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/*!
* The buffer module from node.js, for the browser.
*
* @author Feross Aboukhadijeh <https://feross.org>
* @license MIT
*/
/* eslint-disable no-proto */
'use strict'
var base64 = require('base64-js')
var ieee754 = require('ieee754')
exports.Buffer = Buffer
exports.SlowBuffer = SlowBuffer
exports.INSPECT_MAX_BYTES = 50
var K_MAX_LENGTH = 0x7fffffff
exports.kMaxLength = K_MAX_LENGTH
/**
* If `Buffer.TYPED_ARRAY_SUPPORT`:
* === true Use Uint8Array implementation (fastest)
* === false Print warning and recommend using `buffer` v4.x which has an Object
* implementation (most compatible, even IE6)
*
* Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+,
* Opera 11.6+, iOS 4.2+.
*
* We report that the browser does not support typed arrays if the are not subclassable
* using __proto__. Firefox 4-29 lacks support for adding new properties to `Uint8Array`
* (See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438). IE 10 lacks support
* for __proto__ and has a buggy typed array implementation.
*/
Buffer.TYPED_ARRAY_SUPPORT = typedArraySupport()
if (!Buffer.TYPED_ARRAY_SUPPORT && typeof console !== 'undefined' &&
typeof console.error === 'function') {
console.error(
'This browser lacks typed array (Uint8Array) support which is required by ' +
'`buffer` v5.x. Use `buffer` v4.x if you require old browser support.'
)
}
function typedArraySupport () {
// Can typed array instances can be augmented?
try {
var arr = new Uint8Array(1)
arr.__proto__ = {__proto__: Uint8Array.prototype, foo: function () { return 42 }}
return arr.foo() === 42
} catch (e) {
return false
}
}
Object.defineProperty(Buffer.prototype, 'parent', {
get: function () {
if (!(this instanceof Buffer)) {
return undefined
}
return this.buffer
}
})
Object.defineProperty(Buffer.prototype, 'offset', {
get: function () {
if (!(this instanceof Buffer)) {
return undefined
}
return this.byteOffset
}
})
function createBuffer (length) {
if (length > K_MAX_LENGTH) {
throw new RangeError('Invalid typed array length')
}
// Return an augmented `Uint8Array` instance
var buf = new Uint8Array(length)
buf.__proto__ = Buffer.prototype
return buf
}
/**
* The Buffer constructor returns instances of `Uint8Array` that have their
* prototype changed to `Buffer.prototype`. Furthermore, `Buffer` is a subclass of
* `Uint8Array`, so the returned instances will have all the node `Buffer` methods
* and the `Uint8Array` methods. Square bracket notation works as expected -- it
* returns a single octet.
*
* The `Uint8Array` prototype remains unmodified.
*/
function Buffer (arg, encodingOrOffset, length) {
// Common case.
if (typeof arg === 'number') {
if (typeof encodingOrOffset === 'string') {
throw new Error(
'If encoding is specified then the first argument must be a string'
)
}
return allocUnsafe(arg)
}
return from(arg, encodingOrOffset, length)
}
// Fix subarray() in ES2016. See: https://github.com/feross/buffer/pull/97
if (typeof Symbol !== 'undefined' && Symbol.species &&
Buffer[Symbol.species] === Buffer) {
Object.defineProperty(Buffer, Symbol.species, {
value: null,
configurable: true,
enumerable: false,
writable: false
})
}
Buffer.poolSize = 8192 // not used by this implementation
function from (value, encodingOrOffset, length) {
if (typeof value === 'number') {
throw new TypeError('"value" argument must not be a number')
}
if (isArrayBuffer(value) || (value && isArrayBuffer(value.buffer))) {
return fromArrayBuffer(value, encodingOrOffset, length)
}
if (typeof value === 'string') {
return fromString(value, encodingOrOffset)
}
return fromObject(value)
}
/**
* Functionally equivalent to Buffer(arg, encoding) but throws a TypeError
* if value is a number.
