Xefir/epubreader
Archived
1
1
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 3 Wiki Activity
This repository has been archived on 2024-01-19. You can view files and clone it, but cannot push or open issues or pull requests.
5d6e3431b2
epubreader/vendor/bitjs/archive/unzip.js
Alfred Egger e00fdad14d Initial commit from existing app
2020-04-21 22:37:42 +02:00

1468 lines
44 KiB
JavaScript
Raw Blame History

/**
* unzip.js
*
* Licensed under the MIT License
*
* Copyright(c) 2011 Google Inc.
* Copyright(c) 2011 antimatter15
*
* Reference Documentation:
*
* ZIP format: http://www.pkware.com/documents/casestudies/APPNOTE.TXT
* DEFLATE format: http://tools.ietf.org/html/rfc1951
*/
// This file expects to be invoked as a Worker (see onmessage below).
// ...
// ... but importScripts does not work when CSP2 nonce is active, so inline these instead...
//importScripts('../io/bitstream.js');
//
/*
* bitstream.js
*
* Provides readers for bitstreams.
*
* Licensed under the MIT License
*
* Copyright(c) 2011 Google Inc.
* Copyright(c) 2011 antimatter15
*/
var bitjs = bitjs || {};
bitjs.io = bitjs.io || {};
/**
* This bit stream peeks and consumes bits out of a binary stream.
*/
bitjs.io.BitStream = class {
/**
* @param {ArrayBuffer} ab An ArrayBuffer object or a Uint8Array.
* @param {boolean} rtl Whether the stream reads bits from the byte starting
* from bit 7 to 0 (true) or bit 0 to 7 (false).
* @param {Number} opt_offset The offset into the ArrayBuffer
* @param {Number} opt_length The length of this BitStream
*/
constructor(ab, rtl, opt_offset, opt_length) {
if (!ab || !ab.toString || ab.toString() !== "[object ArrayBuffer]") {
throw "Error! BitArray constructed with an invalid ArrayBuffer object";
}
const offset = opt_offset || 0;
const length = opt_length || ab.byteLength;
this.bytes = new Uint8Array(ab, offset, length);
this.bytePtr = 0; // tracks which byte we are on
this.bitPtr = 0; // tracks which bit we are on (can have values 0 through 7)
this.peekBits = rtl ? this.peekBits_rtl : this.peekBits_ltr;
}
/**
* byte0 byte1 byte2 byte3
* 7......0 | 7......0 | 7......0 | 7......0
*
* The bit pointer starts at bit0 of byte0 and moves left until it reaches
* bit7 of byte0, then jumps to bit0 of byte1, etc.
* @param {number} n The number of bits to peek.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {number} The peeked bits, as an unsigned number.
*/
peekBits_ltr(n, opt_movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return 0;
}
const movePointers = opt_movePointers || false;
const bytes = this.bytes;
let bytePtr = this.bytePtr;
let bitPtr = this.bitPtr;
let result = 0;
let bitsIn = 0;
// keep going until we have no more bits left to peek at
// TODO: Consider putting all bits from bytes we will need into a variable and then
// shifting/masking it to just extract the bits we want.
// This could be considerably faster when reading more than 3 or 4 bits at a time.
while (n > 0) {
if (bytePtr >= bytes.length) {
throw "Error! Overflowed the bit stream! n=" + n + ", bytePtr=" + bytePtr + ", bytes.length=" +
bytes.length + ", bitPtr=" + bitPtr;
return -1;
}
const numBitsLeftInThisByte = (8 - bitPtr);
if (n >= numBitsLeftInThisByte) {
const mask = (bitjs.io.BitStream.BITMASK[numBitsLeftInThisByte] << bitPtr);
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
bytePtr++;
bitPtr = 0;
bitsIn += numBitsLeftInThisByte;
n -= numBitsLeftInThisByte;
}
else {
const mask = (bitjs.io.BitStream.BITMASK[n] << bitPtr);
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
bitPtr += n;
bitsIn += n;
n = 0;
}
}
if (movePointers) {
this.bitPtr = bitPtr;
this.bytePtr = bytePtr;
}
return result;
}
/**
* byte0 byte1 byte2 byte3
* 7......0 | 7......0 | 7......0 | 7......0
*
* The bit pointer starts at bit7 of byte0 and moves right until it reaches
* bit0 of byte0, then goes to bit7 of byte1, etc.
* @param {number} n The number of bits to peek.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {number} The peeked bits, as an unsigned number.
*/
peekBits_rtl(n, opt_movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return 0;
}
const movePointers = opt_movePointers || false;
const bytes = this.bytes;
let bytePtr = this.bytePtr;
let bitPtr = this.bitPtr;
let result = 0;
// keep going until we have no more bits left to peek at
// TODO: Consider putting all bits from bytes we will need into a variable and then
// shifting/masking it to just extract the bits we want.
// This could be considerably faster when reading more than 3 or 4 bits at a time.
while (n > 0) {
if (bytePtr >= bytes.length) {
throw "Error! Overflowed the bit stream! n=" + n + ", bytePtr=" + bytePtr + ", bytes.length=" +
bytes.length + ", bitPtr=" + bitPtr;
return -1;
}
const numBitsLeftInThisByte = (8 - bitPtr);
if (n >= numBitsLeftInThisByte) {
result <<= numBitsLeftInThisByte;
result |= (bitjs.io.BitStream.BITMASK[numBitsLeftInThisByte] & bytes[bytePtr]);
bytePtr++;
bitPtr = 0;
n -= numBitsLeftInThisByte;
}
else {
result <<= n;
result |= ((bytes[bytePtr] & (bitjs.io.BitStream.BITMASK[n] << (8 - n - bitPtr))) >> (8 - n - bitPtr));
bitPtr += n;
n = 0;
}
}
if (movePointers) {
this.bitPtr = bitPtr;
this.bytePtr = bytePtr;
}
return result;
}
/**
* Peek at 16 bits from current position in the buffer.
