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v5: Remove Object implementation
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@feross
feross committed Sep 27, 2016
1 parent 454b519 commit 8746070
Showing 1 changed file with 64 additions and 162 deletions.
226 changes: 64 additions & 162 deletions index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -15,18 +15,20 @@ 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`:
* If `TYPED_ARRAY_SUPPORT`:
* === true Use Uint8Array implementation (fastest)
* === false Use Object implementation (most compatible, even IE6)
* === 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+.
*
* Due to various browser bugs, sometimes the Object implementation will be used even
* when the browser supports typed arrays.
*
* Note:
* Sometimes we report that the browser does not support typed arrays, if there
* exist extreme bugs in the implemetation. For example:
*
* - Firefox 4-29 lacks support for adding new properties to `Uint8Array` instances,
* See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438.
Expand All @@ -35,18 +37,14 @@ exports.INSPECT_MAX_BYTES = 50
*
* - 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()
Buffer.TYPED_ARRAY_SUPPORT = typedArraySupport()

/*
* Export kMaxLength after typed array support is determined.
*/
exports.kMaxLength = kMaxLength()
if (!Buffer.TYPED_ARRAY_SUPPORT) {
console.error(
'This browser lacks typed array (Uint8Array) support which is required by ' +
'`buffer` v5.x. Use v4.x if you require old browser support.')
}

function typedArraySupport () {
try {
Expand All @@ -60,28 +58,13 @@ function typedArraySupport () {
}
}

function kMaxLength () {
return Buffer.TYPED_ARRAY_SUPPORT
? 0x7fffffff
: 0x3fffffff
}

function createBuffer (that, length) {
if (kMaxLength() < length) {
if (K_MAX_LENGTH < length) {
throw new RangeError('Invalid typed array length')
}
if (Buffer.TYPED_ARRAY_SUPPORT) {
// Return an augmented `Uint8Array` instance, for best performance
that = new Uint8Array(length)
that.__proto__ = Buffer.prototype
} else {
// Fallback: Return an object instance of the Buffer class
if (that === null) {
that = new Buffer(length)
}
that.length = length
}

// Return an augmented `Uint8Array` instance
that = new Uint8Array(length)
that.__proto__ = Buffer.prototype
return that
}

Expand All @@ -96,10 +79,6 @@ function createBuffer (that, length) {
*/

function Buffer (arg, encodingOrOffset, length) {
if (!Buffer.TYPED_ARRAY_SUPPORT && !(this instanceof Buffer)) {
return new Buffer(arg, encodingOrOffset, length)
}

// Common case.
if (typeof arg === 'number') {
if (typeof encodingOrOffset === 'string') {
Expand All @@ -112,26 +91,20 @@ function Buffer (arg, encodingOrOffset, length) {
return from(this, arg, encodingOrOffset, length)
}

if (Buffer.TYPED_ARRAY_SUPPORT) {
Buffer.prototype.__proto__ = Uint8Array.prototype
Buffer.__proto__ = Uint8Array
if (typeof Symbol !== 'undefined' && Symbol.species &&
Buffer[Symbol.species] === Buffer) {
// Fix subarray() in ES2016. See: https://github.com/feross/buffer/pull/97
Object.defineProperty(Buffer, Symbol.species, {
value: null,
configurable: true
})
}
}
Buffer.poolSize = 8192 // not used by this implementation
Buffer.prototype.__proto__ = Uint8Array.prototype
Buffer.__proto__ = Uint8Array

// TODO: Legacy, not needed anymore. Remove in next major version.
Buffer._augment = function (arr) {
arr.__proto__ = Buffer.prototype
return arr
// 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
})
}

Buffer.poolSize = 8192 // not used by this implementation

function from (that, value, encodingOrOffset, length) {
if (typeof value === 'number') {
throw new TypeError('"value" argument must not be a number')
Expand Down Expand Up @@ -194,13 +167,7 @@ Buffer.alloc = function (size, fill, encoding) {

function allocUnsafe (that, size) {
assertSize(size)
that = createBuffer(that, size < 0 ? 0 : checked(size) | 0)
if (!Buffer.TYPED_ARRAY_SUPPORT) {
for (var i = 0; i < size; ++i) {
that[i] = 0
}
}
return that
return createBuffer(that, size < 0 ? 0 : checked(size) | 0)
}