* Buffer.from(str[, encoding])
* Buffer.from(array)
* Buffer.from(buffer)
* Buffer.from(arrayBuffer[, byteOffset[, length]])
**/
Buffer.from = function (value, encodingOrOffset, length) {
return from(value, encodingOrOffset, length)
}
// Note: Change prototype *after* Buffer.from is defined to workaround Chrome bug:
// https://github.com/feross/buffer/pull/148
Buffer.prototype.__proto__ = Uint8Array.prototype
Buffer.__proto__ = Uint8Array
function assertSize (size) {
if (typeof size !== 'number') {
throw new TypeError('"size" argument must be of type number')
} else if (size < 0) {
throw new RangeError('"size" argument must not be negative')
}
}
function alloc (size, fill, encoding) {
assertSize(size)
if (size <= 0) {
return createBuffer(size)
}
if (fill !== undefined) {
// Only pay attention to encoding if it's a string. This
// prevents accidentally sending in a number that would
// be interpretted as a start offset.
return typeof encoding === 'string'
? createBuffer(size).fill(fill, encoding)
: createBuffer(size).fill(fill)
}
return createBuffer(size)
}
/**
* Creates a new filled Buffer instance.
* alloc(size[, fill[, encoding]])
**/
Buffer.alloc = function (size, fill, encoding) {
return alloc(size, fill, encoding)
}
function allocUnsafe (size) {
assertSize(size)
return createBuffer(size < 0 ? 0 : checked(size) | 0)
}
/**
* Equivalent to Buffer(num), by default creates a non-zero-filled Buffer instance.
* */
Buffer.allocUnsafe = function (size) {
return allocUnsafe(size)
}
/**
* Equivalent to SlowBuffer(num), by default creates a non-zero-filled Buffer instance.
*/
Buffer.allocUnsafeSlow = function (size) {
return allocUnsafe(size)
}
function fromString (string, encoding) {
if (typeof encoding !== 'string' || encoding === '') {
encoding = 'utf8'
}
if (!Buffer.isEncoding(encoding)) {
throw new TypeError('Unknown encoding: ' + encoding)
}
var length = byteLength(string, encoding) | 0
var buf = createBuffer(length)
var actual = buf.write(string, encoding)
if (actual !== length) {
// Writing a hex string, for example, that contains invalid characters will
// cause everything after the first invalid character to be ignored. (e.g.
// 'abxxcd' will be treated as 'ab')
buf = buf.slice(0, actual)
}
return buf
}
function fromArrayLike (array) {
var length = array.length < 0 ? 0 : checked(array.length) | 0
var buf = createBuffer(length)
for (var i = 0; i < length; i += 1) {
buf[i] = array[i] & 255
}
return buf
}
function fromArrayBuffer (array, byteOffset, length) {
if (byteOffset < 0 || array.byteLength < byteOffset) {
throw new RangeError('"offset" is outside of buffer bounds')
}
if (array.byteLength < byteOffset + (length || 0)) {
throw new RangeError('"length" is outside of buffer bounds')
}
var buf
if (byteOffset === undefined && length === undefined) {
buf = new Uint8Array(array)
} else if (length === undefined) {
buf = new Uint8Array(array, byteOffset)
} else {
buf = new Uint8Array(array, byteOffset, length)
}
// Return an augmented `Uint8Array` instance
buf.__proto__ = Buffer.prototype
return buf
}
function fromObject (obj) {
if (Buffer.isBuffer(obj)) {
var len = checked(obj.length) | 0
var buf = createBuffer(len)
if (buf.length === 0) {
return buf
}
obj.copy(buf, 0, 0, len)
return buf
}
if (obj) {
if (ArrayBuffer.isView(obj) || 'length' in obj) {
if (typeof obj.length !== 'number' || numberIsNaN(obj.length)) {
return createBuffer(0)
}
return fromArrayLike(obj)
}
if (obj.type === 'Buffer' && Array.isArray(obj.data)) {
return fromArrayLike(obj.data)
}
}
throw new TypeError('The first argument must be one of type string, Buffer, ArrayBuffer, Array, or Array-like Object.')
}
function checked (length) {
// Note: cannot use `length < K_MAX_LENGTH` here because that fails when
// length is NaN (which is otherwise coerced to zero.)
