This benchmark measures the time it takes to validate JSON, i.e. to check whether it is well-formed. Validation was chosen as opposed to parsing, as parsing speed depends on the JSON data structure as well. Implementing an efficient JSON container is out of scope for lexy, so it would have a disadvantage over the specialized JSON libraries.
The average validation times for each input are shown in the boxplots below. Lower values are better.
baseline-
This simply adds all input characters of the JSON document without performing actual validation.
lexy-
A JSON validator using the lexy grammar from the example.
pegtl-
A JSON validator using the PEGTL JSON grammar.
nlohmann/json-
A JSON validator using JSON for Modern C++ implemented by
nlohmann::json::accept(). rapidjson-
A JSON validator using rapidjson implemented using a SAX parser with the
rapidjson::BaseReaderHandler. Boost.JSON-
A JSON validator using Boost.JSON implemented using a custom parse handler.
canada.json-
Contains lots of 2-element arrays holding floating-point coordinate pairs. Taken from https://github.com/miloyip/nativejson-benchmark.
citm_catalog.json-
Big JSON file with some variety. Taken from https://github.com/miloyip/nativejson-benchmark.
twitter.json-
Some data from twitter’s API. Taken from https://github.com/miloyip/nativejson-benchmark.
The input data is read using lexy::read_file().
The resulting buffer is then passed to the various implementations using their memory inputs.
Benchmarking is done by nanobench on an AMD FX-6300.