Make CBlock::vtx a vector of shared_ptr<CTransaction>

Author: sipa

src/blockencodings.cpp

@@ -24,7 +24,7 @@ CBlockHeaderAndShortTxIDs::CBlockHeaderAndShortTxIDs(const CBlock& block, bool f
     //TODO: Use our mempool prior to block acceptance to predictively fill more than just the coinbase
     prefilledtxn[0] = {0, block.vtx[0]};
     for (size_t i = 1; i < block.vtx.size(); i++) {
-        const CTransaction& tx = block.vtx[i];
+        const CTransaction& tx = *block.vtx[i];
         shorttxids[i - 1] = GetShortID(fUseWTXID ? tx.GetWitnessHash() : tx.GetHash());
     }
 }
@@ -59,7 +59,7 @@ ReadStatus PartiallyDownloadedBlock::InitData(const CBlockHeaderAndShortTxIDs& c
 
     int32_t lastprefilledindex = -1;
     for (size_t i = 0; i < cmpctblock.prefilledtxn.size(); i++) {
-        if (cmpctblock.prefilledtxn[i].tx.IsNull())
+        if (cmpctblock.prefilledtxn[i].tx->IsNull())
             return READ_STATUS_INVALID;
 
         lastprefilledindex += cmpctblock.prefilledtxn[i].index + 1; //index is a uint16_t, so cant overflow here
@@ -71,7 +71,7 @@ ReadStatus PartiallyDownloadedBlock::InitData(const CBlockHeaderAndShortTxIDs& c
             // have neither a prefilled txn or a shorttxid!
             return READ_STATUS_INVALID;
         }
-        txn_available[lastprefilledindex] = std::make_shared<CTransaction>(cmpctblock.prefilledtxn[i].tx);
+        txn_available[lastprefilledindex] = cmpctblock.prefilledtxn[i].tx;
     }
     prefilled_count = cmpctblock.prefilledtxn.size();
 
@@ -142,7 +142,7 @@ bool PartiallyDownloadedBlock::IsTxAvailable(size_t index) const {
     return txn_available[index] ? true : false;
 }
 
-ReadStatus PartiallyDownloadedBlock::FillBlock(CBlock& block, const std::vector<CTransaction>& vtx_missing) const {
+ReadStatus PartiallyDownloadedBlock::FillBlock(CBlock& block, const std::vector<std::shared_ptr<const CTransaction>>& vtx_missing) const {
     assert(!header.IsNull());
     block = header;
     block.vtx.resize(txn_available.size());
@@ -154,7 +154,7 @@ ReadStatus PartiallyDownloadedBlock::FillBlock(CBlock& block, const std::vector<
                 return READ_STATUS_INVALID;
             block.vtx[i] = vtx_missing[tx_missing_offset++];
         } else
-            block.vtx[i] = *txn_available[i];
+            block.vtx[i] = txn_available[i];
     }
     if (vtx_missing.size() != tx_missing_offset)
         return READ_STATUS_INVALID;
@@ -172,8 +172,8 @@ ReadStatus PartiallyDownloadedBlock::FillBlock(CBlock& block, const std::vector<
 
     LogPrint("cmpctblock", "Successfully reconstructed block %s with %lu txn prefilled, %lu txn from mempool and %lu txn requested\n", header.GetHash().ToString(), prefilled_count, mempool_count, vtx_missing.size());
     if (vtx_missing.size() < 5) {
-        for(const CTransaction& tx : vtx_missing)
-            LogPrint("cmpctblock", "Reconstructed block %s required tx %s\n", header.GetHash().ToString(), tx.GetHash().ToString());
+        for (const auto& tx : vtx_missing)
+            LogPrint("cmpctblock", "Reconstructed block %s required tx %s\n", header.GetHash().ToString(), tx->GetHash().ToString());
     }
 
     return READ_STATUS_OK;

src/blockencodings.h

@@ -14,9 +14,9 @@ class CTxMemPool;
 // Dumb helper to handle CTransaction compression at serialize-time
 struct TransactionCompressor {
 private:
-    CTransaction& tx;
+    std::shared_ptr<const CTransaction>& tx;
 public:
-    TransactionCompressor(CTransaction& txIn) : tx(txIn) {}
+    TransactionCompressor(std::shared_ptr<const CTransaction>& txIn) : tx(txIn) {}
 
