mirror of
https://github.com/codedread/bitjs
synced 2025-10-03 09:39:16 +02:00
Remove pushing and throwing errors from BitStream and update unit tests. Update unrar to use a ByteStream for the RAR file header (like unzip)
This commit is contained in:
codedread
parent
b04e638c93
commit
a6f9026ab1
4 changed files with 122 additions and 231 deletions
131
archive/unrar.js
131
archive/unrar.js
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@ -13,6 +13,7 @@
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// This file expects to be invoked as a Worker (see onmessage below).
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importScripts('../io/bitstream.js');
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importScripts('../io/bytestream.js');
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importScripts('../io/bytebuffer.js');
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importScripts('archive.js');
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importScripts('rarvm.js');
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@ -26,7 +27,7 @@ const UnarchiveState = {
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// State - consider putting these into a class.
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let unarchiveState = UnarchiveState.NOT_STARTED;
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let bitstream = null;
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let bytestream = null;
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let allLocalFiles = null;
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let logToConsole = false;
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@ -53,7 +54,7 @@ const postProgress = function() {
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currentBytesUnarchived,
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totalUncompressedBytesInArchive,
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totalFilesInArchive,
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parseInt(bitstream.getNumBitsRead() / 8, 10),
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parseInt(bytestream.getNumBytesRead(), 10),
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));
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};
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@ -85,88 +86,89 @@ const ENDARC_HEAD = 0x7b;
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*/
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class RarVolumeHeader {
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/**
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* @param {bitjs.io.BitStream} bstream
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* @param {bitjs.io.ByteStream} bstream
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*/
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constructor(bstream) {
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let headBytesRead = 0;
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// byte 1,2
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this.crc = bstream.readBits(16);
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this.crc = bstream.readNumber(2);
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// byte 3
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this.headType = bstream.readBits(8);
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this.headType = bstream.readNumber(1);
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// Get flags
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// bytes 4,5
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this.flags = {};
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this.flags.value = bstream.peekBits(16);
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this.flags.value = bstream.readNumber(2);
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const flagsValue = this.flags.value;
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switch (this.headType) {
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case MAIN_HEAD:
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this.flags.MHD_VOLUME = !!bstream.readBits(1);
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this.flags.MHD_COMMENT = !!bstream.readBits(1);
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this.flags.MHD_LOCK = !!bstream.readBits(1);
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this.flags.MHD_SOLID = !!bstream.readBits(1);
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this.flags.MHD_PACK_COMMENT = !!bstream.readBits(1);
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this.flags.MHD_VOLUME = !!(flagsValue & 0x01);
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this.flags.MHD_COMMENT = !!(flagsValue & 0x02);
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this.flags.MHD_LOCK = !!(flagsValue & 0x04);
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this.flags.MHD_SOLID = !!(flagsValue & 0x08);
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this.flags.MHD_PACK_COMMENT = !!(flagsValue & 0x10);
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this.flags.MHD_NEWNUMBERING = this.flags.MHD_PACK_COMMENT;
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this.flags.MHD_AV = !!bstream.readBits(1);
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this.flags.MHD_PROTECT = !!bstream.readBits(1);
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this.flags.MHD_PASSWORD = !!bstream.readBits(1);
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this.flags.MHD_FIRSTVOLUME = !!bstream.readBits(1);
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this.flags.MHD_ENCRYPTVER = !!bstream.readBits(1);
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bstream.readBits(6); // unused
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this.flags.MHD_AV = !!(flagsValue & 0x20);
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this.flags.MHD_PROTECT = !!(flagsValue & 0x40);
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this.flags.MHD_PASSWORD = !!(flagsValue & 0x80);
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this.flags.MHD_FIRSTVOLUME = !!(flagsValue & 0x100);
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this.flags.MHD_ENCRYPTVER = !!(flagsValue & 0x200);
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//bstream.readBits(6); // unused
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break;
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case FILE_HEAD:
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this.flags.LHD_SPLIT_BEFORE = !!bstream.readBits(1); // 0x0001
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this.flags.LHD_SPLIT_AFTER = !!bstream.readBits(1); // 0x0002
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this.flags.LHD_PASSWORD = !!bstream.readBits(1); // 0x0004
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this.flags.LHD_COMMENT = !!bstream.readBits(1); // 0x0008
