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musix-oss/node_modules/node-forge/lib/util.js

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/**
* Utility functions for web applications.
*
* @author Dave Longley
*
* Copyright (c) 2010-2018 Digital Bazaar, Inc.
*/
var forge = require('./forge');
var baseN = require('./baseN');
/* Utilities API */
var util = module.exports = forge.util = forge.util || {};
// define setImmediate and nextTick
(function() {
// use native nextTick
if(typeof process !== 'undefined' && process.nextTick) {
util.nextTick = process.nextTick;
if(typeof setImmediate === 'function') {
util.setImmediate = setImmediate;
} else {
// polyfill setImmediate with nextTick, older versions of node
// (those w/o setImmediate) won't totally starve IO
util.setImmediate = util.nextTick;
}
return;
}
// polyfill nextTick with native setImmediate
if(typeof setImmediate === 'function') {
util.setImmediate = function() { return setImmediate.apply(undefined, arguments); };
util.nextTick = function(callback) {
return setImmediate(callback);
};
return;
}
/* Note: A polyfill upgrade pattern is used here to allow combining
polyfills. For example, MutationObserver is fast, but blocks UI updates,
so it needs to allow UI updates periodically, so it falls back on
postMessage or setTimeout. */
// polyfill with setTimeout
util.setImmediate = function(callback) {
setTimeout(callback, 0);
};
// upgrade polyfill to use postMessage
if(typeof window !== 'undefined' &&
typeof window.postMessage === 'function') {
var msg = 'forge.setImmediate';
var callbacks = [];
util.setImmediate = function(callback) {
callbacks.push(callback);
// only send message when one hasn't been sent in
// the current turn of the event loop
if(callbacks.length === 1) {
window.postMessage(msg, '*');
}
};
function handler(event) {
if(event.source === window && event.data === msg) {
event.stopPropagation();
var copy = callbacks.slice();
callbacks.length = 0;
copy.forEach(function(callback) {
callback();
});
}
}
window.addEventListener('message', handler, true);
}
// upgrade polyfill to use MutationObserver
if(typeof MutationObserver !== 'undefined') {
// polyfill with MutationObserver
var now = Date.now();
var attr = true;
var div = document.createElement('div');
var callbacks = [];
new MutationObserver(function() {
var copy = callbacks.slice();
callbacks.length = 0;
copy.forEach(function(callback) {
callback();
});
}).observe(div, {attributes: true});
var oldSetImmediate = util.setImmediate;
util.setImmediate = function(callback) {
if(Date.now() - now > 15) {
now = Date.now();
oldSetImmediate(callback);
} else {
callbacks.push(callback);
// only trigger observer when it hasn't been triggered in
// the current turn of the event loop
if(callbacks.length === 1) {
div.setAttribute('a', attr = !attr);
}
}
};
}
util.nextTick = util.setImmediate;
})();
// check if running under Node.js
util.isNodejs =
typeof process !== 'undefined' && process.versions && process.versions.node;
// define isArray
util.isArray = Array.isArray || function(x) {
return Object.prototype.toString.call(x) === '[object Array]';
};
// define isArrayBuffer
util.isArrayBuffer = function(x) {
return typeof ArrayBuffer !== 'undefined' && x instanceof ArrayBuffer;
};
// define isArrayBufferView
util.isArrayBufferView = function(x) {
return x && util.isArrayBuffer(x.buffer) && x.byteLength !== undefined;
};
/**
* Ensure a bits param is 8, 16, 24, or 32. Used to validate input for
* algorithms where bit manipulation, JavaScript limitations, and/or algorithm
* design only allow for byte operations of a limited size.
*
* @param n number of bits.
*
* Throw Error if n invalid.
*/
function _checkBitsParam(n) {
if(!(n === 8 || n === 16 || n === 24 || n === 32)) {
throw new Error('Only 8, 16, 24, or 32 bits supported: ' + n);
}
}
// TODO: set ByteBuffer to best available backing
util.ByteBuffer = ByteStringBuffer;
/** Buffer w/BinaryString backing */
/**
* Constructor for a binary string backed byte buffer.
*
* @param [b] the bytes to wrap (either encoded as string, one byte per
* character, or as an ArrayBuffer or Typed Array).
*/
function ByteStringBuffer(b) {
// TODO: update to match DataBuffer API
// the data in this buffer
this.data = '';
// the pointer for reading from this buffer
this.read = 0;
if(typeof b === 'string') {
this.data = b;
} else if(util.isArrayBuffer(b) || util.isArrayBufferView(b)) {
if(typeof Buffer !== 'undefined' && b instanceof Buffer) {
this.data = b.toString('binary');
} else {
// convert native buffer to forge buffer
// FIXME: support native buffers internally instead
var arr = new Uint8Array(b);
try {
this.data = String.fromCharCode.apply(null, arr);
} catch(e) {
for(var i = 0; i < arr.length; ++i) {
this.putByte(arr[i]);
}
}
}
} else if(b instanceof ByteStringBuffer ||
(typeof b === 'object' && typeof b.data === 'string' &&
typeof b.read === 'number')) {
// copy existing buffer
this.data = b.data;
this.read = b.read;
}
// used for v8 optimization
this._constructedStringLength = 0;
}
util.ByteStringBuffer = ByteStringBuffer;
/* Note: This is an optimization for V8-based browsers. When V8 concatenates
a string, the strings are only joined logically using a "cons string" or
"constructed/concatenated string". These containers keep references to one
another and can result in very large memory usage. For example, if a 2MB
string is constructed by concatenating 4 bytes together at a time, the
memory usage will be ~44MB; so ~22x increase. The strings are only joined
together when an operation requiring their joining takes place, such as
substr(). This function is called when adding data to this buffer to ensure
these types of strings are periodically joined to reduce the memory
footprint. */
var _MAX_CONSTRUCTED_STRING_LENGTH = 4096;
util.ByteStringBuffer.prototype._optimizeConstructedString = function(x) {
this._constructedStringLength += x;
if(this._constructedStringLength > _MAX_CONSTRUCTED_STRING_LENGTH) {
// this substr() should cause the constructed string to join
this.data.substr(0, 1);
this._constructedStringLength = 0;
}
};
/**
* Gets the number of bytes in this buffer.
*
* @return the number of bytes in this buffer.
*/
util.ByteStringBuffer.prototype.length = function() {
return this.data.length - this.read;
};
/**
* Gets whether or not this buffer is empty.
*
* @return true if this buffer is empty, false if not.
*/
util.ByteStringBuffer.prototype.isEmpty = function() {
return this.length() <= 0;
};
/**
* Puts a byte in this buffer.
*
* @param b the byte to put.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putByte = function(b) {
return this.putBytes(String.fromCharCode(b));
};
/**
* Puts a byte in this buffer N times.
*
* @param b the byte to put.
* @param n the number of bytes of value b to put.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.fillWithByte = function(b, n) {
b = String.fromCharCode(b);
var d = this.data;
while(n > 0) {
if(n & 1) {
d += b;
}
n >>>= 1;
if(n > 0) {
b += b;
}
}
this.data = d;
this._optimizeConstructedString(n);
return this;
};
/**
* Puts bytes in this buffer.
*
* @param bytes the bytes (as a UTF-8 encoded string) to put.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putBytes = function(bytes) {
this.data += bytes;
this._optimizeConstructedString(bytes.length);
return this;
};
/**
* Puts a UTF-16 encoded string into this buffer.
*
* @param str the string to put.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putString = function(str) {
return this.putBytes(util.encodeUtf8(str));
};
/**
* Puts a 16-bit integer in this buffer in big-endian order.
*
* @param i the 16-bit integer.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putInt16 = function(i) {
return this.putBytes(
String.fromCharCode(i >> 8 & 0xFF) +
String.fromCharCode(i & 0xFF));
};
/**
* Puts a 24-bit integer in this buffer in big-endian order.
*
* @param i the 24-bit integer.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putInt24 = function(i) {
return this.putBytes(
String.fromCharCode(i >> 16 & 0xFF) +
String.fromCharCode(i >> 8 & 0xFF) +
String.fromCharCode(i & 0xFF));
};
/**
* Puts a 32-bit integer in this buffer in big-endian order.
*
* @param i the 32-bit integer.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putInt32 = function(i) {
return this.putBytes(
String.fromCharCode(i >> 24 & 0xFF) +
String.fromCharCode(i >> 16 & 0xFF) +
String.fromCharCode(i >> 8 & 0xFF) +
String.fromCharCode(i & 0xFF));
};
/**
* Puts a 16-bit integer in this buffer in little-endian order.
*
* @param i the 16-bit integer.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putInt16Le = function(i) {
return this.putBytes(
String.fromCharCode(i & 0xFF) +
String.fromCharCode(i >> 8 & 0xFF));
};
/**
* Puts a 24-bit integer in this buffer in little-endian order.
*
* @param i the 24-bit integer.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putInt24Le = function(i) {
return this.putBytes(
String.fromCharCode(i & 0xFF) +
String.fromCharCode(i >> 8 & 0xFF) +
String.fromCharCode(i >> 16 & 0xFF));
};
/**
* Puts a 32-bit integer in this buffer in little-endian order.
*
* @param i the 32-bit integer.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putInt32Le = function(i) {
return this.putBytes(
String.fromCharCode(i & 0xFF) +
String.fromCharCode(i >> 8 & 0xFF) +
String.fromCharCode(i >> 16 & 0xFF) +
String.fromCharCode(i >> 24 & 0xFF));
};
/**
* Puts an n-bit integer in this buffer in big-endian order.
