fast-json-parser

Fast incremental (streaming) JSON parser for node

performance

At the moment, its about 3 times slower than buffering a node stream then parsing it with JSON.parse

However, its about 3 times faster than oboe.js as well.

Currently works on valid JSON, however it also accepts invalid JSON.

Check out the benchmarks in the perf dir

$ node perf/big-bench.js
testJSONParse: 858.689ms
testOboe: 7263.890ms
testFastJsonParser: 2529.559ms

usage example

A static convenience method is available for node streams:

import { Parser } from "fast-json-parser";

async function test() {
  let result = await Parser.parseStream(stream);
  console.log(result);
}

Or you can use the raw API:

import { Parser } from "fast-json-parser";

function parseStream(stream) {
  return new Promise(resolve => {
    let p = new Parser();
    p.init();
    stream.on("data", data => p.push(data));
    stream.on("end", () => resolve(p.value));
  });
}

build

Install typescript then simply run tsc from the base dir

todo

• moar perf! (buffer based string parser in node?)

forbid:

• forbid leading zero in numbers unless followed by dot
• forbid dot at end of number
• forbid comma before end of array and objects

test:

• end with unicode escape sequence
• add buffer splitting to fuzzer

license

MIT