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1548 lines (1318 loc) · 41.8 KB
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/*!
* The buffer module from node.js, for the browser.
*
* @author Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
* @license MIT
*/
/* eslint-disable no-proto */
'use strict'
var base64 = require('base64-js')
var ieee754 = require('ieee754')
var isArray = require('isarray')
exports.Buffer = Buffer
exports.SlowBuffer = SlowBuffer
exports.INSPECT_MAX_BYTES = 50
Buffer.poolSize = 8192 // not used by this implementation
var rootParent = {}
/**
* If `Buffer.TYPED_ARRAY_SUPPORT`:
* === true Use Uint8Array implementation (fastest)
* === false Use 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+.
*
* Due to various browser bugs, sometimes the Object implementation will be used even
* when the browser supports typed arrays.
*
* Note:
*
* - Firefox 4-29 lacks support for adding new properties to `Uint8Array` instances,
* See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438.
*
* - Safari 5-7 lacks support for changing the `Object.prototype.constructor` property
* on objects.
*
* - Chrome 9-10 is missing the `TypedArray.prototype.subarray` function.
*
* - IE10 has a broken `TypedArray.prototype.subarray` function which returns arrays of
* incorrect length in some situations.
* We detect these buggy browsers and set `Buffer.TYPED_ARRAY_SUPPORT` to `false` so they
* get the Object implementation, which is slower but behaves correctly.
*/
Buffer.TYPED_ARRAY_SUPPORT = global.TYPED_ARRAY_SUPPORT !== undefined
? global.TYPED_ARRAY_SUPPORT
: typedArraySupport()
function typedArraySupport () {
function Bar () {}
try {
var arr = new Uint8Array(1)
arr.foo = function () { return 42 }
arr.constructor = Bar
return arr.foo() === 42 && // typed array instances can be augmented
arr.constructor === Bar && // constructor can be set
typeof arr.subarray === 'function' && // chrome 9-10 lack `subarray`
arr.subarray(1, 1).byteLength === 0 // ie10 has broken `subarray`
} catch (e) {
return false
}
}
function kMaxLength () {
return Buffer.TYPED_ARRAY_SUPPORT
? 0x7fffffff
: 0x3fffffff
}
/**
* Class: Buffer
* =============
*
* The Buffer constructor returns instances of `Uint8Array` that are augmented
* with function properties for all the node `Buffer` API functions. We use
* `Uint8Array` so that square bracket notation works as expected -- it returns
* a single octet.
*
* By augmenting the instances, we can avoid modifying the `Uint8Array`
* prototype.
*/
function Buffer (arg) {
if (!(this instanceof Buffer)) {
// Avoid going through an ArgumentsAdaptorTrampoline in the common case.
if (arguments.length > 1) return new Buffer(arg, arguments[1])
return new Buffer(arg)
}
if (!Buffer.TYPED_ARRAY_SUPPORT) {
this.length = 0
this.parent = undefined
}
// Common case.
if (typeof arg === 'number') {
return fromNumber(this, arg)
}
// Slightly less common case.
if (typeof arg === 'string') {
return fromString(this, arg, arguments.length > 1 ? arguments[1] : 'utf8')
}
// Unusual.
return fromObject(this, arg)
}
function fromNumber (that, length) {
that = allocate(that, length < 0 ? 0 : checked(length) | 0)
if (!Buffer.TYPED_ARRAY_SUPPORT) {
for (var i = 0; i < length; i++) {
that[i] = 0
}
}
return that
}
function fromString (that, string, encoding) {
if (typeof encoding !== 'string' || encoding === '') encoding = 'utf8'
// Assumption: byteLength() return value is always < kMaxLength.
var length = byteLength(string, encoding) | 0
that = allocate(that, length)
that.write(string, encoding)
return that
}
function fromObject (that, object) {
if (Buffer.isBuffer(object)) return fromBuffer(that, object)
if (isArray(object)) return fromArray(that, object)
if (object == null) {
throw new TypeError('must start with number, buffer, array or string')
}
if (typeof ArrayBuffer !== 'undefined') {
if (object.buffer instanceof ArrayBuffer) {
return fromTypedArray(that, object)
}
if (object instanceof ArrayBuffer) {
return fromArrayBuffer(that, object)
}
}
if (object.length) return fromArrayLike(that, object)
return fromJsonObject(that, object)
}
function fromBuffer (that, buffer) {
var length = checked(buffer.length) | 0
that = allocate(that, length)
buffer.copy(that, 0, 0, length)
return that
}
function fromArray (that, array) {
var length = checked(array.length) | 0
that = allocate(that, length)
for (var i = 0; i < length; i += 1) {
that[i] = array[i] & 255
}
return that
}
// Duplicate of fromArray() to keep fromArray() monomorphic.
