Files
json/tests/benchmarks/src/benchmarks.cpp
T
Niels Lohmann 6ba53e63dd Speed up array-to-container from_json (#5833)
* Speed up array-to-container from_json

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Hint the end when converting an object to a standard container

from_json for map-like containers called emplace() without a hint, which
searches the tree for every key. The keys of the source object are sorted, so
inserting with the end as the hint is constant time, as it was in 3.12.0 via
std::inserter. get<std::map<...>>() of a 25,000 entry object: 4.2 ms -> 3.25 ms
(3.12.0: 3.7 ms).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

* Fall back to emplace() in object from_json for containers without emplace_hint()

ordered_map has no hinted insert, so the insert(end(), ...) call broke
from_json into types holding an ordered_map (regression test #5122).
Use emplace_hint() where available and plain emplace() otherwise.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-15 20:01:20 +02:00

651 lines
28 KiB
C++

// __ _____ _____ _____
// __| | __| | | | JSON for Modern C++ (supporting code)
// | | |__ | | | | | | version 3.12.0
// |_____|_____|_____|_|___| https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT
#include <benchmark/benchmark.h>
#include <nlohmann/json.hpp>
#include <fstream>
#include <array>
#include <deque>
#include <numeric>
#include <set>
#include <vector>
#include <test_data.hpp>
using json = nlohmann::json;
//////////////////////////////////////////////////////////////////////////////
// parse JSON from file
//////////////////////////////////////////////////////////////////////////////
static void ParseFile(benchmark::State& state, const char* filename)
{
while (state.KeepRunning())
{
state.PauseTiming();
auto* f = new std::ifstream(filename);
auto* j = new json();
state.ResumeTiming();
*j = json::parse(*f);
state.PauseTiming();
delete f;
delete j;
state.ResumeTiming();
}
std::ifstream file(filename, std::ios::binary | std::ios::ate);
state.SetBytesProcessed(state.iterations() * file.tellg());
}
BENCHMARK_CAPTURE(ParseFile, jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json");
BENCHMARK_CAPTURE(ParseFile, canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
BENCHMARK_CAPTURE(ParseFile, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
BENCHMARK_CAPTURE(ParseFile, twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
BENCHMARK_CAPTURE(ParseFile, floats, TEST_DATA_DIRECTORY "/regression/floats.json");
BENCHMARK_CAPTURE(ParseFile, signed_ints, TEST_DATA_DIRECTORY "/regression/signed_ints.json");
BENCHMARK_CAPTURE(ParseFile, unsigned_ints, TEST_DATA_DIRECTORY "/regression/unsigned_ints.json");
BENCHMARK_CAPTURE(ParseFile, small_signed_ints, TEST_DATA_DIRECTORY "/regression/small_signed_ints.json");
//////////////////////////////////////////////////////////////////////////////
// parse JSON from string
//////////////////////////////////////////////////////////////////////////////
static void ParseString(benchmark::State& state, const char* filename)
{
std::ifstream f(filename);
std::string str((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
while (state.KeepRunning())
{
state.PauseTiming();
auto* j = new json();
state.ResumeTiming();
*j = json::parse(str);
state.PauseTiming();
delete j;
state.ResumeTiming();
}
state.SetBytesProcessed(state.iterations() * str.size());
}
BENCHMARK_CAPTURE(ParseString, jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json");
BENCHMARK_CAPTURE(ParseString, canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
BENCHMARK_CAPTURE(ParseString, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
BENCHMARK_CAPTURE(ParseString, twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
BENCHMARK_CAPTURE(ParseString, floats, TEST_DATA_DIRECTORY "/regression/floats.json");
BENCHMARK_CAPTURE(ParseString, signed_ints, TEST_DATA_DIRECTORY "/regression/signed_ints.json");
BENCHMARK_CAPTURE(ParseString, unsigned_ints, TEST_DATA_DIRECTORY "/regression/unsigned_ints.json");
BENCHMARK_CAPTURE(ParseString, small_signed_ints, TEST_DATA_DIRECTORY "/regression/small_signed_ints.json");
//////////////////////////////////////////////////////////////////////////////
// parse pretty-printed JSON from string
//
// Every file in the corpus above is minified or only lightly spaced, so none of
// them exercise the lexer's whitespace handling. Real-world JSON is frequently
// indented - configuration files, pretty-printed API responses, anything kept
// under version control - where insignificant whitespace can outweigh the data.
