Merge #19589: rpc: Avoid useless mempool query in gettxoutproof

fa5979d rpc: Avoid useless mempool query in gettxoutproof (MarcoFalke)
fa1f7f2 rpc: Style fixups in gettxoutproof (MarcoFalke)

Pull request description:

  `GetTransaction` implicitly and unconditionally asks the mempool global for a transaction. This is problematic for several reasons:

  * `gettxoutproof` is for on-chain txs only and asking the mempool for on-chain txs is confusing and minimally wasteful
  * Globals are confusing and make code harder to test with unit tests

  Fix both issues by passing in an optional mempool. This also helps with #19556

ACKs for top commit:
  hebasto:
    re-ACK fa5979d
  jnewbery:
    utACK fa5979d
  promag:
    Code review ACK fa5979d.

Tree-SHA512: 048361b82abfcc40481181bd44f70cfc9e97d5d6356549df34bbe30b9de7a0a72d2207a3ad0279b21f06293509b284d8967f58ca7e716263a22b20aa4e7f9c54

Author: fanquake

src/rest.cpp

@@ -68,13 +68,32 @@ static bool RESTERR(HTTPRequest* req, enum HTTPStatusCode status, std::string me
 }
 
 /**
- * Get the node context mempool.
+ * Get the node context.
  *
- * Set the HTTP error and return nullptr if node context
- * mempool is not found.
+ * @param[in]  req  The HTTP request, whose status code will be set if node
+ *                  context is not found.
+ * @returns         Pointer to the node context or nullptr if not found.
+ */
+static NodeContext* GetNodeContext(const util::Ref& context, HTTPRequest* req)
+{
+    NodeContext* node = context.Has<NodeContext>() ? &context.Get<NodeContext>() : nullptr;
+    if (!node) {
+        RESTERR(req, HTTP_INTERNAL_SERVER_ERROR,
+                strprintf("%s:%d (%s)\n"
+                          "Internal bug detected: Node context not found!\n"
+                          "You may report this issue here: %s\n",
+                          __FILE__, __LINE__, __func__, PACKAGE_BUGREPORT));
+        return nullptr;
+    }
+    return node;
+}
+
+/**
+ * Get the node context mempool.
  *
- * @param[in]  req the HTTP request
- * return pointer to the mempool or nullptr if no mempool found
+ * @param[in]  req The HTTP request, whose status code will be set if node
+ *                 context mempool is not found.
+ * @returns        Pointer to the mempool or nullptr if no mempool found.
  */
 static CTxMemPool* GetMemPool(const util::Ref& context, HTTPRequest* req)
 {
@@ -371,10 +390,13 @@ static bool rest_tx(const util::Ref& context, HTTPRequest* req, const std::strin
         g_txindex->BlockUntilSyncedToCurrentChain();
     }
 
-    CTransactionRef tx;
+    const NodeContext* const node = GetNodeContext(context, req);
+    if (!node) return false;
     uint256 hashBlock = uint256();
-    if (!GetTransaction(hash, tx, Params().GetConsensus(), hashBlock))
+    const CTransactionRef tx = GetTransaction(/* block_index */ nullptr, node->mempool, hash, Params().GetConsensus(), hashBlock);
+    if (!tx) {
         return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");
+    }
 
     switch (rf) {
     case RetFormat::BINARY: {

src/rpc/rawtransaction.cpp

@@ -157,6 +157,8 @@ static UniValue getrawtransaction(const JSONRPCRequest& request)
                 },
     }.Check(request);
 
+    const NodeContext& node = EnsureNodeContext(request.context);
+
     bool in_active_chain = true;
     uint256 hash = ParseHashV(request.params[0], "parameter 1");
     CBlockIndex* blockindex = nullptr;
@@ -188,9 +190,9 @@ static UniValue getrawtransaction(const JSONRPCRequest& request)
         f_txindex_ready = g_txindex->BlockUntilSyncedToCurrentChain();
     }
 
-    CTransactionRef tx;
     uint256 hash_block;
-    if (!GetTransaction(hash, tx, Params().GetConsensus(), hash_block, blockindex)) {
+    const CTransactionRef tx = GetTransaction(blockindex, node.mempool, hash, Params().GetConsensus(), hash_block);
+    if (!tx) {
         std::string errmsg;
         if (blockindex) {
             if (!(blockindex->nStatus & BLOCK_HAVE_DATA)) {
@@ -245,10 +247,11 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
     for (unsigned int idx = 0; idx < txids.size(); idx++) {
         const UniValue& txid = txids[idx];
         uint256 hash(ParseHashV(txid, "txid"));
-        if (setTxids.count(hash))
-            throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated txid: ")+txid.get_str());
-       setTxids.insert(hash);
-       oneTxid = hash;
+        if (setTxids.count(hash)) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, std::string("Invalid parameter, duplicated txid: ") + txid.get_str());
+        }
+        setTxids.insert(hash);
+        oneTxid = hash;
     }
 
     CBlockIndex* pblockindex = nullptr;
@@ -281,27 +284,31 @@ static UniValue gettxoutproof(const JSONRPCRequest& request)
 
