Make MemPoolAccept::m_limits const

instagibbs · Sep 13, 2023 · 275687f · 275687f
1 parent f1a9fd6
commit 275687f
Showing 1 changed file with 11 additions and 7 deletions.
diff --git a/src/validation.cpp b/src/validation.cpp
@@ -683,7 +683,7 @@ class MemPoolAccept
 
     Chainstate& m_active_chainstate;
 
-    CTxMemPool::Limits m_limits;
+    const CTxMemPool::Limits m_limits;
 
     /** Whether the transaction(s) would replace any mempool transactions. If so, RBF rules apply. */
     bool m_rbf{false};
@@ -873,6 +873,10 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
     if (!bypass_limits && !args.m_package_feerates && !CheckFeeRate(ws.m_vsize, ws.m_modified_fees, state)) return false;
 
     ws.m_iters_conflicting = m_pool.GetIterSet(ws.m_conflicts);
+
+    // We don't modify m_limits directly to avoid polluting it across PreChecks()
+    CTxMemPool::Limits maybe_rbf_limits = m_limits;
+
     // Calculate in-mempool ancestors, up to a limit.
     if (ws.m_conflicts.size() == 1) {
         // In general, when we receive an RBF transaction with mempool conflicts, we want to know whether we
@@ -905,11 +909,11 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
         assert(ws.m_iters_conflicting.size() == 1);
         CTxMemPool::txiter conflict = *ws.m_iters_conflicting.begin();
 
-        m_limits.descendant_count += 1;
-        m_limits.descendant_size_vbytes += conflict->GetSizeWithDescendants();
+        maybe_rbf_limits.descendant_count += 1;
+        maybe_rbf_limits.descendant_size_vbytes += conflict->GetSizeWithDescendants();
     }
 
-    auto ancestors{m_pool.CalculateMemPoolAncestors(*entry, m_limits)};
+    auto ancestors{m_pool.CalculateMemPoolAncestors(*entry, maybe_rbf_limits)};
     if (!ancestors) {
         // If CalculateMemPoolAncestors fails second time, we want the original error string.
         // Contracting/payment channels CPFP carve-out:
@@ -925,9 +929,9 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
         // this, see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html
         CTxMemPool::Limits cpfp_carve_out_limits{
             .ancestor_count = 2,
-            .ancestor_size_vbytes = m_limits.ancestor_size_vbytes,
-            .descendant_count = m_limits.descendant_count + 1,
-            .descendant_size_vbytes = m_limits.descendant_size_vbytes + EXTRA_DESCENDANT_TX_SIZE_LIMIT,
+            .ancestor_size_vbytes = maybe_rbf_limits.ancestor_size_vbytes,
+            .descendant_count = maybe_rbf_limits.descendant_count + 1,
+            .descendant_size_vbytes = maybe_rbf_limits.descendant_size_vbytes + EXTRA_DESCENDANT_TX_SIZE_LIMIT,
         };
         const auto error_message{util::ErrorString(ancestors).original};
         if (ws.m_vsize > EXTRA_DESCENDANT_TX_SIZE_LIMIT) {