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this.flags.LHD_SOLID = !!bstream.readBits(1); // 0x0010
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bstream.readBits(3); // unused
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this.flags.LHD_LARGE = !!bstream.readBits(1); // 0x0100
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this.flags.LHD_UNICODE = !!bstream.readBits(1); // 0x0200
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this.flags.LHD_SALT = !!bstream.readBits(1); // 0x0400
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this.flags.LHD_VERSION = !!bstream.readBits(1); // 0x0800
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this.flags.LHD_EXTTIME = !!bstream.readBits(1); // 0x1000
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this.flags.LHD_EXTFLAGS = !!bstream.readBits(1); // 0x2000
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bstream.readBits(2); // unused
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this.flags.LHD_SPLIT_BEFORE = !!(flagsValue & 0x01);
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this.flags.LHD_SPLIT_AFTER = !!(flagsValue & 0x02);
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this.flags.LHD_PASSWORD = !!(flagsValue & 0x04);
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this.flags.LHD_COMMENT = !!(flagsValue & 0x08);
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this.flags.LHD_SOLID = !!(flagsValue & 0x10);
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// 3 bits unused
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this.flags.LHD_LARGE = !!(flagsValue & 0x100);
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this.flags.LHD_UNICODE = !!(flagsValue & 0x200);
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this.flags.LHD_SALT = !!(flagsValue & 0x400);
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this.flags.LHD_VERSION = !!(flagsValue & 0x800);
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this.flags.LHD_EXTTIME = !!(flagsValue & 0x1000);
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this.flags.LHD_EXTFLAGS = !!(flagsValue & 0x2000);
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// 2 bits unused
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//info(" LHD_SPLIT_BEFORE = " + this.flags.LHD_SPLIT_BEFORE);
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break;
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default:
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bstream.readBits(16);
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break;
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}
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// byte 6,7
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this.headSize = bstream.readBits(16);
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this.headSize = bstream.readNumber(2);
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headBytesRead += 7;
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switch (this.headType) {
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case MAIN_HEAD:
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this.highPosAv = bstream.readBits(16);
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this.posAv = bstream.readBits(32);
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this.highPosAv = bstream.readNumber(2);
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this.posAv = bstream.readNumber(4);
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headBytesRead += 6;
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if (this.flags.MHD_ENCRYPTVER) {
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this.encryptVer = bstream.readBits(8);
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this.encryptVer = bstream.readNumber(1);
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headBytesRead += 1;
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}
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//info("Found MAIN_HEAD with highPosAv=" + this.highPosAv + ", posAv=" + this.posAv);
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break;
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case FILE_HEAD:
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this.packSize = bstream.readBits(32);
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this.unpackedSize = bstream.readBits(32);
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this.hostOS = bstream.readBits(8);
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this.fileCRC = bstream.readBits(32);
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this.fileTime = bstream.readBits(32);
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this.unpVer = bstream.readBits(8);
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this.method = bstream.readBits(8);
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this.nameSize = bstream.readBits(16);
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this.fileAttr = bstream.readBits(32);
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this.packSize = bstream.readNumber(4);
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this.unpackedSize = bstream.readNumber(4);
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this.hostOS = bstream.readNumber(1);
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this.fileCRC = bstream.readNumber(4);
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this.fileTime = bstream.readNumber(4);
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this.unpVer = bstream.readNumber(1);
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this.method = bstream.readNumber(1);
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this.nameSize = bstream.readNumber(2);
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this.fileAttr = bstream.readNumber(4);
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headBytesRead += 25;
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if (this.flags.LHD_LARGE) {
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//info("Warning: Reading in LHD_LARGE 64-bit size values");
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this.HighPackSize = bstream.readBits(32);
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this.HighUnpSize = bstream.readBits(32);
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this.HighPackSize = bstream.readNumber(4);
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this.HighUnpSize = bstream.readNumber(4);
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headBytesRead += 8;
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} else {
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this.HighPackSize = 0;
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@ -184,6 +186,7 @@ class RarVolumeHeader {
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// read in filename
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// TODO: Use readString?