if (length >= K_MAX_LENGTH) {
throw new RangeError('Attempt to allocate Buffer larger than maximum ' +
'size: 0x' + K_MAX_LENGTH.toString(16) + ' bytes')
}
return length | 0
}
function SlowBuffer (length) {
if (+length != length) { // eslint-disable-line eqeqeq
length = 0
}
return Buffer.alloc(+length)
}
Buffer.isBuffer = function isBuffer (b) {
return b != null && b._isBuffer === true
}
Buffer.compare = function compare (a, b) {
if (!Buffer.isBuffer(a) || !Buffer.isBuffer(b)) {
throw new TypeError('Arguments must be Buffers')
}
if (a === b) return 0
var x = a.length
var y = b.length
for (var i = 0, len = Math.min(x, y); i < len; ++i) {
if (a[i] !== b[i]) {
x = a[i]
y = b[i]
break
}
}
if (x < y) return -1
if (y < x) return 1
return 0
}
Buffer.isEncoding = function isEncoding (encoding) {
switch (String(encoding).toLowerCase()) {
case 'hex':
case 'utf8':
case 'utf-8':
case 'ascii':
case 'latin1':
case 'binary':
case 'base64':
case 'ucs2':
case 'ucs-2':
case 'utf16le':
case 'utf-16le':
return true
default:
return false
}
}
Buffer.concat = function concat (list, length) {
if (!Array.isArray(list)) {
throw new TypeError('"list" argument must be an Array of Buffers')
}
if (list.length === 0) {
return Buffer.alloc(0)
}
var i
if (length === undefined) {
length = 0
for (i = 0; i < list.length; ++i) {
length += list[i].length
}
}
var buffer = Buffer.allocUnsafe(length)
var pos = 0
for (i = 0; i < list.length; ++i) {
var buf = list[i]
if (ArrayBuffer.isView(buf)) {
buf = Buffer.from(buf)
}
if (!Buffer.isBuffer(buf)) {
throw new TypeError('"list" argument must be an Array of Buffers')
}
buf.copy(buffer, pos)
pos += buf.length
}
return buffer
}
function byteLength (string, encoding) {
if (Buffer.isBuffer(string)) {
return string.length
}
if (ArrayBuffer.isView(string) || isArrayBuffer(string)) {
return string.byteLength
}
if (typeof string !== 'string') {
string = '' + string
}
var len = string.length
if (len === 0) return 0
// Use a for loop to avoid recursion
var loweredCase = false
for (;;) {
switch (encoding) {
case 'ascii':
case 'latin1':
case 'binary':
return len
case 'utf8':
case 'utf-8':
case undefined:
return utf8ToBytes(string).length
case 'ucs2':
case 'ucs-2':
case 'utf16le':
case 'utf-16le':
return len * 2
case 'hex':
return len >>> 1
case 'base64':
return base64ToBytes(string).length
default:
if (loweredCase) return utf8ToBytes(string).length // assume utf8
encoding = ('' + encoding).toLowerCase()
loweredCase = true
}
}
}
Buffer.byteLength = byteLength
function slowToString (encoding, start, end) {
var loweredCase = false
// No need to verify that "this.length <= MAX_UINT32" since it's a read-only
// property of a typed array.
// This behaves neither like String nor Uint8Array in that we set start/end
// to their upper/lower bounds if the value passed is out of range.
// undefined is handled specially as per ECMA-262 6th Edition,
// Section 13.3.3.7 Runtime Semantics: KeyedBindingInitialization.
if (start === undefined || start < 0) {
start = 0
}
// Return early if start > this.length. Done here to prevent potential uint32
// coercion fail below.
if (start > this.length) {
return ''
}
if (end === undefined || end > this.length) {
end = this.length
}
if (end <= 0) {
return ''
}
// Force coersion to uint32. This will also coerce falsey/NaN values to 0.
end >>>= 0
start >>>= 0
if (end <= start) {
return ''
}
if (!encoding) encoding = 'utf8'
while (true) {
switch (encoding) {
case 'hex':
return hexSlice(this, start, end)
case 'utf8':
case 'utf-8':
return utf8Slice(this, start, end)
case 'ascii':
return asciiSlice(this, start, end)
case 'latin1':
case 'binary':
return latin1Slice(this, start, end)
case 'base64':
return base64Slice(this, start, end)
case 'ucs2':
case 'ucs-2':
case 'utf16le':
case 'utf-16le':
return utf16leSlice(this, start, end)
default:
if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
encoding = (encoding + '').toLowerCase()
loweredCase = true
}
}
}
// This property is used by `Buffer.isBuffer` (and the `is-buffer` npm package)
// to detect a Buffer instance. It's not possible to use `instanceof Buffer`
// reliably in a browserify context because there could be multiple different
// copies of the 'buffer' package in use. This method works even for Buffer
// instances that were created from another copy of the `buffer` package.
