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Split up io like antimatter15 did

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codedread 2017-02-15 21:19:57 -08:00
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io.js
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/*
* io.js
*
* Provides readers for bit/byte streams (reading) and a byte buffer (writing).
*
* Licensed under the MIT License
*
* Copyright(c) 2011 Google Inc.
* Copyright(c) 2011 antimatter15
*/
var bitjs = bitjs || {};
bitjs.io = bitjs.io || {};
(function() {
// mask for getting the Nth bit (zero-based)
bitjs.BIT = [ 0x01, 0x02, 0x04, 0x08,
0x10, 0x20, 0x40, 0x80,
0x100, 0x200, 0x400, 0x800,
0x1000, 0x2000, 0x4000, 0x8000];
// mask for getting N number of bits (0-8)
var BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF ];
/**
* This bit stream peeks and consumes bits out of a binary stream.
*
* @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
*/
bitjs.io.BitStream = function(ab, rtl, opt_offset, opt_length) {
if (!ab || !ab.toString || ab.toString() !== "[object ArrayBuffer]") {
throw "Error! BitArray constructed with an invalid ArrayBuffer object";
}
var offset = opt_offset || 0;
var 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.
*/
bitjs.io.BitStream.prototype.peekBits_ltr = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return 0;
}
var movePointers = movePointers || false,
bytePtr = this.bytePtr,
bitPtr = this.bitPtr,
result = 0,
bitsIn = 0,
bytes = this.bytes;
// 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;
}
var numBitsLeftInThisByte = (8 - bitPtr);
if (n >= numBitsLeftInThisByte) {
var mask = (BITMASK[numBitsLeftInThisByte] << bitPtr);
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
bytePtr++;
bitPtr = 0;
bitsIn += numBitsLeftInThisByte;
n -= numBitsLeftInThisByte;
}
else {
var mask = (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.
*/
bitjs.io.BitStream.prototype.peekBits_rtl = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return 0;
}
var movePointers = movePointers || false,
bytePtr = this.bytePtr,
bitPtr = this.bitPtr,
result = 0,
bytes = this.bytes;
// 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;
}
var numBitsLeftInThisByte = (8 - bitPtr);
if (n >= numBitsLeftInThisByte) {
result <<= numBitsLeftInThisByte;
result |= (BITMASK[numBitsLeftInThisByte] & bytes[bytePtr]);
bytePtr++;
bitPtr = 0;
n -= numBitsLeftInThisByte;
}
else {
result <<= n;
result |= ((bytes[bytePtr] & (BITMASK[n] << (8 - n - bitPtr))) >> (8 - n - bitPtr));
bitPtr += n;
n = 0;
}
}
if (movePointers) {
this.bitPtr = bitPtr;
this.bytePtr = bytePtr;
}
return result;
};
/**
* Some voodoo magic.
*/
bitjs.io.BitStream.prototype.getBits = function() {
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.
*/
bitjs.io.BitStream.prototype.readBits = function(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.
*/
bitjs.io.BitStream.prototype.peekBytes = function(n, 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);
}
var movePointers = movePointers || false;
var bytePtr = this.bytePtr,
bitPtr = this.bitPtr;
var 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.
*/
bitjs.io.BitStream.prototype.readBytes = function(n) {
return this.peekBytes(n, true);
};
/**
* 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.
*
* @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
*/
bitjs.io.ByteStream = function(ab, opt_offset, opt_length) {
var offset = opt_offset || 0;
var 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.
*/
bitjs.io.ByteStream.prototype.peekNumber = function(n) {
// TODO: return error if n would go past the end of the stream?
if (n <= 0 || typeof n != typeof 1)
return -1;
var result = 0;
// read from last byte to first byte and roll them in
var 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.
*/
bitjs.io.ByteStream.prototype.readNumber = function(n) {
var 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.
*/
bitjs.io.ByteStream.prototype.peekSignedNumber = function(n) {
var num = this.peekNumber(n);
var HALF = Math.pow(2, (n * 8) - 1);
var 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.
*/
bitjs.io.ByteStream.prototype.readSignedNumber = function(n) {
var 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.
*/
bitjs.io.ByteStream.prototype.peekBytes = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return null;
}
var 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.
*/
bitjs.io.ByteStream.prototype.readBytes = function(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.
*/
bitjs.io.ByteStream.prototype.peekString = function(n) {
if (n <= 0 || typeof n != typeof 1) {
return "";
}
var result = "";
for (var 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.
*/
bitjs.io.ByteStream.prototype.readString = function(n) {
var strToReturn = this.peekString(n);
this.ptr += n;
return strToReturn;
};
/**
* A write-only Byte buffer which uses a Uint8 Typed Array as a backing store.
* @param {number} numBytes The number of bytes to allocate.
* @constructor
*/
bitjs.io.ByteBuffer = function(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.
*/
bitjs.io.ByteBuffer.prototype.insertByte = function(b) {
// TODO: throw if byte is invalid?
this.data[this.ptr++] = b;
};
/**
* @param {Array.<number>|Uint8Array|Int8Array} bytes The bytes to insert.
*/
bitjs.io.ByteBuffer.prototype.insertBytes = function(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.
*/
bitjs.io.ByteBuffer.prototype.writeNumber = function(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.
var bytes = [];
while (numBytes-- > 0) {
var 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.
*/
bitjs.io.ByteBuffer.prototype.writeSignedNumber = function(num, numBytes) {
if (numBytes < 1) {
throw 'Trying to write into too few bytes: ' + numBytes;
}
var 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.
var bytes = [];
while (numBytes-- > 0) {
var eightBits = num & 255;
bytes.push(eightBits);
num >>= 8;
}
this.insertBytes(bytes);
};
/**
* @param {string} str The ASCII string to write.
*/
bitjs.io.ByteBuffer.prototype.writeASCIIString = function(str) {
for (var i = 0; i < str.length; ++i) {
var curByte = str.charCodeAt(i);
if (curByte < 0 || curByte > 255) {
throw 'Trying to write a non-ASCII string!';
}
this.insertByte(curByte);
}
};
})();

