mirror of
https://github.com/codedread/bitjs
synced 2025-10-03 17:49:16 +02:00
772 lines
27 KiB
JavaScript
772 lines
27 KiB
JavaScript
/**
|
|
* 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).
|
|
importScripts('../io/bitstream-worker.js');
|
|
importScripts('../io/bytebuffer-worker.js');
|
|
importScripts('../io/bytestream-worker.js');
|
|
|
|
const UnarchiveState = {
|
|
NOT_STARTED: 0,
|
|
UNARCHIVING: 1,
|
|
WAITING: 2,
|
|
FINISHED: 3,
|
|
};
|
|
|
|
// State - consider putting these into a class.
|
|
let unarchiveState = UnarchiveState.NOT_STARTED;
|
|
let bytestream = null;
|
|
let allLocalFiles = null;
|
|
let logToConsole = false;
|
|
|
|
// 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({ type: 'info', msg: str });
|
|
};
|
|
const err = function (str) {
|
|
postMessage({ type: 'error', msg: str });
|
|
};
|
|
const postProgress = function () {
|
|
postMessage({
|
|
type: 'progress',
|
|
currentFilename,
|
|
currentFileNumber,
|
|
currentBytesUnarchivedInFile,
|
|
currentBytesUnarchived,
|
|
totalUncompressedBytesInArchive,
|
|
totalFilesInArchive,
|
|
totalCompressedBytesRead: bytestream.getNumBytesRead(),
|
|
});
|
|
};
|
|
|
|
const zLocalFileHeaderSignature = 0x04034b50;
|
|
const zArchiveExtraDataSignature = 0x08064b50;
|
|
const zCentralFileHeaderSignature = 0x02014b50;
|
|
const zDigitalSignatureSignature = 0x05054b50;
|
|
const zEndOfCentralDirSignature = 0x06054b50;
|
|
const zEndOfCentralDirLocatorSignature = 0x07064b50;
|
|
const zDataDescriptorSignature = 0x08074b50;
|
|
|
|
// 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);
|
|
}
|
|
|
|
this.extraField = null;
|
|
if (this.extraFieldLength > 0) {
|
|
this.extraField = bstream.readString(this.extraFieldLength);
|
|
}
|
|
|
|
// Data descriptor is present if this bit is set, compressed size should be zero.
|
|
this.hasDataDescriptor = ((this.generalPurpose & BIT[3]) !== 0);
|
|
if (this.hasDataDescriptor &&
|
|
(this.crc32 !== 0 || this.compressedSize !== 0 || this.uncompressedSize !== 0)) {
|
|
err('Zip local file with a data descriptor and non-zero crc/compressedSize/uncompressedSize');
|
|
}
|
|
|
|
// Read in the compressed data if we have no data descriptor.
|
|
/** @type {Uint8Array} */
|
|
this.fileData = null;
|
|
let descriptorSize = 0;
|
|
if (this.hasDataDescriptor) {
|
|
// Hold on to a reference to the bstream, since that is where the compressed file data begins.
|
|
let savedBstream = bstream.tee();
|
|
|
|
// Seek ahead one byte at a time, looking for the next local file header signature or the end
|
|
// of all local files.
|
|
let foundDataDescriptor = false;
|
|
let numBytesSeeked = 0;
|
|
while (!foundDataDescriptor) {
|
|
while (bstream.peekNumber(4) !== zLocalFileHeaderSignature &&
|
|
bstream.peekNumber(4) !== zArchiveExtraDataSignature &&
|
|
bstream.peekNumber(4) !== zCentralFileHeaderSignature) {
|
|
numBytesSeeked++;
|
|
bstream.readBytes(1);
|
|
}
|
|
|
|
// Copy all the read bytes into a buffer and examine the last 16 bytes to see if they are the
|
|
// data descriptor.
