From 18dacf9bd25154e184b097ee4e8f786d9be25637 Mon Sep 17 00:00:00 2001
From: Russell Yanofsky <russ@yanofsky.org>
Date: Sun, 2 Oct 2016 17:38:48 -0400
Subject: 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
---
 src/bench/ccoins_caching.cpp | 87 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 src/bench/ccoins_caching.cpp

(limited to 'src/bench/ccoins_caching.cpp')

diff --git a/src/bench/ccoins_caching.cpp b/src/bench/ccoins_caching.cpp
new file mode 100644
index 000000000..1e8e3d462
--- /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);
-- 
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