Merge bitcoin/bitcoin#24656: refactor: Move mempool RPCs to rpc/mempool

fac5a51 Move mempool RPCs to rpc/mempool (MarcoFalke)
fa0f666 style: Add static keyword where possible in rpc/mempool (MarcoFalke)

Pull request description:

  This moves the remaining mempool RPCs to `rpc/mempool`. Previously all mempool RPCs from the `blockchain` category have been moved. This patch moves the ones from the `rawtransactions` category.

  In the future, as a follow-up to this refactoring patch, it could be considered whether a new `mempool` category should be introduced.

  Beside a clearer code organization, this pull request should also reduce the compile time and space of the `rawtransactions.cpp` file.

ACKs for top commit:
  promag:
    Code review ACK fac5a51.

Tree-SHA512: 5578b894b68d0595869a9b03ed8dceebe3366f73dec5f090ccc36ff4002b1bc4d58af77546c2d71537c1be03694d9a28c4b1bfbb3569560997879293c5c0301e

Author: MarcoFalke

src/rpc/mempool.cpp

@@ -14,9 +14,219 @@
 #include <rpc/util.h>
 #include <txmempool.h>
 #include <univalue.h>
+#include <util/moneystr.h>
 #include <validation.h>
 
-static std::vector<RPCResult> MempoolEntryDescription() { return {
+using node::DEFAULT_MAX_RAW_TX_FEE_RATE;
+using node::NodeContext;
+
+static RPCHelpMan sendrawtransaction()
+{
+    return RPCHelpMan{"sendrawtransaction",
+        "\nSubmit a raw transaction (serialized, hex-encoded) to local node and network.\n"
+        "\nThe transaction will be sent unconditionally to all peers, so using sendrawtransaction\n"
+        "for manual rebroadcast may degrade privacy by leaking the transaction's origin, as\n"
+        "nodes will normally not rebroadcast non-wallet transactions already in their mempool.\n"
+        "\nA specific exception, RPC_TRANSACTION_ALREADY_IN_CHAIN, may throw if the transaction cannot be added to the mempool.\n"
+        "\nRelated RPCs: createrawtransaction, signrawtransactionwithkey\n",
+        {
+            {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The hex string of the raw transaction"},
+            {"maxfeerate", RPCArg::Type::AMOUNT, RPCArg::Default{FormatMoney(DEFAULT_MAX_RAW_TX_FEE_RATE.GetFeePerK())},
+             "Reject transactions whose fee rate is higher than the specified value, expressed in " + CURRENCY_UNIT +
+                 "/kvB.\nSet to 0 to accept any fee rate.\n"},
+        },
+        RPCResult{
+            RPCResult::Type::STR_HEX, "", "The transaction hash in hex"
+        },
+        RPCExamples{
+            "\nCreate a transaction\n"
+            + HelpExampleCli("createrawtransaction", "\"[{\\\"txid\\\" : \\\"mytxid\\\",\\\"vout\\\":0}]\" \"{\\\"myaddress\\\":0.01}\"") +
+            "Sign the transaction, and get back the hex\n"
+            + HelpExampleCli("signrawtransactionwithwallet", "\"myhex\"") +
+            "\nSend the transaction (signed hex)\n"
+            + HelpExampleCli("sendrawtransaction", "\"signedhex\"") +
+            "\nAs a JSON-RPC call\n"
+            + HelpExampleRpc("sendrawtransaction", "\"signedhex\"")
+                },
+        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
+        {
+            RPCTypeCheck(request.params, {
+                UniValue::VSTR,
+                UniValueType(), // VNUM or VSTR, checked inside AmountFromValue()
+            });
+
+            CMutableTransaction mtx;
+            if (!DecodeHexTx(mtx, request.params[0].get_str())) {
+                throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed. Make sure the tx has at least one input.");
+            }
+            CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
+
+            const CFeeRate max_raw_tx_fee_rate = request.params[1].isNull() ?
+                                                     DEFAULT_MAX_RAW_TX_FEE_RATE :
+                                                     CFeeRate(AmountFromValue(request.params[1]));
+
+            int64_t virtual_size = GetVirtualTransactionSize(*tx);
+            CAmount max_raw_tx_fee = max_raw_tx_fee_rate.GetFee(virtual_size);
+
+            std::string err_string;
+            AssertLockNotHeld(cs_main);
+            NodeContext& node = EnsureAnyNodeContext(request.context);
+            const TransactionError err = BroadcastTransaction(node, tx, err_string, max_raw_tx_fee, /*relay*/ true, /*wait_callback*/ true);
+            if (TransactionError::OK != err) {
+                throw JSONRPCTransactionError(err, err_string);
+            }
+
+            return tx->GetHash().GetHex();
+        },
+    };
+}
+
+static RPCHelpMan testmempoolaccept()
+{
+    return RPCHelpMan{"testmempoolaccept",
+        "\nReturns result of mempool acceptance tests indicating if raw transaction(s) (serialized, hex-encoded) would be accepted by mempool.\n"
+        "\nIf multiple transactions are passed in, parents must come before children and package policies apply: the transactions cannot conflict with any mempool transactions or each other.\n"