*
* @param i the n-bit integer.
* @param n the number of bits in the integer (8, 16, 24, or 32).
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putInt = function(i, n) {
_checkBitsParam(n);
var bytes = '';
do {
n -= 8;
bytes += String.fromCharCode((i >> n) & 0xFF);
} while(n > 0);
return this.putBytes(bytes);
};
/**
* Puts a signed n-bit integer in this buffer in big-endian order. Two's
* complement representation is used.
*
* @param i the n-bit integer.
* @param n the number of bits in the integer (8, 16, 24, or 32).
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putSignedInt = function(i, n) {
// putInt checks n
if(i < 0) {
i += 2 << (n - 1);
}
return this.putInt(i, n);
};
/**
* Puts the given buffer into this buffer.
*
* @param buffer the buffer to put into this one.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.putBuffer = function(buffer) {
return this.putBytes(buffer.getBytes());
};
/**
* Gets a byte from this buffer and advances the read pointer by 1.
*
* @return the byte.
*/
util.ByteStringBuffer.prototype.getByte = function() {
return this.data.charCodeAt(this.read++);
};
/**
* Gets a uint16 from this buffer in big-endian order and advances the read
* pointer by 2.
*
* @return the uint16.
*/
util.ByteStringBuffer.prototype.getInt16 = function() {
var rval = (
this.data.charCodeAt(this.read) << 8 ^
this.data.charCodeAt(this.read + 1));
this.read += 2;
return rval;
};
/**
* Gets a uint24 from this buffer in big-endian order and advances the read
* pointer by 3.
*
* @return the uint24.
*/
util.ByteStringBuffer.prototype.getInt24 = function() {
var rval = (
this.data.charCodeAt(this.read) << 16 ^
this.data.charCodeAt(this.read + 1) << 8 ^
this.data.charCodeAt(this.read + 2));
this.read += 3;
return rval;
};
/**
* Gets a uint32 from this buffer in big-endian order and advances the read
* pointer by 4.
*
* @return the word.
*/
util.ByteStringBuffer.prototype.getInt32 = function() {
var rval = (
this.data.charCodeAt(this.read) << 24 ^
this.data.charCodeAt(this.read + 1) << 16 ^
this.data.charCodeAt(this.read + 2) << 8 ^
this.data.charCodeAt(this.read + 3));
this.read += 4;
return rval;
};
/**
* Gets a uint16 from this buffer in little-endian order and advances the read
* pointer by 2.
*
* @return the uint16.
*/
util.ByteStringBuffer.prototype.getInt16Le = function() {
var rval = (
this.data.charCodeAt(this.read) ^
this.data.charCodeAt(this.read + 1) << 8);
this.read += 2;
return rval;
};
/**
* Gets a uint24 from this buffer in little-endian order and advances the read
* pointer by 3.
*
* @return the uint24.
*/
util.ByteStringBuffer.prototype.getInt24Le = function() {
var rval = (
this.data.charCodeAt(this.read) ^
this.data.charCodeAt(this.read + 1) << 8 ^
this.data.charCodeAt(this.read + 2) << 16);
this.read += 3;
return rval;
};
/**
* Gets a uint32 from this buffer in little-endian order and advances the read
* pointer by 4.
*
* @return the word.
*/
util.ByteStringBuffer.prototype.getInt32Le = function() {
var rval = (
this.data.charCodeAt(this.read) ^
this.data.charCodeAt(this.read + 1) << 8 ^
this.data.charCodeAt(this.read + 2) << 16 ^
this.data.charCodeAt(this.read + 3) << 24);
this.read += 4;
return rval;
};
/**
* Gets an n-bit integer from this buffer in big-endian order and advances the
* read pointer by ceil(n/8).
*
* @param n the number of bits in the integer (8, 16, 24, or 32).
*
* @return the integer.
*/
util.ByteStringBuffer.prototype.getInt = function(n) {
_checkBitsParam(n);
var rval = 0;
do {
// TODO: Use (rval * 0x100) if adding support for 33 to 53 bits.
rval = (rval << 8) + this.data.charCodeAt(this.read++);
n -= 8;
} while(n > 0);
return rval;
};
/**
* Gets a signed n-bit integer from this buffer in big-endian order, using
* two's complement, and advances the read pointer by n/8.
*
* @param n the number of bits in the integer (8, 16, 24, or 32).
*
* @return the integer.
*/
util.ByteStringBuffer.prototype.getSignedInt = function(n) {
// getInt checks n
var x = this.getInt(n);
var max = 2 << (n - 2);
if(x >= max) {
x -= max << 1;
}
return x;
};
/**
* Reads bytes out into a UTF-8 string and clears them from the buffer.
*
* @param count the number of bytes to read, undefined or null for all.
*
* @return a UTF-8 string of bytes.
*/
util.ByteStringBuffer.prototype.getBytes = function(count) {
var rval;
if(count) {
// read count bytes
count = Math.min(this.length(), count);
rval = this.data.slice(this.read, this.read + count);
this.read += count;
} else if(count === 0) {
rval = '';
} else {
// read all bytes, optimize to only copy when needed
rval = (this.read === 0) ? this.data : this.data.slice(this.read);
this.clear();
}
return rval;
};
/**
* Gets a UTF-8 encoded string of the bytes from this buffer without modifying
* the read pointer.
*
* @param count the number of bytes to get, omit to get all.
*
* @return a string full of UTF-8 encoded characters.
*/
util.ByteStringBuffer.prototype.bytes = function(count) {
return (typeof(count) === 'undefined' ?
this.data.slice(this.read) :
this.data.slice(this.read, this.read + count));
};
/**
* Gets a byte at the given index without modifying the read pointer.
*
* @param i the byte index.
*
* @return the byte.
*/
util.ByteStringBuffer.prototype.at = function(i) {
return this.data.charCodeAt(this.read + i);
};
/**
* Puts a byte at the given index without modifying the read pointer.
*
* @param i the byte index.
* @param b the byte to put.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.setAt = function(i, b) {
this.data = this.data.substr(0, this.read + i) +
String.fromCharCode(b) +
this.data.substr(this.read + i + 1);
return this;
};
/**
* Gets the last byte without modifying the read pointer.
*
* @return the last byte.
*/
util.ByteStringBuffer.prototype.last = function() {
return this.data.charCodeAt(this.data.length - 1);
};
/**
* Creates a copy of this buffer.
*
* @return the copy.
*/
util.ByteStringBuffer.prototype.copy = function() {
var c = util.createBuffer(this.data);
c.read = this.read;
return c;
};
/**
* Compacts this buffer.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.compact = function() {
if(this.read > 0) {
this.data = this.data.slice(this.read);
this.read = 0;
}
return this;
};
/**
* Clears this buffer.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.clear = function() {
this.data = '';
this.read = 0;
return this;
};
/**
* Shortens this buffer by triming bytes off of the end of this buffer.
*
* @param count the number of bytes to trim off.
*
* @return this buffer.
*/
util.ByteStringBuffer.prototype.truncate = function(count) {
var len = Math.max(0, this.length() - count);
this.data = this.data.substr(this.read, len);
this.read = 0;
return this;
};
/**
* Converts this buffer to a hexadecimal string.
*
* @return a hexadecimal string.
*/
util.ByteStringBuffer.prototype.toHex = function() {
var rval = '';
for(var i = this.read; i < this.data.length; ++i) {
var b = this.data.charCodeAt(i);
if(b < 16) {
rval += '0';
}
rval += b.toString(16);
}
return rval;
};
/**
* Converts this buffer to a UTF-16 string (standard JavaScript string).
*
* @return a UTF-16 string.
*/
util.ByteStringBuffer.prototype.toString = function() {
return util.decodeUtf8(this.bytes());
};
/** End Buffer w/BinaryString backing */
/** Buffer w/UInt8Array backing */
/**
* FIXME: Experimental. Do not use yet.
*
* Constructor for an ArrayBuffer-backed byte buffer.
*
* The buffer may be constructed from a string, an ArrayBuffer, DataView, or a
* TypedArray.
*
* If a string is given, its encoding should be provided as an option,
* otherwise it will default to 'binary'. A 'binary' string is encoded such
* that each character is one byte in length and size.
*
* If an ArrayBuffer, DataView, or TypedArray is given, it will be used
* *directly* without any copying. Note that, if a write to the buffer requires
* more space, the buffer will allocate a new backing ArrayBuffer to
* accommodate. The starting read and write offsets for the buffer may be
* given as options.
*
* @param [b] the initial bytes for this buffer.
* @param options the options to use:
* [readOffset] the starting read offset to use (default: 0).
* [writeOffset] the starting write offset to use (default: the
* length of the first parameter).
* [growSize] the minimum amount, in bytes, to grow the buffer by to
* accommodate writes (default: 1024).
* [encoding] the encoding ('binary', 'utf8', 'utf16', 'hex') for the
* first parameter, if it is a string (default: 'binary').