// See: https://github.com/feross/buffer/issues/154
Buffer.prototype._isBuffer = true
function swap (b, n, m) {
var i = b[n]
b[n] = b[m]
b[m] = i
}
Buffer.prototype.swap16 = function swap16 () {
var len = this.length
if (len % 2 !== 0) {
throw new RangeError('Buffer size must be a multiple of 16-bits')
}
for (var i = 0; i < len; i += 2) {
swap(this, i, i + 1)
}
return this
}
Buffer.prototype.swap32 = function swap32 () {
var len = this.length
if (len % 4 !== 0) {
throw new RangeError('Buffer size must be a multiple of 32-bits')
}
for (var i = 0; i < len; i += 4) {
swap(this, i, i + 3)
swap(this, i + 1, i + 2)
}
return this
}
Buffer.prototype.swap64 = function swap64 () {
var len = this.length
if (len % 8 !== 0) {
throw new RangeError('Buffer size must be a multiple of 64-bits')
}
for (var i = 0; i < len; i += 8) {
swap(this, i, i + 7)
swap(this, i + 1, i + 6)
swap(this, i + 2, i + 5)
swap(this, i + 3, i + 4)
}
return this
}
Buffer.prototype.toString = function toString () {
var length = this.length
if (length === 0) return ''
if (arguments.length === 0) return utf8Slice(this, 0, length)
return slowToString.apply(this, arguments)
}
Buffer.prototype.toLocaleString = Buffer.prototype.toString
Buffer.prototype.equals = function equals (b) {
if (!Buffer.isBuffer(b)) throw new TypeError('Argument must be a Buffer')
if (this === b) return true
return Buffer.compare(this, b) === 0
}
Buffer.prototype.inspect = function inspect () {
var str = ''
var max = exports.INSPECT_MAX_BYTES
if (this.length > 0) {
str = this.toString('hex', 0, max).match(/.{2}/g).join(' ')
if (this.length > max) str += ' ... '
}
return '<Buffer ' + str + '>'
}
Buffer.prototype.compare = function compare (target, start, end, thisStart, thisEnd) {
if (!Buffer.isBuffer(target)) {
throw new TypeError('Argument must be a Buffer')
}
if (start === undefined) {
start = 0
}
if (end === undefined) {
end = target ? target.length : 0
}
if (thisStart === undefined) {
thisStart = 0
}
if (thisEnd === undefined) {
thisEnd = this.length
}
if (start < 0 || end > target.length || thisStart < 0 || thisEnd > this.length) {
throw new RangeError('out of range index')
}
if (thisStart >= thisEnd && start >= end) {
return 0
}
if (thisStart >= thisEnd) {
return -1
}
if (start >= end) {
return 1
}
start >>>= 0
end >>>= 0
thisStart >>>= 0
thisEnd >>>= 0
if (this === target) return 0
var x = thisEnd - thisStart
var y = end - start
var len = Math.min(x, y)
var thisCopy = this.slice(thisStart, thisEnd)
var targetCopy = target.slice(start, end)
for (var i = 0; i < len; ++i) {
if (thisCopy[i] !== targetCopy[i]) {
x = thisCopy[i]
y = targetCopy[i]
break
}
}
if (x < y) return -1
if (y < x) return 1
return 0
}
// Finds either the first index of `val` in `buffer` at offset >= `byteOffset`,
// OR the last index of `val` in `buffer` at offset <= `byteOffset`.
//
// Arguments:
// - buffer - a Buffer to search
// - val - a string, Buffer, or number
// - byteOffset - an index into `buffer`; will be clamped to an int32
// - encoding - an optional encoding, relevant is val is a string
// - dir - true for indexOf, false for lastIndexOf
function bidirectionalIndexOf (buffer, val, byteOffset, encoding, dir) {
// Empty buffer means no match
if (buffer.length === 0) return -1
// Normalize byteOffset
if (typeof byteOffset === 'string') {
encoding = byteOffset
byteOffset = 0
} else if (byteOffset > 0x7fffffff) {
byteOffset = 0x7fffffff
} else if (byteOffset < -0x80000000) {
byteOffset = -0x80000000
}
byteOffset = +byteOffset // Coerce to Number.