+        "\nIf one transaction fails, other transactions may not be fully validated (the 'allowed' key will be blank).\n"
+        "\nThe maximum number of transactions allowed is " + ToString(MAX_PACKAGE_COUNT) + ".\n"
+        "\nThis checks if transactions violate the consensus or policy rules.\n"
+        "\nSee sendrawtransaction call.\n",
+        {
+            {"rawtxs", RPCArg::Type::ARR, RPCArg::Optional::NO, "An array of hex strings of raw transactions.",
+                {
+                    {"rawtx", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, ""},
+                },
+            },
+            {"maxfeerate", RPCArg::Type::AMOUNT, RPCArg::Default{FormatMoney(DEFAULT_MAX_RAW_TX_FEE_RATE.GetFeePerK())},
+             "Reject transactions whose fee rate is higher than the specified value, expressed in " + CURRENCY_UNIT + "/kvB\n"},
+        },
+        RPCResult{
+            RPCResult::Type::ARR, "", "The result of the mempool acceptance test for each raw transaction in the input array.\n"
+                                      "Returns results for each transaction in the same order they were passed in.\n"
+                                      "Transactions that cannot be fully validated due to failures in other transactions will not contain an 'allowed' result.\n",
+            {
+                {RPCResult::Type::OBJ, "", "",
+                {
+                    {RPCResult::Type::STR_HEX, "txid", "The transaction hash in hex"},
+                    {RPCResult::Type::STR_HEX, "wtxid", "The transaction witness hash in hex"},
+                    {RPCResult::Type::STR, "package-error", /*optional=*/true, "Package validation error, if any (only possible if rawtxs had more than 1 transaction)."},
+                    {RPCResult::Type::BOOL, "allowed", /*optional=*/true, "Whether this tx would be accepted to the mempool and pass client-specified maxfeerate. "
+                                                       "If not present, the tx was not fully validated due to a failure in another tx in the list."},
+                    {RPCResult::Type::NUM, "vsize", /*optional=*/true, "Virtual transaction size as defined in BIP 141. This is different from actual serialized size for witness transactions as witness data is discounted (only present when 'allowed' is true)"},
+                    {RPCResult::Type::OBJ, "fees", /*optional=*/true, "Transaction fees (only present if 'allowed' is true)",
+                    {
+                        {RPCResult::Type::STR_AMOUNT, "base", "transaction fee in " + CURRENCY_UNIT},
+                    }},
+                    {RPCResult::Type::STR, "reject-reason", /*optional=*/true, "Rejection string (only present when 'allowed' is false)"},
+                }},
+            }
+        },
+        RPCExamples{
+            "\nCreate a transaction\n"
+            + HelpExampleCli("createrawtransaction", "\"[{\\\"txid\\\" : \\\"mytxid\\\",\\\"vout\\\":0}]\" \"{\\\"myaddress\\\":0.01}\"") +
+            "Sign the transaction, and get back the hex\n"
+            + HelpExampleCli("signrawtransactionwithwallet", "\"myhex\"") +
+            "\nTest acceptance of the transaction (signed hex)\n"
+            + HelpExampleCli("testmempoolaccept", R"('["signedhex"]')") +
+            "\nAs a JSON-RPC call\n"
+            + HelpExampleRpc("testmempoolaccept", "[\"signedhex\"]")
+                },
+        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
+        {
+            RPCTypeCheck(request.params, {
+                UniValue::VARR,
+                UniValueType(), // VNUM or VSTR, checked inside AmountFromValue()
+            });
+            const UniValue raw_transactions = request.params[0].get_array();
+            if (raw_transactions.size() < 1 || raw_transactions.size() > MAX_PACKAGE_COUNT) {
+                throw JSONRPCError(RPC_INVALID_PARAMETER,
+                                   "Array must contain between 1 and " + ToString(MAX_PACKAGE_COUNT) + " transactions.");
+            }
+
+            const CFeeRate max_raw_tx_fee_rate = request.params[1].isNull() ?
+                                                     DEFAULT_MAX_RAW_TX_FEE_RATE :
+                                                     CFeeRate(AmountFromValue(request.params[1]));
+
+            std::vector<CTransactionRef> txns;
+            txns.reserve(raw_transactions.size());
+            for (const auto& rawtx : raw_transactions.getValues()) {
+                CMutableTransaction mtx;
+                if (!DecodeHexTx(mtx, rawtx.get_str())) {
+                    throw JSONRPCError(RPC_DESERIALIZATION_ERROR,
+                                       "TX decode failed: " + rawtx.get_str() + " Make sure the tx has at least one input.");
+                }
+                txns.emplace_back(MakeTransactionRef(std::move(mtx)));
+            }
+