*/
function DataBuffer(b, options) {
// default options
options = options || {};
// pointers for read from/write to buffer
this.read = options.readOffset || 0;
this.growSize = options.growSize || 1024;
var isArrayBuffer = util.isArrayBuffer(b);
var isArrayBufferView = util.isArrayBufferView(b);
if(isArrayBuffer || isArrayBufferView) {
// use ArrayBuffer directly
if(isArrayBuffer) {
this.data = new DataView(b);
} else {
// TODO: adjust read/write offset based on the type of view
// or specify that this must be done in the options ... that the
// offsets are byte-based
this.data = new DataView(b.buffer, b.byteOffset, b.byteLength);
}
this.write = ('writeOffset' in options ?
options.writeOffset : this.data.byteLength);
return;
}
// initialize to empty array buffer and add any given bytes using putBytes
this.data = new DataView(new ArrayBuffer(0));
this.write = 0;
if(b !== null && b !== undefined) {
this.putBytes(b);
}
if('writeOffset' in options) {
this.write = options.writeOffset;
}
}
util.DataBuffer = DataBuffer;
/**
* Gets the number of bytes in this buffer.
*
* @return the number of bytes in this buffer.
*/
util.DataBuffer.prototype.length = function() {
return this.write - this.read;
};
/**
* Gets whether or not this buffer is empty.
*
* @return true if this buffer is empty, false if not.
*/
util.DataBuffer.prototype.isEmpty = function() {
return this.length() <= 0;
};
/**
* Ensures this buffer has enough empty space to accommodate the given number
* of bytes. An optional parameter may be given that indicates a minimum
* amount to grow the buffer if necessary. If the parameter is not given,
* the buffer will be grown by some previously-specified default amount
* or heuristic.
*
* @param amount the number of bytes to accommodate.
* @param [growSize] the minimum amount, in bytes, to grow the buffer by if
* necessary.
*/
util.DataBuffer.prototype.accommodate = function(amount, growSize) {
if(this.length() >= amount) {
return this;
}
growSize = Math.max(growSize || this.growSize, amount);
// grow buffer
var src = new Uint8Array(
this.data.buffer, this.data.byteOffset, this.data.byteLength);
var dst = new Uint8Array(this.length() + growSize);
dst.set(src);
this.data = new DataView(dst.buffer);
return this;
};
/**
* Puts a byte in this buffer.
*
* @param b the byte to put.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putByte = function(b) {
this.accommodate(1);
this.data.setUint8(this.write++, b);
return this;
};
/**
* Puts a byte in this buffer N times.
*
* @param b the byte to put.
* @param n the number of bytes of value b to put.
*
* @return this buffer.
*/
util.DataBuffer.prototype.fillWithByte = function(b, n) {
this.accommodate(n);
for(var i = 0; i < n; ++i) {
this.data.setUint8(b);
}
return this;
};
/**
* Puts bytes in this buffer. The bytes may be given as a string, an
* ArrayBuffer, a DataView, or a TypedArray.
*
* @param bytes the bytes to put.
* @param [encoding] the encoding for the first parameter ('binary', 'utf8',
* 'utf16', 'hex'), if it is a string (default: 'binary').
*
* @return this buffer.
*/
util.DataBuffer.prototype.putBytes = function(bytes, encoding) {
if(util.isArrayBufferView(bytes)) {
var src = new Uint8Array(bytes.buffer, bytes.byteOffset, bytes.byteLength);
var len = src.byteLength - src.byteOffset;
this.accommodate(len);
var dst = new Uint8Array(this.data.buffer, this.write);
dst.set(src);
this.write += len;
return this;
}
if(util.isArrayBuffer(bytes)) {
var src = new Uint8Array(bytes);
this.accommodate(src.byteLength);
var dst = new Uint8Array(this.data.buffer);
dst.set(src, this.write);
this.write += src.byteLength;
return this;
}
// bytes is a util.DataBuffer or equivalent
if(bytes instanceof util.DataBuffer ||
(typeof bytes === 'object' &&
typeof bytes.read === 'number' && typeof bytes.write === 'number' &&
util.isArrayBufferView(bytes.data))) {
var src = new Uint8Array(bytes.data.byteLength, bytes.read, bytes.length());
this.accommodate(src.byteLength);
var dst = new Uint8Array(bytes.data.byteLength, this.write);
dst.set(src);
this.write += src.byteLength;
return this;
}
if(bytes instanceof util.ByteStringBuffer) {
// copy binary string and process as the same as a string parameter below
bytes = bytes.data;
encoding = 'binary';
}
// string conversion
encoding = encoding || 'binary';
if(typeof bytes === 'string') {
var view;
// decode from string
if(encoding === 'hex') {
this.accommodate(Math.ceil(bytes.length / 2));
view = new Uint8Array(this.data.buffer, this.write);
this.write += util.binary.hex.decode(bytes, view, this.write);
return this;
}
if(encoding === 'base64') {
this.accommodate(Math.ceil(bytes.length / 4) * 3);
view = new Uint8Array(this.data.buffer, this.write);
this.write += util.binary.base64.decode(bytes, view, this.write);
return this;
}
// encode text as UTF-8 bytes
if(encoding === 'utf8') {
// encode as UTF-8 then decode string as raw binary
bytes = util.encodeUtf8(bytes);
encoding = 'binary';
}
// decode string as raw binary
if(encoding === 'binary' || encoding === 'raw') {
// one byte per character
this.accommodate(bytes.length);
view = new Uint8Array(this.data.buffer, this.write);
this.write += util.binary.raw.decode(view);
return this;
}
// encode text as UTF-16 bytes
if(encoding === 'utf16') {
// two bytes per character
this.accommodate(bytes.length * 2);
view = new Uint16Array(this.data.buffer, this.write);
this.write += util.text.utf16.encode(view);
return this;
}
throw new Error('Invalid encoding: ' + encoding);
}
throw Error('Invalid parameter: ' + bytes);
};
/**
* Puts the given buffer into this buffer.
*
* @param buffer the buffer to put into this one.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putBuffer = function(buffer) {
this.putBytes(buffer);
buffer.clear();
return this;
};
/**
* Puts a string into this buffer.
*
* @param str the string to put.
* @param [encoding] the encoding for the string (default: 'utf16').
*
* @return this buffer.
*/
util.DataBuffer.prototype.putString = function(str) {
return this.putBytes(str, 'utf16');
};
/**
* Puts a 16-bit integer in this buffer in big-endian order.
*
* @param i the 16-bit integer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putInt16 = function(i) {
this.accommodate(2);
this.data.setInt16(this.write, i);
this.write += 2;
return this;
};
/**
* Puts a 24-bit integer in this buffer in big-endian order.
*
* @param i the 24-bit integer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putInt24 = function(i) {
this.accommodate(3);
this.data.setInt16(this.write, i >> 8 & 0xFFFF);
this.data.setInt8(this.write, i >> 16 & 0xFF);
this.write += 3;
return this;
};
/**
* Puts a 32-bit integer in this buffer in big-endian order.
*
* @param i the 32-bit integer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putInt32 = function(i) {
this.accommodate(4);
this.data.setInt32(this.write, i);
this.write += 4;
return this;
};
/**
* Puts a 16-bit integer in this buffer in little-endian order.
*
* @param i the 16-bit integer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putInt16Le = function(i) {
this.accommodate(2);
this.data.setInt16(this.write, i, true);
this.write += 2;
return this;
};
/**
* Puts a 24-bit integer in this buffer in little-endian order.
*
* @param i the 24-bit integer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putInt24Le = function(i) {
this.accommodate(3);
this.data.setInt8(this.write, i >> 16 & 0xFF);
this.data.setInt16(this.write, i >> 8 & 0xFFFF, true);
this.write += 3;
return this;
};
/**
* Puts a 32-bit integer in this buffer in little-endian order.
*
* @param i the 32-bit integer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putInt32Le = function(i) {
this.accommodate(4);
this.data.setInt32(this.write, i, true);
this.write += 4;
return this;
};
/**
* Puts an n-bit integer in this buffer in big-endian order.
*
* @param i the n-bit integer.
* @param n the number of bits in the integer (8, 16, 24, or 32).
*
* @return this buffer.
*/
util.DataBuffer.prototype.putInt = function(i, n) {
_checkBitsParam(n);
this.accommodate(n / 8);
do {
n -= 8;
this.data.setInt8(this.write++, (i >> n) & 0xFF);
} while(n > 0);
return this;
};
/**
* Puts a signed n-bit integer in this buffer in big-endian order. Two's
* complement representation is used.
*
* @param i the n-bit integer.
* @param n the number of bits in the integer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.putSignedInt = function(i, n) {
_checkBitsParam(n);
this.accommodate(n / 8);
if(i < 0) {
i += 2 << (n - 1);
}
return this.putInt(i, n);
};
/**
* Gets a byte from this buffer and advances the read pointer by 1.
*
* @return the byte.
*/
util.DataBuffer.prototype.getByte = function() {
return this.data.getInt8(this.read++);
};
/**
* Gets a uint16 from this buffer in big-endian order and advances the read
* pointer by 2.
*
* @return the uint16.
*/
util.DataBuffer.prototype.getInt16 = function() {
var rval = this.data.getInt16(this.read);
this.read += 2;
return rval;
};
/**
* Gets a uint24 from this buffer in big-endian order and advances the read
* pointer by 3.
*
* @return the uint24.
*/
util.DataBuffer.prototype.getInt24 = function() {
var rval = (
this.data.getInt16(this.read) << 8 ^
this.data.getInt8(this.read + 2));
this.read += 3;
return rval;
};
/**
* Gets a uint32 from this buffer in big-endian order and advances the read
* pointer by 4.