|
|
let bufferedByteArr = savedBstream.peekBytes(numBytesSeeked);
|
|
const descriptorStream = new bitjs.io.ByteStream(bufferedByteArr.buffer, numBytesSeeked - 16, 16);
|
|
const maybeDescriptorSig = descriptorStream.readNumber(4);
|
|
const maybeCrc32 = descriptorStream.readNumber(4);
|
|
const maybeCompressedSize = descriptorStream.readNumber(4);
|
|
const maybeUncompressedSize = descriptorStream.readNumber(4);
|
|
|
|
// From the PKZIP App Note: "The signature value 0x08074b50 is also used by some ZIP
|
|
// implementations as a marker for the Data Descriptor record".
|
|
if (maybeDescriptorSig === zDataDescriptorSignature) {
|
|
if (maybeCompressedSize === (numBytesSeeked - 16)) {
|
|
foundDataDescriptor = true;
|
|
descriptorSize = 16;
|
|
}
|
|
} else if (maybeCompressedSize === (numBytesSeeked - 12)) {
|
|
foundDataDescriptor = true;
|
|
descriptorSize = 12;
|
|
}
|
|
|
|
if (foundDataDescriptor) {
|
|
this.crc32 = maybeCrc32;
|
|
this.compressedSize = maybeCompressedSize;
|
|
this.uncompressedSize = maybeUncompressedSize;
|
|
}
|
|
}
|
|
bstream = savedBstream;
|
|
}
|
|
|
|
this.fileData = new Uint8Array(bstream.readBytes(this.compressedSize));
|
|
bstream.readBytes(descriptorSize);
|
|
|
|
// Now that we have all the bytes for this file, we can print out some information.
|
|
if (logToConsole) {
|
|
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}'`);
|
|
info(` hasDataDescriptor = ${this.hasDataDescriptor}`);
|
|
}
|
|
}
|
|
|
|
// determine what kind of compressed data we have and decompress
|
|
unzip() {
|
|
if (!this.fileData) {
|
|
err('unzip() called on a file with out compressed file data');
|
|
}
|
|
|
|
// Zip Version 1.0, no compression (store only)
|
|
if (this.compressionMethod == 0) {
|
|
if (logToConsole) {
|
|
info(`ZIP v${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) {
|
|
if (logToConsole) {
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @typedef SymbolLengthPair
|
|
* @property {number} length
|
|
* @property {number} symbol
|
|
*/
|
|
|
|
/**
|
|
* Returns a table of Huffman codes. Each entry's key is its code and its value is a JavaScript
|
|
* object containing {length: 6, symbol: X}.
|
|
* @param {number[]} bitLengths
|
|
* @returns {Map<number, SymbolLengthPair>}
|
|
*/
|
|
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
|
|
/** @type Map<number, SymbolLengthPair> */
|
|
const table = new Map();
|
|
for (let n = 0; n < numLengths; ++n) {
|
|
const len = bitLengths[n];
|
|
if (len != 0) {
|
|
table.set(next_code[len], { length: len, symbol: n }); //, bitstring: binaryValueToString(next_code[len],len) };
|
|
next_code[len]++;
|
|
}
|
|
}
|
|
|
|
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;
|
|
/** @returns {Map<number, SymbolLengthPair>} */
|
|
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;
|
|
}
|
|
|
|
/** @returns {Map<number, SymbolLengthPair>} */
|
|
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.
|
|
* @param {bitjs.io.BitStream} bstream
|
|
* @param {Map<number, SymbolLengthPair>} hcTable
|
|
* @returns {number}
|
|
*/
|
|
function decodeSymbol(bstream, hcTable) {
|
|
let code = 0;
|
|
let len = 0;
|
|
|
|
// 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.has(code) && hcTable.get(code).length == len) {
|
|
break;
|
|
}
|
|
if (len > hcTable.length) {
|
|
err(`Bit stream out of sync, didn't find a Huffman Code, length was ${len} ` +
|
|
`and table only max code length of ${hcTable.length}`);
|
|
break;
|
|
}
|
|
}
|
|
return hcTable.get(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]
|
|
];
|
|
|
|
/**
|
|
* @param {bitjs.io.BitStream} bstream
|
|
* @param {Map<number, SymbolLengthPair>} hcLiteralTable
|
|
* @param {Map<number, SymbolLengthPair>} hcDistanceTable
|
|
* @param {bitjs.io.ByteBuffer} buffer
|
|
* @returns
|
|
*/
|
|
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 blockSize = 0;
|
|
for (; ;) {
|
|
const symbol = decodeSymbol(bstream, hcLiteralTable);
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* Compression method 8. Deflate: http://tools.ietf.org/html/rfc1951
|
|
* @param {Uint8Array} compressedData A Uint8Array of the compressed file data.