* Bit at (bytePtr,bitPtr) has the highest position in returning data.
* Taken from getbits.hpp in unrar.
* TODO: Move this out of BitStream and into unrar.
*/
getBits() {
return (((((this.bytes[this.bytePtr] & 0xff) << 16) +
((this.bytes[this.bytePtr+1] & 0xff) << 8) +
((this.bytes[this.bytePtr+2] & 0xff))) >>> (8-this.bitPtr)) & 0xffff);
}
/**
* Reads n bits out of the stream, consuming them (moving the bit pointer).
* @param {number} n The number of bits to read.
* @return {number} The read bits, as an unsigned number.
*/
readBits(n) {
return this.peekBits(n, true);
}
/**
* This returns n bytes as a sub-array, advancing the pointer if movePointers
* is true. Only use this for uncompressed blocks as this throws away remaining
* bits in the current byte.
* @param {number} n The number of bytes to peek.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {Uint8Array} The subarray.
*/
peekBytes(n, opt_movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return 0;
}
// from http://tools.ietf.org/html/rfc1951#page-11
// "Any bits of input up to the next byte boundary are ignored."
while (this.bitPtr != 0) {
this.readBits(1);
}
const movePointers = opt_movePointers || false;
let bytePtr = this.bytePtr;
let bitPtr = this.bitPtr;
const result = this.bytes.subarray(bytePtr, bytePtr + n);
if (movePointers) {
this.bytePtr += n;
}
return result;
}
/**
* @param {number} n The number of bytes to read.
* @return {Uint8Array} The subarray.
*/
readBytes(n) {
return this.peekBytes(n, true);
}
}
// mask for getting N number of bits (0-8)
bitjs.io.BitStream.BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF ];
//importScripts('../io/bytebuffer.js');
//
/*
* bytestream.js
*
* Provides a writer for bytes.
*
* Licensed under the MIT License
*
* Copyright(c) 2011 Google Inc.
* Copyright(c) 2011 antimatter15
*/
var bitjs = bitjs || {};
bitjs.io = bitjs.io || {};
/**
* A write-only Byte buffer which uses a Uint8 Typed Array as a backing store.
*/
bitjs.io.ByteBuffer = class {
/**
* @param {number} numBytes The number of bytes to allocate.
*/
constructor(numBytes) {
if (typeof numBytes != typeof 1 || numBytes <= 0) {
throw "Error! ByteBuffer initialized with '" + numBytes + "'";
}
this.data = new Uint8Array(numBytes);
this.ptr = 0;
}
/**
* @param {number} b The byte to insert.
*/
insertByte(b) {
// TODO: throw if byte is invalid?
this.data[this.ptr++] = b;
}
/**
* @param {Array.<number>|Uint8Array|Int8Array} bytes The bytes to insert.
*/
insertBytes(bytes) {
// TODO: throw if bytes is invalid?
this.data.set(bytes, this.ptr);
this.ptr += bytes.length;
}
/**
* Writes an unsigned number into the next n bytes. If the number is too large
* to fit into n bytes or is negative, an error is thrown.
* @param {number} num The unsigned number to write.
* @param {number} numBytes The number of bytes to write the number into.
*/
writeNumber(num, numBytes) {
if (numBytes < 1) {
throw 'Trying to write into too few bytes: ' + numBytes;
}
if (num < 0) {
throw 'Trying to write a negative number (' + num +
') as an unsigned number to an ArrayBuffer';
}
if (num > (Math.pow(2, numBytes * 8) - 1)) {
throw 'Trying to write ' + num + ' into only ' + numBytes + ' bytes';
}
// Roll 8-bits at a time into an array of bytes.
const bytes = [];
while (numBytes-- > 0) {
const eightBits = num & 255;
bytes.push(eightBits);
num >>= 8;
}
this.insertBytes(bytes);
}
/**
* Writes a signed number into the next n bytes. If the number is too large
* to fit into n bytes, an error is thrown.
* @param {number} num The signed number to write.
* @param {number} numBytes The number of bytes to write the number into.
*/
writeSignedNumber(num, numBytes) {
if (numBytes < 1) {
throw 'Trying to write into too few bytes: ' + numBytes;
}
const HALF = Math.pow(2, (numBytes * 8) - 1);
if (num >= HALF || num < -HALF) {
throw 'Trying to write ' + num + ' into only ' + numBytes + ' bytes';
}
// Roll 8-bits at a time into an array of bytes.
const bytes = [];
while (numBytes-- > 0) {
const eightBits = num & 255;
bytes.push(eightBits);
num >>= 8;
}
this.insertBytes(bytes);
}
/**
* @param {string} str The ASCII string to write.
*/
writeASCIIString(str) {
for (let i = 0; i < str.length; ++i) {
const curByte = str.charCodeAt(i);
if (curByte < 0 || curByte > 255) {
throw 'Trying to write a non-ASCII string!';
}
this.insertByte(curByte);
}
};
}
//importScripts('../io/bytestream.js');
//
/*
* bytestream.js
*
* Provides readers for byte streams.
*
* Licensed under the MIT License
*
* Copyright(c) 2011 Google Inc.