*
* @return the word.
*/
util.DataBuffer.prototype.getInt32 = function() {
var rval = this.data.getInt32(this.read);
this.read += 4;
return rval;
};
/**
* Gets a uint16 from this buffer in little-endian order and advances the read
* pointer by 2.
*
* @return the uint16.
*/
util.DataBuffer.prototype.getInt16Le = function() {
var rval = this.data.getInt16(this.read, true);
this.read += 2;
return rval;
};
/**
* Gets a uint24 from this buffer in little-endian order and advances the read
* pointer by 3.
*
* @return the uint24.
*/
util.DataBuffer.prototype.getInt24Le = function() {
var rval = (
this.data.getInt8(this.read) ^
this.data.getInt16(this.read + 1, true) << 8);
this.read += 3;
return rval;
};
/**
* Gets a uint32 from this buffer in little-endian order and advances the read
* pointer by 4.
*
* @return the word.
*/
util.DataBuffer.prototype.getInt32Le = function() {
var rval = this.data.getInt32(this.read, true);
this.read += 4;
return rval;
};
/**
* Gets an n-bit integer from this buffer in big-endian order and advances the
* read pointer by n/8.
*
* @param n the number of bits in the integer (8, 16, 24, or 32).
*
* @return the integer.
*/
util.DataBuffer.prototype.getInt = function(n) {
_checkBitsParam(n);
var rval = 0;
do {
// TODO: Use (rval * 0x100) if adding support for 33 to 53 bits.
rval = (rval << 8) + this.data.getInt8(this.read++);
n -= 8;
} while(n > 0);
return rval;
};
/**
* Gets a signed n-bit integer from this buffer in big-endian order, using
* two's complement, and advances the read pointer by n/8.
*
* @param n the number of bits in the integer (8, 16, 24, or 32).
*
* @return the integer.
*/
util.DataBuffer.prototype.getSignedInt = function(n) {
// getInt checks n
var x = this.getInt(n);
var max = 2 << (n - 2);
if(x >= max) {
x -= max << 1;
}
return x;
};
/**
* Reads bytes out into a UTF-8 string and clears them from the buffer.
*
* @param count the number of bytes to read, undefined or null for all.
*
* @return a UTF-8 string of bytes.
*/
util.DataBuffer.prototype.getBytes = function(count) {
// TODO: deprecate this method, it is poorly named and
// this.toString('binary') replaces it
// add a toTypedArray()/toArrayBuffer() function
var rval;
if(count) {
// read count bytes
count = Math.min(this.length(), count);
rval = this.data.slice(this.read, this.read + count);
this.read += count;
} else if(count === 0) {
rval = '';
} else {
// read all bytes, optimize to only copy when needed
rval = (this.read === 0) ? this.data : this.data.slice(this.read);
this.clear();
}
return rval;
};
/**
* Gets a UTF-8 encoded string of the bytes from this buffer without modifying
* the read pointer.
*
* @param count the number of bytes to get, omit to get all.
*
* @return a string full of UTF-8 encoded characters.
*/
util.DataBuffer.prototype.bytes = function(count) {
// TODO: deprecate this method, it is poorly named, add "getString()"
return (typeof(count) === 'undefined' ?
this.data.slice(this.read) :
this.data.slice(this.read, this.read + count));
};
/**
* Gets a byte at the given index without modifying the read pointer.
*
* @param i the byte index.
*
* @return the byte.
*/
util.DataBuffer.prototype.at = function(i) {
return this.data.getUint8(this.read + i);
};
/**
* Puts a byte at the given index without modifying the read pointer.
*
* @param i the byte index.
* @param b the byte to put.
*
* @return this buffer.
*/
util.DataBuffer.prototype.setAt = function(i, b) {
this.data.setUint8(i, b);
return this;
};
/**
* Gets the last byte without modifying the read pointer.
*
* @return the last byte.
*/
util.DataBuffer.prototype.last = function() {
return this.data.getUint8(this.write - 1);
};
/**
* Creates a copy of this buffer.
*
* @return the copy.
*/
util.DataBuffer.prototype.copy = function() {
return new util.DataBuffer(this);
};
/**
* Compacts this buffer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.compact = function() {
if(this.read > 0) {
var src = new Uint8Array(this.data.buffer, this.read);
var dst = new Uint8Array(src.byteLength);
dst.set(src);
this.data = new DataView(dst);
this.write -= this.read;
this.read = 0;
}
return this;
};
/**
* Clears this buffer.
*
* @return this buffer.
*/
util.DataBuffer.prototype.clear = function() {
this.data = new DataView(new ArrayBuffer(0));
this.read = this.write = 0;
return this;
};
/**
* Shortens this buffer by triming bytes off of the end of this buffer.
*
* @param count the number of bytes to trim off.
*
* @return this buffer.
*/
util.DataBuffer.prototype.truncate = function(count) {
this.write = Math.max(0, this.length() - count);
this.read = Math.min(this.read, this.write);
return this;
};
/**
* Converts this buffer to a hexadecimal string.
*
* @return a hexadecimal string.
*/
util.DataBuffer.prototype.toHex = function() {
var rval = '';
for(var i = this.read; i < this.data.byteLength; ++i) {
var b = this.data.getUint8(i);
if(b < 16) {
rval += '0';
}
rval += b.toString(16);
}
return rval;
};
/**
* Converts this buffer to a string, using the given encoding. If no
* encoding is given, 'utf8' (UTF-8) is used.
*
* @param [encoding] the encoding to use: 'binary', 'utf8', 'utf16', 'hex',
* 'base64' (default: 'utf8').
*
* @return a string representation of the bytes in this buffer.
*/
util.DataBuffer.prototype.toString = function(encoding) {
var view = new Uint8Array(this.data, this.read, this.length());
encoding = encoding || 'utf8';
// encode to string
if(encoding === 'binary' || encoding === 'raw') {
return util.binary.raw.encode(view);
}
if(encoding === 'hex') {
return util.binary.hex.encode(view);
}
if(encoding === 'base64') {
return util.binary.base64.encode(view);
}
// decode to text
if(encoding === 'utf8') {
return util.text.utf8.decode(view);
}
if(encoding === 'utf16') {
return util.text.utf16.decode(view);
}
throw new Error('Invalid encoding: ' + encoding);
};
/** End Buffer w/UInt8Array backing */
/**
* Creates a buffer that stores bytes. A value may be given to put into the
* buffer that is either a string of bytes or a UTF-16 string that will
* be encoded using UTF-8 (to do the latter, specify 'utf8' as the encoding).
*
* @param [input] the bytes to wrap (as a string) or a UTF-16 string to encode
* as UTF-8.
* @param [encoding] (default: 'raw', other: 'utf8').
*/
util.createBuffer = function(input, encoding) {
// TODO: deprecate, use new ByteBuffer() instead
encoding = encoding || 'raw';
if(input !== undefined && encoding === 'utf8') {
input = util.encodeUtf8(input);
}
return new util.ByteBuffer(input);
};
/**
* Fills a string with a particular value. If you want the string to be a byte
* string, pass in String.fromCharCode(theByte).
*
* @param c the character to fill the string with, use String.fromCharCode
* to fill the string with a byte value.
* @param n the number of characters of value c to fill with.
*
* @return the filled string.
*/
util.fillString = function(c, n) {
var s = '';
while(n > 0) {
if(n & 1) {
s += c;
}
n >>>= 1;
if(n > 0) {
c += c;
}
}
return s;
};
/**
* Performs a per byte XOR between two byte strings and returns the result as a
* string of bytes.
*
* @param s1 first string of bytes.
* @param s2 second string of bytes.
* @param n the number of bytes to XOR.
*
* @return the XOR'd result.
*/
util.xorBytes = function(s1, s2, n) {
var s3 = '';
var b = '';
var t = '';
var i = 0;
var c = 0;
for(; n > 0; --n, ++i) {
b = s1.charCodeAt(i) ^ s2.charCodeAt(i);
if(c >= 10) {
s3 += t;
t = '';
c = 0;
}
t += String.fromCharCode(b);
++c;
}
s3 += t;
return s3;
};
/**
* Converts a hex string into a 'binary' encoded string of bytes.
*
* @param hex the hexadecimal string to convert.
*
* @return the binary-encoded string of bytes.
*/
util.hexToBytes = function(hex) {
// TODO: deprecate: "Deprecated. Use util.binary.hex.decode instead."
var rval = '';
var i = 0;
if(hex.length & 1 == 1) {
// odd number of characters, convert first character alone
i = 1;
rval += String.fromCharCode(parseInt(hex[0], 16));
}
// convert 2 characters (1 byte) at a time
for(; i < hex.length; i += 2) {
rval += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
}
return rval;
};
/**
* Converts a 'binary' encoded string of bytes to hex.
*
* @param bytes the byte string to convert.
*
* @return the string of hexadecimal characters.
*/
util.bytesToHex = function(bytes) {
// TODO: deprecate: "Deprecated. Use util.binary.hex.encode instead."
return util.createBuffer(bytes).toHex();
};
/**
* Converts an 32-bit integer to 4-big-endian byte string.
*
* @param i the integer.
*
* @return the byte string.