/**
Expand Down Expand Up @@ -268,14 +235,9 @@ function fromArrayBuffer (that, array, byteOffset, length) {
array = new Uint8Array(array, byteOffset, length)
}

if (Buffer.TYPED_ARRAY_SUPPORT) {
// Return an augmented `Uint8Array` instance, for best performance
that = array
that.__proto__ = Buffer.prototype
} else {
// Fallback: Return an object instance of the Buffer class
that = fromArrayLike(that, array)
}
// Return an augmented `Uint8Array` instance, for best performance
that = array
that.__proto__ = Buffer.prototype
return that
}

Expand Down Expand Up @@ -310,11 +272,11 @@ function fromObject (that, obj) {
}

function checked (length) {
// Note: cannot use `length < kMaxLength()` here because that fails when
// Note: cannot use `length < K_MAX_LENGTH` here because that fails when
// length is NaN (which is otherwise coerced to zero.)
if (length >= kMaxLength()) {
if (length >= K_MAX_LENGTH) {
throw new RangeError('Attempt to allocate Buffer larger than maximum ' +
'size: 0x' + kMaxLength().toString(16) + ' bytes')
'size: 0x' + K_MAX_LENGTH.toString(16) + ' bytes')
}
return length | 0
}
Expand Down Expand Up @@ -698,8 +660,7 @@ function bidirectionalIndexOf (buffer, val, byteOffset, encoding, dir) {
return arrayIndexOf(buffer, val, byteOffset, encoding, dir)
} else if (typeof val === 'number') {
val = val & 0xFF // Search for a byte value [0-255]
if (Buffer.TYPED_ARRAY_SUPPORT &&
typeof Uint8Array.prototype.indexOf === 'function') {
if (typeof Uint8Array.prototype.indexOf === 'function') {
if (dir) {
return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset)
} else {
Expand Down Expand Up @@ -1073,18 +1034,8 @@ Buffer.prototype.slice = function slice (start, end) {

if (end < start) end = start

var newBuf
if (Buffer.TYPED_ARRAY_SUPPORT) {
newBuf = this.subarray(start, end)
newBuf.__proto__ = Buffer.prototype
} else {
var sliceLen = end - start
newBuf = new Buffer(sliceLen, undefined)
for (var i = 0; i < sliceLen; ++i) {
newBuf[i] = this[i + start]
}
}

var newBuf = this.subarray(start, end)
newBuf.__proto__ = Buffer.prototype
return newBuf
}

Expand Down Expand Up @@ -1300,79 +1251,47 @@ Buffer.prototype.writeUInt8 = function writeUInt8 (value, offset, noAssert) {
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 1, 0xff, 0)
if (!Buffer.TYPED_ARRAY_SUPPORT) value = Math.floor(value)
this[offset] = (value & 0xff)
return offset + 1
}

function objectWriteUInt16 (buf, value, offset, littleEndian) {
if (value < 0) value = 0xffff + value + 1
for (var i = 0, j = Math.min(buf.length - offset, 2); i < j; ++i) {
buf[offset + i] = (value & (0xff << (8 * (littleEndian ? i : 1 - i)))) >>>
(littleEndian ? i : 1 - i) * 8
}
}

Buffer.prototype.writeUInt16LE = function writeUInt16LE (value, offset, noAssert) {
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
if (Buffer.TYPED_ARRAY_SUPPORT) {
this[offset] = (value & 0xff)
this[offset + 1] = (value >>> 8)
} else {
objectWriteUInt16(this, value, offset, true)
}
this[offset] = (value & 0xff)
this[offset + 1] = (value >>> 8)
return offset + 2
}

Buffer.prototype.writeUInt16BE = function writeUInt16BE (value, offset, noAssert) {
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
if (Buffer.TYPED_ARRAY_SUPPORT) {
this[offset] = (value >>> 8)
this[offset + 1] = (value & 0xff)
} else {
objectWriteUInt16(this, value, offset, false)
}
this[offset] = (value >>> 8)
this[offset + 1] = (value & 0xff)
return offset + 2
}

function objectWriteUInt32 (buf, value, offset, littleEndian) {
if (value < 0) value = 0xffffffff + value + 1
for (var i = 0, j = Math.min(buf.length - offset, 4); i < j; ++i) {
buf[offset + i] = (value >>> (littleEndian ? i : 3 - i) * 8) & 0xff
}
}

Buffer.prototype.writeUInt32LE = function writeUInt32LE (value, offset, noAssert) {
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
if (Buffer.TYPED_ARRAY_SUPPORT) {
this[offset + 3] = (value >>> 24)
this[offset + 2] = (value >>> 16)
this[offset + 1] = (value >>> 8)
this[offset] = (value & 0xff)
} else {
objectWriteUInt32(this, value, offset, true)
}
this[offset + 3] = (value >>> 24)
this[offset + 2] = (value >>> 16)
this[offset + 1] = (value >>> 8)
this[offset] = (value & 0xff)
return offset + 4
}

Buffer.prototype.writeUInt32BE = function writeUInt32BE (value, offset, noAssert) {
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
if (Buffer.TYPED_ARRAY_SUPPORT) {
this[offset] = (value >>> 24)
this[offset + 1] = (value >>> 16)
this[offset + 2] = (value >>> 8)
this[offset + 3] = (value & 0xff)
} else {
objectWriteUInt32(this, value, offset, false)
}
this[offset] = (value >>> 24)
this[offset + 1] = (value >>> 16)
this[offset + 2] = (value >>> 8)
this[offset + 3] = (value & 0xff)
return offset + 4
}

Expand Down Expand Up @@ -1426,7 +1345,6 @@ Buffer.prototype.writeInt8 = function writeInt8 (value, offset, noAssert) {
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 1, 0x7f, -0x80)
if (!Buffer.TYPED_ARRAY_SUPPORT) value = Math.floor(value)
if (value < 0) value = 0xff + value + 1
this[offset] = (value & 0xff)
return offset + 1
Expand All @@ -1436,40 +1354,28 @@ Buffer.prototype.writeInt16LE = function writeInt16LE (value, offset, noAssert)
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
if (Buffer.TYPED_ARRAY_SUPPORT) {
this[offset] = (value & 0xff)
this[offset + 1] = (value >>> 8)
} else {
objectWriteUInt16(this, value, offset, true)
}
this[offset] = (value & 0xff)
this[offset + 1] = (value >>> 8)
return offset + 2
}

Buffer.prototype.writeInt16BE = function writeInt16BE (value, offset, noAssert) {
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
if (Buffer.TYPED_ARRAY_SUPPORT) {
this[offset] = (value >>> 8)
this[offset + 1] = (value & 0xff)
} else {
objectWriteUInt16(this, value, offset, false)
}
this[offset] = (value >>> 8)
this[offset + 1] = (value & 0xff)
return offset + 2
}

Buffer.prototype.writeInt32LE = function writeInt32LE (value, offset, noAssert) {
value = +value
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
if (Buffer.TYPED_ARRAY_SUPPORT) {
this[offset] = (value & 0xff)
this[offset + 1] = (value >>> 8)
this[offset + 2] = (value >>> 16)
this[offset + 3] = (value >>> 24)
} else {
objectWriteUInt32(this, value, offset, true)
}
this[offset] = (value & 0xff)
this[offset + 1] = (value >>> 8)
this[offset + 2] = (value >>> 16)
this[offset + 3] = (value >>> 24)
return offset + 4
}

Expand All @@ -1478,14 +1384,10 @@ Buffer.prototype.writeInt32BE = function writeInt32BE (value, offset, noAssert)
offset = offset | 0
if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
if (value < 0) value = 0xffffffff + value + 1
if (Buffer.TYPED_ARRAY_SUPPORT) {
this[offset] = (value >>> 24)
this[offset + 1] = (value >>> 16)
this[offset + 2] = (value >>> 8)
this[offset + 3] = (value & 0xff)
} else {
objectWriteUInt32(this, value, offset, false)
}
this[offset] = (value >>> 24)
this[offset + 1] = (value >>> 16)
this[offset + 2] = (value >>> 8)
this[offset + 3] = (value & 0xff)
return offset + 4
}

Expand Down Expand Up @@ -1559,7 +1461,7 @@ Buffer.prototype.copy = function copy (target, targetStart, start, end) {
for (i = len - 1; i >= 0; --i) {
target[i + targetStart] = this[i + start]
}
} else if (len < 1000 || !Buffer.TYPED_ARRAY_SUPPORT) {
} else if (len < 1000) {
// ascending copy from start
for (i = 0; i < len; ++i) {
target[i + targetStart] = this[i + start]
Expand Down

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