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Code Issues Releases Wiki Activity

Start on Issue #16. Make BitStream a module, but provide a Web Worker version of BitStream via a build step

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This commit is contained in:
codedread 2020-04-01 23:08:09 -07:00
parent 469a93d6e1
commit a457564ff0
8 changed files with 1043 additions and 427 deletions
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5
archive/unrar.js
View file

@ -12,7 +12,7 @@
// present.
// This file expects to be invoked as a Worker (see onmessage below).
importScripts('../io/bitstream.js');
importScripts('../io/bitstream-worker.js');
importScripts('../io/bytestream.js');
importScripts('../io/bytebuffer.js');
importScripts('archive.js');
@ -1187,8 +1187,7 @@ function RarWriteData(offset, numBytes) {
/**
* @param {VM_PreparedProgram} prg
*/
function RarExecuteCode(prg)
{
function RarExecuteCode(prg) {
if (prg.GlobalData.length > 0) {
const writtenFileSize = wBuffer.ptr;
prg.InitR[6] = writtenFileSize;

2
archive/unzip.js
View file

@ -13,7 +13,7 @@
*/
// This file expects to be invoked as a Worker (see onmessage below).
importScripts('../io/bitstream.js');
importScripts('../io/bitstream-worker.js');
importScripts('../io/bytebuffer.js');
importScripts('../io/bytestream.js');
importScripts('archive.js');

13
build/Makefile Normal file
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@ -0,0 +1,13 @@
all: bitjs-io bitjs-image-webp-shim
clean:
$(MAKE) -C io clean
$(MAKE) -C image/webp-shim clean
bitjs-io:
$(MAKE) -C io
# Make webp-shim/
bitjs-image-webp-shim:
$(MAKE) -C image/webp-shim

25
build/io/Makefile Normal file
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@ -0,0 +1,25 @@
OUT_PATH=/out/io
BITSTREAM_MODULE=${OUT_PATH}/bitstream.js
BITSTREAM_WORKER=${OUT_PATH}/bitstream-worker.js
BITSTREAM_DEF=bitstream-def.js
DISCLAIMER="// THIS IS A GENERATED FILE! DO NOT EDIT, INSTEAD EDIT THE FILE IN bitjs/build/io."
all: ${BITSTREAM_MODULE} ${BITSTREAM_WORKER}
${BITSTREAM_MODULE}: Makefile ${BITSTREAM_DEF}
echo ${DISCLAIMER} > ${BITSTREAM_MODULE}
echo "export const BitStream =" >> ${BITSTREAM_MODULE}
cat ${BITSTREAM_DEF} >> ${BITSTREAM_MODULE}
${BITSTREAM_WORKER}: Makefile ${BITSTREAM_DEF}
echo ${DISCLAIMER} > ${BITSTREAM_WORKER}
echo "var bitjs = bitjs || {};" >> ${BITSTREAM_WORKER}
echo "bitjs.io = bitjs.io || {};" >> ${BITSTREAM_WORKER}
echo "bitjs.io.BitStream =" >> ${BITSTREAM_WORKER}
cat ${BITSTREAM_DEF} >> ${BITSTREAM_WORKER}
clean:
rm -rf ${BITSTREAM_MODULE}
rm -rf ${BITSTREAM_WORKER}