*/
util.int32ToBytes = function(i) {
return (
String.fromCharCode(i >> 24 & 0xFF) +
String.fromCharCode(i >> 16 & 0xFF) +
String.fromCharCode(i >> 8 & 0xFF) +
String.fromCharCode(i & 0xFF));
};
// base64 characters, reverse mapping
var _base64 =
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
var _base64Idx = [
/*43 -43 = 0*/
/*'+', 1, 2, 3,'/' */
62, -1, -1, -1, 63,
/*'0','1','2','3','4','5','6','7','8','9' */
52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
/*15, 16, 17,'=', 19, 20, 21 */
-1, -1, -1, 64, -1, -1, -1,
/*65 - 43 = 22*/
/*'A','B','C','D','E','F','G','H','I','J','K','L','M', */
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
/*'N','O','P','Q','R','S','T','U','V','W','X','Y','Z' */
13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
/*91 - 43 = 48 */
/*48, 49, 50, 51, 52, 53 */
-1, -1, -1, -1, -1, -1,
/*97 - 43 = 54*/
/*'a','b','c','d','e','f','g','h','i','j','k','l','m' */
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
/*'n','o','p','q','r','s','t','u','v','w','x','y','z' */
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
];
// base58 characters (Bitcoin alphabet)
var _base58 = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';
/**
* Base64 encodes a 'binary' encoded string of bytes.
*
* @param input the binary encoded string of bytes to base64-encode.
* @param maxline the maximum number of encoded characters per line to use,
* defaults to none.
*
* @return the base64-encoded output.
*/
util.encode64 = function(input, maxline) {
// TODO: deprecate: "Deprecated. Use util.binary.base64.encode instead."
var line = '';
var output = '';
var chr1, chr2, chr3;
var i = 0;
while(i < input.length) {
chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++);
// encode 4 character group
line += _base64.charAt(chr1 >> 2);
line += _base64.charAt(((chr1 & 3) << 4) | (chr2 >> 4));
if(isNaN(chr2)) {
line += '==';
} else {
line += _base64.charAt(((chr2 & 15) << 2) | (chr3 >> 6));
line += isNaN(chr3) ? '=' : _base64.charAt(chr3 & 63);
}
if(maxline && line.length > maxline) {
output += line.substr(0, maxline) + '\r\n';
line = line.substr(maxline);
}
}
output += line;
return output;
};
/**
* Base64 decodes a string into a 'binary' encoded string of bytes.
*
* @param input the base64-encoded input.
*
* @return the binary encoded string.
*/
util.decode64 = function(input) {
// TODO: deprecate: "Deprecated. Use util.binary.base64.decode instead."
// remove all non-base64 characters
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, '');
var output = '';
var enc1, enc2, enc3, enc4;
var i = 0;
while(i < input.length) {
enc1 = _base64Idx[input.charCodeAt(i++) - 43];
enc2 = _base64Idx[input.charCodeAt(i++) - 43];
enc3 = _base64Idx[input.charCodeAt(i++) - 43];
enc4 = _base64Idx[input.charCodeAt(i++) - 43];
output += String.fromCharCode((enc1 << 2) | (enc2 >> 4));
if(enc3 !== 64) {
// decoded at least 2 bytes
output += String.fromCharCode(((enc2 & 15) << 4) | (enc3 >> 2));
if(enc4 !== 64) {
// decoded 3 bytes
output += String.fromCharCode(((enc3 & 3) << 6) | enc4);
}
}
}
return output;
};
/**
* UTF-8 encodes the given UTF-16 encoded string (a standard JavaScript
* string). Non-ASCII characters will be encoded as multiple bytes according
* to UTF-8.
*
* @param str the string to encode.
*
* @return the UTF-8 encoded string.
*/
util.encodeUtf8 = function(str) {
return unescape(encodeURIComponent(str));
};
/**
* Decodes a UTF-8 encoded string into a UTF-16 string.
*
* @param str the string to decode.
*
* @return the UTF-16 encoded string (standard JavaScript string).
*/
util.decodeUtf8 = function(str) {
return decodeURIComponent(escape(str));
};
// binary encoding/decoding tools
// FIXME: Experimental. Do not use yet.
util.binary = {
raw: {},
hex: {},
base64: {},
base58: {},
baseN : {
encode: baseN.encode,
decode: baseN.decode
}
};
/**
* Encodes a Uint8Array as a binary-encoded string. This encoding uses
* a value between 0 and 255 for each character.
*
* @param bytes the Uint8Array to encode.
*
* @return the binary-encoded string.
*/
util.binary.raw.encode = function(bytes) {
return String.fromCharCode.apply(null, bytes);
};
/**
* Decodes a binary-encoded string to a Uint8Array. This encoding uses
* a value between 0 and 255 for each character.
*
* @param str the binary-encoded string to decode.
* @param [output] an optional Uint8Array to write the output to; if it
* is too small, an exception will be thrown.
* @param [offset] the start offset for writing to the output (default: 0).
*
* @return the Uint8Array or the number of bytes written if output was given.
*/
util.binary.raw.decode = function(str, output, offset) {
var out = output;
if(!out) {
out = new Uint8Array(str.length);
}
offset = offset || 0;
var j = offset;
for(var i = 0; i < str.length; ++i) {
out[j++] = str.charCodeAt(i);
}
return output ? (j - offset) : out;
};
/**
* Encodes a 'binary' string, ArrayBuffer, DataView, TypedArray, or
* ByteBuffer as a string of hexadecimal characters.
*
* @param bytes the bytes to convert.
*
* @return the string of hexadecimal characters.
*/
util.binary.hex.encode = util.bytesToHex;
/**
* Decodes a hex-encoded string to a Uint8Array.
*
* @param hex the hexadecimal string to convert.
* @param [output] an optional Uint8Array to write the output to; if it
* is too small, an exception will be thrown.
* @param [offset] the start offset for writing to the output (default: 0).
*
* @return the Uint8Array or the number of bytes written if output was given.
*/
util.binary.hex.decode = function(hex, output, offset) {
var out = output;
if(!out) {
out = new Uint8Array(Math.ceil(hex.length / 2));
}
offset = offset || 0;
var i = 0, j = offset;
if(hex.length & 1) {
// odd number of characters, convert first character alone
i = 1;
out[j++] = parseInt(hex[0], 16);
}
// convert 2 characters (1 byte) at a time
for(; i < hex.length; i += 2) {
out[j++] = parseInt(hex.substr(i, 2), 16);
}
return output ? (j - offset) : out;
};
/**
* Base64-encodes a Uint8Array.
*
* @param input the Uint8Array to encode.
* @param maxline the maximum number of encoded characters per line to use,
* defaults to none.
*
* @return the base64-encoded output string.
*/
util.binary.base64.encode = function(input, maxline) {
var line = '';
var output = '';
var chr1, chr2, chr3;
var i = 0;
while(i < input.byteLength) {
chr1 = input[i++];
chr2 = input[i++];
chr3 = input[i++];
// encode 4 character group
line += _base64.charAt(chr1 >> 2);
line += _base64.charAt(((chr1 & 3) << 4) | (chr2 >> 4));
if(isNaN(chr2)) {
line += '==';
} else {
line += _base64.charAt(((chr2 & 15) << 2) | (chr3 >> 6));
line += isNaN(chr3) ? '=' : _base64.charAt(chr3 & 63);
}
if(maxline && line.length > maxline) {
output += line.substr(0, maxline) + '\r\n';
line = line.substr(maxline);
}
}
output += line;
return output;
};
/**
* Decodes a base64-encoded string to a Uint8Array.
*
* @param input the base64-encoded input string.
* @param [output] an optional Uint8Array to write the output to; if it
* is too small, an exception will be thrown.
* @param [offset] the start offset for writing to the output (default: 0).
*
* @return the Uint8Array or the number of bytes written if output was given.
*/
util.binary.base64.decode = function(input, output, offset) {
var out = output;
if(!out) {
out = new Uint8Array(Math.ceil(input.length / 4) * 3);
}
// remove all non-base64 characters
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, '');
offset = offset || 0;
var enc1, enc2, enc3, enc4;
var i = 0, j = offset;
while(i < input.length) {
enc1 = _base64Idx[input.charCodeAt(i++) - 43];
enc2 = _base64Idx[input.charCodeAt(i++) - 43];
enc3 = _base64Idx[input.charCodeAt(i++) - 43];
enc4 = _base64Idx[input.charCodeAt(i++) - 43];
out[j++] = (enc1 << 2) | (enc2 >> 4);
if(enc3 !== 64) {
// decoded at least 2 bytes
out[j++] = ((enc2 & 15) << 4) | (enc3 >> 2);
if(enc4 !== 64) {
// decoded 3 bytes
out[j++] = ((enc3 & 3) << 6) | enc4;
}
}
}
// make sure result is the exact decoded length
return output ? (j - offset) : out.subarray(0, j);
};
// add support for base58 encoding/decoding with Bitcoin alphabet
util.binary.base58.encode = function(input, maxline) {
return util.binary.baseN.encode(input, _base58, maxline);
};
util.binary.base58.decode = function(input, maxline) {
return util.binary.baseN.decode(input, _base58, maxline);
};
// text encoding/decoding tools
// FIXME: Experimental. Do not use yet.
util.text = {
utf8: {},
utf16: {}
};
/**
* Encodes the given string as UTF-8 in a Uint8Array.
*
* @param str the string to encode.
* @param [output] an optional Uint8Array to write the output to; if it
* is too small, an exception will be thrown.
* @param [offset] the start offset for writing to the output (default: 0).