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this.filename = bstream.readBytes(this.nameSize);
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headBytesRead += this.nameSize;
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let _s = '';
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@ -195,13 +198,13 @@ class RarVolumeHeader {
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if (this.flags.LHD_SALT) {
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//info("Warning: Reading in 64-bit salt value");
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this.salt = bstream.readBits(64); // 8 bytes
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this.salt = bstream.readBytes(8); // 8 bytes
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headBytesRead += 8;
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}
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if (this.flags.LHD_EXTTIME) {
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// 16-bit flags
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const extTimeFlags = bstream.readBits(16);
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const extTimeFlags = bstream.readNumber(2);
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headBytesRead += 2;
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// this is adapted straight out of arcread.cpp, Archive::ReadHeader()
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@ -211,12 +214,12 @@ class RarVolumeHeader {
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continue;
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}
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if (I != 0) {
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bstream.readBits(16);
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bstream.readBytes(2);
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headBytesRead += 2;
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}
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const count = (rmode & 3);
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for (let J = 0; J < count; ++J) {
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bstream.readBits(8);
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bstream.readNumber(1);
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headBytesRead += 1;
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}
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}
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@ -232,7 +235,9 @@ class RarVolumeHeader {
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break;
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default:
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if (logToConsole) {
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info("Found a header of type 0x" + byteValueToHexString(this.headType));
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}
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// skip the rest of the header bytes (for now)
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bstream.readBytes(this.headSize - 7);
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break;
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@ -1256,7 +1261,9 @@ function unpack(v) {
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rBuffer = new bitjs.io.ByteBuffer(v.header.unpackedSize);
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if (logToConsole) {
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info("Unpacking " + v.filename + " RAR v" + Ver);
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}
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switch (Ver) {
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case 15: // rar 1.5 compression
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@ -1282,7 +1289,7 @@ function unpack(v) {
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*/
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class RarLocalFile {
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/**
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* @param {bitjs.io.BitStream} bstream
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* @param {bitjs.io.ByteStream} bstream
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*/
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constructor(bstream) {
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this.header = new RarVolumeHeader(bstream);
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@ -1306,7 +1313,9 @@ class RarLocalFile {
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if (!this.header.flags.LHD_SPLIT_BEFORE) {
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// unstore file
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if (this.header.method == 0x30) {
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if (logToConsole) {
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info("Unstore " + this.filename);
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}
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this.isValid = true;
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currentBytesUnarchivedInFile += this.fileData.length;
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@ -1327,34 +1336,38 @@ class RarLocalFile {
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// Reads in the volume and main header.
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function unrar_start() {
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let bstream = bitstream.tee();
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let bstream = bytestream.tee();
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const header = new RarVolumeHeader(bstream);
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if (header.crc == 0x6152 &&
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header.headType == 0x72 &&
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header.flags.value == 0x1A21 &&
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header.headSize == 7) {
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if (logToConsole) {
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info("Found RAR signature");
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}
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const mhead = new RarVolumeHeader(bstream);
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if (mhead.headType != MAIN_HEAD) {
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info("Error! RAR did not include a MAIN_HEAD header");
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} else {
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bitstream = bstream.tee();
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bytestream = bstream.tee();
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}
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}
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}
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function unrar() {
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let bstream = bitstream.tee();
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let bstream = bytestream.tee();
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let localFile = null;
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do {
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localFile = new RarLocalFile(bstream);
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if (logToConsole) {
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info("RAR localFile isValid=" + localFile.isValid + ", volume packSize=" + localFile.header.packSize);
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localFile.header.dump();
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}
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if (localFile && localFile.isValid && localFile.header.packSize > 0) {
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bitstream = bstream.tee();
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bytestream = bstream.tee();
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totalUncompressedBytesInArchive += localFile.header.unpackedSize;
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allLocalFiles.push(localFile);
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@ -1376,7 +1389,7 @@ function unrar() {
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postProgress();
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bitstream = bstream.tee();
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bytestream = bstream.tee();
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};
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// event.data.file has the first ArrayBuffer.