287
build/io/bitstream-def.js Normal file
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@ -0,0 +1,287 @@
/*
* bitstream-def.js
*
* Provides readers for bitstreams.
*
* Licensed under the MIT License
*
* Copyright(c) 2011 Google Inc.
* Copyright(c) 2011 antimatter15
*/
(function () {
// mask for getting N number of bits (0-8)
const BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF];
/**
* This object allows you to peek and consume bits and bytes out of a stream.
* Note that this stream is optimized, and thus, will *NOT* throw an error if
* the end of the stream is reached. Only use this in scenarios where you
* already have all the bits you need.
*/
class BitStream {
/**
* @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 instanceof ArrayBuffer)) {
throw 'Error! BitArray constructed with an invalid ArrayBuffer object';
}
const offset = opt_offset || 0;
const length = opt_length || ab.byteLength;
/**
* The bytes in the stream.
* @type {Uint8Array}
* @private
*/
this.bytes = new Uint8Array(ab, offset, length);
/**
* The byte in the stream that we are currently on.
* @type {Number}
* @private
*/
this.bytePtr = 0;
/**
* The bit in the current byte that we will read next (can have values 0 through 7).
* @type {Number}
* @private
*/
this.bitPtr = 0; // tracks which bit we are on (can have values 0 through 7)
/**
* An ever-increasing number.
* @type {Number}
* @private
*/
this.bitsRead_ = 0;
this.peekBits = rtl ? this.peekBits_rtl : this.peekBits_ltr;
}
/**
* Returns how many bites have been read in the stream since the beginning of time.
*/
getNumBitsRead() {
return this.bitsRead_;
}
/**
* Returns how many bits are currently in the stream left to be read.
*/
getNumBitsLeft() {
const bitsLeftInByte = 8 - this.bitPtr;
return (this.bytes.byteLength - this.bytePtr - 1) * 8 + bitsLeftInByte;
}
/**
* 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, must be a positive integer.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {number} The peeked bits, as an unsigned number.
*/
peekBits_ltr(n, opt_movePointers) {
const NUM = parseInt(n, 10);
let num = NUM;
if (n !== num || num <= 0) {
return 0;
}
const movePointers = opt_movePointers || false;
let 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
while (num > 0) {
// We overflowed the stream, so just return what we got.
if (bytePtr >= bytes.length) {
break;
}
const numBitsLeftInThisByte = (8 - bitPtr);
if (num >= numBitsLeftInThisByte) {
const mask = (BITMASK[numBitsLeftInThisByte] << bitPtr);
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
bytePtr++;
bitPtr = 0;
bitsIn += numBitsLeftInThisByte;
num -= numBitsLeftInThisByte;
} else {
const mask = (BITMASK[num] << bitPtr);
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
bitPtr += num;
break;
}
}
if (movePointers) {
this.bitPtr = bitPtr;
this.bytePtr = bytePtr;
this.bitsRead_ += NUM;
}
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. Must be a positive integer.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {number} The peeked bits, as an unsigned number.
*/
peekBits_rtl(n, opt_movePointers) {
const NUM = parseInt(n, 10);
let num = NUM;
if (n !== num || num <= 0) {
return 0;
}
const movePointers = opt_movePointers || false;
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) {
// 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 |= (BITMASK[numBitsLeftInThisByte] & bytes[bytePtr]);
bytePtr++;
bitPtr = 0;
num -= numBitsLeftInThisByte;
} else {
result <<= num;
const numBits = 8 - num - bitPtr;
result |= ((bytes[bytePtr] & (BITMASK[num] << numBits)) >> numBits);
bitPtr += num;
break;
}
}
if (movePointers) {
this.bitPtr = bitPtr;
this.bytePtr = bytePtr;
this.bitsRead_ += NUM;
}
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. Must be a positive integer.
* @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. Must be a positive integer.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {Uint8Array} The subarray.
*/
peekBytes(n, opt_movePointers) {
const num = parseInt(n, 10);
if (n !== num || num < 0) {
throw 'Error! Called peekBytes() with a non-positive integer: ' + n;
} else if (num === 0) {
return new Uint8Array();
}
// Flush bits until we are byte-aligned.
// 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 numBytesLeft = this.getNumBitsLeft() / 8;
if (num > numBytesLeft) {
throw 'Error! Overflowed the bit stream! n=' + num + ', bytePtr=' + this.bytePtr +
', bytes.length=' + this.bytes.length + ', bitPtr=' + this.bitPtr;
}
const movePointers = opt_movePointers || false;
const result = new Uint8Array(num);
let bytes = this.bytes;
let ptr = this.bytePtr;
let bytesLeftToCopy = num;
while (bytesLeftToCopy > 0) {
const bytesLeftInStream = bytes.length - ptr;
const sourceLength = Math.min(bytesLeftToCopy, bytesLeftInStream);
result.set(bytes.subarray(ptr, ptr + sourceLength), num - bytesLeftToCopy);
ptr += sourceLength;
// Overflowed the stream, just return what we got.
if (ptr >= bytes.length) {
break;
}
bytesLeftToCopy -= sourceLength;
}
if (movePointers) {
this.bytePtr += num;
this.bitsRead_ += (num * 8);
}
return result;
}
/**
* @param {number} n The number of bytes to read.
* @return {Uint8Array} The subarray.
*/
readBytes(n) {
return this.peekBytes(n, true);
}
}
return BitStream;
})();