+            NodeContext& node = EnsureAnyNodeContext(request.context);
+            CTxMemPool& mempool = EnsureMemPool(node);
+            ChainstateManager& chainman = EnsureChainman(node);
+            CChainState& chainstate = chainman.ActiveChainstate();
+            const PackageMempoolAcceptResult package_result = [&] {
+                LOCK(::cs_main);
+                if (txns.size() > 1) return ProcessNewPackage(chainstate, mempool, txns, /* test_accept */ true);
+                return PackageMempoolAcceptResult(txns[0]->GetWitnessHash(),
+                                                  chainman.ProcessTransaction(txns[0], /*test_accept=*/true));
+            }();
+
+            UniValue rpc_result(UniValue::VARR);
+            // We will check transaction fees while we iterate through txns in order. If any transaction fee
+            // exceeds maxfeerate, we will leave the rest of the validation results blank, because it
+            // doesn't make sense to return a validation result for a transaction if its ancestor(s) would
+            // not be submitted.
+            bool exit_early{false};
+            for (const auto& tx : txns) {
+                UniValue result_inner(UniValue::VOBJ);
+                result_inner.pushKV("txid", tx->GetHash().GetHex());
+                result_inner.pushKV("wtxid", tx->GetWitnessHash().GetHex());
+                if (package_result.m_state.GetResult() == PackageValidationResult::PCKG_POLICY) {
+                    result_inner.pushKV("package-error", package_result.m_state.GetRejectReason());
+                }
+                auto it = package_result.m_tx_results.find(tx->GetWitnessHash());
+                if (exit_early || it == package_result.m_tx_results.end()) {
+                    // Validation unfinished. Just return the txid and wtxid.
+                    rpc_result.push_back(result_inner);
+                    continue;
+                }
+                const auto& tx_result = it->second;
+                // Package testmempoolaccept doesn't allow transactions to already be in the mempool.
+                CHECK_NONFATAL(tx_result.m_result_type != MempoolAcceptResult::ResultType::MEMPOOL_ENTRY);
+                if (tx_result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
+                    const CAmount fee = tx_result.m_base_fees.value();
+                    // Check that fee does not exceed maximum fee
+                    const int64_t virtual_size = tx_result.m_vsize.value();
+                    const CAmount max_raw_tx_fee = max_raw_tx_fee_rate.GetFee(virtual_size);
+                    if (max_raw_tx_fee && fee > max_raw_tx_fee) {
+                        result_inner.pushKV("allowed", false);
+                        result_inner.pushKV("reject-reason", "max-fee-exceeded");
+                        exit_early = true;
+                    } else {
+                        // Only return the fee and vsize if the transaction would pass ATMP.
+                        // These can be used to calculate the feerate.
+                        result_inner.pushKV("allowed", true);
+                        result_inner.pushKV("vsize", virtual_size);
+                        UniValue fees(UniValue::VOBJ);
+                        fees.pushKV("base", ValueFromAmount(fee));
+                        result_inner.pushKV("fees", fees);
+                    }
+                } else {
+                    result_inner.pushKV("allowed", false);
+                    const TxValidationState state = tx_result.m_state;
+                    if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS) {
+                        result_inner.pushKV("reject-reason", "missing-inputs");
+                    } else {
+                        result_inner.pushKV("reject-reason", state.GetRejectReason());
+                    }
+                }
+                rpc_result.push_back(result_inner);
+            }
+            return rpc_result;
+        },
+    };
+}
+
+static std::vector<RPCResult> MempoolEntryDescription()
+{
+    return {
         RPCResult{RPCResult::Type::NUM, "vsize", "virtual transaction size as defined in BIP 141. This is different from actual serialized size for witness transactions as witness data is discounted."},
         RPCResult{RPCResult::Type::NUM, "weight", "transaction weight as defined in BIP 141."},
         RPCResult{RPCResult::Type::STR_AMOUNT, "fee", /*optional=*/true,
@@ -50,7 +260,8 @@ static std::vector<RPCResult> MempoolEntryDescription() { return {
             {RPCResult{RPCResult::Type::STR_HEX, "transactionid", "child transaction id"}}},
         RPCResult{RPCResult::Type::BOOL, "bip125-replaceable", "Whether this transaction could be replaced due to BIP125 (replace-by-fee)"},
         RPCResult{RPCResult::Type::BOOL, "unbroadcast", "Whether this transaction is currently unbroadcast (initial broadcast not yet acknowledged by any peers)"},
-};}
+    };
+}
 