if (numberIsNaN(byteOffset)) {
// byteOffset: it it's undefined, null, NaN, "foo", etc, search whole buffer
byteOffset = dir ? 0 : (buffer.length - 1)
}
// Normalize byteOffset: negative offsets start from the end of the buffer
if (byteOffset < 0) byteOffset = buffer.length + byteOffset
if (byteOffset >= buffer.length) {
if (dir) return -1
else byteOffset = buffer.length - 1
} else if (byteOffset < 0) {
if (dir) byteOffset = 0
else return -1
}
// Normalize val
if (typeof val === 'string') {
val = Buffer.from(val, encoding)
}
// Finally, search either indexOf (if dir is true) or lastIndexOf
if (Buffer.isBuffer(val)) {
// Special case: looking for empty string/buffer always fails
if (val.length === 0) {
return -1
}
return arrayIndexOf(buffer, val, byteOffset, encoding, dir)
} else if (typeof val === 'number') {
val = val & 0xFF // Search for a byte value [0-255]
if (typeof Uint8Array.prototype.indexOf === 'function') {
if (dir) {
return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset)
} else {
return Uint8Array.prototype.lastIndexOf.call(buffer, val, byteOffset)
}
}
return arrayIndexOf(buffer, [ val ], byteOffset, encoding, dir)
}
throw new TypeError('val must be string, number or Buffer')
}
function arrayIndexOf (arr, val, byteOffset, encoding, dir) {
var indexSize = 1
var arrLength = arr.length
var valLength = val.length
if (encoding !== undefined) {
encoding = String(encoding).toLowerCase()
if (encoding === 'ucs2' || encoding === 'ucs-2' ||
encoding === 'utf16le' || encoding === 'utf-16le') {
if (arr.length < 2 || val.length < 2) {
return -1
}
indexSize = 2
arrLength /= 2
valLength /= 2
byteOffset /= 2
}
}
function read (buf, i) {
if (indexSize === 1) {
return buf[i]
} else {
return buf.readUInt16BE(i * indexSize)
}
}
var i
if (dir) {
var foundIndex = -1
for (i = byteOffset; i < arrLength; i++) {
if (read(arr, i) === read(val, foundIndex === -1 ? 0 : i - foundIndex)) {
if (foundIndex === -1) foundIndex = i
if (i - foundIndex + 1 === valLength) return foundIndex * indexSize
} else {
if (foundIndex !== -1) i -= i - foundIndex
foundIndex = -1
}
}
} else {
if (byteOffset + valLength > arrLength) byteOffset = arrLength - valLength
for (i = byteOffset; i >= 0; i--) {
var found = true
for (var j = 0; j < valLength; j++) {
if (read(arr, i + j) !== read(val, j)) {
found = false
break
}
}
if (found) return i
}
}
return -1
}
Buffer.prototype.includes = function includes (val, byteOffset, encoding) {
return this.indexOf(val, byteOffset, encoding) !== -1
}
Buffer.prototype.indexOf = function indexOf (val, byteOffset, encoding) {
return bidirectionalIndexOf(this, val, byteOffset, encoding, true)
}
Buffer.prototype.lastIndexOf = function lastIndexOf (val, byteOffset, encoding) {
return bidirectionalIndexOf(this, val, byteOffset, encoding, false)
}
function hexWrite (buf, string, offset, length) {
offset = Number(offset) || 0
var remaining = buf.length - offset
if (!length) {
length = remaining
} else {
length = Number(length)
if (length > remaining) {
length = remaining
}
}
var strLen = string.length
if (length > strLen / 2) {
length = strLen / 2
}
for (var i = 0; i < length; ++i) {
var parsed = parseInt(string.substr(i * 2, 2), 16)
if (numberIsNaN(parsed)) return i
buf[offset + i] = parsed
}
return i
}
function utf8Write (buf, string, offset, length) {
return blitBuffer(utf8ToBytes(string, buf.length - offset), buf, offset, length)
}
function asciiWrite (buf, string, offset, length) {
return blitBuffer(asciiToBytes(string), buf, offset, length)
}
function latin1Write (buf, string, offset, length) {
return asciiWrite(buf, string, offset, length)
}
function base64Write (buf, string, offset, length) {
return blitBuffer(base64ToBytes(string), buf, offset, length)
}
function ucs2Write (buf, string, offset, length) {
return blitBuffer(utf16leToBytes(string, buf.length - offset), buf, offset, length)
}
Buffer.prototype.write = function write (string, offset, length, encoding) {
// Buffer#write(string)
if (offset === undefined) {
encoding = 'utf8'
length = this.length
offset = 0
// Buffer#write(string, encoding)
} else if (length === undefined && typeof offset === 'string') {
encoding = offset
length = this.length
offset = 0