* Copyright(c) 2011 antimatter15
*/
var bitjs = bitjs || {};
bitjs.io = bitjs.io || {};
/**
* This object allows you to peek and consume bytes as numbers and strings
* out of an ArrayBuffer. In this buffer, everything must be byte-aligned.
*/
bitjs.io.ByteStream = class {
/**
* @param {ArrayBuffer} ab The ArrayBuffer object.
* @param {number=} opt_offset The offset into the ArrayBuffer
* @param {number=} opt_length The length of this BitStream
*/
constructor(ab, opt_offset, opt_length) {
const offset = opt_offset || 0;
const length = opt_length || ab.byteLength;
this.bytes = new Uint8Array(ab, offset, length);
this.ptr = 0;
}
/**
* Peeks at the next n bytes as an unsigned number but does not advance the
* pointer
* TODO: This apparently cannot read more than 4 bytes as a number?
* @param {number} n The number of bytes to peek at.
* @return {number} The n bytes interpreted as an unsigned number.
*/
peekNumber(n) {
// TODO: return error if n would go past the end of the stream?
if (n <= 0 || typeof n != typeof 1) {
return -1;
}
let result = 0;
// read from last byte to first byte and roll them in
let curByte = this.ptr + n - 1;
while (curByte >= this.ptr) {
result <<= 8;
result |= this.bytes[curByte];
--curByte;
}
return result;
}
/**
* Returns the next n bytes as an unsigned number (or -1 on error)
* and advances the stream pointer n bytes.
* @param {number} n The number of bytes to read.
* @return {number} The n bytes interpreted as an unsigned number.
*/
readNumber(n) {
const num = this.peekNumber( n );
this.ptr += n;
return num;
}
/**
* Returns the next n bytes as a signed number but does not advance the
* pointer.
* @param {number} n The number of bytes to read.
* @return {number} The bytes interpreted as a signed number.
*/
peekSignedNumber(n) {
let num = this.peekNumber(n);
const HALF = Math.pow(2, (n * 8) - 1);
const FULL = HALF * 2;
if (num >= HALF) num -= FULL;
return num;
}
/**
* Returns the next n bytes as a signed number and advances the stream pointer.
* @param {number} n The number of bytes to read.
* @return {number} The bytes interpreted as a signed number.
*/
readSignedNumber(n) {
const num = this.peekSignedNumber(n);
this.ptr += n;
return num;
}
/**
* This returns n bytes as a sub-array, advancing the pointer if movePointers
* is true.
* @param {number} n The number of bytes to read.
* @param {boolean} movePointers Whether to move the pointers.
* @return {Uint8Array} The subarray.
*/
peekBytes(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return null;
}
const result = this.bytes.subarray(this.ptr, this.ptr + n);
if (movePointers) {
this.ptr += n;
}
return result;
}
/**
* Reads the next n bytes as a sub-array.
* @param {number} n The number of bytes to read.
* @return {Uint8Array} The subarray.
*/
readBytes(n) {
return this.peekBytes(n, true);
}
/**
* Peeks at the next n bytes as a string but does not advance the pointer.
* @param {number} n The number of bytes to peek at.
* @return {string} The next n bytes as a string.
*/
peekString(n) {
if (n <= 0 || typeof n != typeof 1) {
return "";
}
let result = "";
for (let p = this.ptr, end = this.ptr + n; p < end; ++p) {
result += String.fromCharCode(this.bytes[p]);
}
return result;
}
/**
* Returns the next n bytes as an ASCII string and advances the stream pointer
* n bytes.
* @param {number} n The number of bytes to read.
* @return {string} The next n bytes as a string.
*/
readString(n) {
const strToReturn = this.peekString(n);
this.ptr += n;
return strToReturn;
}
}
//importScripts('archive.js');
//
/**
* archive.js
*
* Provides base functionality for unarchiving.
*
* Licensed under the MIT License
*
* Copyright(c) 2011 Google Inc.
*/
var bitjs = bitjs || {};
bitjs.archive = bitjs.archive || {};
/**
* An unarchive event.
*/
bitjs.archive.UnarchiveEvent = class {
/**
* @param {string} type The event type.
*/
constructor(type) {
/**
* The event type.
* @type {string}
*/
this.type = type;
}
}
/**
* The UnarchiveEvent types.
*/
bitjs.archive.UnarchiveEvent.Type = {
START: 'start',
PROGRESS: 'progress',
EXTRACT: 'extract',
FINISH: 'finish',
INFO: 'info',
ERROR: 'error'
};
/**
* Useful for passing info up to the client (for debugging).
*/
bitjs.archive.UnarchiveInfoEvent = class extends bitjs.archive.UnarchiveEvent {
/**
* @param {string} msg The info message.
*/
constructor(msg) {
super(bitjs.archive.UnarchiveEvent.Type.INFO);
/**
* The information message.
* @type {string}
*/
this.msg = msg;
}
}
/**
* An unrecoverable error has occured.
*/
bitjs.archive.UnarchiveErrorEvent = class extends bitjs.archive.UnarchiveEvent {
/**
* @param {string} msg The error message.
*/
constructor(msg) {
super(bitjs.archive.UnarchiveEvent.Type.ERROR);
/**
* The information message.
* @type {string}
*/
this.msg = msg;
}
}
/**
* Start event.
*/
bitjs.archive.UnarchiveStartEvent = class extends bitjs.archive.UnarchiveEvent {
constructor() {
super(bitjs.archive.UnarchiveEvent.Type.START);
}
}
/**
* Finish event.
*/
bitjs.archive.UnarchiveFinishEvent = class extends bitjs.archive.UnarchiveEvent {
constructor() {
super(bitjs.archive.UnarchiveEvent.Type.FINISH);
}
}
/**
* Progress event.