 static void entryToJSON(const CTxMemPool& pool, UniValue& info, const CTxMemPoolEntry& e) EXCLUSIVE_LOCKS_REQUIRED(pool.cs)
 {
@@ -164,7 +375,7 @@ UniValue MempoolToJSON(const CTxMemPool& pool, bool verbose, bool include_mempoo
     }
 }
 
-RPCHelpMan getrawmempool()
+static RPCHelpMan getrawmempool()
 {
     return RPCHelpMan{"getrawmempool",
         "\nReturns all transaction ids in memory pool as a json array of string transaction ids.\n"
@@ -214,7 +425,7 @@ RPCHelpMan getrawmempool()
     };
 }
 
-RPCHelpMan getmempoolancestors()
+static RPCHelpMan getmempoolancestors()
 {
     return RPCHelpMan{"getmempoolancestors",
         "\nIf txid is in the mempool, returns all in-mempool ancestors.\n",
@@ -278,7 +489,7 @@ RPCHelpMan getmempoolancestors()
     };
 }
 
-RPCHelpMan getmempooldescendants()
+static RPCHelpMan getmempooldescendants()
 {
     return RPCHelpMan{"getmempooldescendants",
         "\nIf txid is in the mempool, returns all in-mempool descendants.\n",
@@ -343,7 +554,7 @@ RPCHelpMan getmempooldescendants()
     };
 }
 
-RPCHelpMan getmempoolentry()
+static RPCHelpMan getmempoolentry()
 {
     return RPCHelpMan{"getmempoolentry",
         "\nReturns mempool data for given transaction\n",
@@ -394,7 +605,7 @@ UniValue MempoolInfoToJSON(const CTxMemPool& pool)
     return ret;
 }
 
-RPCHelpMan getmempoolinfo()
+static RPCHelpMan getmempoolinfo()
 {
     return RPCHelpMan{"getmempoolinfo",
         "\nReturns details on the active state of the TX memory pool.\n",
@@ -423,7 +634,7 @@ RPCHelpMan getmempoolinfo()
     };
 }
 
-RPCHelpMan savemempool()
+static RPCHelpMan savemempool()
 {
     return RPCHelpMan{"savemempool",
         "\nDumps the mempool to disk. It will fail until the previous dump is fully loaded.\n",
@@ -463,6 +674,8 @@ void RegisterMempoolRPCCommands(CRPCTable& t)
     static const CRPCCommand commands[]{
         // category     actor (function)
         // --------     ----------------
+        {"rawtransactions", &sendrawtransaction},
+        {"rawtransactions", &testmempoolaccept},
         {"blockchain", &getmempoolancestors},
         {"blockchain", &getmempooldescendants},
         {"blockchain", &getmempoolentry},