[txorphanage] account for weight of orphans

Author: glozow

src/txorphanage.cpp

@@ -42,6 +42,7 @@ bool TxOrphanage::AddTx(const CTransactionRef& tx, NodeId peer)
     for (const CTxIn& txin : tx->vin) {
         m_outpoint_to_orphan_it[txin.prevout].insert(ret.first);
     }
+    m_total_orphan_usage += sz;
 
     LogDebug(BCLog::TXPACKAGES, "stored orphan tx %s (wtxid=%s), weight: %u (mapsz %u outsz %u)\n", hash.ToString(), wtxid.ToString(), sz,
              m_orphans.size(), m_outpoint_to_orphan_it.size());
@@ -77,6 +78,9 @@ int TxOrphanage::EraseTx(const Wtxid& wtxid)
             m_outpoint_to_orphan_it.erase(itPrev);
     }
 
+    const auto tx_size{it->second.GetUsage()};
+    m_total_orphan_usage -= tx_size;
+
     size_t old_pos = it->second.list_pos;
     assert(m_orphan_list[old_pos] == it);
     if (old_pos + 1 != m_orphan_list.size()) {

src/txorphanage.h

@@ -5,6 +5,7 @@
 #ifndef BITCOIN_TXORPHANAGE_H
 #define BITCOIN_TXORPHANAGE_H
 
+#include <consensus/validation.h>
 #include <net.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
@@ -83,15 +84,27 @@ class TxOrphanage {
         /** Peers added with AddTx or AddAnnouncer. */
         std::set<NodeId> announcers;
         NodeSeconds nTimeExpire;
+
+        /** Get the weight of this transaction, an approximation of its memory usage. */
+        unsigned int GetUsage() const {
+            return GetTransactionWeight(*tx);
+        }
     };
 
     std::vector<OrphanTxBase> GetOrphanTransactions() const;
 
+    /** Get the total usage (weight) of all orphans. If an orphan has multiple announcers, its usage is
+     * only counted once within this total. */
+    unsigned int TotalOrphanUsage() const { return m_total_orphan_usage; }
+
 protected:
     struct OrphanTx : public OrphanTxBase {
         size_t list_pos;
     };
 
+    /** Total usage (weight) of all entries in m_orphans. */
+    unsigned int m_total_orphan_usage{0};
+
     /** Map from wtxid to orphan transaction record. Limited by
      *  -maxorphantx/DEFAULT_MAX_ORPHAN_TRANSACTIONS */
     std::map<Wtxid, OrphanTx> m_orphans;