/* eslint-disable require-buffer */ 'use strict'; const binding = process.binding('buffer'); const smalloc = process.binding('smalloc'); const internalUtil = require('internal/util'); const alloc = smalloc.alloc; const truncate = smalloc.truncate; const sliceOnto = smalloc.sliceOnto; const kMaxLength = smalloc.kMaxLength; exports.Buffer = Buffer; exports.SlowBuffer = SlowBuffer; exports.INSPECT_MAX_BYTES = 50; Buffer.poolSize = 8 * 1024; var poolSize, poolOffset, allocPool; function createPool() { poolSize = Buffer.poolSize; allocPool = alloc({}, poolSize); poolOffset = 0; } createPool(); 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); } this.length = 0; this.parent = undefined; // Common case. if (typeof(arg) === 'number') { fromNumber(this, arg); return; } // Slightly less common case. if (typeof(arg) === 'string') { fromString(this, arg, arguments.length > 1 ? arguments[1] : 'utf8'); return; } // Unusual. fromObject(this, arg); } function fromNumber(that, length) { allocate(that, length < 0 ? 0 : checked(length) | 0); } 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; allocate(that, length); var actual = that.write(string, encoding) | 0; if (actual !== length) { // Fix up for truncated base64 input. Don't bother returning // the unused two or three bytes to the pool. that.length = actual; truncate(that, actual); } } function fromObject(that, object) { if (object instanceof Buffer) return fromBuffer(that, object); if (Array.isArray(object)) return fromArray(that, object); if (object == null) throw new TypeError('must start with number, buffer, array or string'); if (object.buffer instanceof ArrayBuffer) return fromTypedArray(that, object); if (object.length) return fromArrayLike(that, object); return fromJsonObject(that, object); } function fromBuffer(that, buffer) { var length = checked(buffer.length) | 0; allocate(that, length); buffer.copy(that, 0, 0, length); } function fromArray(that, array) { var length = checked(array.length) | 0; allocate(that, length); for (var i = 0; i < length; i += 1) that[i] = array[i] & 255; } // Duplicate of fromArray() to keep fromArray() monomorphic. function fromTypedArray(that, array) { var length = checked(array.length) | 0; 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; } function fromArrayLike(that, array) { var length = checked(array.length) | 0; allocate(that, length); for (var i = 0; i < length; i += 1) that[i] = array[i] & 255; } // 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' && Array.isArray(object.data)) { array = object.data; length = checked(array.length) | 0; } allocate(that, length); for (var i = 0; i < length; i += 1) that[i] = array[i] & 255; } function allocate(that, length) { var fromPool = length !== 0 && length <= Buffer.poolSize >>> 1; if (fromPool) that.parent = palloc(that, length); else alloc(that, length); that.length = length; } function palloc(that, length) { if (length > poolSize - poolOffset) createPool(); var start = poolOffset; var end = start + length; var buf = sliceOnto(allocPool, that, start, end); poolOffset = end; // Ensure aligned slices if (poolOffset & 0x7) { poolOffset |= 0x7; poolOffset++; } return buf; } 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(length) { length = length >>> 0; if (length > kMaxLength) { throw new RangeError('Attempt to allocate Buffer larger than maximum ' + 'size: 0x' + kMaxLength.toString(16) + ' bytes'); } var b = new NativeBuffer(length); alloc(b, length); return b; } // Bypass all checks for instantiating unallocated Buffer required for // Objects created in C++. Significantly faster than calling the Buffer // function. function NativeBuffer(length) { this.length = length >>> 0; // Set this to keep the object map the same. this.parent = undefined; } NativeBuffer.prototype = Buffer.prototype; // add methods to Buffer prototype binding.setupBufferJS(NativeBuffer); // Static methods Buffer.isBuffer = function isBuffer(b) { return b instanceof Buffer; }; Buffer.compare = function compare(a, b) { if (!(a instanceof Buffer) || !(b instanceof Buffer)) throw new TypeError('Arguments must be Buffers'); if (a === b) return 0; return binding.compare(a, b); }; Buffer.isEncoding = function(encoding) { switch ((encoding + '').toLowerCase()) { case 'hex': case 'utf8': case 'utf-8': case 'ascii': case 'binary': case 'base64': case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': case 'raw': return true; default: return false; } }; Buffer.concat = function(list, length) { if (!Array.isArray(list)) throw new TypeError('list argument must be an Array of Buffers.'); if (list.length === 0) return new Buffer(0); else if (list.length === 1) return list[0]; if (length === undefined) { length = 0; for (var i = 0; i < list.length; i++) length += list[i].length; } else { length = length >>> 0; } var buffer = new Buffer(length); var pos = 0; for (var i = 0; i < list.length; i++) { var buf = list[i]; buf.copy(buffer, pos); pos += buf.length; } return