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/*
* 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 || {};
(function() {
// mask for getting the Nth bit (zero-based)
bitjs.BIT = [ 0x01, 0x02, 0x04, 0x08,
0x10, 0x20, 0x40, 0x80,
0x100, 0x200, 0x400, 0x800,
0x1000, 0x2000, 0x4000, 0x8000];
// mask for getting N number of bits (0-8)
var BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF ];
/**
* This bit stream peeks and consumes bits out of a binary stream.
*
* @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
*/
bitjs.io.BitStream = function(ab, rtl, opt_offset, opt_length) {
if (!ab || !ab.toString || ab.toString() !== "[object ArrayBuffer]") {
throw "Error! BitArray constructed with an invalid ArrayBuffer object";
}
var offset = opt_offset || 0;
var 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.
*/
bitjs.io.BitStream.prototype.peekBits_ltr = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return 0;
}
var movePointers = movePointers || false,
bytePtr = this.bytePtr,
bitPtr = this.bitPtr,
result = 0,
bitsIn = 0,
bytes = this.bytes;
// 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;
}
var numBitsLeftInThisByte = (8 - bitPtr);
if (n >= numBitsLeftInThisByte) {
var mask = (BITMASK[numBitsLeftInThisByte] << bitPtr);
result |= (((bytes[bytePtr] & mask) >> bitPtr) << bitsIn);
bytePtr++;
bitPtr = 0;
bitsIn += numBitsLeftInThisByte;
n -= numBitsLeftInThisByte;
}
else {
var mask = (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.
*/
bitjs.io.BitStream.prototype.peekBits_rtl = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return 0;
}
var movePointers = movePointers || false,
bytePtr = this.bytePtr,
bitPtr = this.bitPtr,
result = 0,
bytes = this.bytes;
// 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;
}
var numBitsLeftInThisByte = (8 - bitPtr);
if (n >= numBitsLeftInThisByte) {
result <<= numBitsLeftInThisByte;
result |= (BITMASK[numBitsLeftInThisByte] & bytes[bytePtr]);
bytePtr++;
bitPtr = 0;
n -= numBitsLeftInThisByte;
}
else {
result <<= n;
result |= ((bytes[bytePtr] & (BITMASK[n] << (8 - n - bitPtr))) >> (8 - n - bitPtr));
bitPtr += n;
n = 0;
}
}
if (movePointers) {
this.bitPtr = bitPtr;
this.bytePtr = bytePtr;
}
return result;
};
/**
* Some voodoo magic.
*/
bitjs.io.BitStream.prototype.getBits = function() {
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.
*/
bitjs.io.BitStream.prototype.readBits = function(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.
*/
bitjs.io.BitStream.prototype.peekBytes = function(n, 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);
}
var movePointers = movePointers || false;
var bytePtr = this.bytePtr,
bitPtr = this.bitPtr;
var 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.
*/
bitjs.io.BitStream.prototype.readBytes = function(n) {
return this.peekBytes(n, true);
};
})();