291
io/bitstream-worker.js Normal file
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@ -0,0 +1,291 @@
// THIS IS A GENERATED FILE! DO NOT EDIT, INSTEAD EDIT THE FILE IN bitjs/build/io.
var bitjs = bitjs || {};
bitjs.io = bitjs.io || {};
bitjs.io.BitStream =
/*
* bitstream-def.js
*
* Provides readers for bitstreams.
*
* Licensed under the MIT License
*
* Copyright(c) 2011 Google Inc.
* Copyright(c) 2011 antimatter15
*/
(function () {
// mask for getting N number of bits (0-8)
const BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF];
/**
* This object allows you to peek and consume bits and bytes out of a stream.
* Note that this stream is optimized, and thus, will *NOT* throw an error if
* the end of the stream is reached. Only use this in scenarios where you
* already have all the bits you need.
*/
class BitStream {
/**
* @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 instanceof ArrayBuffer)) {
throw 'Error! BitArray constructed with an invalid ArrayBuffer object';
}
const offset = opt_offset || 0;
const length = opt_length || ab.byteLength;
/**
* The bytes in the stream.
* @type {Uint8Array}
* @private
*/
this.bytes = new Uint8Array(ab, offset, length);
/**
* The byte in the stream that we are currently on.
* @type {Number}
* @private
*/
this.bytePtr = 0;
/**
* The bit in the current byte that we will read next (can have values 0 through 7).
* @type {Number}
* @private
*/
this.bitPtr = 0; // tracks which bit we are on (can have values 0 through 7)
/**
* An ever-increasing number.
* @type {Number}
* @private
*/
this.bitsRead_ = 0;
this.peekBits = rtl ? this.peekBits_rtl : this.peekBits_ltr;
}
/**
* Returns how many bites have been read in the stream since the beginning of time.
*/
getNumBitsRead() {
return this.bitsRead_;
}
/**
* Returns how many bits are currently in the stream left to be read.
*/
getNumBitsLeft() {
const bitsLeftInByte = 8 - this.bitPtr;
return (this.bytes.byteLength - this.bytePtr - 1) * 8 + bitsLeftInByte;
}
/**
* 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, must be a positive integer.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {number} The peeked bits, as an unsigned number.
*/
peekBits_ltr(n, opt_movePointers) {
const NUM = parseInt(n, 10);
let num = NUM;
if (n !== num || num <= 0) {
return 0;
}
const movePointers = opt_movePointers || false;
let 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
while (num > 0) {
// We overflowed the stream, so just return what we got.
if (bytePtr >= bytes.length) {
break;
}
const numBitsLeftInThisByte = (8 - bitPtr);
if (num >= numBitsLeftInThisByte) {
const mask = (BITMASK[numBitsLeftInThisByte] << bitPtr);
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
bytePtr++;
bitPtr = 0;
bitsIn += numBitsLeftInThisByte;
num -= numBitsLeftInThisByte;
} else {
const mask = (BITMASK[num] << bitPtr);
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
bitPtr += num;
break;
}
}
if (movePointers) {
this.bitPtr = bitPtr;
this.bytePtr = bytePtr;
this.bitsRead_ += NUM;
}
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. Must be a positive integer.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {number} The peeked bits, as an unsigned number.
*/
peekBits_rtl(n, opt_movePointers) {
const NUM = parseInt(n, 10);
let num = NUM;
if (n !== num || num <= 0) {
return 0;
}
const movePointers = opt_movePointers || false;
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) {
// 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 |= (BITMASK[numBitsLeftInThisByte] & bytes[bytePtr]);
bytePtr++;
bitPtr = 0;
num -= numBitsLeftInThisByte;
} else {
result <<= num;
const numBits = 8 - num - bitPtr;
result |= ((bytes[bytePtr] & (BITMASK[num] << numBits)) >> numBits);
bitPtr += num;
break;
}
}
if (movePointers) {
this.bitPtr = bitPtr;
this.bytePtr = bytePtr;
this.bitsRead_ += NUM;
}
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. Must be a positive integer.
* @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. Must be a positive integer.
* @param {boolean=} movePointers Whether to move the pointer, defaults false.
* @return {Uint8Array} The subarray.
*/
peekBytes(n, opt_movePointers) {
const num = parseInt(n, 10);
if (n !== num || num < 0) {
throw 'Error! Called peekBytes() with a non-positive integer: ' + n;
} else if (num === 0) {
return new Uint8Array();
}
// Flush bits until we are byte-aligned.
// 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 numBytesLeft = this.getNumBitsLeft() / 8;
if (num > numBytesLeft) {
throw 'Error! Overflowed the bit stream! n=' + num + ', bytePtr=' + this.bytePtr +
', bytes.length=' + this.bytes.length + ', bitPtr=' + this.bitPtr;
}
const movePointers = opt_movePointers || false;
const result = new Uint8Array(num);
let bytes = this.bytes;
let ptr = this.bytePtr;
let bytesLeftToCopy = num;
while (bytesLeftToCopy > 0) {
const bytesLeftInStream = bytes.length - ptr;
const sourceLength = Math.min(bytesLeftToCopy, bytesLeftInStream);
result.set(bytes.subarray(ptr, ptr + sourceLength), num - bytesLeftToCopy);
ptr += sourceLength;
// Overflowed the stream, just return what we got.
if (ptr >= bytes.length) {
break;
}
bytesLeftToCopy -= sourceLength;
}
if (movePointers) {
this.bytePtr += num;
this.bitsRead_ += (num * 8);
}
return result;
}
/**
* @param {number} n The number of bytes to read.
* @return {Uint8Array} The subarray.
*/
readBytes(n) {
return this.peekBytes(n, true);
}
}
return BitStream;
})();

