bsubhashni / yasjl

Json library

yasjl

Yet another simple/streaming/stack-based json library

Features

• Works on bytebuf, allows streaming partial reads
• Use json pointers to read specific values in bytebufs
• Callbacks to get notifications on values
• Supports "-" for json array any element match
• Zero copy for parsing, but copies value only on request using a callback

Takes inspiration from Jsonsl, blackberry json-parser

Example

Create Json pointers with callback to fetch value

JsonPointer[] jsonPointers = {
    new JsonPointer("/results/-",  new JsonPointerCB1() {
        public void call(ByteBuf buf) {
            //get value for the json pointer
            System.out.println(buf.toString(Charset.defaultCharset()));
            buf.release();
        })
};

Initialize the parser with the ByteBuf which has the JSON content and json pointers

parser.initialize(buf, jsonPointers);

Parse the current readable bytes and does callback if there was a reference to a json pointer. This will throw EOFException if more content is required to finish parsing

parser.parse(); 

Simple benchmark results

size: 78.2 MB,      level-depth: 0,     time: 26ms
size: 3.2 MB,       level-depth: 3,     time: 345ms
size: 429.2 kB,     level-depth: 4,     time: 9ms
size: 9.7 MB,       level-depth: 5,     time: 69ms
size: 9.7 MB,       level-depth: 5,     time: 58ms
size: 16.8 kB,      level-depth: 2,     time: 0ms
size: 874 B,        level-depth: 4,     time: 0ms
size: 775 B,        level-depth: 5,     time: 0ms
size: 243 B,        level-depth: 4,     time: 0ms
size: 3.5 kB,       level-depth: 4,     time: 0ms
size: 4.2 kB,       level-depth: 4,     time: 0ms
size: 602 B,        level-depth: 4,     time: 0ms
size: 1.1 kB,       level-depth: 6,     time: 0ms
size: 1.4 kB,       level-depth: 5,     time: 0ms
size: 18.4 kB,      level-depth: 5,     time: 0ms
size: 39.5 kB,      level-depth: 4,     time: 1ms
size: 1.2 kB,       level-depth: 6,     time: 1ms

Bench usage

Bench <json-file> <iteration-count>