Use `int32_t` type for most transaction size/weight values

This change gets rid of a few casts and makes the following commit diff
smaller.

6 files changed, 27 insertions, 25 deletions

diff --git a/src/consensus/validation.h b/src/consensus/validation.h
index ad8ee676b2..d5bf08cd61 100644
--- a/src/consensus/validation.h
+++ b/src/consensus/validation.h
@@ -145,7 +145,7 @@ class BlockValidationState : public ValidationState<BlockValidationResult> {};
 // using only serialization with and without witness data. As witness_size
 // is equal to total_size - stripped_size, this formula is identical to:
 // weight = (stripped_size * 3) + total_size.
-static inline int64_t GetTransactionWeight(const CTransaction& tx)
+static inline int32_t GetTransactionWeight(const CTransaction& tx)
 {
     return ::GetSerializeSize(tx, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) * (WITNESS_SCALE_FACTOR - 1) + ::GetSerializeSize(tx, PROTOCOL_VERSION);
 }
diff --git a/src/kernel/mempool_entry.h b/src/kernel/mempool_entry.h
index e1ba4296ef..969ddcd1ce 100644
--- a/src/kernel/mempool_entry.h
+++ b/src/kernel/mempool_entry.h
@@ -75,7 +75,7 @@ private:
     mutable Parents m_parents;
     mutable Children m_children;
     const CAmount nFee;             //!< Cached to avoid expensive parent-transaction lookups
-    const size_t nTxWeight;         //!< ... and avoid recomputing tx weight (also used for GetTxSize())
+    const int32_t nTxWeight;         //!< ... and avoid recomputing tx weight (also used for GetTxSize())
     const size_t nUsageSize;        //!< ... and total memory usage
     const int64_t nTime;            //!< Local time when entering the mempool
     const unsigned int entryHeight; //!< Chain height when entering the mempool
@@ -88,12 +88,14 @@ private:
     // mempool; if we remove this transaction we must remove all of these
     // descendants as well.
     uint64_t nCountWithDescendants{1}; //!< number of descendant transactions
-    uint64_t nSizeWithDescendants;     //!< ... and size
+    // Using int64_t instead of int32_t to avoid signed integer overflow issues.
+    int64_t nSizeWithDescendants;      //!< ... and size
     CAmount nModFeesWithDescendants;   //!< ... and total fees (all including us)
 
     // Analogous statistics for ancestor transactions
     uint64_t nCountWithAncestors{1};
-    uint64_t nSizeWithAncestors;
+    // Using int64_t instead of int32_t to avoid signed integer overflow issues.
+    int64_t nSizeWithAncestors;
     CAmount nModFeesWithAncestors;
     int64_t nSigOpCostWithAncestors;
 
@@ -104,7 +106,7 @@ public:
                     int64_t sigops_cost, LockPoints lp)
         : tx{tx},
           nFee{fee},
-          nTxWeight(GetTransactionWeight(*tx)),
+          nTxWeight{GetTransactionWeight(*tx)},
           nUsageSize{RecursiveDynamicUsage(tx)},
           nTime{time},
           entryHeight{entry_height},
@@ -121,11 +123,11 @@ public:
     const CTransaction& GetTx() const { return *this->tx; }
     CTransactionRef GetSharedTx() const { return this->tx; }
     const CAmount& GetFee() const { return nFee; }
-    size_t GetTxSize() const
+    int32_t GetTxSize() const
     {
         return GetVirtualTransactionSize(nTxWeight, sigOpCost, ::nBytesPerSigOp);
     }
-    size_t GetTxWeight() const { return nTxWeight; }
+    int32_t GetTxWeight() const { return nTxWeight; }
     std::chrono::seconds GetTime() const { return std::chrono::seconds{nTime}; }
     unsigned int GetHeight() const { return entryHeight; }
     int64_t GetSigOpCost() const { return sigOpCost; }
@@ -134,9 +136,9 @@ public:
     const LockPoints& GetLockPoints() const { return lockPoints; }
 