     ADD_SERIALIZE_METHODS;
 
@@ -72,7 +72,7 @@ class BlockTransactions {
 public:
     // A BlockTransactions message
     uint256 blockhash;
-    std::vector<CTransaction> txn;
+    std::vector<std::shared_ptr<const CTransaction>> txn;
 
     BlockTransactions() {}
     BlockTransactions(const BlockTransactionsRequest& req) :
@@ -104,7 +104,7 @@ struct PrefilledTransaction {
     // Used as an offset since last prefilled tx in CBlockHeaderAndShortTxIDs,
     // as a proper transaction-in-block-index in PartiallyDownloadedBlock
     uint16_t index;
-    CTransaction tx;
+    std::shared_ptr<const CTransaction> tx;
 
     ADD_SERIALIZE_METHODS;
 
@@ -202,7 +202,7 @@ class PartiallyDownloadedBlock {
 
     ReadStatus InitData(const CBlockHeaderAndShortTxIDs& cmpctblock);
     bool IsTxAvailable(size_t index) const;
-    ReadStatus FillBlock(CBlock& block, const std::vector<CTransaction>& vtx_missing) const;
+    ReadStatus FillBlock(CBlock& block, const std::vector<std::shared_ptr<const CTransaction>>& vtx_missing) const;
 };
 
 #endif

src/chainparams.cpp

@@ -31,7 +31,7 @@ static CBlock CreateGenesisBlock(const char* pszTimestamp, const CScript& genesi
     genesis.nBits    = nBits;
     genesis.nNonce   = nNonce;
     genesis.nVersion = nVersion;
-    genesis.vtx.push_back(txNew);
+    genesis.vtx.push_back(std::make_shared<const CTransaction>(std::move(txNew)));
     genesis.hashPrevBlock.SetNull();
     genesis.hashMerkleRoot = BlockMerkleRoot(genesis);
     return genesis;

src/consensus/merkle.cpp

@@ -160,7 +160,7 @@ uint256 BlockMerkleRoot(const CBlock& block, bool* mutated)
     std::vector<uint256> leaves;
     leaves.resize(block.vtx.size());
     for (size_t s = 0; s < block.vtx.size(); s++) {
-        leaves[s] = block.vtx[s].GetHash();
+        leaves[s] = block.vtx[s]->GetHash();
     }
     return ComputeMerkleRoot(leaves, mutated);
 }
@@ -171,7 +171,7 @@ uint256 BlockWitnessMerkleRoot(const CBlock& block, bool* mutated)
     leaves.resize(block.vtx.size());
     leaves[0].SetNull(); // The witness hash of the coinbase is 0.
     for (size_t s = 1; s < block.vtx.size(); s++) {
-        leaves[s] = block.vtx[s].GetWitnessHash();
+        leaves[s] = block.vtx[s]->GetWitnessHash();
     }
     return ComputeMerkleRoot(leaves, mutated);
 }
@@ -181,7 +181,7 @@ std::vector<uint256> BlockMerkleBranch(const CBlock& block, uint32_t position)
     std::vector<uint256> leaves;
     leaves.resize(block.vtx.size());
     for (size_t s = 0; s < block.vtx.size(); s++) {
-        leaves[s] = block.vtx[s].GetHash();
+        leaves[s] = block.vtx[s]->GetHash();
     }
     return ComputeMerkleBranch(leaves, position);
 }

src/core_memusage.h

@@ -69,8 +69,8 @@ static inline size_t RecursiveDynamicUsage(const CMutableTransaction& tx) {
 
 static inline size_t RecursiveDynamicUsage(const CBlock& block) {
     size_t mem = memusage::DynamicUsage(block.vtx);
-    for (std::vector<CTransaction>::const_iterator it = block.vtx.begin(); it != block.vtx.end(); it++) {
-        mem += RecursiveDynamicUsage(*it);
+    for (const auto& tx : block.vtx) {
+        mem += memusage::DynamicUsage(tx) + RecursiveDynamicUsage(*tx);
     }
     return mem;
 }