// Buffer#write(string, offset[, length][, encoding])
} else if (isFinite(offset)) {
offset = offset >>> 0
if (isFinite(length)) {
length = length >>> 0
if (encoding === undefined) encoding = 'utf8'
} else {
encoding = length
length = undefined
}
} else {
throw new Error(
'Buffer.write(string, encoding, offset[, length]) is no longer supported'
)
}
var remaining = this.length - offset
if (length === undefined || length > remaining) length = remaining
if ((string.length > 0 && (length < 0 || offset < 0)) || offset > this.length) {
throw new RangeError('Attempt to write outside buffer bounds')
}
if (!encoding) encoding = 'utf8'
var loweredCase = false
for (;;) {
switch (encoding) {
case 'hex':
return hexWrite(this, string, offset, length)
case 'utf8':
case 'utf-8':
return utf8Write(this, string, offset, length)
case 'ascii':
return asciiWrite(this, string, offset, length)
case 'latin1':
case 'binary':
return latin1Write(this, string, offset, length)
case 'base64':
// Warning: maxLength not taken into account in base64Write
return base64Write(this, string, offset, length)
case 'ucs2':
case 'ucs-2':
case 'utf16le':
case 'utf-16le':
return ucs2Write(this, string, offset, length)
default:
if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
encoding = ('' + encoding).toLowerCase()
loweredCase = true
}
}
}
Buffer.prototype.toJSON = function toJSON () {
return {
type: 'Buffer',
data: Array.prototype.slice.call(this._arr || this, 0)
}
}
function base64Slice (buf, start, end) {
if (start === 0 && end === buf.length) {
return base64.fromByteArray(buf)
} else {
return base64.fromByteArray(buf.slice(start, end))
}
}
function utf8Slice (buf, start, end) {
end = Math.min(buf.length, end)
var res = []
var i = start
while (i < end) {
var firstByte = buf[i]
var codePoint = null
var bytesPerSequence = (firstByte > 0xEF) ? 4
: (firstByte > 0xDF) ? 3
: (firstByte > 0xBF) ? 2
: 1
if (i + bytesPerSequence <= end) {
var secondByte, thirdByte, fourthByte, tempCodePoint
switch (bytesPerSequence) {
case 1:
if (firstByte < 0x80) {
codePoint = firstByte
}
break
case 2:
secondByte = buf[i + 1]
if ((secondByte & 0xC0) === 0x80) {
tempCodePoint = (firstByte & 0x1F) << 0x6 | (secondByte & 0x3F)
if (tempCodePoint > 0x7F) {
codePoint = tempCodePoint
}
}
break
case 3:
secondByte = buf[i + 1]
thirdByte = buf[i + 2]
if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80) {
tempCodePoint = (firstByte & 0xF) << 0xC | (secondByte & 0x3F) << 0x6 | (thirdByte & 0x3F)
if (tempCodePoint > 0x7FF && (tempCodePoint < 0xD800 || tempCodePoint > 0xDFFF)) {
codePoint = tempCodePoint
}
}
break
case 4:
secondByte = buf[i + 1]
thirdByte = buf[i + 2]
fourthByte = buf[i + 3]
if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80 && (fourthByte & 0xC0) === 0x80) {
tempCodePoint = (firstByte & 0xF) << 0x12 | (secondByte & 0x3F) << 0xC | (thirdByte & 0x3F) << 0x6 | (fourthByte & 0x3F)
if (tempCodePoint > 0xFFFF && tempCodePoint < 0x110000) {
codePoint = tempCodePoint
}
}
}
}
if (codePoint === null) {
// we did not generate a valid codePoint so insert a
// replacement char (U+FFFD) and advance only 1 byte
codePoint = 0xFFFD
bytesPerSequence = 1
} else if (codePoint > 0xFFFF) {
// encode to utf16 (surrogate pair dance)
codePoint -= 0x10000
res.push(codePoint >>> 10 & 0x3FF | 0xD800)
codePoint = 0xDC00 | codePoint & 0x3FF
}
res.push(codePoint)
i += bytesPerSequence
}
return decodeCodePointsArray(res)
}
// Based on http://stackoverflow.com/a/22747272/680742, the browser with
// the lowest limit is Chrome, with 0x10000 args.
// We go 1 magnitude less, for safety
var MAX_ARGUMENTS_LENGTH = 0x1000
function decodeCodePointsArray (codePoints) {
var len = codePoints.length
if (len <= MAX_ARGUMENTS_LENGTH) {
return String.fromCharCode.apply(String, codePoints) // avoid extra slice()
}
// Decode in chunks to avoid "call stack size exceeded".
var res = ''
var i = 0
while (i < len) {
res += String.fromCharCode.apply(
String,
codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH)
)
}
return res
}
function asciiSlice (buf, start, end) {
var ret = ''
end = Math.min(buf.length, end)
for (var i = start; i < end; ++i) {
ret += String.fromCharCode(buf[i] & 0x7F)
}
return ret