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
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+++ b/src/bench/ccoins_caching.cpp
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+// 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);