*
* @return the Uint8Array or the number of bytes written if output was given.
*/
util.text.utf8.encode = function(str, output, offset) {
str = util.encodeUtf8(str);
var out = output;
if(!out) {
out = new Uint8Array(str.length);
}
offset = offset || 0;
var j = offset;
for(var i = 0; i < str.length; ++i) {
out[j++] = str.charCodeAt(i);
}
return output ? (j - offset) : out;
};
/**
* Decodes the UTF-8 contents from a Uint8Array.
*
* @param bytes the Uint8Array to decode.
*
* @return the resulting string.
*/
util.text.utf8.decode = function(bytes) {
return util.decodeUtf8(String.fromCharCode.apply(null, bytes));
};
/**
* Encodes the given string as UTF-16 in a Uint8Array.
*
* @param str the string to encode.
* @param [output] an optional Uint8Array to write the output to; if it
* is too small, an exception will be thrown.
* @param [offset] the start offset for writing to the output (default: 0).
*
* @return the Uint8Array or the number of bytes written if output was given.
*/
util.text.utf16.encode = function(str, output, offset) {
var out = output;
if(!out) {
out = new Uint8Array(str.length * 2);
}
var view = new Uint16Array(out.buffer);
offset = offset || 0;
var j = offset;
var k = offset;
for(var i = 0; i < str.length; ++i) {
view[k++] = str.charCodeAt(i);
j += 2;
}
return output ? (j - offset) : out;
};
/**
* Decodes the UTF-16 contents from a Uint8Array.
*
* @param bytes the Uint8Array to decode.
*
* @return the resulting string.
*/
util.text.utf16.decode = function(bytes) {
return String.fromCharCode.apply(null, new Uint16Array(bytes.buffer));
};
/**
* Deflates the given data using a flash interface.
*
* @param api the flash interface.
* @param bytes the data.
* @param raw true to return only raw deflate data, false to include zlib
* header and trailer.
*
* @return the deflated data as a string.
*/
util.deflate = function(api, bytes, raw) {
bytes = util.decode64(api.deflate(util.encode64(bytes)).rval);
// strip zlib header and trailer if necessary
if(raw) {
// zlib header is 2 bytes (CMF,FLG) where FLG indicates that
// there is a 4-byte DICT (alder-32) block before the data if
// its 5th bit is set
var start = 2;
var flg = bytes.charCodeAt(1);
if(flg & 0x20) {
start = 6;
}
// zlib trailer is 4 bytes of adler-32
bytes = bytes.substring(start, bytes.length - 4);
}
return bytes;
};
/**
* Inflates the given data using a flash interface.
*
* @param api the flash interface.
* @param bytes the data.
* @param raw true if the incoming data has no zlib header or trailer and is
* raw DEFLATE data.
*
* @return the inflated data as a string, null on error.
*/
util.inflate = function(api, bytes, raw) {
// TODO: add zlib header and trailer if necessary/possible
var rval = api.inflate(util.encode64(bytes)).rval;
return (rval === null) ? null : util.decode64(rval);
};
/**
* Sets a storage object.
*
* @param api the storage interface.
* @param id the storage ID to use.
* @param obj the storage object, null to remove.
*/
var _setStorageObject = function(api, id, obj) {
if(!api) {
throw new Error('WebStorage not available.');
}
var rval;
if(obj === null) {
rval = api.removeItem(id);
} else {
// json-encode and base64-encode object
obj = util.encode64(JSON.stringify(obj));
rval = api.setItem(id, obj);
}
// handle potential flash error
if(typeof(rval) !== 'undefined' && rval.rval !== true) {
var error = new Error(rval.error.message);
error.id = rval.error.id;
error.name = rval.error.name;
throw error;
}
};
/**
* Gets a storage object.
*
* @param api the storage interface.
* @param id the storage ID to use.
*
* @return the storage object entry or null if none exists.
*/
var _getStorageObject = function(api, id) {
if(!api) {
throw new Error('WebStorage not available.');
}
// get the existing entry
var rval = api.getItem(id);
/* Note: We check api.init because we can't do (api == localStorage)
on IE because of "Class doesn't support Automation" exception. Only
the flash api has an init method so this works too, but we need a
better solution in the future. */
// flash returns item wrapped in an object, handle special case
if(api.init) {
if(rval.rval === null) {
if(rval.error) {
var error = new Error(rval.error.message);
error.id = rval.error.id;
error.name = rval.error.name;
throw error;
}
// no error, but also no item
rval = null;
} else {
rval = rval.rval;
}
}
// handle decoding
if(rval !== null) {
// base64-decode and json-decode data
rval = JSON.parse(util.decode64(rval));
}
return rval;
};
/**
* Stores an item in local storage.
*
* @param api the storage interface.
* @param id the storage ID to use.
* @param key the key for the item.
* @param data the data for the item (any javascript object/primitive).
*/
var _setItem = function(api, id, key, data) {
// get storage object
var obj = _getStorageObject(api, id);
if(obj === null) {
// create a new storage object
obj = {};
}
// update key
obj[key] = data;
// set storage object
_setStorageObject(api, id, obj);
};
/**
* Gets an item from local storage.
*
* @param api the storage interface.
* @param id the storage ID to use.
* @param key the key for the item.
*
* @return the item.
*/
var _getItem = function(api, id, key) {
// get storage object
var rval = _getStorageObject(api, id);
if(rval !== null) {
// return data at key
rval = (key in rval) ? rval[key] : null;
}
return rval;
};
/**
* Removes an item from local storage.
*
* @param api the storage interface.
* @param id the storage ID to use.
* @param key the key for the item.
*/
var _removeItem = function(api, id, key) {
// get storage object
var obj = _getStorageObject(api, id);
if(obj !== null && key in obj) {
// remove key
delete obj[key];
// see if entry has no keys remaining
var empty = true;
for(var prop in obj) {
empty = false;
break;
}
if(empty) {
// remove entry entirely if no keys are left
obj = null;
}
// set storage object
_setStorageObject(api, id, obj);
}
};
/**
* Clears the local disk storage identified by the given ID.
*
* @param api the storage interface.
* @param id the storage ID to use.
*/
var _clearItems = function(api, id) {
_setStorageObject(api, id, null);
};
/**
* Calls a storage function.
*
* @param func the function to call.
* @param args the arguments for the function.
* @param location the location argument.
*
* @return the return value from the function.
*/
var _callStorageFunction = function(func, args, location) {
var rval = null;
// default storage types
if(typeof(location) === 'undefined') {
location = ['web', 'flash'];
}
// apply storage types in order of preference
var type;
var done = false;
var exception = null;
for(var idx in location) {
type = location[idx];
try {
if(type === 'flash' || type === 'both') {
if(args[0] === null) {
throw new Error('Flash local storage not available.');
}
rval = func.apply(this, args);
done = (type === 'flash');
}
if(type === 'web' || type === 'both') {
args[0] = localStorage;
rval = func.apply(this, args);
done = true;
}
} catch(ex) {
exception = ex;
}
if(done) {
break;
}
}
if(!done) {
throw exception;
}
return rval;
};
/**
* Stores an item on local disk.
*
* The available types of local storage include 'flash', 'web', and 'both'.
*
* The type 'flash' refers to flash local storage (SharedObject). In order
* to use flash local storage, the 'api' parameter must be valid. The type
* 'web' refers to WebStorage, if supported by the browser. The type 'both'
* refers to storing using both 'flash' and 'web', not just one or the
* other.
*
* The location array should list the storage types to use in order of
* preference:
*
* ['flash']: flash only storage
* ['web']: web only storage
* ['both']: try to store in both
* ['flash','web']: store in flash first, but if not available, 'web'
* ['web','flash']: store in web first, but if not available, 'flash'
*
* The location array defaults to: ['web', 'flash']
*
* @param api the flash interface, null to use only WebStorage.
* @param id the storage ID to use.
* @param key the key for the item.
* @param data the data for the item (any javascript object/primitive).
* @param location an array with the preferred types of storage to use.
*/
util.setItem = function(api, id, key, data, location) {
_callStorageFunction(_setItem, arguments, location);
};
/**
* Gets an item on local disk.
*
* Set setItem() for details on storage types.
*
* @param api the flash interface, null to use only WebStorage.
* @param id the storage ID to use.
* @param key the key for the item.
* @param location an array with the preferred types of storage to use.
*
* @return the item.
*/
util.getItem = function(api, id, key, location) {
return _callStorageFunction(_getItem, arguments, location);
};
/**
* Removes an item on local disk.
*
* Set setItem() for details on storage types.
*
* @param api the flash interface.
* @param id the storage ID to use.
* @param key the key for the item.
* @param location an array with the preferred types of storage to use.
*/
util.removeItem = function(api, id, key, location) {
_callStorageFunction(_removeItem, arguments, location);
};
/**
* Clears the local disk storage identified by the given ID.
*
* Set setItem() for details on storage types.
*
* @param api the flash interface if flash is available.
* @param id the storage ID to use.
* @param location an array with the preferred types of storage to use.
*/
util.clearItems = function(api, id, location) {
_callStorageFunction(_clearItems, arguments, location);
};
/**
* Parses the scheme, host, and port from an http(s) url.
*
* @param str the url string.
*
* @return the parsed url object or null if the url is invalid.
