yetangitu/bitjs
1
0
Fork 0
mirror of https://github.com/codedread/bitjs synced 2025-10-03 17:49:16 +02:00
Code Issues Releases Wiki Activity

jsdoc tweaks

Browse source
This commit is contained in:
codedread 2013-07-08 22:12:12 -07:00
parent 262d86c17f
commit 6d86b98b95
1 changed files with 80 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

113
io.js
View file

@ -27,11 +27,11 @@ var BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF ];
/** /**
* This bit stream peeks and consumes bits out of a binary stream. * This bit stream peeks and consumes bits out of a binary stream.
* *
* {ArrayBuffer} ab An ArrayBuffer object or a Uint8Array. * @param {ArrayBuffer} ab An ArrayBuffer object or a Uint8Array.
* {boolean} rtl Whether the stream reads bits from the byte starting * @param {boolean} rtl Whether the stream reads bits from the byte starting
* from bit 7 to 0 (true) or bit 0 to 7 (false). * from bit 7 to 0 (true) or bit 0 to 7 (false).
* {Number} opt_offset The offset into the ArrayBuffer * @param {Number} opt_offset The offset into the ArrayBuffer
* {Number} opt_length The length of this BitStream * @param {Number} opt_length The length of this BitStream
*/ */
bitjs.io.BitStream = function(ab, rtl, opt_offset, opt_length) { bitjs.io.BitStream = function(ab, rtl, opt_offset, opt_length) {
if (!ab || !ab.toString || ab.toString() !== "[object ArrayBuffer]") { if (!ab || !ab.toString || ab.toString() !== "[object ArrayBuffer]") {
@ -46,11 +46,14 @@ bitjs.io.BitStream = function(ab, rtl, opt_offset, opt_length) {
this.peekBits = rtl ? this.peekBits_rtl : this.peekBits_ltr; this.peekBits = rtl ? this.peekBits_rtl : this.peekBits_ltr;
}; };
// byte0 byte1 byte2 byte3
// 7......0 | 7......0 | 7......0 | 7......0 /**
// * byte0 byte1 byte2 byte3
// The bit pointer starts at bit0 of byte0 and moves left until it reaches * 7......0 | 7......0 | 7......0 | 7......0
// bit7 of byte0, then jumps to bit0 of byte1, etc. *
* The bit pointer starts at bit0 of byte0 and moves left until it reaches
* bit7 of byte0, then jumps to bit0 of byte1, etc.
*/
bitjs.io.BitStream.prototype.peekBits_ltr = function(n, movePointers) { bitjs.io.BitStream.prototype.peekBits_ltr = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) { if (n <= 0 || typeof n != typeof 1) {
return 0; return 0;
@ -102,11 +105,14 @@ bitjs.io.BitStream.prototype.peekBits_ltr = function(n, movePointers) {
return result; return result;
}; };
// byte0 byte1 byte2 byte3
// 7......0 | 7......0 | 7......0 | 7......0 /**
// * byte0 byte1 byte2 byte3
// The bit pointer starts at bit7 of byte0 and moves right until it reaches * 7......0 | 7......0 | 7......0 | 7......0
// bit0 of byte0, then goes to bit7 of byte1, etc. *
* The bit pointer starts at bit7 of byte0 and moves right until it reaches
* bit0 of byte0, then goes to bit7 of byte1, etc.
*/
bitjs.io.BitStream.prototype.peekBits_rtl = function(n, movePointers) { bitjs.io.BitStream.prototype.peekBits_rtl = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) { if (n <= 0 || typeof n != typeof 1) {
return 0; return 0;
@ -155,21 +161,29 @@ bitjs.io.BitStream.prototype.peekBits_rtl = function(n, movePointers) {
return result; return result;
}; };
//some voodoo magic
/**
* Some voodoo magic.
*/
bitjs.io.BitStream.prototype.getBits = function() { bitjs.io.BitStream.prototype.getBits = function() {
return (((((this.bytes[this.bytePtr] & 0xff) << 16) + return (((((this.bytes[this.bytePtr] & 0xff) << 16) +
((this.bytes[this.bytePtr+1] & 0xff) << 8) + ((this.bytes[this.bytePtr+1] & 0xff) << 8) +
((this.bytes[this.bytePtr+2] & 0xff))) >>> (8-this.bitPtr)) & 0xffff); ((this.bytes[this.bytePtr+2] & 0xff))) >>> (8-this.bitPtr)) & 0xffff);
}; };
/**
*/
bitjs.io.BitStream.prototype.readBits = function(n) { bitjs.io.BitStream.prototype.readBits = function(n) {
return this.peekBits(n, true); 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 * This returns n bytes as a sub-array, advancing the pointer if movePointers
// the current byte. * is true. Only use this for uncompressed blocks as this throws away remaining
* bits in the current byte.
*/
bitjs.io.BitStream.prototype.peekBytes = function(n, movePointers) { bitjs.io.BitStream.prototype.peekBytes = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) { if (n <= 0 || typeof n != typeof 1) {
return 0; return 0;
@ -194,7 +208,10 @@ bitjs.io.BitStream.prototype.peekBytes = function(n, movePointers) {