     LOCK(cs_main);
 
-    if (pblockindex == nullptr)
-    {
-        CTransactionRef tx;
-        if (!GetTransaction(oneTxid, tx, Params().GetConsensus(), hashBlock) || hashBlock.IsNull())
+    if (pblockindex == nullptr) {
+        const CTransactionRef tx = GetTransaction(/* block_index */ nullptr, /* mempool */ nullptr, oneTxid, Params().GetConsensus(), hashBlock);
+        if (!tx || hashBlock.IsNull()) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Transaction not yet in block");
+        }
         pblockindex = LookupBlockIndex(hashBlock);
         if (!pblockindex) {
             throw JSONRPCError(RPC_INTERNAL_ERROR, "Transaction index corrupt");
         }
     }
 
     CBlock block;
-    if(!ReadBlockFromDisk(block, pblockindex, Params().GetConsensus()))
+    if (!ReadBlockFromDisk(block, pblockindex, Params().GetConsensus())) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Can't read block from disk");
+    }
 
     unsigned int ntxFound = 0;
-    for (const auto& tx : block.vtx)
-        if (setTxids.count(tx->GetHash()))
+    for (const auto& tx : block.vtx) {
+        if (setTxids.count(tx->GetHash())) {
             ntxFound++;
-    if (ntxFound != setTxids.size())
+        }
+    }
+    if (ntxFound != setTxids.size()) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Not all transactions found in specified or retrieved block");
+    }
 
     CDataStream ssMB(SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
     CMerkleBlock mb(block, setTxids);

src/validation.cpp

@@ -1089,45 +1089,33 @@ bool AcceptToMemoryPool(CTxMemPool& pool, TxValidationState &state, const CTrans
     return AcceptToMemoryPoolWithTime(chainparams, pool, state, tx, GetTime(), plTxnReplaced, bypass_limits, nAbsurdFee, test_accept);
 }
 
-/**
- * Return transaction in txOut, and if it was found inside a block, its hash is placed in hashBlock.
- * If blockIndex is provided, the transaction is fetched from the corresponding block.
- */
-bool GetTransaction(const uint256& hash, CTransactionRef& txOut, const Consensus::Params& consensusParams, uint256& hashBlock, const CBlockIndex* const block_index)
+CTransactionRef GetTransaction(const CBlockIndex* const block_index, const CTxMemPool* const mempool, const uint256& hash, const Consensus::Params& consensusParams, uint256& hashBlock)
 {
     LOCK(cs_main);
 
-    if (!block_index) {
-        CTransactionRef ptx = mempool.get(hash);
-        if (ptx) {
-            txOut = ptx;
-            return true;
-        }
-
-        if (g_txindex) {
-            return g_txindex->FindTx(hash, hashBlock, txOut);
-        }
-    } else {
+    if (block_index) {
         CBlock block;
         if (ReadBlockFromDisk(block, block_index, consensusParams)) {
             for (const auto& tx : block.vtx) {
                 if (tx->GetHash() == hash) {
-                    txOut = tx;
                     hashBlock = block_index->GetBlockHash();
-                    return true;
+                    return tx;
                 }
             }
         }
+        return nullptr;
     }
-
-    return false;
+    if (mempool) {
+        CTransactionRef ptx = mempool->get(hash);
+        if (ptx) return ptx;
+    }
+    if (g_txindex) {
+        CTransactionRef tx;
+        if (g_txindex->FindTx(hash, hashBlock, tx)) return tx;
+    }
+    return nullptr;
 }
 
-
-
-
-
-
 //////////////////////////////////////////////////////////////////////////////
 //
 // CBlock and CBlockIndex

src/validation.h

@@ -164,8 +164,19 @@ bool LoadGenesisBlock(const CChainParams& chainparams);
 void UnloadBlockIndex();
 /** Run an instance of the script checking thread */
 void ThreadScriptCheck(int worker_num);
-/** Retrieve a transaction (from memory pool, or from disk, if possible) */
-bool GetTransaction(const uint256& hash, CTransactionRef& tx, const Consensus::Params& params, uint256& hashBlock, const CBlockIndex* const blockIndex = nullptr);
+/**
+ * Return transaction from the block at block_index.
+ * If block_index is not provided, fall back to mempool.
+ * If mempool is not provided or the tx couldn't be found in mempool, fall back to g_txindex.
+ *
+ * @param[in]  block_index     The block to read from disk, or nullptr
+ * @param[in]  mempool         If block_index is not provided, look in the mempool, if provided
+ * @param[in]  hash            The txid
+ * @param[in]  consensusParams The params
+ * @param[out] hashBlock       The hash of block_index, if the tx was found via block_index
+ * @returns                    The tx if found, otherwise nullptr
+ */
+CTransactionRef GetTransaction(const CBlockIndex* const block_index, const CTxMemPool* const mempool, const uint256& hash, const Consensus::Params& consensusParams, uint256& hashBlock);
 /**
  * Find the best known block, and make it the tip of the block chain
  *