bench: Add basic CheckEphemeralSpends benchmark

src/bench/CMakeLists.txt

@@ -35,6 +35,7 @@ add_executable(bench_bitcoin
   load_external.cpp
   lockedpool.cpp
   logging.cpp
+  mempool_ephemeral_spends.cpp
   mempool_eviction.cpp
   mempool_stress.cpp
   merkle_root.cpp

src/bench/mempool_ephemeral_spends.cpp

@@ -0,0 +1,83 @@
+// Copyright (c) 2011-2022 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <bench/bench.h>
+#include <consensus/amount.h>
+#include <kernel/cs_main.h>
+#include <policy/ephemeral_policy.h>
+#include <policy/policy.h>
+#include <primitives/transaction.h>
+#include <script/script.h>
+#include <sync.h>
+#include <test/util/setup_common.h>
+#include <txmempool.h>
+#include <util/check.h>
+
+#include <cstdint>
+#include <memory>
+#include <vector>
+
+
+static void AddTx(const CTransactionRef& tx, CTxMemPool& pool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs)
+{
+    int64_t nTime{0};
+    unsigned int nHeight{1};
+    uint64_t sequence{0};
+    bool spendsCoinbase{false};
+    unsigned int sigOpCost{4};
+    uint64_t fee{0};
+    LockPoints lp;
+    pool.addUnchecked(CTxMemPoolEntry(
+        tx, fee, nTime, nHeight, sequence,
+        spendsCoinbase, sigOpCost, lp));
+}
+
+static void MempoolCheckEphemeralSpends(benchmark::Bench& bench)
+{
+    const auto testing_setup = MakeNoLogFileContext<const TestingSetup>();
+
+    int number_outputs{1000};
+    if (bench.complexityN() > 1) {
+        number_outputs = static_cast<int>(bench.complexityN());
+    }
+
+    // Tx with many outputs
+    CMutableTransaction tx1 = CMutableTransaction();
+    tx1.vin.resize(1);
+    tx1.vout.resize(number_outputs);
+    for (size_t i = 0; i < tx1.vout.size(); i++) {
+        tx1.vout[i].scriptPubKey = CScript();
+        // Each output progressively larger
+        tx1.vout[i].nValue = i * CENT;
+    }
+
+    const auto& parent_txid = tx1.GetHash();
+
+    // Spends all outputs of tx1, other details don't matter
+    CMutableTransaction tx2 = CMutableTransaction();
+    tx2.vin.resize(tx1.vout.size());
+    for (size_t i = 0; i < tx2.vin.size(); i++) {
+        tx2.vin[0].prevout.hash = parent_txid;
+        tx2.vin[0].prevout.n = i;
+    }
+    tx2.vout.resize(1);
+
+    CTxMemPool& pool = *Assert(testing_setup->m_node.mempool);
+    LOCK2(cs_main, pool.cs);
+    // Create transaction references outside the "hot loop"
+    const CTransactionRef tx1_r{MakeTransactionRef(tx1)};
+    const CTransactionRef tx2_r{MakeTransactionRef(tx2)};
+
+    AddTx(tx1_r, pool);
+
+    uint32_t iteration{0};
+
+    bench.run([&]() NO_THREAD_SAFETY_ANALYSIS {
+
+        CheckEphemeralSpends({tx2_r}, /*dust_relay_rate=*/CFeeRate(iteration * COIN / 10), pool);
+        iteration++;
+    });
+}
+
+BENCHMARK(MempoolCheckEphemeralSpends, benchmark::PriorityLevel::HIGH);