return result; return result;
}; };
bitjs.io.BitStream.prototype.readBytes = function( n ) {
/**
*/
bitjs.io.BitStream.prototype.readBytes = function(n) {
return this.peekBytes(n, true); return this.peekBytes(n, true);
}; };
@ -206,9 +223,9 @@ bitjs.io.BitStream.prototype.readBytes = function( n ) {
* This object is much easier to write than the above BitStream since * This object is much easier to write than the above BitStream since
* everything is byte-aligned. * everything is byte-aligned.
* *
* {ArrayBuffer} ab The ArrayBuffer object. * @param {ArrayBuffer} ab The ArrayBuffer object.
* {Number} opt_offset The offset into the ArrayBuffer * @param {Number} opt_offset The offset into the ArrayBuffer
* {Number} opt_length The length of this BitStream * @param {Number} opt_length The length of this BitStream
*/ */
bitjs.io.ByteStream = function(ab, opt_offset, opt_length) { bitjs.io.ByteStream = function(ab, opt_offset, opt_length) {
var offset = opt_offset || 0; var offset = opt_offset || 0;
@ -217,9 +234,13 @@ bitjs.io.ByteStream = function(ab, opt_offset, opt_length) {
this.ptr = 0; 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? /**
bitjs.io.ByteStream.prototype.peekNumber = function( n ) { * 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?
*/
bitjs.io.ByteStream.prototype.peekNumber = function(n) {
// TODO: return error if n would go past the end of the stream? // TODO: return error if n would go past the end of the stream?
if (n <= 0 || typeof n != typeof 1) if (n <= 0 || typeof n != typeof 1)
return -1; return -1;
@ -235,16 +256,22 @@ bitjs.io.ByteStream.prototype.peekNumber = function( n ) {
return result; return result;
}; };
// returns the next n bytes as an unsigned number (or -1 on error)
// and advances the stream pointer n bytes /**
bitjs.io.ByteStream.prototype.readNumber = function( n ) { * Returns the next n bytes as an unsigned number (or -1 on error) and advances
* the stream pointer n bytes.
*/
bitjs.io.ByteStream.prototype.readNumber = function(n) {
var num = this.peekNumber( n ); var num = this.peekNumber( n );
this.ptr += n; this.ptr += n;
return num; return num;
}; };
// This returns n bytes as a sub-array, advancing the pointer if movePointers
// is true. /**
* This returns n bytes as a sub-array, advancing the pointer if movePointers
* is true.
*/
bitjs.io.ByteStream.prototype.peekBytes = function(n, movePointers) { bitjs.io.ByteStream.prototype.peekBytes = function(n, movePointers) {
if (n <= 0 || typeof n != typeof 1) { if (n <= 0 || typeof n != typeof 1) {
return 0; return 0;
@ -259,12 +286,18 @@ bitjs.io.ByteStream.prototype.peekBytes = function(n, movePointers) {
return result; return result;
}; };
bitjs.io.ByteStream.prototype.readBytes = function( n ) {
/**
*/
bitjs.io.ByteStream.prototype.readBytes = function(n) {
return this.peekBytes(n, true); return this.peekBytes(n, true);
}; };
// peeks at the next n bytes as a string but does not advance the pointer
bitjs.io.ByteStream.prototype.peekString = function( n ) { /**
* Peeks at the next n bytes as a string but does not advance the pointer.
*/
bitjs.io.ByteStream.prototype.peekString = function(n) {
if (n <= 0 || typeof n != typeof 1) { if (n <= 0 || typeof n != typeof 1) {
return 0; return 0;
} }
@ -276,8 +309,10 @@ bitjs.io.ByteStream.prototype.peekString = function( n ) {
return result; return result;
}; };
// returns the next n bytes as a string
// and advances the stream pointer n bytes /**
* Returns the next n bytes as a string and advances the stream pointer n bytes.
*/
bitjs.io.ByteStream.prototype.readString = function(n) { bitjs.io.ByteStream.prototype.readString = function(n) {
var strToReturn = this.peekString(n); var strToReturn = this.peekString(n);
this.ptr += n; this.ptr += n;
@ -296,11 +331,17 @@ bitjs.io.ByteBuffer = function(numBytes) {
this.ptr = 0; this.ptr = 0;
}; };
/**
*/
bitjs.io.ByteBuffer.prototype.insertByte = function(b) { bitjs.io.ByteBuffer.prototype.insertByte = function(b) {
// TODO: throw if byte is invalid? // TODO: throw if byte is invalid?
this.data[this.ptr++] = b; this.data[this.ptr++] = b;
}; };
/**
*/
bitjs.io.ByteBuffer.prototype.insertBytes = function(bytes) { bitjs.io.ByteBuffer.prototype.insertBytes = function(bytes) {
// TODO: throw if bytes is invalid? // TODO: throw if bytes is invalid?
this.data.set(bytes, this.ptr); this.data.set(bytes, this.ptr);