// Re-serializing a document with an indentation and parsing that keeps the
// content identical to the ParseString row above, so the pair isolates the cost
// of the whitespace alone.
//////////////////////////////////////////////////////////////////////////////
static void ParseIndented(benchmark::State& state, const char* filename, int indent)
{
std::ifstream f(filename);
std::string str((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
const std::string indented = json::parse(str).dump(indent);
while (state.KeepRunning())
{
state.PauseTiming();
auto* j = new json();
state.ResumeTiming();
*j = json::parse(indented);
state.PauseTiming();
delete j;
state.ResumeTiming();
}
state.SetBytesProcessed(state.iterations() * indented.size());
}
BENCHMARK_CAPTURE(ParseIndented, jeopardy / 4, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", 4);
BENCHMARK_CAPTURE(ParseIndented, canada / 4, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", 4);
BENCHMARK_CAPTURE(ParseIndented, citm_catalog / 4, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", 4);
BENCHMARK_CAPTURE(ParseIndented, twitter / 4, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", 4);
//////////////////////////////////////////////////////////////////////////////
// parse JSON from string into an ordered_json
//
// Same as ParseString above, but with nlohmann::ordered_json, whose objects
// keep their members in a vector: the pair of rows shows what preserving the
// insertion order costs.
//////////////////////////////////////////////////////////////////////////////
static void ParseStringOrdered(benchmark::State& state, const char* filename)
{
std::ifstream f(filename);
std::string str((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
while (state.KeepRunning())
{
state.PauseTiming();
auto* j = new nlohmann::ordered_json();
state.ResumeTiming();
*j = nlohmann::ordered_json::parse(str);
state.PauseTiming();
delete j;
state.ResumeTiming();
}
state.SetBytesProcessed(state.iterations() * str.size());
}
BENCHMARK_CAPTURE(ParseStringOrdered, jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json");
BENCHMARK_CAPTURE(ParseStringOrdered, canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
BENCHMARK_CAPTURE(ParseStringOrdered, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
BENCHMARK_CAPTURE(ParseStringOrdered, twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
//////////////////////////////////////////////////////////////////////////////
// serialize JSON
//////////////////////////////////////////////////////////////////////////////
static void Dump(benchmark::State& state, const char* filename, int indent)
{
std::ifstream f(filename);
std::string str((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
json j = json::parse(str);
while (state.KeepRunning())
{
std::string output = j.dump(indent);
benchmark::DoNotOptimize(output);
}
state.SetBytesProcessed(state.iterations() * j.dump(indent).size());
}
BENCHMARK_CAPTURE(Dump, jeopardy / -, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", -1);
BENCHMARK_CAPTURE(Dump, jeopardy / 4, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", 4);
BENCHMARK_CAPTURE(Dump, canada / -, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", -1);
BENCHMARK_CAPTURE(Dump, canada / 4, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", 4);
BENCHMARK_CAPTURE(Dump, citm_catalog / -, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", -1);
BENCHMARK_CAPTURE(Dump, citm_catalog / 4, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", 4);
BENCHMARK_CAPTURE(Dump, twitter / -, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", -1);
BENCHMARK_CAPTURE(Dump, twitter / 4, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", 4);
BENCHMARK_CAPTURE(Dump, floats / -, TEST_DATA_DIRECTORY "/regression/floats.json", -1);
BENCHMARK_CAPTURE(Dump, floats / 4, TEST_DATA_DIRECTORY "/regression/floats.json", 4);
BENCHMARK_CAPTURE(Dump, signed_ints / -, TEST_DATA_DIRECTORY "/regression/signed_ints.json", -1);
BENCHMARK_CAPTURE(Dump, signed_ints / 4, TEST_DATA_DIRECTORY "/regression/signed_ints.json", 4);
BENCHMARK_CAPTURE(Dump, unsigned_ints / -, TEST_DATA_DIRECTORY "/regression/unsigned_ints.json", -1);
BENCHMARK_CAPTURE(Dump, unsigned_ints / 4, TEST_DATA_DIRECTORY "/regression/unsigned_ints.json", 4);