buffer; }; function base64ByteLength(str, bytes) { // Handle padding if (str.charCodeAt(bytes - 1) === 0x3D) bytes--; if (bytes > 1 && str.charCodeAt(bytes - 1) === 0x3D) bytes--; // Base64 ratio: 3/4 return (bytes * 3) >>> 2; } 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 binding.byteLengthUtf8(string); case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': return len * 2; case 'hex': return len >>> 1; case 'base64': return base64ByteLength(string, len); default: // The C++ binding defaulted to UTF8, we should too. if (loweredCase) return binding.byteLengthUtf8(string); 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 this.hexSlice(start, end); case 'utf8': case 'utf-8': return this.utf8Slice(start, end); case 'ascii': return this.asciiSlice(start, end); case 'binary': return this.binarySlice(start, end); case 'base64': return this.base64Slice(start, end); case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': return this.ucs2Slice(start, end); default: if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding); encoding = (encoding + '').toLowerCase(); loweredCase = true; } } } Buffer.prototype.toString = function() { const length = this.length | 0; if (arguments.length === 0) return this.utf8Slice(0, length); return slowToString.apply(this, arguments); }; Buffer.prototype.equals = function equals(b) { if (!(b instanceof Buffer)) throw new TypeError('Argument must be a Buffer'); if (this === b) return true; return binding.compare(this, b) === 0; }; // Inspect 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 '<' + this.constructor.name + ' ' + str + '>'; }; Buffer.prototype.compare = function compare(b) { if (!(b instanceof Buffer)) throw new TypeError('Argument must be a Buffer'); if (this === b) return 0; return binding.compare(this, b); }; Buffer.prototype.indexOf = function indexOf(val, byteOffset) { if (byteOffset > 0x7fffffff) byteOffset = 0x7fffffff; else if (byteOffset < -0x80000000) byteOffset = -0x80000000; byteOffset >>= 0; if (typeof val === 'string') return binding.indexOfString(this, val, byteOffset); if (val instanceof Buffer) return binding.indexOfBuffer(this, val, byteOffset); if (typeof val === 'number') return binding.indexOfNumber(this, val, byteOffset); throw new TypeError('val must be string, number or Buffer'); }; Buffer.prototype.fill = function fill(val, start, end) { start = start >> 0; end = (end === undefined) ? this.length : end >> 0; if (start < 0 || end > this.length) throw new RangeError('out of range index'); if (end <= start) return this; if (typeof val !== 'string') { val = val >>> 0; } else if (val.length === 1) { var code = val.charCodeAt(0); if (code < 256) val = code; } binding.fill(this, val, start, end); return this; }; // XXX remove in v0.13 Buffer.prototype.get = internalUtil.deprecate(function get(offset) { offset = ~~offset; if (offset < 0 || offset >= this.length) throw new RangeError('index out of range'); return this[offset]; }, 'Buffer.get is deprecated. Use array indexes instead.'); // XXX remove in v0.13 Buffer.prototype.set = internalUtil.deprecate(function set(offset, v) { offset = ~~offset; if (offset < 0 || offset >= this.length) throw new RangeError('index out of range'); return this[offset] = v; }, 'Buffer.set is deprecated. Use array indexes instead.'); // TODO(trevnorris): fix these checks to follow new standard // write(string, offset = 0, length = buffer.length, encoding = 'utf8') var writeWarned = false; const writeMsg = 'Buffer.write(string, encoding, offset, length) is ' + 'deprecated. Use write(string[, offset[, length]]' + '[, encoding]) instead.'; Buffer.prototype.write = function(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; } // XXX legacy write(string, encoding, offset, length) - remove in v0.13 } else { writeWarned = internalUtil.printDeprecationMessage(writeMsg, writeWarned); 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)) throw new RangeError('attempt to write outside buffer bounds'); if (!encoding) encoding = 'utf8'; var loweredCase = false; for (;;) { switch (encoding) { case 'hex': return this.hexWrite(string, offset, length); case 'utf8': case 'utf-8': return this.utf8Write(string, offset, length); case 'ascii': return this.asciiWrite(string, offset, length); case 'binary': return this.binaryWrite(string, offset, length); case 'base64': // Warning: maxLength not taken into account in base64Write return this.base64Write(string, offset, length); case 'ucs2': case 'ucs-2': case 'utf16le': case 'utf-16le': return this.ucs2Write(string, offset, length); default: if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding); encoding = ('' + encoding).toLowerCase(); loweredCase = true; } } }; Buffer.prototype.toJSON = function() { return { type: 'Buffer', data: Array.prototype.slice.call(this, 0) }; }; // TODO(trevnorris): currently works like Array.prototype.slice(), which // doesn't follow the new standard for throwing on out of range