|
|
* @param {number} numDecompressedBytes
|
|
* @returns {Uint8Array} The decompressed array.
|
|
*/
|
|
function inflate(compressedData, numDecompressedBytes) {
|
|
// Bit stream representing the compressed data.
|
|
/** @type {bitjs.io.BitStream} */
|
|
const bstream = new bitjs.io.BitStream(compressedData.buffer,
|
|
false /* rtl */,
|
|
compressedData.byteOffset,
|
|
compressedData.byteLength);
|
|
/** @type {bitjs.io.ByteBuffer} */
|
|
const buffer = new bitjs.io.ByteBuffer(numDecompressedBytes);
|
|
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;
|
|
// 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;
|
|
const maxCodeLengths = numLiteralLengthCodes + numDistanceCodes;
|
|
while (literalCodeLengths.length < maxCodeLengths) {
|
|
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;
|
|
}
|
|
|
|
function archiveUnzip() {
|
|
let bstream = bytestream.tee();
|
|
|
|
// loop until we don't see any more local files or we find a data descriptor.
|
|
while (bstream.peekNumber(4) == zLocalFileHeaderSignature) {
|
|
// Note that this could throw an error if the bstream overflows, which is caught in the
|
|
// message handler.
|
|
const oneLocalFile = new ZipLocalFile(bstream);
|
|
// this should strip out directories/folders
|
|
if (oneLocalFile && oneLocalFile.uncompressedSize > 0 && oneLocalFile.fileData) {
|
|
// If we make it to this point and haven't thrown an error, we have successfully
|
|
// read in the data for a local file, so we can update the actual bytestream.
|
|
bytestream = bstream.tee();
|
|
|
|
allLocalFiles.push(oneLocalFile);
|
|
totalUncompressedBytesInArchive += oneLocalFile.uncompressedSize;
|
|
|
|
// update progress
|
|
currentFilename = oneLocalFile.filename;
|
|
currentFileNumber = allLocalFiles.length - 1;
|
|
currentBytesUnarchivedInFile = 0;
|
|
|
|
// Actually do the unzipping.
|
|
oneLocalFile.unzip();
|
|
|
|
if (oneLocalFile.fileData != null) {
|
|
postMessage({ type: 'extract', unarchivedFile: oneLocalFile }, [oneLocalFile.fileData.buffer]);
|
|
postProgress();
|
|
}
|
|
}
|
|
}
|
|
totalFilesInArchive = allLocalFiles.length;
|
|
|
|
// archive extra data record
|
|
if (bstream.peekNumber(4) == zArchiveExtraDataSignature) {
|
|
if (logToConsole) {
|
|
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) {
|
|
if (logToConsole) {
|
|
info(' Found a Central File Header');
|
|
}
|
|
|
|
// read all file headers
|
|
while (bstream.peekNumber(4) == zCentralFileHeaderSignature) {
|
|
bstream.readNumber(4); // signature
|
|
const cdfh = {
|
|
versionMadeBy: bstream.readNumber(2),
|
|
versionNeededToExtract: bstream.readNumber(2),
|
|
generalPurposeBitFlag: bstream.readNumber(2),
|
|
compressionMethod: bstream.readNumber(2),
|
|
lastModFileTime: bstream.readNumber(2),
|
|
lastModFileDate: bstream.readNumber(2),
|
|
crc32: bstream.readNumber(4),
|
|
compressedSize: bstream.readNumber(4),
|
|
uncompressedSize: bstream.readNumber(4),
|
|
fileNameLength: bstream.readNumber(2),
|
|
extraFieldLength: bstream.readNumber(2),
|
|
fileCommentLength: bstream.readNumber(2),
|
|
diskNumberStart: bstream.readNumber(2),
|
|
internalFileAttributes: bstream.readNumber(2),
|
|