BENCHMARK_CAPTURE(Dump, small_signed_ints / -, TEST_DATA_DIRECTORY "/regression/small_signed_ints.json", -1);
BENCHMARK_CAPTURE(Dump, small_signed_ints / 4, TEST_DATA_DIRECTORY "/regression/small_signed_ints.json", 4);
//////////////////////////////////////////////////////////////////////////////
// serialize CBOR
//////////////////////////////////////////////////////////////////////////////
static void ToCbor(benchmark::State& state, const char* filename)
{
std::ifstream f(filename);
std::string str((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
json j = json::parse(str);
while (state.KeepRunning())
{
json::to_cbor(j);
}
state.SetBytesProcessed(state.iterations() * json::to_cbor(j).size());
}
BENCHMARK_CAPTURE(ToCbor, jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json");
BENCHMARK_CAPTURE(ToCbor, canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
BENCHMARK_CAPTURE(ToCbor, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
BENCHMARK_CAPTURE(ToCbor, twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
BENCHMARK_CAPTURE(ToCbor, floats, TEST_DATA_DIRECTORY "/regression/floats.json");
BENCHMARK_CAPTURE(ToCbor, signed_ints, TEST_DATA_DIRECTORY "/regression/signed_ints.json");
BENCHMARK_CAPTURE(ToCbor, unsigned_ints, TEST_DATA_DIRECTORY "/regression/unsigned_ints.json");
BENCHMARK_CAPTURE(ToCbor, small_signed_ints, TEST_DATA_DIRECTORY "/regression/small_signed_ints.json");
//////////////////////////////////////////////////////////////////////////////
// Parse Msgpack
//////////////////////////////////////////////////////////////////////////////
static void FromMsgpack(benchmark::State& state, const char* filename)
{
std::ifstream f(filename);
std::string str((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
auto bytes = json::to_msgpack(json::parse(str));
std::ofstream o("test.msgpack");
o.write((char*)bytes.data(), bytes.size());
o.flush();
o.close();
for (auto _ : state)
{
state.PauseTiming();
auto* j = new json();
auto file = fopen("test.msgpack", "rb");
state.ResumeTiming();
*j = json::from_msgpack(file);
state.PauseTiming();
fclose(file);
delete j;
state.ResumeTiming();
}
state.SetBytesProcessed(state.iterations() * bytes.size());
}
BENCHMARK_CAPTURE(FromMsgpack, jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json");
BENCHMARK_CAPTURE(FromMsgpack, canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json");
BENCHMARK_CAPTURE(FromMsgpack, citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json");
BENCHMARK_CAPTURE(FromMsgpack, twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json");
BENCHMARK_CAPTURE(FromMsgpack, floats, TEST_DATA_DIRECTORY "/regression/floats.json");
BENCHMARK_CAPTURE(FromMsgpack, signed_ints, TEST_DATA_DIRECTORY "/regression/signed_ints.json");
BENCHMARK_CAPTURE(FromMsgpack, unsigned_ints, TEST_DATA_DIRECTORY "/regression/unsigned_ints.json");
BENCHMARK_CAPTURE(FromMsgpack, small_signed_ints, TEST_DATA_DIRECTORY "/regression/small_signed_ints.json");
//////////////////////////////////////////////////////////////////////////////
// serialize binary CBOR
//////////////////////////////////////////////////////////////////////////////
static void BinaryToCbor(benchmark::State& state)
{
std::vector<uint8_t> data(256);
std::iota(data.begin(), data.end(), 0);
auto it = data.begin();
std::vector<uint8_t> in;
in.reserve(state.range(0));
for (int i = 0; i < state.range(0); ++i)
{
if (it == data.end())
{
it = data.begin();
}
in.push_back(*it);
++it;
}
json::binary_t bin{in};
json j{{"type", "binary"}, {"data", bin}};
while (state.KeepRunning())
{
json::to_cbor(j);
}
state.SetBytesProcessed(state.iterations() * json::to_cbor(j).size());
}
BENCHMARK(BinaryToCbor)->RangeMultiplier(2)->Range(8, 8 << 12);
//////////////////////////////////////////////////////////////////////////////
// parse binary formats
//////////////////////////////////////////////////////////////////////////////
// Only MessagePack had a read benchmark (FromMsgpack above, left untouched so
// its numbers stay comparable across releases). The benchmarks below cover the
// other formats, and read from a contiguous buffer as well as from a FILE*:
// most callers pass a container, and the two adapters compile to different
// code. The test data repository ships JSON only, so the input for each is
// derived at setup time by serializing a parsed test file.
/// binary format to benchmark; the _optimized variants add UBJSON/BJData size
/// and type annotations, which the readers handle in a separate code path
enum class binary_format
{
cbor,
msgpack,
ubjson,
ubjson_optimized,
bjdata,
bjdata_optimized,
bson,
bon8
};
static std::vector<std::uint8_t> to_binary(const json& j, const binary_format format)
{
switch (format)
{
case binary_format::cbor:
return json::to_cbor(j);
case binary_format::msgpack:
return json::to_msgpack(j);
case binary_format::ubjson:
return json::to_ubjson(j);
case binary_format::ubjson_optimized:
return json::to_ubjson(j, true, true);
case binary_format::bjdata:
return json::to_bjdata(j);
case binary_format::bjdata_optimized:
return json::to_bjdata(j, true, true);
case binary_format::bon8:
return json::to_bon8(j);
case binary_format::bson:
default:
return json::to_bson(j);
}
}
static json from_binary(const std::vector<std::uint8_t>& bytes, const binary_format format)
{
switch (format)
{
case binary_format::cbor:
return json::from_cbor(bytes);
case binary_format::msgpack:
return json::from_msgpack(bytes);
case binary_format::ubjson:
case binary_format::ubjson_optimized:
return json::from_ubjson(bytes);
case binary_format::bjdata:
case binary_format::bjdata_optimized:
return json::from_bjdata(bytes);
case binary_format::bon8:
return json::from_bon8(bytes);
case binary_format::bson:
default:
return json::from_bson(bytes);
}
}
static json from_binary(std::FILE* file, const binary_format format)
{
switch (format)
{
case binary_format::cbor:
return json::from_cbor(file);
case binary_format::msgpack:
return json::from_msgpack(file);
case binary_format::ubjson:
case binary_format::ubjson_optimized:
return json::from_ubjson(file);
case binary_format::bjdata:
case binary_format::bjdata_optimized:
return json::from_bjdata(file);
case binary_format::bon8:
return json::from_bon8(file);
case binary_format::bson:
default:
return json::from_bson(file);
}
}
/*!
@brief serialize a parsed test file to @a format
Returns an empty vector and marks the benchmark as skipped if the file cannot
be represented in the format, rather than letting the exception escape: BSON
requires an object at the top level, and several test files are arrays.
*/
static std::vector<std::uint8_t> binary_input(benchmark::State& state, const char* filename, const binary_format format)
{
std::ifstream f(filename);
std::string const str((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
const json j = json::parse(str);
if (format == binary_format::bson && !j.is_object())
{
state.SkipWithError("BSON requires an object at the top level");
return {};
}
return to_binary(j, format);
}
static void FromBinaryBuffer(benchmark::State& state, const char* filename, const binary_format format)
{
const std::vector<std::uint8_t> bytes = binary_input(state, filename, format);
if (bytes.empty())
{
return;
}
for (auto _ : state)
{
// the value is destroyed outside the timed section, because destroying
// a large DOM is not what this benchmark measures
state.PauseTiming();
auto* j = new json();
state.ResumeTiming();
*j = from_binary(bytes, format);
state.PauseTiming();
delete j;
state.ResumeTiming();
}
state.SetBytesProcessed(state.iterations() * bytes.size());
}
BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / floats, TEST_DATA_DIRECTORY "/regression/floats.json", binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / signed_ints, TEST_DATA_DIRECTORY "/regression/signed_ints.json", binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryBuffer, msgpack / jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", binary_format::msgpack);
BENCHMARK_CAPTURE(FromBinaryBuffer, msgpack / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::msgpack);
BENCHMARK_CAPTURE(FromBinaryBuffer, msgpack / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::msgpack);
BENCHMARK_CAPTURE(FromBinaryBuffer, msgpack / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::msgpack);
BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson / jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson_optimized / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::ubjson_optimized);
BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson_optimized / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::ubjson_optimized);
BENCHMARK_CAPTURE(FromBinaryBuffer, bjdata / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::bjdata);
BENCHMARK_CAPTURE(FromBinaryBuffer, bjdata / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bjdata);
BENCHMARK_CAPTURE(FromBinaryBuffer, bjdata_optimized / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::bjdata_optimized);
BENCHMARK_CAPTURE(FromBinaryBuffer, bjdata_optimized / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bjdata_optimized);
BENCHMARK_CAPTURE(FromBinaryBuffer, bon8 / jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", binary_format::bon8);
BENCHMARK_CAPTURE(FromBinaryBuffer, bon8 / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::bon8);
BENCHMARK_CAPTURE(FromBinaryBuffer, bon8 / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::bon8);
BENCHMARK_CAPTURE(FromBinaryBuffer, bon8 / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bon8);
// BSON requires an object at the top level, so the array-rooted test files
// (jeopardy and the regression files) cannot be captured here
BENCHMARK_CAPTURE(FromBinaryBuffer, bson / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::bson);
BENCHMARK_CAPTURE(FromBinaryBuffer, bson / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::bson);
BENCHMARK_CAPTURE(FromBinaryBuffer, bson / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bson);
static void FromBinaryFile(benchmark::State& state, const char* filename, const binary_format format)
{
const std::vector<std::uint8_t> bytes = binary_input(state, filename, format);
if (bytes.empty())
{
return;
}
const char* tmp = "benchmark_input.bin";
std::ofstream o(tmp, std::ios::binary);
o.write(reinterpret_cast<const char*>(bytes.data()), static_cast<std::streamsize>(bytes.size()));
o.flush();
o.close();
for (auto _ : state)
{
state.PauseTiming();
auto* j = new json();
auto* file = std::fopen(tmp, "rb");
state.ResumeTiming();
*j = from_binary(file, format);
state.PauseTiming();
std::fclose(file);
delete j;
state.ResumeTiming();
}
state.SetBytesProcessed(state.iterations() * bytes.size());
}
BENCHMARK_CAPTURE(FromBinaryFile, cbor / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryFile, cbor / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryFile, ubjson / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryFile, ubjson / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryFile, bjdata / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bjdata);
BENCHMARK_CAPTURE(FromBinaryFile, bon8 / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::bon8);
BENCHMARK_CAPTURE(FromBinaryFile, bon8 / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bon8);
BENCHMARK_CAPTURE(FromBinaryFile, bson / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bson);
//////////////////////////////////////////////////////////////////////////////
// parse binary formats: value shapes
//////////////////////////////////////////////////////////////////////////////
// The test files above are wide and shallow, but the readers' cost is per
// container, so these cover the shapes that stress the container handling
// itself. Every shape is wrapped in an object so that BSON, which requires an
// object at the top level, measures the same value as the other formats.
