snappyjs

SnappyJS

A pure JavaScript implementation of Google's Snappy compression library.

This implementation is reasonably fast (see benchmark below). It takes advantage of ArrayBuffer.

Install

If using with Node.js,

npm install snappyjs

If using with Bower,

bower install snappyjs

Usage

SnappyJS works with Node.js 0.10 or later.

var SnappyJS = require('snappyjs')
var buffer = new ArrayBuffer(100)
// fill data in buffer
var compressed = SnappyJS.compress(buffer)
var uncompressed = SnappyJS.uncompress(compressed)

You can also use SnappyJS in browser. Adding dist/snappyjs.js or dist/snappyjs.min.js will introduce SnappyJS in the global scope. SnappyJS relies on ArrayBuffer. All major browsers support it now (http://caniuse.com/#feat=typedarrays). Also, as I tested, SnappyJS has high performance on latest version of Google Chrome, Safari, Firefox, and Microsoft Edge.

API

SnappyJS.compress(input)

Compress input, which must be type of ArrayBuffer or Buffer. Compressed byte stream is returned, with same type of input.

SnappyJS.uncompress(compressed)

Uncompress compressed, which must be type of ArrayBuffer or Buffer. Uncompressed byte stream is returned, with same type of compressed.

Benchmark

Although JavaScript is dynamic-typing, all major JS engines are highly optimized. Thus well-crafted JavaScript code can have competitive performance even compared to native C++ code.

I benchmark SnappyJS against node-snappy (which is Node.js binding of native implementation).

Command for benchmark is node benchmark. Below is the result running on Node.js v5.5.0.

Real text #1 (length 618425, byte length 1236850):
node-snappy#compress x 170 ops/sec ±0.96% (74 runs sampled)
snappyjs#compress x 54.34 ops/sec ±1.27% (67 runs sampled)
node-snappy#uncompress x 461 ops/sec ±1.60% (73 runs sampled)
snappyjs#uncompress x 164 ops/sec ±1.31% (70 runs sampled)

Real text #2 (length 3844590, byte length 7689180):
node-snappy#compress x 42.77 ops/sec ±1.33% (54 runs sampled)
snappyjs#compress x 17.78 ops/sec ±1.20% (46 runs sampled)
node-snappy#uncompress x 101 ops/sec ±4.43% (61 runs sampled)
snappyjs#uncompress x 40.93 ops/sec ±0.88% (52 runs sampled)

Random string (length 1000000, byte length 2000000):
node-snappy#compress x 125 ops/sec ±1.76% (73 runs sampled)
snappyjs#compress x 29.34 ops/sec ±2.41% (52 runs sampled)
node-snappy#uncompress x 381 ops/sec ±3.33% (66 runs sampled)
snappyjs#uncompress x 163 ops/sec ±1.40% (70 runs sampled)

From the result, we see that SnappyJS has 35%~40% performance of native implementation on uncompression, and 25%~35% performance on compression.

License

MIT License