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/*
* 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 || {};
(function() {
/**
* A write-only Byte buffer which uses a Uint8 Typed Array as a backing store.
* @param {number} numBytes The number of bytes to allocate.
* @constructor
*/
bitjs.io.ByteBuffer = function(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.
*/
bitjs.io.ByteBuffer.prototype.insertByte = function(b) {
// TODO: throw if byte is invalid?
this.data[this.ptr++] = b;
};
/**
* @param {Array.<number>|Uint8Array|Int8Array} bytes The bytes to insert.
*/
bitjs.io.ByteBuffer.prototype.insertBytes = function(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.
*/
bitjs.io.ByteBuffer.prototype.writeNumber = function(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.
var bytes = [];
while (numBytes-- > 0) {
var 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.
*/
bitjs.io.ByteBuffer.prototype.writeSignedNumber = function(num, numBytes) {
if (numBytes < 1) {
throw 'Trying to write into too few bytes: ' + numBytes;
}
var 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.
var bytes = [];
while (numBytes-- > 0) {
var eightBits = num & 255;
bytes.push(eightBits);
num >>= 8;
}
this.insertBytes(bytes);
};
/**
* @param {string} str The ASCII string to write.
*/
bitjs.io.ByteBuffer.prototype.writeASCIIString = function(str) {
for (var i = 0; i < str.length; ++i) {
var curByte = str.charCodeAt(i);
if (curByte < 0 || curByte > 255) {
throw 'Trying to write a non-ASCII string!';
}
this.insertByte(curByte);
}
};
})();

164
io/bytestream.js Normal file
View file

@ -0,0 +1,164 @@
/*
* 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 || {};
(function() {
/**
* 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.
*
* @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
*/
bitjs.io.ByteStream = function(ab, opt_offset, opt_length) {
var offset = opt_offset || 0;
var 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.
*/
bitjs.io.ByteStream.prototype.peekNumber = function(n) {
// TODO: return error if n would go past the end of the stream?
if (n <= 0 || typeof n != typeof 1)
return -1;
var result = 0;
// read from last byte to first byte and roll them in
var 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.
*/
bitjs.io.ByteStream.prototype.readNumber = function(n) {
var 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.
*/
bitjs.io.ByteStream.prototype.peekSignedNumber = function(n) {
var num = this.peekNumber(n);
var HALF = Math.pow(2, (n * 8) - 1);
var 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.
*/
bitjs.io.ByteStream.prototype.readSignedNumber = function(n) {
var 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.
*/
bitjs.io.ByteStream.prototype.peekBytes = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) {
return null;
}
var 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.
*/
bitjs.io.ByteStream.prototype.readBytes = function(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.
*/
bitjs.io.ByteStream.prototype.peekString = function(n) {
if (n <= 0 || typeof n != typeof 1) {
return "";
}
var result = "";
for (var 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.
*/
bitjs.io.ByteStream.prototype.readString = function(n) {
var strToReturn = this.peekString(n);
this.ptr += n;
return strToReturn;
};
})();

