bitjs/archive/decompress.js

/**
 * decompress.js
 *
 * Provides base functionality for unarchiving/decompression.
 *
 * Licensed under the MIT License
 *
 * Copyright(c) 2021 Google Inc.
 */

 import { UnarchiveAppendEvent, UnarchiveErrorEvent, UnarchiveEvent, UnarchiveEventType,
  UnarchiveExtractEvent, UnarchiveFinishEvent, UnarchiveInfoEvent,
  UnarchiveProgressEvent, UnarchiveStartEvent, Unarchiver,
  UnrarrerInternal, UntarrerInternal, UnzipperInternal,
  getUnarchiverInternal } from './decompress-internal.js';

export {
  UnarchiveAppendEvent,
  UnarchiveErrorEvent,
  UnarchiveEvent,
  UnarchiveEventType,
  UnarchiveExtractEvent,
  UnarchiveFinishEvent,
  UnarchiveInfoEvent,
  UnarchiveProgressEvent,
  UnarchiveStartEvent,
  Unarchiver,
} 

/**
* All extracted files returned by an Unarchiver will implement
* the following interface:
*/

/**
 * @typedef UnarchivedFile
 * @property {string} filename
 * @property {Uint8Array} fileData
 */

/**
* The goal is to make this testable - send getUnarchiver() an array buffer of
* an archive, call start on the unarchiver, expect the returned result.
*
* Problem: It relies on Web Workers, and that won't work in a nodejs context.
* Solution: Make archive.js very thin, have it feed web-specific things into
*           an internal module that is isomorphic JavaScript.
*
* TODO:
* - write unit tests for archive-internal.js that use the nodejs Worker
*   equivalent.
* - maybe use @pgriess/node-webworker or @audreyt/node-webworker-threads or
*   just node's worker_threads ?
*/

const createWorkerFn = (scriptFilename) => new Worker(scriptFilename);

// Thin wrappers of compressors for clients who want to construct a specific
// unarchiver themselves rather than use getUnarchiver().
export class Unzipper extends UnzipperInternal {
  constructor(ab, options) { super(ab, createWorkerFn, options); }
}

export class Unrarrer extends UnrarrerInternal {
  constructor(ab, options) { super(ab, createWorkerFn, options); }
}

export class Untarrer extends UntarrerInternal {
  constructor(ab, options) { super(ab, createWorkerFn, options); }
}

/**
* Factory method that creates an unarchiver based on the byte signature found
* in the arrayBuffer.
* @param {ArrayBuffer} ab The ArrayBuffer to unarchive. Note that this ArrayBuffer
*     must not be referenced after calling this method, as the ArrayBuffer is marked
*     as Transferable and sent to a Worker thread once start() is called.
* @param {Object|string} options An optional object of options, or a string
*     representing where the path to the unarchiver script files.
* @return {Unarchiver}
*/
export function getUnarchiver(ab, options = {}) {
  return getUnarchiverInternal(ab, createWorkerFn, options);
}