// Copyright (c) 2016-2020 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/bench.h>
#include <bench/data.h>

#include <rpc/blockchain.h>
#include <streams.h>
#include <test/util/setup_common.h>
#include <validation.h>

#include <univalue.h>

namespace {

struct TestBlockAndIndex {
    TestingSetup test_setup{};
    CBlock block{};
    uint256 blockHash{};
    CBlockIndex blockindex{};

    TestBlockAndIndex()
    {
        CDataStream stream(benchmark::data::block413567, SER_NETWORK, PROTOCOL_VERSION);
        char a = '\0';
        stream.write(&a, 1); // Prevent compaction

        stream >> block;

        blockHash = block.GetHash();
        blockindex.phashBlock = &blockHash;
        blockindex.nBits = 403014710;
    }
};

} // namespace

static void BlockToJsonVerbose(benchmark::Bench& bench)
{
    TestBlockAndIndex data;
    bench.run([&] {
        auto univalue = blockToJSON(data.block, &data.blockindex, &data.blockindex, /*verbose*/ true);
        ankerl::nanobench::doNotOptimizeAway(univalue);
    });
}

BENCHMARK(BlockToJsonVerbose);

static void BlockToJsonVerboseWrite(benchmark::Bench& bench)
{
    TestBlockAndIndex data;
    auto univalue = blockToJSON(data.block, &data.blockindex, &data.blockindex, /*verbose*/ true);
    bench.run([&] {
        auto str = univalue.write();
        ankerl::nanobench::doNotOptimizeAway(str);
    });
}

BENCHMARK(BlockToJsonVerboseWrite);

// Copyright (c) 2016-2020 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/bench.h>
#include <bench/data.h>

#include <rpc/blockchain.h>
#include <streams.h>
#include <test/util/setup_common.h>
#include <validation.h>

#include <univalue.h>

static void BlockToJsonVerbose(benchmark::Bench& bench)
{
    TestingSetup test_setup{};

    CDataStream stream(benchmark::data::block413567, SER_NETWORK, PROTOCOL_VERSION);
    char a = '\0';
    stream.write(&a, 1); // Prevent compaction

    CBlock block;
    stream >> block;

    CBlockIndex blockindex;
    const uint256 blockHash = block.GetHash();
    blockindex.phashBlock = &blockHash;
    blockindex.nBits = 403014710;

    bench.run([&] {
        (void)blockToJSON(block, &blockindex, &blockindex, /*verbose*/ true);
    });
}

BENCHMARK(BlockToJsonVerbose);

--- 
+++ 
@@ -12,25 +12,49 @@
 
 #include <univalue.h>
 
+namespace {
+
+struct TestBlockAndIndex {
+    TestingSetup test_setup{};
+    CBlock block{};
+    uint256 blockHash{};
+    CBlockIndex blockindex{};
+
+    TestBlockAndIndex()
+    {
+        CDataStream stream(benchmark::data::block413567, SER_NETWORK, PROTOCOL_VERSION);
+        char a = '\0';
+        stream.write(&a, 1); // Prevent compaction
+
+        stream >> block;
+
+        blockHash = block.GetHash();
+        blockindex.phashBlock = &blockHash;
+        blockindex.nBits = 403014710;
+    }
+};
+
+} // namespace
+
 static void BlockToJsonVerbose(benchmark::Bench& bench)
 {
-    TestingSetup test_setup{};
-
-    CDataStream stream(benchmark::data::block413567, SER_NETWORK, PROTOCOL_VERSION);
-    char a = '\0';
-    stream.write(&a, 1); // Prevent compaction
-
-    CBlock block;
-    stream >> block;
-
-    CBlockIndex blockindex;
-    const uint256 blockHash = block.GetHash();
-    blockindex.phashBlock = &blockHash;
-    blockindex.nBits = 403014710;
-
+    TestBlockAndIndex data;
     bench.run([&] {
-        (void)blockToJSON(block, &blockindex, &blockindex, /*verbose*/ true);
+        auto univalue = blockToJSON(data.block, &data.blockindex, &data.blockindex, /*verbose*/ true);
+        ankerl::nanobench::doNotOptimizeAway(univalue);
     });
 }
 
 BENCHMARK(BlockToJsonVerbose);
+
+static void BlockToJsonVerboseWrite(benchmark::Bench& bench)
+{
+    TestBlockAndIndex data;
+    auto univalue = blockToJSON(data.block, &data.blockindex, &data.blockindex, /*verbose*/ true);
+    bench.run([&] {
+        auto str = univalue.write();
+        ankerl::nanobench::doNotOptimizeAway(str);
+    });
+}
+
+BENCHMARK(BlockToJsonVerboseWrite);
Add benchmark to write JSON into a string

The benchmark BlockToJsonVerbose only tests generating (and destroying)
the JSON data structure, but serializing into a string is also a
performance critical aspect of the RPC calls.

Also, use ankerl::nanobench::doNotOptimizeAway to make sure the compiler
can't optimize the result of the calls away.