function fromTypedArray (that, array) {
var length = checked(array.length) | 0
that = allocate(that, length)
// Truncating the elements is probably not what people expect from typed
// arrays with BYTES_PER_ELEMENT > 1 but it's compatible with the behavior
// of the old Buffer constructor.
for (var i = 0; i < length; i += 1) {
that[i] = array[i] & 255
}
return that
}
function fromArrayBuffer (that, array) {
if (Buffer.TYPED_ARRAY_SUPPORT) {
// Return an augmented `Uint8Array` instance, for best performance
array.byteLength
that = Buffer._augment(new Uint8Array(array))
} else {
// Fallback: Return an object instance of the Buffer class
that = fromTypedArray(that, new Uint8Array(array))
}
return that
}
function fromArrayLike (that, array) {
var length = checked(array.length) | 0
that = allocate(that, length)
for (var i = 0; i < length; i += 1) {
that[i] = array[i] & 255
}
return that
}
// Deserialize { type: 'Buffer', data: [1,2,3,...] } into a Buffer object.
// Returns a zero-length buffer for inputs that don't conform to the spec.
function fromJsonObject (that, object) {
var array
var length = 0
if (object.type === 'Buffer' && isArray(object.data)) {
array = object.data
length = checked(array.length) | 0
}
that = allocate(that, length)
for (var i = 0; i < length; i += 1) {
that[i] = array[i] & 255
}
return that
}
if (Buffer.TYPED_ARRAY_SUPPORT) {
Buffer.prototype.__proto__ = Uint8Array.prototype
Buffer.__proto__ = Uint8Array
} else {
// pre-set for values that may exist in the future
Buffer.prototype.length = undefined
Buffer.prototype.parent = undefined
}
function allocate (that, length) {
if (Buffer.TYPED_ARRAY_SUPPORT) {
// Return an augmented `Uint8Array` instance, for best performance
that = Buffer._augment(new Uint8Array(length))
that.__proto__ = Buffer.prototype
} else {
// Fallback: Return an object instance of the Buffer class
that.length = length
that._isBuffer = true
}
var fromPool = length !== 0 && length <= Buffer.poolSize >>> 1
if (fromPool) that.parent = rootParent
return that
}
function checked (length) {
// Note: cannot use `length < kMaxLength` here because that fails when
// length is NaN (which is otherwise coerced to zero.)
if (length >= kMaxLength()) {
throw new RangeError('Attempt to allocate Buffer larger than maximum ' +
'size: 0x' + kMaxLength().toString(16) + ' bytes')
}
return length | 0
}
function SlowBuffer (subject, encoding) {
if (!(this instanceof SlowBuffer)) return new SlowBuffer(subject, encoding)
var buf = new Buffer(subject, encoding)
delete buf.parent
return buf
}
Buffer.isBuffer = function isBuffer (b) {
return !!(b != null && b._isBuffer)
}
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
var i = 0
var len = Math.min(x, y)
while (i < len) {
if (a[i] !== b[i]) break
++i
}
if (i !== len) {
x = a[i]
y = b[i]
}
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 'binary':
case 'base64':
case 'raw':
case 'ucs2':
case 'ucs-2':
case 'utf16le':
case 'utf-16le':
return true
default:
return false
}
}
Buffer.concat = function concat (list, length) {
if (!isArray(list)) throw new TypeError('list argument must be an Array of Buffers.')