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@ -1386,8 +1399,8 @@ onmessage = function(event) {
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logToConsole = !!event.data.logToConsole;
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// This is the very first time we have been called. Initialize the bytestream.
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if (!bitstream) {
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bitstream = new bitjs.io.BitStream(bytes);
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if (!bytestream) {
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bytestream = new bitjs.io.ByteStream(bytes);
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currentFilename = "";
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currentFileNumber = 0;
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@ -1398,7 +1411,7 @@ onmessage = function(event) {
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allLocalFiles = [];
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postMessage(new bitjs.archive.UnarchiveStartEvent());
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} else {
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bitstream.push(bytes);
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bytestream.push(bytes);
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}
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if (unarchiveState === UnarchiveState.NOT_STARTED) {
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143
io/bitstream.js
143
io/bitstream.js
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@ -13,10 +13,11 @@ var bitjs = bitjs || {};
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bitjs.io = bitjs.io || {};
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// TODO: Add method for tee-ing off the stream with tests.
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/**
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* This object allows you to peek and consume bits and bytes out of a stream.
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* More bits can be pushed into the back of the stream via the push() method.
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* Note that this stream is optimized, and thus, will *NOT* throw an error if
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* the end of the stream is reached. Only use this in scenarios where you
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* already have all the bits you need.
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*/
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bitjs.io.BitStream = class {
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/**
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@ -35,21 +36,14 @@ bitjs.io.BitStream = class {
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const length = opt_length || ab.byteLength;
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/**
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* The current page of bytes in the stream.
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* The bytes in the stream.
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* @type {Uint8Array}
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* @private
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*/
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this.bytes = new Uint8Array(ab, offset, length);
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/**
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* The next pages of bytes in the stream.
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* @type {Array<Uint8Array>}
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* @private
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*/
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this.pages_ = [];
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/**
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* The byte in the current page that we are currently on.
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* The byte in the stream that we are currently on.
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* @type {Number}
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* @private
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*/
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@ -84,27 +78,7 @@ bitjs.io.BitStream = class {
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*/
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getNumBitsLeft() {
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const bitsLeftInByte = 8 - this.bitPtr;
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const bitsLeftInCurrentPage = (this.bytes.byteLength - this.bytePtr - 1) * 8 + bitsLeftInByte;
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return this.pages_.reduce((acc, arr) => acc + arr.length * 8, bitsLeftInCurrentPage);
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}
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/**
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* Move the pointer ahead n bits. The bytePtr and current page are updated as needed.
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* This is a private method, no validation is done.
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* @param {number} n Number of bits to increment.
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* @private
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*/
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movePointer_(n) {
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this.bitPtr += n;
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this.bitsRead_ += n;
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while (this.bitPtr >= 8) {
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this.bitPtr -= 8;
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this.bytePtr++;
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while (this.bytePtr >= this.bytes.length && this.pages_.length > 0) {
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this.bytePtr -= this.bytes.length;
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this.bytes = this.pages_.shift();
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}
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}
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return (this.bytes.byteLength - this.bytePtr - 1) * 8 + bitsLeftInByte;
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}
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/**
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@ -120,20 +94,13 @@ bitjs.io.BitStream = class {
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peekBits_ltr(n, opt_movePointers) {
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const NUM = parseInt(n, 10);
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let num = NUM;
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if (n !== num || num < 0) {
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throw 'Error! Called peekBits_ltr() with a non-positive integer';
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} else if (num === 0) {
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if (n !== num || num <= 0) {
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return 0;
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}
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if (num > this.getNumBitsLeft()) {
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throw 'Error! Overflowed the bit stream! n=' + n + ', bytePtr=' + this.bytePtr +
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', bytes.length=' + this.bytes.length + ', bitPtr=' + this.bitPtr;
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}
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const BITMASK = bitjs.io.BitStream.BITMASK;
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const movePointers = opt_movePointers || false;
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let curPage = this.bytes;
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let pageIndex = 0;
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let bytes = this.bytes;
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let bytePtr = this.bytePtr;
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let bitPtr = this.bitPtr;
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let result = 0;
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@ -141,32 +108,33 @@ bitjs.io.BitStream = class {
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// keep going until we have no more bits left to peek at
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while (num > 0) {
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if (bytePtr >= curPage.length && this.pages_.length > 0) {
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curPage = this.pages_[pageIndex++];
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bytePtr = 0;
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// We overflowed the stream, so just return what we got.