*/
bitjs.archive.UnarchiveProgressEvent = class extends bitjs.archive.UnarchiveEvent {
/**
* @param {string} currentFilename
* @param {number} currentFileNumber
* @param {number} currentBytesUnarchivedInFile
* @param {number} currentBytesUnarchived
* @param {number} totalUncompressedBytesInArchive
* @param {number} totalFilesInArchive
*/
constructor(currentFilename, currentFileNumber, currentBytesUnarchivedInFile,
currentBytesUnarchived, totalUncompressedBytesInArchive, totalFilesInArchive) {
super(bitjs.archive.UnarchiveEvent.Type.PROGRESS);
this.currentFilename = currentFilename;
this.currentFileNumber = currentFileNumber;
this.currentBytesUnarchivedInFile = currentBytesUnarchivedInFile;
this.totalFilesInArchive = totalFilesInArchive;
this.currentBytesUnarchived = currentBytesUnarchived;
this.totalUncompressedBytesInArchive = totalUncompressedBytesInArchive;
}
}
/**
* Extract event.
*/
bitjs.archive.UnarchiveExtractEvent = class extends bitjs.archive.UnarchiveEvent {
/**
* @param {UnarchivedFile} unarchivedFile
*/
constructor(unarchivedFile) {
super(bitjs.archive.UnarchiveEvent.Type.EXTRACT);
/**
* @type {UnarchivedFile}
*/
this.unarchivedFile = unarchivedFile;
}
}
/**
* All extracted files returned by an Unarchiver will implement
* the following interface:
*
* interface UnarchivedFile {
* string filename
* TypedArray fileData
* }
*
*/
/**
* Base class for all Unarchivers.
*/
bitjs.archive.Unarchiver = class {
/**
* @param {ArrayBuffer} arrayBuffer The Array Buffer.
* @param {string} opt_pathToBitJS Optional string for where the BitJS files are located.
*/
constructor(arrayBuffer, opt_pathToBitJS) {
/**
* The ArrayBuffer object.
* @type {ArrayBuffer}
* @protected
*/
this.ab = arrayBuffer;
/**
* The path to the BitJS files.
* @type {string}
* @private
*/
this.pathToBitJS_ = opt_pathToBitJS || '/';
/**
* A map from event type to an array of listeners.
* @type {Map.<string, Array>}
*/
this.listeners_ = {};
for (let type in bitjs.archive.UnarchiveEvent.Type) {
this.listeners_[bitjs.archive.UnarchiveEvent.Type[type]] = [];
}
/**
* Private web worker initialized during start().
* @type {Worker}
* @private
*/
this.worker_ = null;
}
/**
* This method must be overridden by the subclass to return the script filename.
* @return {string} The script filename.
* @protected.
*/
getScriptFileName() {
throw 'Subclasses of AbstractUnarchiver must overload getScriptFileName()';
}
/**
* Adds an event listener for UnarchiveEvents.
*
* @param {string} Event type.
* @param {function} An event handler function.
*/
addEventListener(type, listener) {
if (type in this.listeners_) {
if (this.listeners_[type].indexOf(listener) == -1) {
this.listeners_[type].push(listener);
}
}
}
/**
* Removes an event listener.
*
* @param {string} Event type.
* @param {EventListener|function} An event listener or handler function.
*/
removeEventListener(type, listener) {
if (type in this.listeners_) {
const index = this.listeners_[type].indexOf(listener);
if (index != -1) {
this.listeners_[type].splice(index, 1);
}
}
}
/**
* Receive an event and pass it to the listener functions.
*
* @param {bitjs.archive.UnarchiveEvent} e
* @private
*/
handleWorkerEvent_(e) {
if ((e instanceof bitjs.archive.UnarchiveEvent || e.type) &&
this.listeners_[e.type] instanceof Array) {
this.listeners_[e.type].forEach(function (listener) { listener(e) });
if (e.type == bitjs.archive.UnarchiveEvent.Type.FINISH) {
this.worker_.terminate();
}
} else {
console.log(e);
}
}
/**
* Starts the unarchive in a separate Web Worker thread and returns immediately.
*/
start() {
const me = this;
const scriptFileName = this.pathToBitJS_ + this.getScriptFileName();
if (scriptFileName) {
this.worker_ = new Worker(scriptFileName);
this.worker_.onerror = function(e) {
console.log('Worker error: message = ' + e.message);
throw e;
};
this.worker_.onmessage = function(e) {
if (typeof e.data == 'string') {
// Just log any strings the workers pump our way.
console.log(e.data);
} else {
// Assume that it is an UnarchiveEvent. Some browsers preserve the 'type'
// so that instanceof UnarchiveEvent returns true, but others do not.
me.handleWorkerEvent_(e.data);
}
};
this.worker_.postMessage({file: this.ab});
}
}
/**
* Terminates the Web Worker for this Unarchiver and returns immediately.
*/
stop() {
if (this.worker_) {
this.worker_.terminate();
}
}
}
/**
* Unzipper
*/
bitjs.archive.Unzipper = class extends bitjs.archive.Unarchiver {
constructor(arrayBuffer, opt_pathToBitJS) {
super(arrayBuffer, opt_pathToBitJS);
}
getScriptFileName() { return 'archive/unzip.js'; }
}
/**
* Unrarrer
*/
bitjs.archive.Unrarrer = class extends bitjs.archive.Unarchiver {
constructor(arrayBuffer, opt_pathToBitJS) {
super(arrayBuffer, opt_pathToBitJS);
}
getScriptFileName() { return 'archive/unrar.js'; }
}
/**
* Untarrer
* @extends {bitjs.archive.Unarchiver}
* @constructor
*/
bitjs.archive.Untarrer = class extends bitjs.archive.Unarchiver {
constructor(arrayBuffer, opt_pathToBitJS) {
super(arrayBuffer, opt_pathToBitJS);
}
getScriptFileName() { return 'archive/untar.js'; };
}
/**
* Factory method that creates an unarchiver based on the byte signature found
* in the arrayBuffer.
