrphanageAddTx(const CTransactionRef& tx, NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
+    /** Erase an orphan by txid */
+    int EraseTx(const uint256& txid) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
 
-/** 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);
+    /** Erase all orphans announced by a peer (eg, after that peer disconnects) */
+    void EraseForPeer(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(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);
+    /** Erase all orphans included in / invalidated by a new block */
+    void EraseForBlock(const CBlock& block) EXCLUSIVE_LOCKS_REQUIRED(!g_cs_orphans);
+
+    /** Limit the orphanage to the given maximum */
+    unsigned int LimitOrphans(unsigned int nMaxOrphans) EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
+
+    /** Add any orphans that list a particular tx as a parent into a peer's work set
+     * (ie orphans that may have found their final missing parent, and so should be reconsidered for the mempool) */
+    void AddChildrenToWorkSet(const CTransaction& tx, std::set<uint256>& orphan_work_set) const EXCLUSIVE_LOCKS_REQUIRED(g_cs_orphans);
+
+protected:
+    struct COrphanTx {
+        CTransactionRef tx;
+        NodeId fromPeer;
+        int64_t nTimeExpire;
+        size_t list_pos;
+    };
+
+    /** Map from txid to orphan transaction record. Limited by
+     *  -maxorphantx/DEFAULT_MAX_ORPHAN_TRANSACTIONS */
+    std::map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(g_cs_orphans);
+
+    using OrphanMap = decltype(mapOrphanTransactions);
 
     struct IteratorComparator
     {
@@ -49,9 +67,14 @@ extern std::map<uint256, std::map<uint256, COrphanTx>::iterator> g_orphans_by_wt
 
     /** 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);
+    std::map<COutPoint, std::set<OrphanMap::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);
+    std::vector<OrphanMap::iterator> g_orphan_list GUARDED_BY(g_cs_orphans);
+
+    /** Index from wtxid into the mapOrphanTransactions to lookup orphan
+     *  transactions using their witness ids. */
+    std::map<uint256, OrphanMap::iterator> g_orphans_by_wtxid GUARDED_BY(g_cs_orphans);
+};
 
 #endif // BITCOIN_TXORPHANAGE_H
-- 
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