19
io/bitstream.js
View file

@ -1,5 +1,7 @@
// THIS IS A GENERATED FILE! DO NOT EDIT, INSTEAD EDIT THE FILE IN bitjs/build/io.
export const BitStream =
/*
* bitstream.js
* bitstream-def.js
*
* Provides readers for bitstreams.
*
@ -9,9 +11,9 @@
* Copyright(c) 2011 antimatter15
*/
var bitjs = bitjs || {};
bitjs.io = bitjs.io || {};
(function () {
// mask for getting N number of bits (0-8)
const BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF];
/**
* This object allows you to peek and consume bits and bytes out of a stream.
@ -19,7 +21,7 @@ bitjs.io = bitjs.io || {};
* the end of the stream is reached. Only use this in scenarios where you
* already have all the bits you need.
*/
bitjs.io.BitStream = class {
class BitStream {
/**
* @param {ArrayBuffer} ab An ArrayBuffer object or a Uint8Array.
* @param {boolean} rtl Whether the stream reads bits from the byte starting
@ -98,7 +100,6 @@ bitjs.io.BitStream = class {
return 0;
}
const BITMASK = bitjs.io.BitStream.BITMASK;
const movePointers = opt_movePointers || false;
let bytes = this.bytes;
let bytePtr = this.bytePtr;
@ -157,7 +158,6 @@ bitjs.io.BitStream = class {
return 0;
}
const BITMASK = bitjs.io.BitStream.BITMASK;
const movePointers = opt_movePointers || false;
let bytes = this.bytes;
let bytePtr = this.bytePtr;
@ -284,5 +284,6 @@ bitjs.io.BitStream = class {
}
}
// mask for getting N number of bits (0-8)
bitjs.io.BitStream.BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF ];
return BitStream;
})();

2
tests/io-bitstream-test.html
View file

@ -3,7 +3,7 @@
<head>
<title>Unit tests for bitjs.io.BitStream</title>
<script src="muther.js"></script>
<script src="../io/bitstream.js"></script>
<script src="../io/bitstream-worker.js"></script>
</head>
<body>
<script>