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, 87 insertions, 0 deletions

diff --git a/src/bench/ccoins_caching.cpp b/src/bench/ccoins_caching.cpp
new file mode 100644
index 0000000000..1e8e3d462f
--- /dev/null
+++ b/src/bench/ccoins_caching.cpp
@@ -0,0 +1,87 @@
+// 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 "coins.h"
+#include "policy/policy.h"
+#include "wallet/crypter.h"
+
+#include <vector>
+
+// FIXME: Dedup with SetupDummyInputs in test/transaction_tests.cpp.
+//
+// Helper: create two dummy transactions, each with
+// two outputs.  The first has 11 and 50 CENT outputs
+// paid to a TX_PUBKEY, the second 21 and 22 CENT outputs
+// paid to a TX_PUBKEYHASH.
+//
+static std::vector<CMutableTransaction>
+SetupDummyInputs(CBasicKeyStore& keystoreRet, CCoinsViewCache& coinsRet)
+{
+    std::vector<CMutableTransaction> dummyTransactions;
+    dummyTransactions.resize(2);
+
+    // Add some keys to the keystore:
+    CKey key[4];
+    for (int i = 0; i < 4; i++) {
+        key[i].MakeNewKey(i % 2);
+        keystoreRet.AddKey(key[i]);
+    }
+
+    // Create some dummy input transactions
+    dummyTransactions[0].vout.resize(2);
+    dummyTransactions[0].vout[0].nValue = 11 * CENT;
+    dummyTransactions[0].vout[0].scriptPubKey << ToByteVector(key[0].GetPubKey()) << OP_CHECKSIG;
+    dummyTransactions[0].vout[1].nValue = 50 * CENT;
+    dummyTransactions[0].vout[1].scriptPubKey << ToByteVector(key[1].GetPubKey()) << OP_CHECKSIG;
+    coinsRet.ModifyCoins(dummyTransactions[0].GetHash())->FromTx(dummyTransactions[0], 0);
+
+    dummyTransactions[1].vout.resize(2);
+    dummyTransactions[1].vout[0].nValue = 21 * CENT;
+    dummyTransactions[1].vout[0].scriptPubKey = GetScriptForDestination(key[2].GetPubKey().GetID());
+    dummyTransactions[1].vout[1].nValue = 22 * CENT;
+    dummyTransactions[1].vout[1].scriptPubKey = GetScriptForDestination(key[3].GetPubKey().GetID());
+    coinsRet.ModifyCoins(dummyTransactions[1].GetHash())->FromTx(dummyTransactions[1], 0);
+
+    return dummyTransactions;
+}
+
+// Microbenchmark for simple accesses to a CCoinsViewCache database. Note from
+// laanwj, "replicating the actual usage patterns of the client is hard though,
+// many times micro-benchmarks of the database showed completely different
+// characteristics than e.g. reindex timings. But that's not a requirement of
+// every benchmark."
+// (https://github.com/bitcoin/bitcoin/issues/7883#issuecomment-224807484)
+static void CCoinsCaching(benchmark::State& state)
+{
+    CBasicKeyStore keystore;
+    CCoinsView coinsDummy;
+    CCoinsViewCache coins(&coinsDummy);
+    std::vector<CMutableTransaction> dummyTransactions = SetupDummyInputs(keystore, coins);
+
+    CMutableTransaction t1;
+    t1.vin.resize(3);
+    t1.vin[0].prevout.hash = dummyTransactions[0].GetHash();
+    t1.vin[0].prevout.n = 1;
+    t1.vin[0].scriptSig << std::vector<unsigned char>(65, 0);
+    t1.vin[1].prevout.hash = dummyTransactions[1].GetHash();
+    t1.vin[1].prevout.n = 0;
+    t1.vin[1].scriptSig << std::vector<unsigned char>(65, 0) << std::vector<unsigned char>(33, 4);
+    t1.vin[2].prevout.hash = dummyTransactions[1].GetHash();
+    t1.vin[2].prevout.n = 1;
+    t1.vin[2].scriptSig << std::vector<unsigned char>(65, 0) << std::vector<unsigned char>(33, 4);
+    t1.vout.resize(2);
+    t1.vout[0].nValue = 90 * CENT;
+    t1.vout[0].scriptPubKey << OP_1;
+
+    // Benchmark.
+    while (state.KeepRunning()) {
+        bool success = AreInputsStandard(t1, coins);
+        assert(success);
+        CAmount value = coins.GetValueIn(t1);
+        assert(value == (50 + 21 + 22) * CENT);
+    }
+}
+
+BENCHMARK(CCoinsCaching);