* @param {ArrayBuffer} ab
* @param {string=} opt_pathToBitJS Path to the unarchiver script files.
* @return {bitjs.archive.Unarchiver}
*/
bitjs.archive.GetUnarchiver = function(ab, opt_pathToBitJS) {
let unarchiver = null;
const pathToBitJS = opt_pathToBitJS || '';
const h = new Uint8Array(ab, 0, 10);
if (h[0] == 0x52 && h[1] == 0x61 && h[2] == 0x72 && h[3] == 0x21) { // Rar!
unarchiver = new bitjs.archive.Unrarrer(ab, pathToBitJS);
} else if (h[0] == 0x50 && h[1] == 0x4B) { // PK (Zip)
unarchiver = new bitjs.archive.Unzipper(ab, pathToBitJS);
} else { // Try with tar
unarchiver = new bitjs.archive.Untarrer(ab, pathToBitJS);
}
return unarchiver;
};
// Progress variables.
let currentFilename = "";
let currentFileNumber = 0;
let currentBytesUnarchivedInFile = 0;
let currentBytesUnarchived = 0;
let totalUncompressedBytesInArchive = 0;
let totalFilesInArchive = 0;
// Helper functions.
const info = function(str) {
postMessage(new bitjs.archive.UnarchiveInfoEvent(str));
};
const err = function(str) {
postMessage(new bitjs.archive.UnarchiveErrorEvent(str));
};
const postProgress = function() {
postMessage(new bitjs.archive.UnarchiveProgressEvent(
currentFilename,
currentFileNumber,
currentBytesUnarchivedInFile,
currentBytesUnarchived,
totalUncompressedBytesInArchive,
totalFilesInArchive));
};
const zLocalFileHeaderSignature = 0x04034b50;
const zArchiveExtraDataSignature = 0x08064b50;
const zCentralFileHeaderSignature = 0x02014b50;
const zDigitalSignatureSignature = 0x05054b50;
const zEndOfCentralDirSignature = 0x06064b50;
const zEndOfCentralDirLocatorSignature = 0x07064b50;
// mask for getting the Nth bit (zero-based)
const BIT = [ 0x01, 0x02, 0x04, 0x08,
0x10, 0x20, 0x40, 0x80,
0x100, 0x200, 0x400, 0x800,
0x1000, 0x2000, 0x4000, 0x8000];
class ZipLocalFile {
// takes a ByteStream and parses out the local file information
constructor(bstream) {
if (typeof bstream != typeof {} || !bstream.readNumber || typeof bstream.readNumber != typeof function(){}) {
return null;
}
bstream.readNumber(4); // swallow signature
this.version = bstream.readNumber(2);
this.generalPurpose = bstream.readNumber(2);
this.compressionMethod = bstream.readNumber(2);
this.lastModFileTime = bstream.readNumber(2);
this.lastModFileDate = bstream.readNumber(2);
this.crc32 = bstream.readNumber(4);
this.compressedSize = bstream.readNumber(4);
this.uncompressedSize = bstream.readNumber(4);
this.fileNameLength = bstream.readNumber(2);
this.extraFieldLength = bstream.readNumber(2);
this.filename = null;
if (this.fileNameLength > 0) {
this.filename = bstream.readString(this.fileNameLength);
}
info("Zip Local File Header:");
info(" version=" + this.version);
info(" general purpose=" + this.generalPurpose);
info(" compression method=" + this.compressionMethod);
info(" last mod file time=" + this.lastModFileTime);
info(" last mod file date=" + this.lastModFileDate);
info(" crc32=" + this.crc32);
info(" compressed size=" + this.compressedSize);
info(" uncompressed size=" + this.uncompressedSize);
info(" file name length=" + this.fileNameLength);
info(" extra field length=" + this.extraFieldLength);
info(" filename = '" + this.filename + "'");
this.extraField = null;
if (this.extraFieldLength > 0) {
this.extraField = bstream.readString(this.extraFieldLength);
info(" extra field=" + this.extraField);
}
// read in the compressed data
this.fileData = null;
if (this.compressedSize > 0) {
this.fileData = new Uint8Array(bstream.readBytes(this.compressedSize));
}
// TODO: deal with data descriptor if present (we currently assume no data descriptor!)
// "This descriptor exists only if bit 3 of the general purpose bit flag is set"
// But how do you figure out how big the file data is if you don't know the compressedSize
// from the header?!?