*/
util.parseUrl = function(str) {
// FIXME: this regex looks a bit broken
var regex = /^(https?):\/\/([^:&^\/]*):?(\d*)(.*)$/g;
regex.lastIndex = 0;
var m = regex.exec(str);
var url = (m === null) ? null : {
full: str,
scheme: m[1],
host: m[2],
port: m[3],
path: m[4]
};
if(url) {
url.fullHost = url.host;
if(url.port) {
if(url.port !== 80 && url.scheme === 'http') {
url.fullHost += ':' + url.port;
} else if(url.port !== 443 && url.scheme === 'https') {
url.fullHost += ':' + url.port;
}
} else if(url.scheme === 'http') {
url.port = 80;
} else if(url.scheme === 'https') {
url.port = 443;
}
url.full = url.scheme + '://' + url.fullHost;
}
return url;
};
/* Storage for query variables */
var _queryVariables = null;
/**
* Returns the window location query variables. Query is parsed on the first
* call and the same object is returned on subsequent calls. The mapping
* is from keys to an array of values. Parameters without values will have
* an object key set but no value added to the value array. Values are
* unescaped.
*
* ...?k1=v1&k2=v2:
* {
* "k1": ["v1"],
* "k2": ["v2"]
* }
*
* ...?k1=v1&k1=v2:
* {
* "k1": ["v1", "v2"]
* }
*
* ...?k1=v1&k2:
* {
* "k1": ["v1"],
* "k2": []
* }
*
* ...?k1=v1&k1:
* {
* "k1": ["v1"]
* }
*
* ...?k1&k1:
* {
* "k1": []
* }
*
* @param query the query string to parse (optional, default to cached
* results from parsing window location search query).
*
* @return object mapping keys to variables.
*/
util.getQueryVariables = function(query) {
var parse = function(q) {
var rval = {};
var kvpairs = q.split('&');
for(var i = 0; i < kvpairs.length; i++) {
var pos = kvpairs[i].indexOf('=');
var key;
var val;
if(pos > 0) {
key = kvpairs[i].substring(0, pos);
val = kvpairs[i].substring(pos + 1);
} else {
key = kvpairs[i];
val = null;
}
if(!(key in rval)) {
rval[key] = [];
}
// disallow overriding object prototype keys
if(!(key in Object.prototype) && val !== null) {
rval[key].push(unescape(val));
}
}
return rval;
};
var rval;
if(typeof(query) === 'undefined') {
// set cached variables if needed
if(_queryVariables === null) {
if(typeof(window) !== 'undefined' && window.location && window.location.search) {
// parse window search query
_queryVariables = parse(window.location.search.substring(1));
} else {
// no query variables available
_queryVariables = {};
}
}
rval = _queryVariables;
} else {
// parse given query
rval = parse(query);
}
return rval;
};
/**
* Parses a fragment into a path and query. This method will take a URI
* fragment and break it up as if it were the main URI. For example:
* /bar/baz?a=1&b=2
* results in:
* {
* path: ["bar", "baz"],
* query: {"k1": ["v1"], "k2": ["v2"]}
* }
*
* @return object with a path array and query object.
*/
util.parseFragment = function(fragment) {
// default to whole fragment
var fp = fragment;
var fq = '';
// split into path and query if possible at the first '?'
var pos = fragment.indexOf('?');
if(pos > 0) {
fp = fragment.substring(0, pos);
fq = fragment.substring(pos + 1);
}
// split path based on '/' and ignore first element if empty
var path = fp.split('/');
if(path.length > 0 && path[0] === '') {
path.shift();
}
// convert query into object
var query = (fq === '') ? {} : util.getQueryVariables(fq);
return {
pathString: fp,
queryString: fq,
path: path,
query: query
};
};
/**
* Makes a request out of a URI-like request string. This is intended to
* be used where a fragment id (after a URI '#') is parsed as a URI with
* path and query parts. The string should have a path beginning and
* delimited by '/' and optional query parameters following a '?'. The
* query should be a standard URL set of key value pairs delimited by
* '&'. For backwards compatibility the initial '/' on the path is not
* required. The request object has the following API, (fully described
* in the method code):
* {
* path: <the path string part>.
* query: <the query string part>,
* getPath(i): get part or all of the split path array,
* getQuery(k, i): get part or all of a query key array,
* getQueryLast(k, _default): get last element of a query key array.
* }
*
* @return object with request parameters.
*/
util.makeRequest = function(reqString) {
var frag = util.parseFragment(reqString);
var req = {
// full path string
path: frag.pathString,
// full query string
query: frag.queryString,
/**
* Get path or element in path.
*
* @param i optional path index.
*
* @return path or part of path if i provided.
*/
getPath: function(i) {
return (typeof(i) === 'undefined') ? frag.path : frag.path[i];
},
/**
* Get query, values for a key, or value for a key index.
*
* @param k optional query key.
* @param i optional query key index.
*
* @return query, values for a key, or value for a key index.
*/
getQuery: function(k, i) {
var rval;
if(typeof(k) === 'undefined') {
rval = frag.query;
} else {
rval = frag.query[k];
if(rval && typeof(i) !== 'undefined') {
rval = rval[i];
}
}
return rval;
},
getQueryLast: function(k, _default) {
var rval;
var vals = req.getQuery(k);
if(vals) {
rval = vals[vals.length - 1];
} else {
rval = _default;
}
return rval;
}
};
return req;
};
/**
* Makes a URI out of a path, an object with query parameters, and a
* fragment. Uses jQuery.param() internally for query string creation.
* If the path is an array, it will be joined with '/'.
*
* @param path string path or array of strings.
* @param query object with query parameters. (optional)
* @param fragment fragment string. (optional)
*
* @return string object with request parameters.
*/
util.makeLink = function(path, query, fragment) {
// join path parts if needed
path = jQuery.isArray(path) ? path.join('/') : path;
var qstr = jQuery.param(query || {});
fragment = fragment || '';
return path +
((qstr.length > 0) ? ('?' + qstr) : '') +
((fragment.length > 0) ? ('#' + fragment) : '');
};
/**
* Follows a path of keys deep into an object hierarchy and set a value.
* If a key does not exist or it's value is not an object, create an
* object in it's place. This can be destructive to a object tree if
* leaf nodes are given as non-final path keys.
* Used to avoid exceptions from missing parts of the path.
*
* @param object the starting object.
* @param keys an array of string keys.
* @param value the value to set.
*/
util.setPath = function(object, keys, value) {
// need to start at an object
if(typeof(object) === 'object' && object !== null) {
var i = 0;
var len = keys.length;
while(i < len) {
var next = keys[i++];
if(i == len) {
// last
object[next] = value;
} else {
// more
var hasNext = (next in object);
if(!hasNext ||
(hasNext && typeof(object[next]) !== 'object') ||
(hasNext && object[next] === null)) {
object[next] = {};
}
object = object[next];
}
}
}
};
/**
* Follows a path of keys deep into an object hierarchy and return a value.
* If a key does not exist, create an object in it's place.
* Used to avoid exceptions from missing parts of the path.
*
* @param object the starting object.
* @param keys an array of string keys.
* @param _default value to return if path not found.
*
* @return the value at the path if found, else default if given, else
* undefined.
*/
util.getPath = function(object, keys, _default) {
var i = 0;
var len = keys.length;
var hasNext = true;
while(hasNext && i < len &&
typeof(object) === 'object' && object !== null) {
var next = keys[i++];
hasNext = next in object;
if(hasNext) {
object = object[next];
}
}
return (hasNext ? object : _default);
};
/**
* Follow a path of keys deep into an object hierarchy and delete the
* last one. If a key does not exist, do nothing.
* Used to avoid exceptions from missing parts of the path.
*
* @param object the starting object.
* @param keys an array of string keys.
*/
util.deletePath = function(object, keys) {
// need to start at an object
if(typeof(object) === 'object' && object !== null) {
var i = 0;
var len = keys.length;
while(i < len) {
var next = keys[i++];
if(i == len) {
// last
delete object[next];
} else {
// more
if(!(next in object) ||
(typeof(object[next]) !== 'object') ||
(object[next] === null)) {
break;
}
object = object[next];
}
}
}
};
/**
* Check if an object is empty.
*
* Taken from:
* http://stackoverflow.com/questions/679915/how-do-i-test-for-an-empty-javascript-object-from-json/679937#679937
*
* @param object the object to check.
*/
util.isEmpty = function(obj) {
for(var prop in obj) {
if(obj.hasOwnProperty(prop)) {
return false;
}
}
return true;
};
/**
* Format with simple printf-style interpolation.
*
* %%: literal '%'
* %s,%o: convert next argument into a string.
*
* @param format the string to format.
* @param ... arguments to interpolate into the format string.
*/
util.format = function(format) {
var re = /%./g;
// current match
var match;
// current part
var part;
// current arg index
var argi = 0;
// collected parts to recombine later
var parts = [];
// last index found
var last = 0;
// loop while matches remain
while((match = re.exec(format))) {
part = format.substring(last, re.lastIndex - 2);
// don't add empty strings (ie, parts between %s%s)
if(part.length > 0) {
parts.push(part);
}
last = re.lastIndex;
// switch on % code
var code = match[0][1];
switch(code) {
case 's':
case 'o':
// check if enough arguments were given
if(argi < arguments.length) {
parts.push(arguments[argi++ + 1]);
} else {
parts.push('<?>');
}
break;
// FIXME: do proper formating for numbers, etc
//case 'f':
//case 'd':
case '%':
parts.push('%');
break;
default:
parts.push('<%' + code + '?>');
}
}
// add trailing part of format string
parts.push(format.substring(last));
return parts.join('');
};
/**
* Formats a number.