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if (bytePtr >= bytes.length) {
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break;
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}
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const numBitsLeftInThisByte = (8 - bitPtr);
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if (num >= numBitsLeftInThisByte) {
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const mask = (bitjs.io.BitStream.BITMASK[numBitsLeftInThisByte] << bitPtr);
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result |= (((curPage[bytePtr] & mask) >> bitPtr) << bitsIn);
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const mask = (BITMASK[numBitsLeftInThisByte] << bitPtr);
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result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
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bytePtr++;
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bitPtr = 0;
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bitsIn += numBitsLeftInThisByte;
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num -= numBitsLeftInThisByte;
|
||||
} else {
|
||||
const mask = (bitjs.io.BitStream.BITMASK[num] << bitPtr);
|
||||
result |= (((curPage[bytePtr] & mask) >> bitPtr) << bitsIn);
|
||||
const mask = (BITMASK[num] << bitPtr);
|
||||
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
|
||||
|
||||
bitPtr += num;
|
||||
bitsIn += num;
|
||||
num = 0;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (movePointers) {
|
||||
this.movePointer_(NUM);
|
||||
this.bitPtr = bitPtr;
|
||||
this.bytePtr = bytePtr;
|
||||
this.bitsRead_ += NUM;
|
||||
}
|
||||
|
||||
return result;
|
||||
|
|
@ -185,50 +153,45 @@ bitjs.io.BitStream = class {
|
|||
peekBits_rtl(n, opt_movePointers) {
|
||||
const NUM = parseInt(n, 10);
|
||||
let num = NUM;
|
||||
if (n !== num || num < 0) {
|
||||
throw 'Error! Called peekBits_rtl() with a non-positive integer';
|
||||
} else if (num === 0) {
|
||||
if (n !== num || num <= 0) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (num > this.getNumBitsLeft()) {
|
||||
throw 'Error! Overflowed the bit stream! n=' + n + ', bytePtr=' + this.bytePtr +
|
||||
', bytes.length=' + this.bytes.length + ', bitPtr=' + this.bitPtr;
|
||||
}
|
||||
|
||||
const BITMASK = bitjs.io.BitStream.BITMASK;
|
||||
const movePointers = opt_movePointers || false;
|
||||
let curPage = this.bytes;
|
||||
let pageIndex = 0;
|
||||
let 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
|
||||
while (num > 0) {
|
||||
if (bytePtr >= curPage.length && this.pages_.length > 0) {
|
||||
curPage = this.pages_[pageIndex++];
|
||||
bytePtr = 0;
|
||||
// We overflowed the stream, so just return the bits we got.
|
||||
if (bytePtr >= bytes.length) {
|
||||
break;
|
||||
}
|
||||
|
||||
const numBitsLeftInThisByte = (8 - bitPtr);
|
||||
if (num >= numBitsLeftInThisByte) {
|
||||
result <<= numBitsLeftInThisByte;
|
||||
result |= (bitjs.io.BitStream.BITMASK[numBitsLeftInThisByte] & curPage[bytePtr]);
|
||||
result |= (BITMASK[numBitsLeftInThisByte] & bytes[bytePtr]);
|
||||
bytePtr++;
|
||||
bitPtr = 0;
|
||||
num -= numBitsLeftInThisByte;
|
||||
} else {
|
||||
result <<= num;
|
||||
const numBits = 8 - num - bitPtr;
|
||||
result |= ((curPage[bytePtr] & (bitjs.io.BitStream.BITMASK[num] << numBits)) >> numBits);
|
||||
