Add microbenchmarks to profile more code paths.

The new benchmarks exercise script validation, CCoinsDBView caching,
mempool eviction, and wallet coin selection code.

All of the benchmarks added here are extremely simple and don't
necessarily mirror common real world conditions or interesting
performance edge cases. Details about how specific benchmarks can be
improved are noted in comments.

Github-Issue: #7883

1 files changed, 103 insertions, 0 deletions

diff --git a/src/bench/verify_script.cpp b/src/bench/verify_script.cpp
new file mode 100644
index 0000000000..dc3940cdbd
--- /dev/null
+++ b/src/bench/verify_script.cpp
@@ -0,0 +1,103 @@
+// Copyright (c) 2016 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.h"
+#include "key.h"
+#if defined(HAVE_CONSENSUS_LIB)
+#include "script/bitcoinconsensus.h"
+#endif
+#include "script/script.h"
+#include "script/sign.h"
+#include "streams.h"
+
+// FIXME: Dedup with BuildCreditingTransaction in test/script_tests.cpp.
+static CMutableTransaction BuildCreditingTransaction(const CScript& scriptPubKey)
+{
+    CMutableTransaction txCredit;
+    txCredit.nVersion = 1;
+    txCredit.nLockTime = 0;
+    txCredit.vin.resize(1);
+    txCredit.vout.resize(1);
+    txCredit.vin[0].prevout.SetNull();
+    txCredit.vin[0].scriptSig = CScript() << CScriptNum(0) << CScriptNum(0);
+    txCredit.vin[0].nSequence = CTxIn::SEQUENCE_FINAL;
+    txCredit.vout[0].scriptPubKey = scriptPubKey;
+    txCredit.vout[0].nValue = 1;
+
+    return txCredit;
+}
+
+// FIXME: Dedup with BuildSpendingTransaction in test/script_tests.cpp.
+static CMutableTransaction BuildSpendingTransaction(const CScript& scriptSig, const CMutableTransaction& txCredit)
+{
+    CMutableTransaction txSpend;
+    txSpend.nVersion = 1;
+    txSpend.nLockTime = 0;
+    txSpend.vin.resize(1);
+    txSpend.vout.resize(1);
+    txSpend.wit.vtxinwit.resize(1);
+    txSpend.vin[0].prevout.hash = txCredit.GetHash();
+    txSpend.vin[0].prevout.n = 0;
+    txSpend.vin[0].scriptSig = scriptSig;
+    txSpend.vin[0].nSequence = CTxIn::SEQUENCE_FINAL;
+    txSpend.vout[0].scriptPubKey = CScript();
+    txSpend.vout[0].nValue = txCredit.vout[0].nValue;
+
+    return txSpend;
+}
+
+// Microbenchmark for verification of a basic P2WPKH script. Can be easily
+// modified to measure performance of other types of scripts.
+static void VerifyScriptBench(benchmark::State& state)
+{
+    const int flags = SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_P2SH;
+    const int witnessversion = 0;
+
+    // Keypair.
+    CKey key;
+    const unsigned char vchKey[32] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
+    key.Set(vchKey, vchKey + 32, false);
+    CPubKey pubkey = key.GetPubKey();
+    uint160 pubkeyHash;
+    CHash160().Write(pubkey.begin(), pubkey.size()).Finalize(pubkeyHash.begin());
+
+    // Script.
+    CScript scriptPubKey = CScript() << witnessversion << ToByteVector(pubkeyHash);
+    CScript scriptSig;
+    CScript witScriptPubkey = CScript() << OP_DUP << OP_HASH160 << ToByteVector(pubkeyHash) << OP_EQUALVERIFY << OP_CHECKSIG;
+    CTransaction txCredit = BuildCreditingTransaction(scriptPubKey);
+    CMutableTransaction txSpend = BuildSpendingTransaction(scriptSig, txCredit);
+    CScriptWitness& witness = txSpend.wit.vtxinwit[0].scriptWitness;
+    witness.stack.emplace_back();
+    key.Sign(SignatureHash(witScriptPubkey, txSpend, 0, SIGHASH_ALL, txCredit.vout[0].nValue, SIGVERSION_WITNESS_V0), witness.stack.back(), 0);
+    witness.stack.back().push_back(static_cast<unsigned char>(SIGHASH_ALL));
+    witness.stack.push_back(ToByteVector(pubkey));
+
+    // Benchmark.
+    while (state.KeepRunning()) {
+        ScriptError err;
+        bool success = VerifyScript(
+            txSpend.vin[0].scriptSig,
+            txCredit.vout[0].scriptPubKey,
+            &txSpend.wit.vtxinwit[0].scriptWitness,
+            flags,
+            MutableTransactionSignatureChecker(&txSpend, 0, txCredit.vout[0].nValue),
+            &err);
+        assert(err == SCRIPT_ERR_OK);
+        assert(success);
+
+#if defined(HAVE_CONSENSUS_LIB)
+        CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
+        stream << txSpend;
+        int csuccess = bitcoinconsensus_verify_script_with_amount(
+            begin_ptr(txCredit.vout[0].scriptPubKey),
+            txCredit.vout[0].scriptPubKey.size(),
+            txCredit.vout[0].nValue,
+            (const unsigned char*)&stream[0], stream.size(), 0, flags, nullptr);
+        assert(csuccess == 1);
+#endif
+    }
+}
+
+BENCHMARK(VerifyScriptBench);