if ((this.generalPurpose & BIT[3]) != 0) {
this.crc32 = bstream.readNumber(4);
this.compressedSize = bstream.readNumber(4);
this.uncompressedSize = bstream.readNumber(4);
}
}
// determine what kind of compressed data we have and decompress
unzip() {
// Zip Version 1.0, no compression (store only)
if (this.compressionMethod == 0 ) {
info("ZIP v"+this.version+", store only: " + this.filename + " (" + this.compressedSize + " bytes)");
currentBytesUnarchivedInFile = this.compressedSize;
currentBytesUnarchived += this.compressedSize;
}
// version == 20, compression method == 8 (DEFLATE)
else if (this.compressionMethod == 8) {
info("ZIP v2.0, DEFLATE: " + this.filename + " (" + this.compressedSize + " bytes)");
this.fileData = inflate(this.fileData, this.uncompressedSize);
}
else {
err("UNSUPPORTED VERSION/FORMAT: ZIP v" + this.version + ", compression method=" + this.compressionMethod + ": " + this.filename + " (" + this.compressedSize + " bytes)");
this.fileData = null;
}
}
}
// Takes an ArrayBuffer of a zip file in
// returns null on error
// returns an array of DecompressedFile objects on success
const unzip = function(arrayBuffer) {
postMessage(new bitjs.archive.UnarchiveStartEvent());
currentFilename = "";
currentFileNumber = 0;
currentBytesUnarchivedInFile = 0;
currentBytesUnarchived = 0;
totalUncompressedBytesInArchive = 0;
totalFilesInArchive = 0;
currentBytesUnarchived = 0;
const bstream = new bitjs.io.ByteStream(arrayBuffer);
// detect local file header signature or return null
if (bstream.peekNumber(4) == zLocalFileHeaderSignature) {
const localFiles = [];
// loop until we don't see any more local files
while (bstream.peekNumber(4) == zLocalFileHeaderSignature) {
const oneLocalFile = new ZipLocalFile(bstream);
// this should strip out directories/folders
if (oneLocalFile && oneLocalFile.uncompressedSize > 0 && oneLocalFile.fileData) {
localFiles.push(oneLocalFile);
totalUncompressedBytesInArchive += oneLocalFile.uncompressedSize;
}
}
totalFilesInArchive = localFiles.length;
// got all local files, now sort them
localFiles.sort((a,b) => a.filename > b.filename ? 1 : -1);
// archive extra data record
if (bstream.peekNumber(4) == zArchiveExtraDataSignature) {
info(" Found an Archive Extra Data Signature");
// skipping this record for now
bstream.readNumber(4);
const archiveExtraFieldLength = bstream.readNumber(4);
bstream.readString(archiveExtraFieldLength);
}
// central directory structure
// TODO: handle the rest of the structures (Zip64 stuff)
if (bstream.peekNumber(4) == zCentralFileHeaderSignature) {
info(" Found a Central File Header");
// read all file headers
while (bstream.peekNumber(4) == zCentralFileHeaderSignature) {
bstream.readNumber(4); // signature
bstream.readNumber(2); // version made by
bstream.readNumber(2); // version needed to extract
bstream.readNumber(2); // general purpose bit flag
bstream.readNumber(2); // compression method
bstream.readNumber(2); // last mod file time
bstream.readNumber(2); // last mod file date
bstream.readNumber(4); // crc32
bstream.readNumber(4); // compressed size
bstream.readNumber(4); // uncompressed size
const fileNameLength = bstream.readNumber(2); // file name length
const extraFieldLength = bstream.readNumber(2); // extra field length
const fileCommentLength = bstream.readNumber(2); // file comment length
bstream.readNumber(2); // disk number start
bstream.readNumber(2); // internal file attributes
bstream.readNumber(4); // external file attributes
bstream.readNumber(4); // relative offset of local header
bstream.readString(fileNameLength); // file name
bstream.readString(extraFieldLength); // extra field
bstream.readString(fileCommentLength); // file comment
}
}
// digital signature
if (bstream.peekNumber(4) == zDigitalSignatureSignature) {
info(" Found a Digital Signature");
bstream.readNumber(4);
const sizeOfSignature = bstream.readNumber(2);
bstream.readString(sizeOfSignature); // digital signature data
}
// report # files and total length
if (localFiles.length > 0) {
postProgress();
}
// now do the unzipping of each file
for (let i = 0; i < localFiles.length; ++i) {
const localfile = localFiles[i];
// update progress
currentFilename = localfile.filename;
currentFileNumber = i;
currentBytesUnarchivedInFile = 0;
// actually do the unzipping
localfile.unzip();
if (localfile.fileData != null) {
postMessage(new bitjs.archive.UnarchiveExtractEvent(localfile));
postProgress();
}
}
postProgress();
postMessage(new bitjs.archive.UnarchiveFinishEvent());
}
}
// returns a table of Huffman codes
// each entry's index is its code and its value is a JavaScript object
// containing {length: 6, symbol: X}
function getHuffmanCodes(bitLengths) {
// ensure bitLengths is an array containing at least one element
if (typeof bitLengths != typeof [] || bitLengths.length < 1) {
err("Error! getHuffmanCodes() called with an invalid array");
return null;
}
// Reference: http://tools.ietf.org/html/rfc1951#page-8
const numLengths = bitLengths.length;
const bl_count = [];
let MAX_BITS = 1;
// Step 1: count up how many codes of each length we have
for (let i = 0; i < numLengths; ++i) {
