# dev-env **Repository Path**: hominsu/dev-env ## Basic Information - **Project Name**: dev-env - **Description**: Contains various common docker images - **Primary Language**: Unknown - **License**: MIT - **Default Branch**: main - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 1 - **Forks**: 0 - **Created**: 2022-07-03 - **Last Updated**: 2024-05-29 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README

neujson

JSON parser/generator in C++20
Explore the docs »

View Demo · Report Bug · Request Feature

Translations: [English](README.md) | [简体中文](README_zh.md) ## 简介 neujson 是一个 C++ 的 JSON 解析器及生成器。它同时支持 SAX 和 DOM 风格的 API。 ## 安装 ### 克隆 neujson 的源代码 ```bash git clone https://github.com/hominsu/neujson.git ``` ### 编译和安装下面的命令将在本地构建和安装 neujson： ```bash cd neujson mkdir -p cmake/build pushd cmake/build cmake ../.. make -j make install popd ``` 如果你没有安装目录的权限，请使用 `sudo`： ```bash sudo make install ``` #### 同时构建示例程序示例的源代码已经包含在 `neujson` 的源代码中，你已经在上一步中克隆了源代码，只需要额外添加一个的 `cmake` 选项： ```bash cmake -DNEUJSON_BUILD_EXAMPLES=ON ../.. ``` #### 同时构建基准测试构建基准测试，需要使用 `git submodule` 拉取第三方依赖，并检出到相应的分支，然后添加基准测试的 `cmake` 选项： ```bash git submodule update --init --recursive pushd cmake/build cmake -DNEUJSON_BUILD_BENCHMARK=ON ../.. ... ``` ## 卸载使用一下命令可以卸载 neujson： ```bash pushd cmake/build make uninstall popd ``` 如果你没有安装目录的权限，请使用 `sudo`： ```bash sudo make uninstall ``` ## 用法一目了然此简单例子解析一个 JSON 字符串至一个 document (DOM)，对 DOM 作出简单修改，最终把 DOM 转换（stringify）至 JSON 字符串。 ```c++ #include #include "neujson/document.h" #include "neujson/string_write_stream.h" #include "neujson/writer.h" #include "sample.h" int main() { // 1. Parse a JSON string into DOM. neujson::Document doc; if (const auto err = doc.Parse(kSample[0]); err != neujson::error::OK) { puts(neujson::ParseErrorStr(err)); return EXIT_FAILURE; } // 2. Modify it by DOM. auto &s = doc[0]["Longitude"]; s.SetDouble(s.GetDouble() + 100.0); // 3. Stringify the DOM neujson::StringWriteStream os; neujson::Writer writer(os); doc.WriteTo(writer); // Output fprintf(stdout, "%.*s", static_cast(os.get().length()), os.get().data()); return 0; } ``` 输出: ```json [{"precision":"zip","Latitude":37.766800000000003,"Longitude":-22.395899999999997,"Address":"","City":"SAN FRANCISCO","State":"CA","Zip":"94107","Country":"US"},{"precision":"zip","Latitude":37.371991000000001,"Longitude":-122.02602,"Address":"","City":"SUNNYVALE","State":"CA","Zip":"94085","Country":"US"}] ``` ## 基准性能测试基准性能测试基于 google benchmark 进行 ### JSON data | JSON file | Size | Description | | :----------------------------------------------------------: | :----: | :----------------------------------------------------------: | | `canada.json`[source](https://github.com/mloskot/json_benchmark/blob/master/data/canada.json) | 2199KB | 加拿大边境轮廓，格式为: [GeoJSON](http://geojson.org/)；包含大量的实数。 | | `citm_catalog.json`[source](https://github.com/RichardHightower/json-parsers-benchmark/blob/master/data/citm_catalog.json) | 1737KB | 一个带有缩进的大型基准测试文件，用于多个Java JSON解析器基准测试。 | ### Sample Results 下面是使用 MacBook Air (M1, 2020) 和 Apple clang 13.1.6 得到的结果 ```bash Run on (8 X 24.1212 MHz CPU s) CPU Caches: L1 Data 64 KiB (x8) L1 Instruction 128 KiB (x8) L2 Unified 4096 KiB (x2) Load Average: 2.04, 1.78, 1.74 -------------------------------------------------------------------------------------------------------- Benchmark Time CPU Iterations -------------------------------------------------------------------------------------------------------- BM_neujson_read_parse/citm_catalog.json 7.04 ms 7.04 ms 72 BM_nlohmann_read_parse/citm_catalog.json 10.6 ms 10.6 ms 66 BM_rapidjson_read_parse/citm_catalog.json 2.96 ms 2.96 ms 236 BM_neujson_read_parse_write_file/citm_catalog.json 7.92 ms 7.92 ms 88 BM_nlohmann_read_parse_write_file/citm_catalog.json 12.5 ms 12.5 ms 56 BM_rapidjson_read_parse_write_file/citm_catalog.json 4.10 ms 4.10 ms 170 BM_neujson_read_parse_write_string/citm_catalog.json 8.03 ms 8.03 ms 87 BM_nlohmann_read_parse_write_string/citm_catalog.json 12.7 ms 12.7 ms 55 BM_rapidjson_read_parse_write_string/citm_catalog.json 3.90 ms 3.90 ms 180 BM_neujson_read_parse_pretty_write_file/citm_catalog.json 8.84 ms 8.84 ms 79 BM_nlohmann_read_parse_pretty_write_file/citm_catalog.json 13.3 ms 13.3 ms 53 BM_rapidjson_read_parse_pretty_write_file/citm_catalog.json 4.56 ms 4.55 ms 154 BM_neujson_read_parse_pretty_write_string/citm_catalog.json 9.44 ms 9.44 ms 72 BM_nlohmann_read_parse_pretty_write_string/citm_catalog.json 14.2 ms 14.2 ms 50 BM_rapidjson_read_parse_pretty_write_string/citm_catalog.json 4.19 ms 4.19 ms 167 BM_neujson_read_parse/canada.json 31.6 ms 31.6 ms 22 BM_nlohmann_read_parse/canada.json 39.1 ms 39.1 ms 18 BM_rapidjson_read_parse/canada.json 3.38 ms 3.38 ms 207 BM_neujson_read_parse_write_file/canada.json 68.2 ms 68.2 ms 10 BM_nlohmann_read_parse_write_file/canada.json 47.6 ms 47.6 ms 15 BM_rapidjson_read_parse_write_file/canada.json 12.5 ms 12.5 ms 55 BM_neujson_read_parse_write_string/canada.json 69.4 ms 69.4 ms 10 BM_nlohmann_read_parse_write_string/canada.json 48.5 ms 48.5 ms 14 BM_rapidjson_read_parse_write_string/canada.json 10.7 ms 10.7 ms 63 BM_neujson_read_parse_pretty_write_file/canada.json 72.3 ms 72.3 ms 10 BM_nlohmann_read_parse_pretty_write_file/canada.json 51.2 ms 51.2 ms 14 BM_rapidjson_read_parse_pretty_write_file/canada.json 13.7 ms 13.7 ms 51 BM_neujson_read_parse_pretty_write_string/canada.json 75.9 ms 75.9 ms 9 BM_nlohmann_read_parse_pretty_write_string/canada.json 55.0 ms 55.0 ms 13 BM_rapidjson_read_parse_pretty_write_string/canada.json 12.4 ms 12.4 ms 56 ``` 下面是使用 i5-9500 以及 CentOS-8-Stream 和 gcc 8.5.0 (Red Hat 8.5.0-10) 得到的结果 ```bash Run on (6 X 4166.48 MHz CPU s) CPU Caches: L1 Data 32 KiB (x6) L1 Instruction 32 KiB (x6) L2 Unified 256 KiB (x6) L3 