A header-only JSON parser/generator in C++20. It supports both SAX and DOM style API.
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- Simple, Fast. neujson contains only header files, does not rely on Boost, and takes full advantage of the template's features. You can "assemble" neujson's Handler at will.
- API simplicity. neujson supports both DOM and SAX-style API, where SAX allows custom handlers for streaming processing.
- Unicode friendly. neujson fully supports UTF-8 codec and can parse utF-8 characters such as '\u0000'.
- Multiple input/output streams. neujson has built-in string input/output streams and file input/output streams, and make full use of memory buffers to improve read and write speed.
- STD Streams Wrapper. neujson provides official wrappers for std::istream and std::ostream, can be combined with neujson's built-in input/output streams.
- Performant. neujson internally implements standards such as IEEE754 and uses high-performance algorithms built into different compilers. neujson also plans to implement Grisu2 algorithm and use SIMD instructions to speed up conversion between floating point numbers and strings.
This simple example parses a JSON string into a document (DOM), make a simple modification of the DOM, and finally stringify the DOM to a JSON string.
#include <cstdio>
#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<int>(os.get().length()), os.get().data());
return 0;
}Output:
[{"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"}]git clone https://github.com/hominsu/neujson.gitThis project requires C++17. This library uses following projects：
When building tests:
When building examples:
All dependencies are automatically retrieved from github during building, and you do not need to configure them.
With th CMake build types, you can control whether examples and tests are built.
cmake -H. -Bbuild \
-DCMAKE_BUILD_TYPE=Release \
-DCMAKE_INSTALL_PREFIX=/Users/hominsu/utils/install \
-DNEUJSON_BUILD_EXAMPLES=ON \
-DNEUJSON_BUILD_TESTS=ON
cmake --build ./build --parallel $(nproc)
ctest -VV --test-dir ./build/ --output-on-failure
cmake --install ./buildOr just installed as a CMake package.
cmake -H. -Bbuild \
-DNEUJSON_BUILD_EXAMPLES=OFF \
-DNEUJSON_BUILD_TESTS=OFF
cmake --install ./buildUinstall
cd build
make uninstallLocated with find_package in CMake.
find_package(neujson REQUIRED)
target_include_directories(foo PUBLIC ${neujson_INCLUDE_DIRS})To build with benchmark，use git submodule to fetch all the data from that third party project and check out the appropriate commit first, then add the benchmark CMake option:
git submodule update --init --recursive
pushd cmake/build
cmake -DNEUJSON_BUILD_BENCHMARK=ON ../..
...The benchmark is base on the google benchmark
| JSON file | Size | Description |
|---|---|---|
canada.jsonsource |
2199KB | Contour of Canada border in GeoJSON format. Contains a lot of real numbers. |
citm_catalog.jsonsource |
1737KB | A big benchmark file with indentation used in several Java JSON parser benchmarks. |
The followings are some snapshots from the results of MacBook Air (M1, 2020) with Apple clang 13.1.6
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 56The followings are some snapshots from the results of i5-9500 with gcc 8.5.0 (Red Hat 8.5.0-10) in CentOS-8-Stream
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 54RapidJSON: A fast JSON parser/generator for C++ with both SAX/DOM style API
Special thanks to JetBrains for licensing free All Products Pack for this open source projects
Thanks goes to these wonderful people (emoji key):
 Homing So 💻 📖 🎨 💡 🚇 📦 |
This project follows the all-contributors specification. Contributions of any kind welcome!
Distributed under the MIT license. See LICENSE for more information.