const length = bitLengths[i];
// test to ensure each bit length is a positive, non-zero number
if (typeof length != typeof 1 || length < 0) {
err("bitLengths contained an invalid number in getHuffmanCodes(): " + length + " of type " + (typeof length));
return null;
}
// increment the appropriate bitlength count
if (bl_count[length] == undefined) bl_count[length] = 0;
// a length of zero means this symbol is not participating in the huffman coding
if (length > 0) bl_count[length]++;
if (length > MAX_BITS) MAX_BITS = length;
}
// Step 2: Find the numerical value of the smallest code for each code length
const next_code = [];
let code = 0;
for (let bits = 1; bits <= MAX_BITS; ++bits) {
const length = bits-1;
// ensure undefined lengths are zero
if (bl_count[length] == undefined) bl_count[length] = 0;
code = (code + bl_count[bits-1]) << 1;
next_code[bits] = code;
}
// Step 3: Assign numerical values to all codes
const table = {};
let tableLength = 0;
for (let n = 0; n < numLengths; ++n) {
const len = bitLengths[n];
if (len != 0) {
table[next_code[len]] = { length: len, symbol: n }; //, bitstring: binaryValueToString(next_code[len],len) };
tableLength++;
next_code[len]++;
}
}
table.maxLength = tableLength;
return table;
}
/*
The Huffman codes for the two alphabets are fixed, and are not
represented explicitly in the data. The Huffman code lengths
for the literal/length alphabet are:
Lit Value Bits Codes
--------- ---- -----
0 - 143 8 00110000 through
10111111
144 - 255 9 110010000 through
111111111
256 - 279 7 0000000 through
0010111
280 - 287 8 11000000 through
11000111
*/
// fixed Huffman codes go from 7-9 bits, so we need an array whose index can hold up to 9 bits
let fixedHCtoLiteral = null;
let fixedHCtoDistance = null;
function getFixedLiteralTable() {
// create once
if (!fixedHCtoLiteral) {
const bitlengths = new Array(288);
for (let i = 0; i <= 143; ++i) bitlengths[i] = 8;
for (let i = 144; i <= 255; ++i) bitlengths[i] = 9;
for (let i = 256; i <= 279; ++i) bitlengths[i] = 7;
for (let i = 280; i <= 287; ++i) bitlengths[i] = 8;
// get huffman code table
fixedHCtoLiteral = getHuffmanCodes(bitlengths);
}
return fixedHCtoLiteral;
}
function getFixedDistanceTable() {
// create once
if (!fixedHCtoDistance) {
const bitlengths = new Array(32);
for (let i = 0; i < 32; ++i) { bitlengths[i] = 5; }
// get huffman code table
fixedHCtoDistance = getHuffmanCodes(bitlengths);
}
return fixedHCtoDistance;
}
// extract one bit at a time until we find a matching Huffman Code
// then return that symbol
function decodeSymbol(bstream, hcTable) {
let code = 0;
let len = 0;
let match = false;
// loop until we match
for (;;) {
// read in next bit
const bit = bstream.readBits(1);
code = (code<<1) | bit;
++len;
// check against Huffman Code table and break if found
if (hcTable.hasOwnProperty(code) && hcTable[code].length == len) {
break;
}
if (len > hcTable.maxLength) {
err("Bit stream out of sync, didn't find a Huffman Code, length was " + len +
" and table only max code length of " + hcTable.maxLength);
break;
}
}
return hcTable[code].symbol;
}
const CodeLengthCodeOrder = [16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15];
/*
Extra Extra Extra
Code Bits Length(s) Code Bits Lengths Code Bits Length(s)
---- ---- ------ ---- ---- ------- ---- ---- -------
257 0 3 267 1 15,16 277 4 67-82
258 0 4 268 1 17,18 278 4 83-98
259 0 5 269 2 19-22 279 4 99-114
260 0 6 270 2 23-26 280 4 115-130
261 0 7 271 2 27-30 281 5 131-162
262 0 8 272 2 31-34 282 5 163-194
263 0 9 273 3 35-42 283 5 195-226
264 0 10 274 3 43-50 284 5 227-257
265 1 11,12 275 3 51-58 285 0 258
266 1 13,14 276 3 59-66
*/
const LengthLookupTable = [
[0,3], [0,4], [0,5], [0,6],
[0,7], [0,8], [0,9], [0,10],
[1,11], [1,13], [1,15], [1,17],
[2,19], [2,23], [2,27], [2,31],
[3,35], [3,43], [3,51], [3,59],
[4,67], [4,83], [4,99], [4,115],
[5,131], [5,163], [5,195], [5,227],
[0,258]
];
/*
Extra Extra Extra
Code Bits Dist Code Bits Dist Code Bits Distance
---- ---- ---- ---- ---- ------ ---- ---- --------
0 0 1 10 4 33-48 20 9 1025-1536
1 0 2 11 4 49-64 21 9 1537-2048
2 0 3 12 5 65-96 22 10 2049-3072
3 0 4 13 5 97-128 23 10 3073-4096
4 1 5,6 14 6 129-192 24 11 4097-6144
5 1 7,8 15 6 193-256 25 11 6145-8192
6 2 9-12 16 7 257-384 26 12 8193-12288
7 2 13-16 17 7 385-512 27 12 12289-16384
8 3 17-24 18 8 513-768 28 13 16385-24576
9 3 25-32 19 8 769-1024 29 13 24577-32768
*/
const DistLookupTable = [
[0,1], [0,2], [0,3], [0,4],
[1,5], [1,7],
[2,9], [2,13],
[3,17], [3,25],
[4,33], [4,49],
[5,65], [5,97],
[6,129], [6,193],
[7,257], [7,385],
[8,513], [8,769],
[9,1025], [9,1537],
[10,2049], [10,3073],
[11,4097], [11,6145],
[12,8193], [12,12289],
[13,16385], [13,24577]
];
function inflateBlockData(bstream, hcLiteralTable, hcDistanceTable, buffer) {
/*
loop (until end of block code recognized)
decode literal/length value from input stream
if value < 256
copy value (literal byte) to output stream
otherwise
if value = end of block (256)
break from loop
otherwise (value = 257..285)
decode distance from input stream
move backwards distance bytes in the output
stream, and copy length bytes from this
position to the output stream.