Unified 9216 KiB (x1) Load Average: 0.80, 0.52, 0.45 -------------------------------------------------------------------------------------------------------- Benchmark Time CPU Iterations -------------------------------------------------------------------------------------------------------- BM_neujson_read_parse/citm_catalog.json 8.59 ms 8.58 ms 74 BM_nlohmann_read_parse/citm_catalog.json 14.7 ms 14.6 ms 48 BM_rapidjson_read_parse/citm_catalog.json 2.38 ms 2.37 ms 293 BM_neujson_read_parse_write_file/citm_catalog.json 10.1 ms 10.1 ms 70 BM_nlohmann_read_parse_write_file/citm_catalog.json 17.5 ms 17.5 ms 40 BM_rapidjson_read_parse_write_file/citm_catalog.json 3.39 ms 3.39 ms 206 BM_neujson_read_parse_write_string/citm_catalog.json 10.9 ms 10.9 ms 65 BM_nlohmann_read_parse_write_string/citm_catalog.json 17.5 ms 17.5 ms 40 BM_rapidjson_read_parse_write_string/citm_catalog.json 3.20 ms 3.19 ms 218 BM_neujson_read_parse_pretty_write_file/citm_catalog.json 11.3 ms 11.3 ms 60 BM_nlohmann_read_parse_pretty_write_file/citm_catalog.json 18.8 ms 18.7 ms 38 BM_rapidjson_read_parse_pretty_write_file/citm_catalog.json 3.70 ms 3.69 ms 189 BM_neujson_read_parse_pretty_write_string/citm_catalog.json 14.5 ms 14.5 ms 49 BM_nlohmann_read_parse_pretty_write_string/citm_catalog.json 18.5 ms 18.5 ms 38 BM_rapidjson_read_parse_pretty_write_string/citm_catalog.json 3.57 ms 3.57 ms 196 BM_neujson_read_parse/canada.json 27.8 ms 27.7 ms 25 BM_nlohmann_read_parse/canada.json 41.8 ms 41.8 ms 17 BM_rapidjson_read_parse/canada.json 4.59 ms 4.58 ms 152 BM_neujson_read_parse_write_file/canada.json 100 ms 100 ms 7 BM_nlohmann_read_parse_write_file/canada.json 53.5 ms 53.4 ms 13 BM_rapidjson_read_parse_write_file/canada.json 13.6 ms 13.6 ms 51 BM_neujson_read_parse_write_string/canada.json 106 ms 106 ms 7 BM_nlohmann_read_parse_write_string/canada.json 53.3 ms 53.3 ms 13 BM_rapidjson_read_parse_write_string/canada.json 11.9 ms 11.9 ms 58 BM_neujson_read_parse_pretty_write_file/canada.json 106 ms 106 ms 7 BM_nlohmann_read_parse_pretty_write_file/canada.json 58.6 ms 58.6 ms 12 BM_rapidjson_read_parse_pretty_write_file/canada.json 14.4 ms 14.4 ms 49 BM_neujson_read_parse_pretty_write_string/canada.json 119 ms 119 ms 6 BM_nlohmann_read_parse_pretty_write_string/canada.json 64.9 ms 64.8 ms 11 BM_rapidjson_read_parse_pretty_write_string/canada.json 12.8 ms 12.8 ms 54 ``` ## 参考 [RapidJSON](https://github.com/Tencent/rapidjson): A fast JSON parser/generator for C++ with both SAX/DOM style API ## 鸣谢 ![JetBrains Logo (Main) logo](https://resources.jetbrains.com/storage/products/company/brand/logos/jb_beam.svg) 特别感谢 [JetBrains](https://www.jetbrains.com/) 为本开源项目提供免费的 `All Products Pack` 授权 ## Contributors ✨ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/docs/en/emoji-key)):

_{Homing So}
💻 📖 🎨 💡 🚇 📦 ⚠️

This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!