if (list.length === 0) {
return new Buffer(0)
}
var i
if (length === undefined) {
length = 0
for (i = 0; i < list.length; i++) {
length += list[i].length
}
}
var buf = new Buffer(length)
var pos = 0
for (i = 0; i < list.length; i++) {
var item = list[i]
item.copy(buf, pos)
pos += item.length
}
return buf
}
function byteLength (string, encoding) {
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 'binary':
// Deprecated
case 'raw':
case 'raws':
return len
case 'utf8':
case 'utf-8':
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
start = start | 0
end = end === undefined || end === Infinity ? this.length : end | 0
if (!encoding) encoding = 'utf8'
if (start < 0) start = 0
if (end > this.length) end = this.length
if (end <= start) return ''
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 'binary':
return binarySlice(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
}
}
}
Buffer.prototype.toString = function toString () {
var length = this.length | 0
if (length === 0) return ''
if (arguments.length === 0) return utf8Slice(this, 0, length)
return slowToString.apply(this, arguments)
}
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 (b) {
if (!Buffer.isBuffer(b)) throw new TypeError('Argument must be a Buffer')
if (this === b) return 0
return Buffer.compare(this, b)
}
Buffer.prototype.indexOf = function indexOf (val, byteOffset) {
if (byteOffset > 0x7fffffff) byteOffset = 0x7fffffff
else if (byteOffset < -0x80000000) byteOffset = -0x80000000
byteOffset >>= 0
if (this.length === 0) return -1
if (byteOffset >= this.length) return -1
// Negative offsets start from the end of the buffer
if (byteOffset < 0) byteOffset = Math.max(this.length + byteOffset, 0)
if (typeof val === 'string') {
if (val.length === 0) return -1 // special case: looking for empty string always fails
return String.prototype.indexOf.call(this, val, byteOffset)
}
if (Buffer.isBuffer(val)) {
return arrayIndexOf(this, val, byteOffset)
}
if (typeof val === 'number') {
if (Buffer.TYPED_ARRAY_SUPPORT && Uint8Array.prototype.indexOf === 'function') {
return Uint8Array.prototype.indexOf.call(this, val, byteOffset)
}
return arrayIndexOf(this, [ val ], byteOffset)
}
function arrayIndexOf (arr, val, byteOffset) {
var foundIndex = -1
for (var i = 0; byteOffset + i < arr.length; i++) {
if (arr[byteOffset + i] === val[foundIndex === -1 ? 0 : i - foundIndex]) {
if (foundIndex === -1) foundIndex = i
if (i - foundIndex + 1 === val.length) return byteOffset + foundIndex
} else {
foundIndex = -1
}
}
return -1
}
throw new TypeError('val must be string, number or Buffer')
}
// `get` is deprecated
Buffer.prototype.get = function get (offset) {
console.log('.get() is deprecated. Access using array indexes instead.')
return this.readUInt8(offset)
}
// `set` is deprecated
Buffer.prototype.set = function set (v, offset) {
console.log('.set() is deprecated. Access using array indexes instead.')
return this.writeUInt8(v, offset)
}
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
}
}
// must be an even number of digits
var strLen = string.length
if (strLen % 2 !== 0) throw new Error('Invalid hex string')
if (length > strLen / 2) {
length = strLen / 2
}
for (var i = 0; i < length; i++) {
var parsed = parseInt(string.substr(i * 2, 2), 16)
if (isNaN(parsed)) throw new Error('Invalid hex string')
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 binaryWrite (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
}
// legacy write(string, encoding, offset, length) - remove in v0.13
} else {
var swap = encoding
encoding = offset
offset = length | 0
length = swap
}
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 'binary':
return binaryWrite(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
}
function binarySlice (buf, start, end) {
var ret = ''
end = Math.min(buf.length, end)
for (var i = start; i < end; i++) {
ret += String.fromCharCode(buf[i])
}
return ret
}
function hexSlice (buf, start, end) {
var len = buf.length
if (!start || start < 0) start = 0
if (!end || end < 0 || end > len) end = len
var out = ''
for (var i = start; i < end; i++) {
out += toHex(buf[i])
}
return out
}
function utf16leSlice (buf, start, end) {
var bytes = buf.slice(start, end)
var res = ''
for (var i = 0; i < bytes.length; i += 2) {
res += String.fromCharCode(bytes[i] + bytes[i + 1] * 256)
}
return res
}
Buffer.prototype.slice = function slice (start, end) {
var len = this.length
start = ~~start
end = end === undefined ? len : ~~end
if (start < 0) {
start += len
if (start < 0) start = 0
} else if (start > len) {
start = len
}
if (end < 0) {
end += len
if (end < 0) end = 0
} else if (end > len) {
end = len
}
if (end < start) end = start
var newBuf
if (Buffer.TYPED_ARRAY_SUPPORT) {
newBuf = Buffer._augment(this.subarray(start, end))
} else {
var sliceLen = end - start
newBuf = new Buffer(sliceLen, undefined)
for (var i = 0; i < sliceLen; i++) {
newBuf[i] = this[i + start]
}
}
if (newBuf.length) newBuf.parent = this.parent || this
return newBuf
}
/*
* Need to make sure that buffer isn't trying to write out of bounds.
