From: Feross Aboukhadijeh Date: Sat, 24 Sep 2016 01:53:27 +0000 (-0700) Subject: v5: Remove Object implementation X-Git-Url: https://zoso.dev/?a=commitdiff_plain;h=8746070093390396e497be53e900240c51c2ba49;p=buffer.git v5: Remove Object implementation --- diff --git a/index.js b/index.js index b55b9aa..4c5e251 100644 --- a/index.js +++ b/index.js @@ -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. @@ -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 { @@ -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 } @@ -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') { @@ -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') @@ -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) } /** @@ -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 } @@ -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 } @@ -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 { @@ -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 } @@ -1300,29 +1251,16 @@ 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 } @@ -1330,34 +1268,19 @@ 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 } @@ -1365,14 +1288,10 @@ 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 } @@ -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 @@ -1436,12 +1354,8 @@ 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 } @@ -1449,12 +1363,8 @@ 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 } @@ -1462,14 +1372,10 @@ 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 } @@ -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 } @@ -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]