result |= ((bytes[bytePtr] & (BITMASK[num] << numBits)) >> numBits);
|
||||
|
||||
bitPtr += num;
|
||||
num = 0;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (movePointers) {
|
||||
this.movePointer_(NUM);
|
||||
this.bitPtr = bitPtr;
|
||||
this.bytePtr = bytePtr;
|
||||
this.bitsRead_ += NUM;
|
||||
}
|
||||
|
||||
return result;
|
||||
|
|
@ -286,20 +249,19 @@ bitjs.io.BitStream = class {
|
|||
|
||||
const movePointers = opt_movePointers || false;
|
||||
const result = new Uint8Array(num);
|
||||
let curPage = this.bytes;
|
||||
let bytes = this.bytes;
|
||||
let ptr = this.bytePtr;
|
||||
let bytesLeftToCopy = num;
|
||||
let pageIndex = 0;
|
||||
while (bytesLeftToCopy > 0) {
|
||||
const bytesLeftInPage = curPage.length - ptr;
|
||||
const sourceLength = Math.min(bytesLeftToCopy, bytesLeftInPage);
|
||||
const bytesLeftInStream = bytes.length - ptr;
|
||||
const sourceLength = Math.min(bytesLeftToCopy, bytesLeftInStream);
|
||||
|
||||
result.set(curPage.subarray(ptr, ptr + sourceLength), num - bytesLeftToCopy);
|
||||
result.set(bytes.subarray(ptr, ptr + sourceLength), num - bytesLeftToCopy);
|
||||
|
||||
ptr += sourceLength;
|
||||
if (ptr >= curPage.length) {
|
||||
curPage = this.pages_[pageIndex++];
|
||||
ptr = 0;
|
||||
// Overflowed the stream, just return what we got.
|
||||
if (ptr >= bytes.length) {
|
||||
break;
|
||||
}
|
||||
|
||||
bytesLeftToCopy -= sourceLength;
|
||||
|
|
@ -320,33 +282,6 @@ bitjs.io.BitStream = class {
|
|||
readBytes(n) {
|
||||
return this.peekBytes(n, true);
|
||||
}
|
||||
|
||||
/**
|
||||
* Feeds more bytes into the back of the stream.
|
||||
* @param {ArrayBuffer} ab
|
||||
*/
|
||||
push(ab) {
|
||||
if (!(ab instanceof ArrayBuffer)) {
|
||||
throw 'Error! BitStream.push() called with an invalid ArrayBuffer object';
|
||||
}
|
||||
|
||||
this.pages_.push(new Uint8Array(ab));
|
||||
}
|
||||
|
||||
/**
|
||||
* Creates a new BitStream from this BitStream that can be read / peeked.
|
||||
* @return {bitjs.io.BitStream} A clone of this BitStream.
|
||||
*/
|
||||
tee() {
|
||||
const clone = new bitjs.io.BitStream(this.bytes.buffer);
|
||||
clone.bytes = this.bytes;
|
||||
clone.pages_ = this.pages_.slice();
|
||||
clone.bytePtr = this.bytePtr;
|
||||
clone.bitPtr = this.bitPtr;
|
||||
clone.peekBits = this.peekBits;
|
||||
clone.bitsRead_ = this.bitsRead_;
|
||||
return clone;
|
||||
}
|
||||
}
|
||||
|
||||
// mask for getting N number of bits (0-8)
|
||||
|
|
|
|||
|
|
@ -13,7 +13,6 @@ var bitjs = bitjs || {};
|
|||
bitjs.io = bitjs.io || {};
|
||||
|
||||
|
||||
// TODO: Add method for tee-ing off the stream with tests.
|
||||
/**
|
||||
* This object allows you to peek and consume bytes as numbers and strings out
|
||||
* of a stream. More bytes can be pushed into the back of the stream via the
|
||||
|
|
@ -185,7 +184,7 @@ bitjs.io.ByteStream = class {
|
|||
*/
|
||||
peekBytes(n, movePointers) {
|
||||
const num = parseInt(n, 10);
|
||||
if (n !== num || num <= 0) {
|
||||
if (n !== num || num < 0) {
|
||||
throw 'Error! Called peekBytes() with a non-positive integer';
|
||||
} else if (num === 0) {
|
||||
return new Uint8Array();
|
||||
|
|
|
|||
|
|
@ -32,9 +32,8 @@
|
|||
// 10010 = 2 + 16 = 18
|
||||
assertEquals(18, stream.readBits(5));
|
||||
|
||||
// Only 1 bit left in the buffer, make sure it throws an error if we try to read more.