     // Adjusts the descendant state.
-    void UpdateDescendantState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount);
+    void UpdateDescendantState(int32_t modifySize, CAmount modifyFee, int64_t modifyCount);
     // Adjusts the ancestor state
-    void UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int64_t modifySigOps);
+    void UpdateAncestorState(int32_t modifySize, CAmount modifyFee, int64_t modifyCount, int64_t modifySigOps);
     // Updates the modified fees with descendants/ancestors.
     void UpdateModifiedFee(CAmount fee_diff)
     {
@@ -152,13 +154,13 @@ public:
     }
 
     uint64_t GetCountWithDescendants() const { return nCountWithDescendants; }
-    uint64_t GetSizeWithDescendants() const { return nSizeWithDescendants; }
+    int64_t GetSizeWithDescendants() const { return nSizeWithDescendants; }
     CAmount GetModFeesWithDescendants() const { return nModFeesWithDescendants; }
 
     bool GetSpendsCoinbase() const { return spendsCoinbase; }
 
     uint64_t GetCountWithAncestors() const { return nCountWithAncestors; }
-    uint64_t GetSizeWithAncestors() const { return nSizeWithAncestors; }
+    int64_t GetSizeWithAncestors() const { return nSizeWithAncestors; }
     CAmount GetModFeesWithAncestors() const { return nModFeesWithAncestors; }
     int64_t GetSigOpCostWithAncestors() const { return nSigOpCostWithAncestors; }
 
diff --git a/src/policy/policy.h b/src/policy/policy.h
index 394fb34230..9135cae91c 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -24,7 +24,7 @@ static constexpr unsigned int DEFAULT_BLOCK_MAX_WEIGHT{MAX_BLOCK_WEIGHT - 4000};
 /** Default for -blockmintxfee, which sets the minimum feerate for a transaction in blocks created by mining code **/
 static constexpr unsigned int DEFAULT_BLOCK_MIN_TX_FEE{1000};
 /** The maximum weight for transactions we're willing to relay/mine */
-static constexpr unsigned int MAX_STANDARD_TX_WEIGHT{400000};
+static constexpr int32_t MAX_STANDARD_TX_WEIGHT{400000};
 /** The minimum non-witness size for transactions we're willing to relay/mine: one larger than 64  */
 static constexpr unsigned int MIN_STANDARD_TX_NONWITNESS_SIZE{65};
 /** Maximum number of signature check operations in an IsStandard() P2SH script */
diff --git a/src/test/miniminer_tests.cpp b/src/test/miniminer_tests.cpp
index 371147b0e2..b26f7dafe3 100644
--- a/src/test/miniminer_tests.cpp
+++ b/src/test/miniminer_tests.cpp
@@ -137,7 +137,7 @@ BOOST_FIXTURE_TEST_CASE(miniminer_1p1c, TestChain100Setup)
 
     std::vector<CTransactionRef> all_transactions{tx1, tx2, tx3, tx4, tx5, tx6, tx7, tx8};
     struct TxDimensions {
-        size_t vsize; CAmount mod_fee; CFeeRate feerate;
+        int32_t vsize; CAmount mod_fee; CFeeRate feerate;
     };
     std::map<uint256, TxDimensions> tx_dims;
     for (const auto& tx : all_transactions) {
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 9ce4a17c5e..cb1d8b84ca 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -75,7 +75,7 @@ void CTxMemPool::UpdateForDescendants(txiter updateIt, cacheMap& cachedDescendan
     }
     // descendants now contains all in-mempool descendants of updateIt.
     // Update and add to cached descendant map
-    int64_t modifySize = 0;
+    int32_t modifySize = 0;
     CAmount modifyFee = 0;
     int64_t modifyCount = 0;
     for (const CTxMemPoolEntry& descendant : descendants) {
@@ -91,7 +91,7 @@ void CTxMemPool::UpdateForDescendants(txiter updateIt, cacheMap& cachedDescendan
             // Don't directly remove the transaction here -- doing so would
             // invalidate iterators in cachedDescendants. Mark it for removal
             // by inserting into descendants_to_remove.
-            if (descendant.GetCountWithAncestors() > uint64_t(m_limits.ancestor_count) || descendant.GetSizeWithAncestors() > uint64_t(m_limits.ancestor_size_vbytes)) {
+            if (descendant.GetCountWithAncestors() > uint64_t(m_limits.ancestor_count) || descendant.GetSizeWithAncestors() > m_limits.ancestor_size_vbytes) {
                 descendants_to_remove.insert(descendant.GetTx().GetHash());
             }
         }
@@ -278,8 +278,8 @@ void CTxMemPool::UpdateAncestorsOf(bool add, txiter it, setEntries &setAncestors
     for (const CTxMemPoolEntry& parent : parents) {
         UpdateChild(mapTx.iterator_to(parent), it, add);
     }
-    const int64_t updateCount = (add ? 1 : -1);
-    const int64_t updateSize = updateCount * it->GetTxSize();
+    const int32_t updateCount = (add ? 1 : -1);
+    const int32_t updateSize{updateCount * it->GetTxSize()};
     const CAmount updateFee = updateCount * it->GetModifiedFee();
     for (txiter ancestorIt : setAncestors) {
         mapTx.modify(ancestorIt, [=](CTxMemPoolEntry& e) { e.UpdateDescendantState(updateSize, updateFee, updateCount); });
@@ -323,7 +323,7 @@ void CTxMemPool::UpdateForRemoveFromMempool(const setEntries &entriesToRemove, b
             setEntries setDescendants;
             CalculateDescendants(removeIt, setDescendants);
             setDescendants.erase(removeIt); // don't update state for self
-            int64_t modifySize = -((int64_t)removeIt->GetTxSize());
+            int32_t modifySize = -removeIt->GetTxSize();
             CAmount modifyFee = -removeIt->GetModifiedFee();
             int modifySigOps = -removeIt->GetSigOpCost();
             for (txiter dit : setDescendants) {
@@ -365,19 +365,19 @@ void CTxMemPool::UpdateForRemoveFromMempool(const setEntries &entriesToRemove, b
     }
 }
 