/// deeply nested arrays: one container per level, no other work
static json make_nested()
{
json nested = json::array();
json* p = &nested;
for (std::size_t i = 1; i < 1000; ++i)
{
p->push_back(json::array());
p = &p->operator[](0);
}
json j = json::object();
j["data"] = std::move(nested);
return j;
}
/// many sibling containers: maximum container churn, minimum nesting
static json make_containers()
{
json data = json::array();
for (std::size_t i = 0; i < 100000; ++i)
{
data.push_back(json::array({1, 2}));
}
json j = json::object();
j["data"] = std::move(data);
return j;
}
/// one flat array of numbers: the scalar decoding path, which must not move
static json make_scalars()
{
json data = json::array();
for (std::size_t i = 0; i < 1000000; ++i)
{
data.push_back(i);
}
json j = json::object();
j["data"] = std::move(data);
return j;
}
static void FromBinaryShape(benchmark::State& state, json (*build)(), const binary_format format)
{
const std::vector<std::uint8_t> bytes = to_binary(build(), format);
for (auto _ : state)
{
state.PauseTiming();
auto* j = new json();
state.ResumeTiming();
*j = from_binary(bytes, format);
state.PauseTiming();
delete j;
state.ResumeTiming();
}
state.SetBytesProcessed(state.iterations() * bytes.size());
}
BENCHMARK_CAPTURE(FromBinaryShape, nested / cbor, make_nested, binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryShape, nested / msgpack, make_nested, binary_format::msgpack);
BENCHMARK_CAPTURE(FromBinaryShape, nested / ubjson, make_nested, binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryShape, nested / bjdata, make_nested, binary_format::bjdata);
BENCHMARK_CAPTURE(FromBinaryShape, nested / bson, make_nested, binary_format::bson);
BENCHMARK_CAPTURE(FromBinaryShape, nested / bon8, make_nested, binary_format::bon8);
BENCHMARK_CAPTURE(FromBinaryShape, containers / cbor, make_containers, binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryShape, containers / msgpack, make_containers, binary_format::msgpack);
BENCHMARK_CAPTURE(FromBinaryShape, containers / ubjson, make_containers, binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryShape, containers / ubjson_optimized, make_containers, binary_format::ubjson_optimized);
BENCHMARK_CAPTURE(FromBinaryShape, containers / bjdata, make_containers, binary_format::bjdata);
BENCHMARK_CAPTURE(FromBinaryShape, containers / bson, make_containers, binary_format::bson);
BENCHMARK_CAPTURE(FromBinaryShape, containers / bon8, make_containers, binary_format::bon8);
// BSON names every array element, so a large array measures key generation
// rather than scalar decoding and is left out here
BENCHMARK_CAPTURE(FromBinaryShape, scalars / cbor, make_scalars, binary_format::cbor);
BENCHMARK_CAPTURE(FromBinaryShape, scalars / msgpack, make_scalars, binary_format::msgpack);
BENCHMARK_CAPTURE(FromBinaryShape, scalars / ubjson, make_scalars, binary_format::ubjson);
BENCHMARK_CAPTURE(FromBinaryShape, scalars / bjdata, make_scalars, binary_format::bjdata);
BENCHMARK_CAPTURE(FromBinaryShape, scalars / bon8, make_scalars, binary_format::bon8);
/*!
@brief parse an indefinite-length CBOR string
The writer never emits this form, so the input is assembled by hand: 0x7F
opens the string, each chunk is a one-character string, and 0xFF closes it.
*/
static void FromCborChunkedString(benchmark::State& state, const std::size_t chunks)
{
std::vector<std::uint8_t> bytes;
bytes.reserve(2 * chunks + 2);
bytes.push_back(0x7F);
for (std::size_t i = 0; i < chunks; ++i)
{
bytes.push_back(0x61); // string of length 1
bytes.push_back(0x61); // 'a'
}
bytes.push_back(0xFF);
for (auto _ : state)
{
json j = json::from_cbor(bytes);
benchmark::DoNotOptimize(j);
}
state.SetBytesProcessed(state.iterations() * bytes.size());
}
BENCHMARK_CAPTURE(FromCborChunkedString, 10000 chunks, 10000);
// conversion of a JSON array into standard containers
template<typename Container>
static void GetArray(benchmark::State& state)
{
json j = json::array();
for (int i = 0; i < 1000; ++i)
{
j.push_back(i);
}
for (auto _ : state)
{
auto c = j.get<Container>();
benchmark::DoNotOptimize(c);
}
state.SetItemsProcessed(state.iterations() * 1000);
}
BENCHMARK_TEMPLATE(GetArray, std::vector<int>);
BENCHMARK_TEMPLATE(GetArray, std::deque<int>);
BENCHMARK_TEMPLATE(GetArray, std::set<int>);
BENCHMARK_TEMPLATE(GetArray, std::array<int, 1000>);
BENCHMARK_MAIN();