|
||||
assertThrows(() => stream.readBits(2),
|
||||
'Did not throw when trying to read bits past the end of the stream during RTL');
|
||||
// Ensure the last bit is read, even if we flow past the end of the stream.
|
||||
assertEquals(1, stream.readBits(2));
|
||||
},
|
||||
|
||||
testBitPeekAndRead_LTR() {
|
||||
|
|
@ -50,9 +49,8 @@
|
|||
// 11001 = 1 + 8 + 16 = 25
|
||||
assertEquals(25, stream.readBits(5));
|
||||
|
||||
// Only 1 bit left in the buffer, make sure it throws an error if we try to read more.
|
||||
assertThrows(() => stream.readBits(2),
|
||||
'Did not throw when trying to read bits past the end of the stream during LTR');
|
||||
// Only 1 bit left in the buffer, make sure it reads in, even if we over-read.
|
||||
assertEquals(0, stream.readBits(2));
|
||||
},
|
||||
|
||||
testBitStreamReadBytes() {
|
||||
|
|
@ -74,60 +72,6 @@
|
|||
assertThrows(() => stream.readBytes(3),
|
||||
'Did not throw when trying to read bytes past the end of the stream');
|
||||
},
|
||||
|
||||
testBitStreamReadAfterPush_RTL() {
|
||||
array = new Uint8Array(1);
|
||||
array[0] = Number('0b01010110');
|
||||
const stream = new bitjs.io.BitStream(array.buffer, true /* rtl */);
|
||||
const readBits = stream.readBits(8);
|
||||
assertEquals(0x56, readBits, 'Could not read 8 bits: ' + readBits);
|
||||
assertThrows(() => stream.readBits(4),
|
||||
'Did not throw when trying to read a bit past the end of the stream');
|
||||
|
||||
const anotherArray = new Uint8Array(1);
|
||||
anotherArray[0] = Number('0b01010110');
|
||||
stream.push(anotherArray.buffer);
|
||||
|
||||
assertEquals(0x5, stream.readBits(4),
|
||||
'Could not read in next 4 bits after pushing in RTL');
|
||||
assertEquals(0x6, stream.readBits(4),
|
||||
'Could not read in next 4 bits after pushing in RTL');
|
||||
},
|
||||
|
||||
testBitStreamReadAfterPush_LTR() {
|
||||
array = new Uint8Array(1);
|
||||
array[0] = Number('0b01010110');
|
||||
const stream = new bitjs.io.BitStream(array.buffer, false /* rtl */);
|
||||
const readBits = stream.readBits(8);
|
||||
assertEquals(0x56, readBits, 'Could not read 8 bits: ' + readBits);
|
||||
assertThrows(() => stream.readBits(4),
|
||||
'Did not throw when trying to read a bit past the end of the stream');
|
||||
|
||||
const anotherArray = new Uint8Array(1);
|
||||
anotherArray[0] = Number('0b01010110');
|
||||
stream.push(anotherArray.buffer);
|
||||
|
||||
assertEquals(0x6, stream.readBits(4),
|
||||
'Could not read in next 4 bits after pushing in LTR');
|
||||
assertEquals(0x5, stream.readBits(4),
|
||||
'Could not read in next 4 bits after pushing in LTR');
|
||||
},
|
||||
|
||||
testTee() {
|
||||
for (let i = 0; i < 4; ++i) array[i] = 65 + i;
|
||||
const stream = new bitjs.io.BitStream(array.buffer);
|
||||
stream.readBits(1);
|
||||
|
||||
const anotherArray = new Uint8Array(4);
|
||||
for (let i = 0; i < 4; ++i) anotherArray[i] = 69 + i;
|
||||
stream.push(anotherArray.buffer);
|
||||
|
||||
const teed = stream.tee();
|
||||
teed.readBytes(5);
|
||||
assertEquals(8 * 8 - 1, stream.getNumBitsLeft());
|
||||
// readBytes() throws away any unused bits.
|
||||
assertEquals(2 * 8, teed.getNumBitsLeft());
|
||||
},
|
||||
},
|
||||
});
|
||||
</script>
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue