@stardazed/inflate v1.0.0

@stardazed/inflate

Zip inflate algorithm implementation. Decompresses data compressed with zlib. Supports optional DEFLATE headers and preset dictionaries.

Installation

npm install @stardazed/inflate
pnpm install @stardazed/inflate
yarn add @stardazed/inflate

Usage

In most cases, just call inflate on deflated data and you're done. This call will correctly interpret and handle a DEFLATE header if it is present.

⚠️ Important: Gzip headers are not currently supported, you must provide the buffer without any gzip headers.

import { inflate } from "@stardazed/inflate";

const deflatedData = /* must be a Uint8Array */;
inflate(deflatedData).then(
	data => /* act on inflated buffer */,
	error => /* the data was incomplete or invalid */
);

If you want more control over the process, including streaming in data chunks as you receive them, then use the Inflater class.

The Inflater class takes the following options:

dataIncludesHeader: boolean (default true) If set, the DEFLATE header and optional preset dictionary checksum will be parsed and verified. Set to false if you only have the compressed data, e.g. of a gzip file.

allowPartialData: boolean (default: false) If set to true, then you can call finish mid-stream. This is only useful if you know you have incomplete data.

presetDictionary: Uint8Array (default: undefined) Provide an optional precalculated lookup dictionary. Only used if the data indicates it needs an external dictionary in the DEFLATE header. If used, the Adler32 checksum of the dictionary is verified against the checksum stored in the deflated data. If dataIncludesHeader is false, then this is ignored.

import { Inflater } from "@stardazed/inflate";

const inflater = new Inflater(options /* see above */);

// then, each time a new chunk of data becomes available:
try {
    inflater.append(chunk); // chunk must be an Uint8Array
}
catch (error) {
    // handle errors (could be bad data, invalid header, etc.)
}

// when all data has been appended:
try {
	const data = inflater.finish();
	// ...act on data
}
catch (error) {
	// an error will be thrown if the deflated data was incomplete
	// and you did not specify allowPartialData in the options
}

Copyright

Based on zlib Copyright (c) 1995-2018 Jean-loup Gailly and Mark Adler inflate.js (c) 2013 by Gildas Lormeau, part of the zip.js library See: https://gildas-lormeau.github.io/zip.js/ inflate.js is based on JZlib 1.0.2 ymnk, JCraft,Inc. (c) Arthur Langereis (@zenmumbler): conversion to TypeScript, modularized, modernized, optimized and extended

License

zlib