*
* http://snipplr.com/view/5945/javascript-numberformat--ported-from-php/
*/
util.formatNumber = function(number, decimals, dec_point, thousands_sep) {
// http://kevin.vanzonneveld.net
// + original by: Jonas Raoni Soares Silva (http://www.jsfromhell.com)
// + improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
// + bugfix by: Michael White (http://crestidg.com)
// + bugfix by: Benjamin Lupton
// + bugfix by: Allan Jensen (http://www.winternet.no)
// + revised by: Jonas Raoni Soares Silva (http://www.jsfromhell.com)
// * example 1: number_format(1234.5678, 2, '.', '');
// * returns 1: 1234.57
var n = number, c = isNaN(decimals = Math.abs(decimals)) ? 2 : decimals;
var d = dec_point === undefined ? ',' : dec_point;
var t = thousands_sep === undefined ?
'.' : thousands_sep, s = n < 0 ? '-' : '';
var i = parseInt((n = Math.abs(+n || 0).toFixed(c)), 10) + '';
var j = (i.length > 3) ? i.length % 3 : 0;
return s + (j ? i.substr(0, j) + t : '') +
i.substr(j).replace(/(\d{3})(?=\d)/g, '$1' + t) +
(c ? d + Math.abs(n - i).toFixed(c).slice(2) : '');
};
/**
* Formats a byte size.
*
* http://snipplr.com/view/5949/format-humanize-file-byte-size-presentation-in-javascript/
*/
util.formatSize = function(size) {
if(size >= 1073741824) {
size = util.formatNumber(size / 1073741824, 2, '.', '') + ' GiB';
} else if(size >= 1048576) {
size = util.formatNumber(size / 1048576, 2, '.', '') + ' MiB';
} else if(size >= 1024) {
size = util.formatNumber(size / 1024, 0) + ' KiB';
} else {
size = util.formatNumber(size, 0) + ' bytes';
}
return size;
};
/**
* Converts an IPv4 or IPv6 string representation into bytes (in network order).
*
* @param ip the IPv4 or IPv6 address to convert.
*
* @return the 4-byte IPv6 or 16-byte IPv6 address or null if the address can't
* be parsed.
*/
util.bytesFromIP = function(ip) {
if(ip.indexOf('.') !== -1) {
return util.bytesFromIPv4(ip);
}
if(ip.indexOf(':') !== -1) {
return util.bytesFromIPv6(ip);
}
return null;
};
/**
* Converts an IPv4 string representation into bytes (in network order).
*
* @param ip the IPv4 address to convert.
*
* @return the 4-byte address or null if the address can't be parsed.
*/
util.bytesFromIPv4 = function(ip) {
ip = ip.split('.');
if(ip.length !== 4) {
return null;
}
var b = util.createBuffer();
for(var i = 0; i < ip.length; ++i) {
var num = parseInt(ip[i], 10);
if(isNaN(num)) {
return null;
}
b.putByte(num);
}
return b.getBytes();
};
/**
* Converts an IPv6 string representation into bytes (in network order).
*
* @param ip the IPv6 address to convert.
*
* @return the 16-byte address or null if the address can't be parsed.
*/
util.bytesFromIPv6 = function(ip) {
var blanks = 0;
ip = ip.split(':').filter(function(e) {
if(e.length === 0) ++blanks;
return true;
});
var zeros = (8 - ip.length + blanks) * 2;
var b = util.createBuffer();
for(var i = 0; i < 8; ++i) {
if(!ip[i] || ip[i].length === 0) {
b.fillWithByte(0, zeros);
zeros = 0;
continue;
}
var bytes = util.hexToBytes(ip[i]);
if(bytes.length < 2) {
b.putByte(0);
}
b.putBytes(bytes);
}
return b.getBytes();
};
/**
* Converts 4-bytes into an IPv4 string representation or 16-bytes into
* an IPv6 string representation. The bytes must be in network order.
*
* @param bytes the bytes to convert.
*
* @return the IPv4 or IPv6 string representation if 4 or 16 bytes,
* respectively, are given, otherwise null.
*/
util.bytesToIP = function(bytes) {
if(bytes.length === 4) {
return util.bytesToIPv4(bytes);
}
if(bytes.length === 16) {
return util.bytesToIPv6(bytes);
}
return null;
};
/**
* Converts 4-bytes into an IPv4 string representation. The bytes must be
* in network order.
*
* @param bytes the bytes to convert.
*
* @return the IPv4 string representation or null for an invalid # of bytes.
*/
util.bytesToIPv4 = function(bytes) {
if(bytes.length !== 4) {
return null;
}
var ip = [];
for(var i = 0; i < bytes.length; ++i) {
ip.push(bytes.charCodeAt(i));
}
return ip.join('.');
};
/**
* Converts 16-bytes into an IPv16 string representation. The bytes must be
* in network order.
*
* @param bytes the bytes to convert.
*
* @return the IPv16 string representation or null for an invalid # of bytes.
*/
util.bytesToIPv6 = function(bytes) {
if(bytes.length !== 16) {
return null;
}
var ip = [];
var zeroGroups = [];
var zeroMaxGroup = 0;
for(var i = 0; i < bytes.length; i += 2) {
var hex = util.bytesToHex(bytes[i] + bytes[i + 1]);
// canonicalize zero representation
while(hex[0] === '0' && hex !== '0') {
hex = hex.substr(1);
}
if(hex === '0') {
var last = zeroGroups[zeroGroups.length - 1];
var idx = ip.length;
if(!last || idx !== last.end + 1) {
zeroGroups.push({start: idx, end: idx});
} else {
last.end = idx;
if((last.end - last.start) >
(zeroGroups[zeroMaxGroup].end - zeroGroups[zeroMaxGroup].start)) {
zeroMaxGroup = zeroGroups.length - 1;
}
}
}
ip.push(hex);
}
if(zeroGroups.length > 0) {
var group = zeroGroups[zeroMaxGroup];
// only shorten group of length > 0
if(group.end - group.start > 0) {
ip.splice(group.start, group.end - group.start + 1, '');
if(group.start === 0) {
ip.unshift('');
}
if(group.end === 7) {
ip.push('');
}
}
}
return ip.join(':');
};
/**
* Estimates the number of processes that can be run concurrently. If
* creating Web Workers, keep in mind that the main JavaScript process needs
* its own core.
*
* @param options the options to use:
* update true to force an update (not use the cached value).
* @param callback(err, max) called once the operation completes.
*/
util.estimateCores = function(options, callback) {
if(typeof options === 'function') {
callback = options;
options = {};
}
options = options || {};
if('cores' in util && !options.update) {
return callback(null, util.cores);
}
if(typeof navigator !== 'undefined' &&
'hardwareConcurrency' in navigator &&
navigator.hardwareConcurrency > 0) {
util.cores = navigator.hardwareConcurrency;
return callback(null, util.cores);
}
if(typeof Worker === 'undefined') {
// workers not available
util.cores = 1;
return callback(null, util.cores);
}
if(typeof Blob === 'undefined') {
// can't estimate, default to 2
util.cores = 2;
return callback(null, util.cores);
}
// create worker concurrency estimation code as blob
var blobUrl = URL.createObjectURL(new Blob(['(',
function() {
self.addEventListener('message', function(e) {
// run worker for 4 ms
var st = Date.now();
var et = st + 4;
while(Date.now() < et);
self.postMessage({st: st, et: et});
});
}.toString(),
')()'], {type: 'application/javascript'}));
// take 5 samples using 16 workers
sample([], 5, 16);
function sample(max, samples, numWorkers) {
if(samples === 0) {
// get overlap average
var avg = Math.floor(max.reduce(function(avg, x) {
return avg + x;
}, 0) / max.length);
util.cores = Math.max(1, avg);
URL.revokeObjectURL(blobUrl);
return callback(null, util.cores);
}
map(numWorkers, function(err, results) {
max.push(reduce(numWorkers, results));
sample(max, samples - 1, numWorkers);
});
}
function map(numWorkers, callback) {
var workers = [];
var results = [];
for(var i = 0; i < numWorkers; ++i) {
var worker = new Worker(blobUrl);
worker.addEventListener('message', function(e) {
results.push(e.data);
if(results.length === numWorkers) {
for(var i = 0; i < numWorkers; ++i) {
workers[i].terminate();
}
callback(null, results);
}
});
workers.push(worker);
}
for(var i = 0; i < numWorkers; ++i) {
workers[i].postMessage(i);
}
}
function reduce(numWorkers, results) {
// find overlapping time windows
var overlaps = [];
for(var n = 0; n < numWorkers; ++n) {
var r1 = results[n];
var overlap = overlaps[n] = [];
for(var i = 0; i < numWorkers; ++i) {
if(n === i) {
continue;
}
var r2 = results[i];
if((r1.st > r2.st && r1.st < r2.et) ||
(r2.st > r1.st && r2.st < r1.et)) {
overlap.push(i);
}
}
}
// get maximum overlaps ... don't include overlapping worker itself
// as the main JS process was also being scheduled during the work and
// would have to be subtracted from the estimate anyway
return overlaps.reduce(function(max, overlap) {
return Math.max(max, overlap.length);
}, 0);
}
};
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