js-lzma

js-lzma is a port of the LZMA decompression algorithm to JavaScript.

The source code is a manual translation from the original Java version found in the LZMA SDK.

Usage

If you have the content of a .lzma file then just call to the decompressFile function:

LZMA.decompressFile(inStream, outStream);

Where:

• inStream is the input data stream to decompress
• outStream is the output data stream

If you want more control about the process then you can use the decompress function:

LZMA.decompress(properties, inStream, outStream, outSize);

Where:

• properties is the input data stream with LZMA properties
• inStream is the input data stream to decompress
• outStream is the output data stream
• outSize is the expected size of output data stream

Streams

Input data streams must be JavaScript objects exposing a public readByte function:

var inStream = {
  data: [ /* Put your compressed data here */ ],
  offset: 0,
  readByte: function(){
    return this.data[this.offset ++];
  }
};

Output data streams must be JavaScript objects exposing a public writeByte function:

var outStream = {
  data: [ /* Uncompressed data will be putted here */ ],
  offset: 0,
  writeByte: function(value){
    this.data[this.offset ++] = value;
  }
};

Ok, you can mix both on a more generic one. And change Array to String, some sort of Typed Array, or whatever you want.

Properties

LZMA properties are described in the LZMA SDK.

Just five bytes. The first one containing lc, lp and pb parameters, and the last four the dictionary size (little endian encoding).

Limitations

Output size is limited to 32 bits.

What about compression function?

Sorry, don't. This library is part of another project of mine that only needed the decompression algorithm.