Benchmark Chainstate::ConnectBlock duration

Measure ConnectBlock performance for
- blocks containing only schnorr sigs
- blocks containing both schnorr and ecdsa sigs
- blocks containing only ecdsa sigs

This will allow testing and measurement of performance improvement for features like
batch verification of schnorr signatures

Author: Eunovo

src/bench/CMakeLists.txt

@@ -22,6 +22,7 @@ add_executable(bench_bitcoin
   checkblockindex.cpp
   checkqueue.cpp
   cluster_linearize.cpp
+  connectblock.cpp
   crypto_hash.cpp
   descriptors.cpp
   disconnected_transactions.cpp

src/bench/connectblock.cpp

@@ -0,0 +1,137 @@
+// Copyright (c) 2025 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 <addresstype.h>
+#include <bench/bench.h>
+#include <interfaces/chain.h>
+#include <kernel/cs_main.h>
+#include <script/interpreter.h>
+#include <sync.h>
+#include <test/util/setup_common.h>
+#include <validation.h>
+
+#include <cassert>
+#include <vector>
+
+/*
+ * Creates a test block containing transactions with the following properties:
+ * - Each transaction has the same number of inputs and outputs
+ * - All Taproot inputs use simple key path spends (no script path spends)
+ * - All signatures use SIGHASH_ALL (default sighash)
+ * - Each transaction spends all outputs from the previous transaction
+ */
+CBlock CreateTestBlock(
+    TestChain100Setup& test_setup,
+    const std::vector<CKey>& keys,
+    const std::vector<CTxOut>& outputs,
+    int num_txs = 1000)
+{
+    Chainstate& chainstate{test_setup.m_node.chainman->ActiveChainstate()};
+
+    const WitnessV1Taproot coinbase_taproot{XOnlyPubKey(test_setup.coinbaseKey.GetPubKey())};
+
+    // Create the outputs that will be spent in the first transaction of the test block
+    // Doing this in a separate block excludes the validation of its inputs from the benchmark
+    auto& coinbase_to_spend{test_setup.m_coinbase_txns[0]};
+    const auto [first_tx, _]{test_setup.CreateValidTransaction(
+        {coinbase_to_spend},
+        {COutPoint(coinbase_to_spend->GetHash(), 0)},
+        chainstate.m_chain.Height() + 1, keys, outputs, {}, {})};
+    const CScript coinbase_spk{GetScriptForDestination(coinbase_taproot)};
+    test_setup.CreateAndProcessBlock({first_tx}, coinbase_spk, &chainstate);
+
+    std::vector<CMutableTransaction> txs;
+    txs.reserve(num_txs);
+    CTransactionRef tx_to_spend{MakeTransactionRef(first_tx)};
+    for (int i{0}; i < num_txs; i++) {
+        std::vector<COutPoint> inputs;
+        inputs.reserve(outputs.size());
+
+        for (size_t j{0}; j < outputs.size(); j++) {
+            inputs.emplace_back(tx_to_spend->GetHash(), j);
+        }
+
+        const auto [taproot_tx, _]{test_setup.CreateValidTransaction(
+            {tx_to_spend}, inputs, chainstate.m_chain.Height() + 1, keys, outputs, {}, {})};
+        txs.emplace_back(taproot_tx);
+        tx_to_spend = MakeTransactionRef(taproot_tx);
+    }
+
+    // Coinbase output can use any output type as it is not spent and will not change the benchmark
+    return test_setup.CreateBlock(txs, coinbase_spk, chainstate);
+}
+
+/*
+ * Creates key pairs and corresponding outputs for the benchmark transactions.