externalFileAttributes: bstream.readNumber(4),
|
|
relativeOffset: bstream.readNumber(4),
|
|
};
|
|
cdfh.fileName = bstream.readString(cdfh.fileNameLength);
|
|
cdfh.extraField = bstream.readString(cdfh.extraFieldLength);
|
|
cdfh.fileComment = bstream.readString(cdfh.fileCommentLength);
|
|
if (logToConsole) {
|
|
console.log('Central Directory File Header:');
|
|
for (const field in cdfh) {
|
|
console.log(` ${field} = ${cdfh[field]}`);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// digital signature
|
|
if (bstream.peekNumber(4) == zDigitalSignatureSignature) {
|
|
if (logToConsole) {
|
|
info(' Found a Digital Signature');
|
|
}
|
|
|
|
bstream.readNumber(4);
|
|
const sizeOfSignature = bstream.readNumber(2);
|
|
bstream.readString(sizeOfSignature); // digital signature data
|
|
}
|
|
|
|
let metadata = {};
|
|
if (bstream.peekNumber(4) == zEndOfCentralDirSignature) {
|
|
bstream.readNumber(4); // signature
|
|
const eocds = {
|
|
numberOfThisDisk: bstream.readNumber(2),
|
|
diskWhereCentralDirectoryStarts: bstream.readNumber(2),
|
|
numberOfCentralDirectoryRecordsOnThisDisk: bstream.readNumber(2),
|
|
totalNumberOfCentralDirectoryRecords: bstream.readNumber(2),
|
|
sizeOfCentralDirectory: bstream.readNumber(4),
|
|
offsetOfStartOfCentralDirectory: bstream.readNumber(4),
|
|
commentLength: bstream.readNumber(2),
|
|
};
|
|
eocds.comment = bstream.readString(eocds.commentLength);
|
|
if (logToConsole) {
|
|
console.log('End of Central Dir Signature:');
|
|
for (const field in eocds) {
|
|
console.log(` ${field} = ${eocds[field]}`);
|
|
}
|
|
}
|
|
metadata.comment = eocds.comment;
|
|
}
|
|
|
|
postProgress();
|
|
|
|
bytestream = bstream.tee();
|
|
|
|
unarchiveState = UnarchiveState.FINISHED;
|
|
postMessage({ type: 'finish', metadata });
|
|
}
|
|
|
|
// event.data.file has the first ArrayBuffer.
|
|
// event.data.bytes has all subsequent ArrayBuffers.
|
|
onmessage = function (event) {
|
|
const bytes = event.data.file || event.data.bytes;
|
|
logToConsole = !!event.data.logToConsole;
|
|
|
|
// This is the very first time we have been called. Initialize the bytestream.
|
|
if (!bytestream) {
|
|
bytestream = new bitjs.io.ByteStream(bytes);
|
|
} else {
|
|
bytestream.push(bytes);
|
|
// TODO: Shouldn't this return here if it's not waiting?
|
|
}
|
|
|
|
if (unarchiveState === UnarchiveState.NOT_STARTED) {
|
|
currentFilename = '';
|
|
currentFileNumber = 0;
|
|
currentBytesUnarchivedInFile = 0;
|
|
currentBytesUnarchived = 0;
|
|
totalUncompressedBytesInArchive = 0;
|
|
totalFilesInArchive = 0;
|
|
currentBytesUnarchived = 0;
|
|
allLocalFiles = [];
|
|
|
|
postMessage({ type: 'start' });
|
|
|
|
unarchiveState = UnarchiveState.UNARCHIVING;
|
|
|
|
postProgress();
|
|
}
|
|
|
|
if (unarchiveState === UnarchiveState.UNARCHIVING ||
|
|
unarchiveState === UnarchiveState.WAITING) {
|
|
try {
|
|
archiveUnzip();
|
|
} catch (e) {
|
|
if (typeof e === 'string' && e.startsWith('Error! Overflowed')) {
|
|
// Overrun the buffer.
|
|
unarchiveState = UnarchiveState.WAITING;
|
|
} else {
|
|
console.error('Found an error while unzipping');
|
|
console.dir(e);
|
|
throw e;
|
|
}
|
|
}
|
|
}
|
|
};
|