*/
let numSymbols = 0;
let blockSize = 0;
for (;;) {
const symbol = decodeSymbol(bstream, hcLiteralTable);
++numSymbols;
if (symbol < 256) {
// copy literal byte to output
buffer.insertByte(symbol);
blockSize++;
} else {
// end of block reached
if (symbol == 256) {
break;
} else {
const lengthLookup = LengthLookupTable[symbol - 257];
let length = lengthLookup[1] + bstream.readBits(lengthLookup[0]);
const distLookup = DistLookupTable[decodeSymbol(bstream, hcDistanceTable)];
let distance = distLookup[1] + bstream.readBits(distLookup[0]);
// now apply length and distance appropriately and copy to output
// TODO: check that backward distance < data.length?
// http://tools.ietf.org/html/rfc1951#page-11
// "Note also that the referenced string may overlap the current
// position; for example, if the last 2 bytes decoded have values
// X and Y, a string reference with <length = 5, distance = 2>
// adds X,Y,X,Y,X to the output stream."
//
// loop for each character
let ch = buffer.ptr - distance;
blockSize += length;
if(length > distance) {
const data = buffer.data;
while (length--) {
buffer.insertByte(data[ch++]);
}
} else {
buffer.insertBytes(buffer.data.subarray(ch, ch + length))
}
} // length-distance pair
} // length-distance pair or end-of-block
} // loop until we reach end of block
return blockSize;
}
// {Uint8Array} compressedData A Uint8Array of the compressed file data.
// compression method 8
// deflate: http://tools.ietf.org/html/rfc1951
function inflate(compressedData, numDecompressedBytes) {
// Bit stream representing the compressed data.
const bstream = new bitjs.io.BitStream(compressedData.buffer,
false /* rtl */,
compressedData.byteOffset,
compressedData.byteLength);
const buffer = new bitjs.io.ByteBuffer(numDecompressedBytes);
let numBlocks = 0;
let blockSize = 0;
// block format: http://tools.ietf.org/html/rfc1951#page-9
let bFinal = 0;
do {
bFinal = bstream.readBits(1);
let bType = bstream.readBits(2);
blockSize = 0;
++numBlocks;
// no compression
if (bType == 0) {
// skip remaining bits in this byte
while (bstream.bitPtr != 0) bstream.readBits(1);
const len = bstream.readBits(16);
const nlen = bstream.readBits(16);
// TODO: check if nlen is the ones-complement of len?
if (len > 0) buffer.insertBytes(bstream.readBytes(len));
blockSize = len;
}
// fixed Huffman codes
else if(bType == 1) {
blockSize = inflateBlockData(bstream, getFixedLiteralTable(), getFixedDistanceTable(), buffer);
}
// dynamic Huffman codes
else if(bType == 2) {
const numLiteralLengthCodes = bstream.readBits(5) + 257;
const numDistanceCodes = bstream.readBits(5) + 1;
const numCodeLengthCodes = bstream.readBits(4) + 4;
// populate the array of code length codes (first de-compaction)
const codeLengthsCodeLengths = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];
for (let i = 0; i < numCodeLengthCodes; ++i) {
codeLengthsCodeLengths[ CodeLengthCodeOrder[i] ] = bstream.readBits(3);
}
// get the Huffman Codes for the code lengths
const codeLengthsCodes = getHuffmanCodes(codeLengthsCodeLengths);
// now follow this mapping
/*
0 - 15: Represent code lengths of 0 - 15
16: Copy the previous code length 3 - 6 times.
The next 2 bits indicate repeat length
(0 = 3, ... , 3 = 6)
Example: Codes 8, 16 (+2 bits 11),
16 (+2 bits 10) will expand to
12 code lengths of 8 (1 + 6 + 5)
17: Repeat a code length of 0 for 3 - 10 times.
(3 bits of length)
18: Repeat a code length of 0 for 11 - 138 times
(7 bits of length)
*/
// to generate the true code lengths of the Huffman Codes for the literal
// and distance tables together
const literalCodeLengths = [];
let prevCodeLength = 0;
while (literalCodeLengths.length < numLiteralLengthCodes + numDistanceCodes) {
const symbol = decodeSymbol(bstream, codeLengthsCodes);
if (symbol <= 15) {
literalCodeLengths.push(symbol);
prevCodeLength = symbol;
} else if (symbol == 16) {
let repeat = bstream.readBits(2) + 3;
while (repeat--) {
literalCodeLengths.push(prevCodeLength);
}
} else if (symbol == 17) {
let repeat = bstream.readBits(3) + 3;
while (repeat--) {
literalCodeLengths.push(0);
}
} else if (symbol == 18) {
let repeat = bstream.readBits(7) + 11;
while (repeat--) {
literalCodeLengths.push(0);
}
}
}
// now split the distance code lengths out of the literal code array
const distanceCodeLengths = literalCodeLengths.splice(numLiteralLengthCodes, numDistanceCodes);
// now generate the true Huffman Code tables using these code lengths
const hcLiteralTable = getHuffmanCodes(literalCodeLengths);
const hcDistanceTable = getHuffmanCodes(distanceCodeLengths);
blockSize = inflateBlockData(bstream, hcLiteralTable, hcDistanceTable, buffer);
} else { // error
err("Error! Encountered deflate block of type 3");
return null;
}
// update progress
currentBytesUnarchivedInFile += blockSize;
currentBytesUnarchived += blockSize;
postProgress();
} while (bFinal != 1);
// we are done reading blocks if the bFinal bit was set for this block
// return the buffer data bytes
return buffer.data;
}
// event.data.file has the ArrayBuffer.
onmessage = function(event) {
unzip(event.data.file, true);
};
Reference in New Issue View Git Blame Copy Permalink