Merge #20944: rpc: Return total fee in getmempoolinfo

fa362064e383163a2585ffbc71ac1ea3bcc92663 rpc: Return total fee in mempool (MarcoFalke)

Pull request description:

  This avoids having to loop over the whole mempool to query each entry's fee

ACKs for top commit:
  achow101:
    ACK fa362064e383163a2585ffbc71ac1ea3bcc92663
  glozow:
    ACK https://github.com/bitcoin/bitcoin/pull/20944/commits/fa362064e383163a2585ffbc71ac1ea3bcc92663 🧸
  jnewbery:
    ACK fa362064e383163a2585ffbc71ac1ea3bcc92663

Tree-SHA512: e2fa1664df39c9e187f9229fc35764ccf436f6f75889c5a206d34fff473fc21efbf2bb143f4ca7895c27659218c22884d0ec4195e7a536a5a96973fc9dd82d08

1 files changed, 10 insertions, 3 deletions

diff --git a/src/txmempool.h b/src/txmempool.h
index 0a9cd81ff5..c0df33fe13 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -19,8 +19,8 @@
 #include <optional.h>
 #include <policy/feerate.h>
 #include <primitives/transaction.h>
-#include <sync.h>
 #include <random.h>
+#include <sync.h>
 #include <util/hasher.h>
 
 #include <boost/multi_index_container.hpp>
@@ -478,8 +478,9 @@ private:
     std::atomic<unsigned int> nTransactionsUpdated{0}; //!< Used by getblocktemplate to trigger CreateNewBlock() invocation
     CBlockPolicyEstimator* minerPolicyEstimator;
 
-    uint64_t totalTxSize;      //!< sum of all mempool tx's virtual sizes. Differs from serialized tx size since witness data is discounted. Defined in BIP 141.
-    uint64_t cachedInnerUsage; //!< sum of dynamic memory usage of all the map elements (NOT the maps themselves)
+    uint64_t totalTxSize GUARDED_BY(cs);      //!< sum of all mempool tx's virtual sizes. Differs from serialized tx size since witness data is discounted. Defined in BIP 141.
+    CAmount m_total_fee GUARDED_BY(cs);       //!< sum of all mempool tx's fees (NOT modified fee)
+    uint64_t cachedInnerUsage GUARDED_BY(cs); //!< sum of dynamic memory usage of all the map elements (NOT the maps themselves)
 
     mutable int64_t lastRollingFeeUpdate;
     mutable bool blockSinceLastRollingFeeBump;
@@ -724,6 +725,12 @@ public:
         return totalTxSize;
     }
 
+    CAmount GetTotalFee() const EXCLUSIVE_LOCKS_REQUIRED(cs)
+    {
+        AssertLockHeld(cs);
+        return m_total_fee;
+    }
+
     bool exists(const GenTxid& gtxid) const
     {
         LOCK(cs);