6
io_test.html → io/io_test.html
View file

@ -2,8 +2,10 @@
<html>
<head>
<title>Unit tests for bitjs.io.ByteStream and bitjs.io.ByteBuffer</title>
<script src="muther.js"></script>
<script src="io.js"></script>
<script src="../muther.js"></script>
<script src="bitstream.js"></script>
<script src="bytebuffer.js"></script>
<script src="bytestream.js"></script>
</head>
<body>
<script>

7
unrar.js
View file

@ -10,7 +10,8 @@
*/
// This file expects to be invoked as a Worker (see onmessage below).
importScripts('io.js');
importScripts('io/bitstream.js');
importScripts('io/bytebuffer.js');
importScripts('archive.js');
// Progress variables.
@ -865,7 +866,7 @@ var unrar = function(arrayBuffer) {
// extract the number at the end of both filenames
/*
var aindex = aname.length, bindex = bname.length;
// Find the last number character from the back of the filename.
while (aname[aindex-1] < '0' || aname[aindex-1] > '9') --aindex;
while (bname[bindex-1] < '0' || bname[bindex-1] > '9') --bindex;
@ -873,7 +874,7 @@ var unrar = function(arrayBuffer) {
// Find the first number character from the back of the filename
while (aname[aindex-1] >= '0' && aname[aindex-1] <= '9') --aindex;
while (bname[bindex-1] >= '0' && bname[bindex-1] <= '9') --bindex;
// parse them into numbers and return comparison
var anum = parseInt(aname.substr(aindex), 10),
bnum = parseInt(bname.substr(bindex), 10);

2
untar.js
View file

@ -9,7 +9,7 @@
*/
// This file expects to be invoked as a Worker (see onmessage below).
importScripts('io.js');
importScripts('io/bytestream.js');
importScripts('archive.js');
// Progress variables.

