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Native JSON Benchmark

Copyright(c) 2014-2016 Milo Yip (miloyip@gmail.com)

Introduction

This benchmark evaluates the conformance and performance of 41 open-source C/C++ libraries with JSON parsing/generation capabilities. Performance means speed, memory, and code size.

Performance should be concerned only if the results are correct. This benchmark also test the conformance of library towards the JSON standards (RFC7159, ECMA-404).

Performance of JSON parsing/generation may be critical for server-side applications, mobile/embedded systems, or any application that requires processing of large size or number of JSONs. Native (C/C++) libraries are important because they should provide the best possible performance, while other languages may create bindings of native libraries.

The results show that several performance measurements vary in large scale among libraries. For example, the parsing time can be over 100 times. These differences came from many factors, including design and implementation details. For example, memory allocation strategies, design of variant type for JSON, number-string conversions, etc.

This benchmark may be useful for optimizing existing libraries and developing new, high-performance libraries.

Disclaimer

The original author (Milo Yip) of this benchmark is also the primary author of RapidJSON.

Although the development of benchmark is attempted to be as objective and fair as possible, every benchmarks have their drawbacks, and are limited to particular testing procedures, datasets and platforms. And also, this benchmark does not compare additional features that a library may support, or the user-friendliness of APIs, securities, cross-platform, etc. The author encourage users to benchmarks with their own data sets and platforms.

Benchmarks and Measurements

Conformance

Performance

All benchmarks contain the following measurements:

Libraries

Currently 43 libraries are successfully benchmarked. They are listed in alphabetic order:

Libraries with Git repository are included as submodule in thirdparty path. Other libraries are add as files in thirdparty path.

The exact commit of submodule can be navigated at here.

To measure the overheads of the benchmark process, a strdup test is added for comparison. It simply allocate and copy the input string in Parse and Stringify benchmark.

Besides, some libraries was tried to integrated in this benchmark but failed:

JSON data

All tested JSON data are in UTF-8.

The benchmark program reads data/data.txt which contains file names of JSON to be tested.

Build and Run

1. Execute git submodule update --init and git -C thirdparty/boost update --init to download all submodules (libraries).
2. Obtain premake5.
3. Copy premake5 executable to build/ path (or system path).
4. Run premake.bat or premake.sh in build/
5. On Windows, build the solution at build/vs2015/.
6. On other platforms, run GNU make -f benchmark.make config=release_x32 && make -f nativejson.make config=release_x32 (or release_x64) at build/gmake/
7. Optional: run build/machine.sh for UNIX or CYGWIN to use CPU info to generate prefix of result filename.
8. Run the nativejson_release_... executable is generated at bin/
9. The results in CSV format will be written to result/.
10. Run GNU make in result/ to generate results in HTML.

For simplicity, on Linux/OSX users can simply run make (or make CONFIG=release_x32) at project root to run 4-10 above.

Some libraries, such as Boost, POCO, V8, etc., need to be installed by user manually.

Sample Results

Update on: 2016-9-9

A collection of benchmarks results can be viewed HERE. Select "Benchmark" from the menu to check available benchmark configurations. The presentation is powered by Google Charts with interactivity.

The followings are some snapshots from the results of MacBook Pro (Retina, 15-inch, Mid 2015, Corei7-4980HQ@2.80GHz) with clang 7.0 64-bit.

Conformance

This is the average score of 4 conformance benchmarks. Higher is better. Details.

Parsing Time

This is the total duration of parsing 3 JSONs to DOM representation, sorted in ascending order. Lower is better. Details

Parsing Memory

This is the total memory after parsing 3 JSONs to DOM representation, sorted in ascending order. Lower is better. Details

(Note: The results for Qt is incorrect as the benchmark failed to hook its memory allocations)

Stringify Time

This is the total duration of stringifying 3 DOMs to JSONs, sorted in ascending order. Lower is better. Details

Prettify Time

This is the total duration of prettifying 3 DOMs to JSONs, sorted in ascending order. Lower is better. Details

Code Size

The is the size of executable program, which parses a JSON from stdin to a DOM and then computes the statistics of the DOM. Lower is better. Details

FAQ

1. How to add a library?

   Use submodule add https://...xxx.git thirdparty/xxx to add the libary's repository as a submobule. If that is not possible, just copy the files into 'thirdparty/xxx'.

   For C libary, add a xxx_all.c in src/cjsonlibs, which #include all the necessary .c files of the library. And then create a tests/xxxtest.cpp.it

   For C++ library, just need to create a tests/xxxtest.cpp, which #include all the necessary .cpp files of the library.

   You may find a existing library which similar to your case as a start of implementing tests/xxxtest.cpp.

   Please submit a pull request if the integration work properly.

2. What if the build process is failed, or the benchmark crashes?

   This happens on some platforms as not every libaray is stable for all platforms.

   You can simply delete the local tests/xxxtest.cpp and re-run the build.

   BTW, if you are adding a library, you can remove all tests/xxxtest.cpp except tests/rapidjsontest.cpp and your test. This make the build process fast. RapidJSON's test is needed as a reference to compare statistics results only.

3. On which platform the benchmark can be run?

   The author tests it on OSX/clang, Winwdows/vs2015, Ubuntu/clang3.7+gcc5.0 (via Travis CI). The benchmark may work in other platforms as well but you will need to generate the build files via premake5, and resolve any potential issues.

4. How to reduce the build process time?

   You can preserve the tests of libaries that you only need, as in question 2. You can also use make ARGS=--verify-only, make ARGS=--performance-only, make ARGS=--conformance-only to execute the required part.

Other native JSON benchmarks

• Basic benchmarks for miscellaneous C++ JSON parsers and generators by Mateusz Loskot (Jun 2013)

• Casablanca

• json spirit

• JsonCpp

• libjson

• rapidjson

• QJsonDocument

• JSON Parser Benchmarking by Chad Austin (Jan 2013)

• sajson

• RapidJSON

• vjson (Replaced by gason)

• YAJL

• Jansson