+ * - For Schnorr signatures: Creates simple key path spendable outputs
+ * - For Ecdsa signatures: Creates P2WPKH (native SegWit v0) outputs
+ * - All outputs have value of 1 BTC
+ */
+std::pair<std::vector<CKey>, std::vector<CTxOut>> CreateKeysAndOutputs(const CKey& coinbaseKey, size_t num_schnorr, size_t num_ecdsa)
+{
+    std::vector<CKey> keys{coinbaseKey};
+    keys.reserve(num_schnorr + num_ecdsa + 1);
+
+    std::vector<CTxOut> outputs;
+    outputs.reserve(num_schnorr + num_ecdsa);
+
+    for (size_t i{0}; i < num_ecdsa; ++i) {
+        keys.emplace_back(GenerateRandomKey());
+        outputs.emplace_back(COIN, GetScriptForDestination(WitnessV0KeyHash{keys.back().GetPubKey()}));
+    }
+
+    for (size_t i{0}; i < num_schnorr; ++i) {
+        keys.emplace_back(GenerateRandomKey());
+        outputs.emplace_back(COIN, GetScriptForDestination(WitnessV1Taproot{XOnlyPubKey(keys.back().GetPubKey())}));
+    }
+
+    return {keys, outputs};
+}
+
+void BenchmarkConnectBlock(benchmark::Bench& bench, std::vector<CKey>& keys, std::vector<CTxOut>& outputs, TestChain100Setup& test_setup)
+{
+    const auto& test_block{CreateTestBlock(test_setup, keys, outputs)};
+    bench.unit("block").run([&] {
+        LOCK(cs_main);
+        auto& chainman{test_setup.m_node.chainman};
+        auto& chainstate{chainman->ActiveChainstate()};
+        BlockValidationState test_block_state;
+        auto* pindex{chainman->m_blockman.AddToBlockIndex(test_block, chainman->m_best_header)}; // Doing this here doesn't impact the benchmark
+        CCoinsViewCache viewNew{&chainstate.CoinsTip()};
+
+        assert(chainstate.ConnectBlock(test_block, test_block_state, pindex, viewNew));
+    });
+}
+
+static void ConnectBlockAllSchnorr(benchmark::Bench& bench)
+{
+    const auto test_setup{MakeNoLogFileContext<TestChain100Setup>()};
+    auto [keys, outputs]{CreateKeysAndOutputs(test_setup->coinbaseKey, /*num_schnorr=*/4, /*num_ecdsa=*/0)};
+    BenchmarkConnectBlock(bench, keys, outputs, *test_setup);
+}
+
+/**
+ * This benchmark is expected to be slower than the AllSchnorr or Ecdsa benchmark
+ * because it uses transactions with both Schnorr and Ecdsa signatures
+ * which requires the transaction to be hashed multiple times for
+ * the different signature algorithms
+ */
+static void ConnectBlockMixedEcdsaSchnorr(benchmark::Bench& bench)
+{
+    const auto test_setup{MakeNoLogFileContext<TestChain100Setup>()};
+    // Blocks in range 848000 to 868000 have a roughly 20 to 80 ratio of schnorr to ecdsa inputs
+    auto [keys, outputs]{CreateKeysAndOutputs(test_setup->coinbaseKey, /*num_schnorr=*/1, /*num_ecdsa=*/4)};
+    BenchmarkConnectBlock(bench, keys, outputs, *test_setup);
+}
+
+static void ConnectBlockAllEcdsa(benchmark::Bench& bench)
+{
+    const auto test_setup{MakeNoLogFileContext<TestChain100Setup>()};
+    auto [keys, outputs]{CreateKeysAndOutputs(test_setup->coinbaseKey, /*num_schnorr=*/0, /*num_ecdsa=*/4)};
+    BenchmarkConnectBlock(bench, keys, outputs, *test_setup);
+}
+
+BENCHMARK(ConnectBlockAllSchnorr, benchmark::PriorityLevel::HIGH);
+BENCHMARK(ConnectBlockMixedEcdsaSchnorr, benchmark::PriorityLevel::HIGH);
+BENCHMARK(ConnectBlockAllEcdsa, benchmark::PriorityLevel::HIGH);