90
unzip.js
View file

@ -11,7 +11,9 @@
*/
// This file expects to be invoked as a Worker (see onmessage below).
importScripts('io.js');
importScripts('io/bitstream.js');
importScripts('io/bytebuffer.js');
importScripts('io/bytestream.js');
importScripts('archive.js');
// Progress variables.
@ -51,7 +53,7 @@ var ZipLocalFile = function(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);
@ -63,12 +65,12 @@ var ZipLocalFile = function(bstream) {
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);
@ -81,20 +83,20 @@ var ZipLocalFile = function(bstream) {
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.bytes.buffer, bstream.ptr, this.compressedSize);
bstream.ptr += 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
@ -155,7 +157,7 @@ var unzip = function(arrayBuffer) {
}
}
totalFilesInArchive = localFiles.length;
// got all local files, now sort them
localFiles.sort(function(a,b) {
var aname = a.filename;
@ -175,7 +177,7 @@ var unzip = function(arrayBuffer) {
// Find the first number character from the back of the filename
while (aname[aindex-1] >= '0' && aname[aindex-1] <= '9') --aindex;
while (bname[bindex-1] >= '0' && bname[bindex-1] <= '9') --bindex;
// parse them into numbers and return comparison
var anum = parseInt(aname.substr(aindex), 10),
bnum = parseInt(bname.substr(bindex), 10);
@ -192,7 +194,7 @@ var unzip = function(arrayBuffer) {
var archiveExtraFieldLength = bstream.readNumber(4);
bstream.readString(archiveExtraFieldLength);
}
// central directory structure
// TODO: handle the rest of the structures (Zip64 stuff)
if (bstream.peekNumber(4) == zCentralFileHeaderSignature) {
@ -217,13 +219,13 @@ var unzip = function(arrayBuffer) {
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
bstream.readString(fileCommentLength); // file comment
}
}
// digital signature
if (bstream.peekNumber(4) == zDigitalSignatureSignature) {
info(" Found a Digital Signature");
@ -232,24 +234,24 @@ var unzip = function(arrayBuffer) {
var 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 (var i = 0; i < localFiles.length; ++i) {
var localfile = localFiles[i];
// update progress
// 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();
@ -269,12 +271,12 @@ function getHuffmanCodes(bitLengths) {
err("Error! getHuffmanCodes() called with an invalid array");
return null;
}
// Reference: http://tools.ietf.org/html/rfc1951#page-8
var numLengths = bitLengths.length,
bl_count = [],
MAX_BITS = 1;
// Step 1: count up how many codes of each length we have
for (var i = 0; i < numLengths; ++i) {
var length = bitLengths[i];
@ -287,10 +289,10 @@ function getHuffmanCodes(bitLengths) {
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
var next_code = [],
code = 0;
@ -301,7 +303,7 @@ function getHuffmanCodes(bitLengths) {
code = (code + bl_count[bits-1]) << 1;
next_code[bits] = code;
}
// Step 3: Assign numerical values to all codes
var table = {}, tableLength = 0;
for (var n = 0; n < numLengths; ++n) {
@ -313,7 +315,7 @@ function getHuffmanCodes(bitLengths) {
}
}
table.maxLength = tableLength;
return table;
}
@ -321,7 +323,7 @@ function getHuffmanCodes(bitLengths) {
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
@ -344,18 +346,19 @@ function getFixedLiteralTable() {
for (i = 144; i <= 255; ++i) bitlengths[i] = 9;
for (i = 256; i <= 279; ++i) bitlengths[i] = 7;
for (i = 280; i <= 287; ++i) bitlengths[i] = 8;
// get huffman code table
fixedHCtoLiteral = getHuffmanCodes(bitlengths);
}
return fixedHCtoLiteral;
}
function getFixedDistanceTable() {
// create once
if (!fixedHCtoDistance) {
var bitlengths = new Array(32);
for (var i = 0; i < 32; ++i) { bitlengths[i] = 5; }
// get huffman code table
fixedHCtoDistance = getHuffmanCodes(bitlengths);
}
@ -367,21 +370,20 @@ function getFixedDistanceTable() {
function decodeSymbol(bstream, hcTable) {
var code = 0, len = 0;
var match = false;
// loop until we match
for (;;) {
// read in next bit
var 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 +
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;
}
@ -405,7 +407,6 @@ var CodeLengthCodeOrder = [16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2
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
*/
var LengthLookupTable = [
[0,3], [0,4], [0,5], [0,6],
@ -488,13 +489,13 @@ function inflateBlockData(bstream, hcLiteralTable, hcDistanceTable, buffer) {
// 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
var ch = buffer.ptr - distance;
blockSize += length;
@ -506,7 +507,6 @@ function inflateBlockData(bstream, hcLiteralTable, hcDistanceTable, buffer) {
} 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
@ -538,7 +538,6 @@ function inflate(compressedData, numDecompressedBytes) {
var len = bstream.readBits(16),
nlen = bstream.readBits(16);
// TODO: check if nlen is the ones-complement of len?
if(len > 0) buffer.insertBytes(bstream.readBytes(len));
blockSize = len;
}
@ -551,17 +550,17 @@ function inflate(compressedData, numDecompressedBytes) {
var numLiteralLengthCodes = bstream.readBits(5) + 257;
var numDistanceCodes = bstream.readBits(5) + 1,
numCodeLengthCodes = bstream.readBits(4) + 4;
// populate the array of code length codes (first de-compaction)
// populate the array of code length codes (first de-compaction)
var codeLengthsCodeLengths = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];
for (var i = 0; i < numCodeLengthCodes; ++i) {
codeLengthsCodeLengths[ CodeLengthCodeOrder[i] ] = bstream.readBits(3);
}
// get the Huffman Codes for the code lengths
var codeLengthsCodes = getHuffmanCodes(codeLengthsCodeLengths);
// now follow this mapping
// now follow this mapping
/*
0 - 15: Represent code lengths of 0 - 15
16: Copy the previous code length 3 - 6 times.
@ -604,10 +603,10 @@ function inflate(compressedData, numDecompressedBytes) {
}
}
}
// now split the distance code lengths out of the literal code array
var distanceCodeLengths = literalCodeLengths.splice(numLiteralLengthCodes, numDistanceCodes);
// now generate the true Huffman Code tables using these code lengths
var hcLiteralTable = getHuffmanCodes(literalCodeLengths),
hcDistanceTable = getHuffmanCodes(distanceCodeLengths);
@ -623,10 +622,9 @@ function inflate(compressedData, numDecompressedBytes) {
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;
}