*/
function checkOffset (offset, ext, length) {
if ((offset % 1) !== 0 || offset < 0) throw new RangeError('offset is not uint')
if (offset + ext > length) throw new RangeError('Trying to access beyond buffer length')
}
Buffer.prototype.readUIntLE = function readUIntLE (offset, byteLength, noAssert) {
offset = offset | 0
byteLength = byteLength | 0
if (!noAssert) checkOffset(offset, byteLength, this.length)
var val = this[offset]
var mul = 1
var i = 0
while (++i < byteLength && (mul *= 0x100)) {
val += this[offset + i] * mul
}
return val
}
Buffer.prototype.readUIntBE = function readUIntBE (offset, byteLength, noAssert) {
offset = offset | 0
byteLength = byteLength | 0
if (!noAssert) {
checkOffset(offset, byteLength, this.length)
}
var val = this[offset + --byteLength]
var mul = 1
while (byteLength > 0 && (mul *= 0x100)) {
val += this[offset + --byteLength] * mul
}
return val
}
Buffer.prototype.readUInt8 = function readUInt8 (offset, noAssert) {
if (!noAssert) checkOffset(offset, 1, this.length)
return this[offset]
}
Buffer.prototype.readUInt16LE = function readUInt16LE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 2, this.length)
return this[offset] | (this[offset + 1] << 8)
}
Buffer.prototype.readUInt16BE = function readUInt16BE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 2, this.length)
return (this[offset] << 8) | this[offset + 1]
}
Buffer.prototype.readUInt32LE = function readUInt32LE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 4, this.length)
return ((this[offset]) |
(this[offset + 1] << 8) |
(this[offset + 2] << 16)) +
(this[offset + 3] * 0x1000000)
}
Buffer.prototype.readUInt32BE = function readUInt32BE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 4, this.length)
return (this[offset] * 0x1000000) +
((this[offset + 1] << 16) |
(this[offset + 2] << 8) |
this[offset + 3])
}
Buffer.prototype.readIntLE = function readIntLE (offset, byteLength, noAssert) {
offset = offset | 0
byteLength = byteLength | 0
if (!noAssert) checkOffset(offset, byteLength, this.length)
var val = this[offset]
var mul = 1
var i = 0
while (++i < byteLength && (mul *= 0x100)) {
val += this[offset + i] * mul
}
mul *= 0x80
if (val >= mul) val -= Math.pow(2, 8 * byteLength)
return val
}
Buffer.prototype.readIntBE = function readIntBE (offset, byteLength, noAssert) {
offset = offset | 0
byteLength = byteLength | 0
if (!noAssert) checkOffset(offset, byteLength, this.length)
var i = byteLength
var mul = 1
var val = this[offset + --i]
while (i > 0 && (mul *= 0x100)) {
val += this[offset + --i] * mul
}
mul *= 0x80
if (val >= mul) val -= Math.pow(2, 8 * byteLength)
return val
}
Buffer.prototype.readInt8 = function readInt8 (offset, noAssert) {
if (!noAssert) checkOffset(offset, 1, this.length)
if (!(this[offset] & 0x80)) return (this[offset])
return ((0xff - this[offset] + 1) * -1)
}
Buffer.prototype.readInt16LE = function readInt16LE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 2, this.length)
var val = this[offset] | (this[offset + 1] << 8)
return (val & 0x8000) ? val | 0xFFFF0000 : val
}
Buffer.prototype.readInt16BE = function readInt16BE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 2, this.length)
var val = this[offset + 1] | (this[offset] << 8)
return (val & 0x8000) ? val | 0xFFFF0000 : val
}
Buffer.prototype.readInt32LE = function readInt32LE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 4, this.length)
return (this[offset]) |
(this[offset + 1] << 8) |
(this[offset + 2] << 16) |
(this[offset + 3] << 24)
}
Buffer.prototype.readInt32BE = function readInt32BE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 4, this.length)
return (this[offset] << 24) |
(this[offset + 1] << 16) |
(this[offset + 2] << 8) |
(this[offset + 3])
}
Buffer.prototype.readFloatLE = function readFloatLE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 4, this.length)
return ieee754.read(this, offset, true, 23, 4)
}
Buffer.prototype.readFloatBE = function readFloatBE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 4, this.length)
return ieee754.read(this, offset, false, 23, 4)
}
Buffer.prototype.readDoubleLE = function readDoubleLE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 8, this.length)
return ieee754.read(this, offset, true, 52, 8)
}
Buffer.prototype.readDoubleBE = function readDoubleBE (offset, noAssert) {
if (!noAssert) checkOffset(offset, 8, this.length)
return ieee754.read(this, offset, false, 52, 8)
}
function checkInt (buf, value, offset, ext, max, min) {
if (!Buffer.isBuffer(buf)) throw new TypeError('buffer must be a Buffer instance')
if (value > max || value < min) throw new RangeError('value is out of bounds')
if (offset + ext > buf.length) throw new RangeError('index out of range')
}
Buffer.prototype.writeUIntLE = function writeUIntLE (value, offset, byteLength, noAssert) {
value = +value
offset = offset | 0
byteLength = byteLength | 0
if (!noAssert) checkInt(this, value, offset, byteLength, Math.pow(2, 8 * byteLength), 0)
var mul = 1
var i = 0
this[offset] = value & 0xFF
while (++i < byteLength && (mul *= 0x100)) {
this[offset + i] = (value / mul) & 0xFF
}
return offset + byteLength
}