-void CTxMemPoolEntry::UpdateDescendantState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount)
+void CTxMemPoolEntry::UpdateDescendantState(int32_t modifySize, CAmount modifyFee, int64_t modifyCount)
 {
     nSizeWithDescendants += modifySize;
-    assert(int64_t(nSizeWithDescendants) > 0);
+    assert(nSizeWithDescendants > 0);
     nModFeesWithDescendants = SaturatingAdd(nModFeesWithDescendants, modifyFee);
     nCountWithDescendants += modifyCount;
     assert(int64_t(nCountWithDescendants) > 0);
 }
 
-void CTxMemPoolEntry::UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int64_t modifySigOps)
+void CTxMemPoolEntry::UpdateAncestorState(int32_t modifySize, CAmount modifyFee, int64_t modifyCount, int64_t modifySigOps)
 {
     nSizeWithAncestors += modifySize;
-    assert(int64_t(nSizeWithAncestors) > 0);
+    assert(nSizeWithAncestors > 0);
     nModFeesWithAncestors = SaturatingAdd(nModFeesWithAncestors, modifyFee);
     nCountWithAncestors += modifyCount;
     assert(int64_t(nCountWithAncestors) > 0);
@@ -699,7 +699,7 @@ void CTxMemPool::check(const CCoinsViewCache& active_coins_tip, int64_t spendhei
         // Verify ancestor state is correct.
         auto ancestors{AssumeCalculateMemPoolAncestors(__func__, *it, Limits::NoLimits())};
         uint64_t nCountCheck = ancestors.size() + 1;
-        uint64_t nSizeCheck = it->GetTxSize();
+        int32_t nSizeCheck = it->GetTxSize();
         CAmount nFeesCheck = it->GetModifiedFee();
         int64_t nSigOpCheck = it->GetSigOpCost();
 
@@ -720,7 +720,7 @@ void CTxMemPool::check(const CCoinsViewCache& active_coins_tip, int64_t spendhei
         // Check children against mapNextTx
         CTxMemPoolEntry::Children setChildrenCheck;
         auto iter = mapNextTx.lower_bound(COutPoint(it->GetTx().GetHash(), 0));
-        uint64_t child_sizes = 0;
+        int32_t child_sizes{0};
         for (; iter != mapNextTx.end() && iter->first->hash == it->GetTx().GetHash(); ++iter) {
             txiter childit = mapTx.find(iter->second->GetHash());
             assert(childit != mapTx.end()); // mapNextTx points to in-mempool transactions
diff --git a/src/txmempool.h b/src/txmempool.h
index 1ea029e949..846def02cd 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -222,7 +222,7 @@ struct TxMempoolInfo
     CAmount fee;
 
     /** Virtual size of the transaction. */
-    size_t vsize;
+    int32_t vsize;
 
     /** The fee delta. */
     int64_t nFeeDelta;