JSON-Compress

Update to version 1.7.0

Changelog

Background

One of the problems you can have developing rich internet applications (RIA) using Javascript is the amount of data being transported to and from the server. When data comes from server, this data could be GZipped, but this is not possible when the big amount of data comes from the browser to the server.

JSON-Compress was born to change the way browser vendors think and become an standard when send information to the server efficiently.

JSON-Compress has two differents approaches to reduce the size of the amount of data to be transported:

• JSONC.compress - Compress JSON objects using a map to reduce the size of the keys in JSON objects.
  • Be careful with this method because it's really impressive if you use it with a JSON with a big amount of data, but it could be awful if you use it to compress JSON objects with small amount of data because it could increase the final size.
  • The rate compression could variate from 7.5% to 32.81% depending of the type and values of data.
• JSONC.pack - Compress JSON objects using GZIP compression algorithm, to make the job JSONC uses a modification to use the gzip library and it encodes the gzipped string with Base64 to avoid url encode.
  • Gzip - @beatgammit - https://github.com/beatgammit/gzip-js
  • Base64 - http://www.webtoolkit.info/
  • You can use pack to compress any JSON objects even if these objects are not been compressed using JSONC See Usage for more details.

Install

Add library to your project

// Download from GitHub because this is not my original work
yarn add https://github.com/Alamantus/JSON-Compress.git
// or
npm install git+https://github.com/Alamantus/JSON-Compress.git

Usage

Load for use in script:

// Returns the JSONC object with the following methods.
var JSONC = require( 'json-compress' );

Compress a JSON object:

// Returns a JSON object but compressed.
var compressedJSON = JSONC.compress( json );

Decompress a JSON object:

// Returns the original JSON object.
var json = JSONC.decompress( compressedJSON );

Compress a normal JSON object as a Gzipped string:

// Returns the LZW representation as string of the JSON object.
var lzwString = JSONC.pack( json );

Decompress a normal JSON object from a Gzipped string:

// Returns the original JSON object.
var json = JSONC.unpack( gzippedString );

Compress a JSON object with JSONC before compressing as a Gzipped string:

// Returns the LZW representation as string of the JSON object.
var lzwString = JSONC.pack( json, true );

Decompress a JSON object that was compressed with JSONC from a Gzipped string:

// Returns the original JSON object.
var json = JSONC.unpack( gzippedString, true );

Prevent Key Collisions

If compressing a JSON object that contains keys that are single characters, there may be a collision with those keys and the generated map keys of the compressed JSON object. The safest way to prevent this is to not use single-character keys, but when you need these short keys, you can use the collision prevention flag.

Using key/map collision prevention will slow down the compression of JSON objects, and it may slow it down significantly if the object is particularly lage. Be aware of this before using the options below.

Compress a JSON object, checking for object key collisions:

// Returns a JSON object but compressed, ensuring that any
// single-character keys have no collision with the map.
var compressedJSON = JSONC.compress( json, true );

Compress a JSON object with JSONC before compressing as a Gzipped string, checking for object key collisions:

// Returns the LZW representation as string of the JSON object, ensuring
// that any single-character keys have no collision with the map.
var lzwString = JSONC.pack( json, true, true );

Modify global JSON

You should probably NOT do this, but it makes it more convenient to use

// Inject JSONC functions into global JSON object
require( 'json-compress' ).inject( JSON );
// Use JSONC functions directly from JSON object
var compressedJSON = JSON.compress( json );
var json = JSON.decompress( compressedJSON );
var lzwString = JSON.pack( json );
var json = JSON.unpack( lzwString );