indexes. Buffer.prototype.slice = function(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 buf = new NativeBuffer(); sliceOnto(this, buf, start, end); buf.length = end - start; if (buf.length > 0) buf.parent = this.parent === undefined ? this : this.parent; return buf; }; function checkOffset(offset, ext, length) { if (offset + ext > length) throw new RangeError('index out of range'); } Buffer.prototype.readUIntLE = function(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(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(offset, noAssert) { offset = offset >>> 0; if (!noAssert) checkOffset(offset, 1, this.length); return this[offset]; }; Buffer.prototype.readUInt16LE = function(offset, noAssert) { offset = offset >>> 0; if (!noAssert) checkOffset(offset, 2, this.length); return this[offset] | (this[offset + 1] << 8); }; Buffer.prototype.readUInt16BE = function(offset, noAssert) { offset = offset >>> 0; if (!noAssert) checkOffset(offset, 2, this.length); return (this[offset] << 8) | this[offset + 1]; }; Buffer.prototype.readUInt32LE = function(offset, noAssert) { offset = offset >>> 0; 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(offset, noAssert) { offset = offset >>> 0; 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(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(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(offset, noAssert) { offset = offset >>> 0; if (!noAssert) checkOffset(offset, 1, this.length); var val = this[offset]; return !(val & 0x80) ? val : (0xff - val + 1) * -1; }; Buffer.prototype.readInt16LE = function(offset, noAssert) { offset = offset >>> 0; 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(offset, noAssert) { offset = offset >>> 0; 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(offset, noAssert) { offset = offset >>> 0; 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(offset, noAssert) { offset = offset >>> 0; 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) { offset = offset >>> 0; if (!noAssert) checkOffset(offset, 4, this.length); return binding.readFloatLE(this, offset); }; Buffer.prototype.readFloatBE = function readFloatBE(offset, noAssert) { offset = offset >>> 0; if (!noAssert) checkOffset(offset, 4, this.length); return binding.readFloatBE(this, offset); }; Buffer.prototype.readDoubleLE = function readDoubleLE(offset, noAssert) { offset = offset >>> 0; if (!noAssert) checkOffset(offset, 8, this.length); return binding.readDoubleLE(this, offset); }; Buffer.prototype.readDoubleBE = function readDoubleBE(offset, noAssert) { offset = offset >>> 0; if (!noAssert) checkOffset(offset, 8, this.length); return binding.readDoubleBE(this, offset); }; function checkInt(buffer, value, offset, ext, max, min) { if (!(buffer instanceof Buffer)) throw new TypeError('buffer must be a Buffer instance'); if (value > max || value < min) throw new TypeError('value is out of bounds'); if (offset + ext > buffer.length) throw new RangeError('index out of range'); } Buffer.prototype.writeUIntLE = function(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; while (++i < byteLength && (mul *= 0x100)) this[offset + i] = (value / mul) >>> 0; return offset + byteLength; }; Buffer.prototype.writeUIntBE = function(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 i = byteLength - 1; var mul = 1; this[offset + i] = value; while (--i >= 0 && (mul *= 0x100)) this[offset + i] = (value / mul) >>> 0; return offset + byteLength; }; Buffer.prototype.writeUInt8 = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 1, 0xff, 0); this[offset] = value; return offset + 1; }; Buffer.prototype.writeUInt16LE = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0); this[offset] = value; this[offset + 1] = (value >>> 8); return offset + 2; }; Buffer.prototype.writeUInt16BE = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0); this[offset] = (value >>> 8); this[offset + 1] = value; return offset + 2; }; Buffer.prototype.writeUInt32LE = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0); this[offset + 3] = (value >>> 24); this[offset + 2] = (value >>> 16); this[offset + 1] = (value >>> 8); this[offset] = value; return offset + 4; }; Buffer.prototype.writeUInt32BE = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0); this[offset] = (value >>> 24); this[offset + 1] = (value >>> 16); this[offset + 2] = (value >>> 8); this[offset + 3] = value; return offset + 4; }; Buffer.prototype.writeIntLE = function(value, offset, byteLength, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) { checkInt(this, value, offset, byteLength, Math.pow(2, 8 * byteLength - 1) - 1, -Math.pow(2, 8 * byteLength - 1)); } var i = 0; var mul = 1; var sub = value < 0 ? 1 : 0; this[offset] = value; while (++i < byteLength && (mul *= 0x100)) this[offset + i] = ((value / mul) >> 0) - sub; return offset + byteLength; }; Buffer.prototype.writeIntBE = function(value, offset, byteLength, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) { checkInt(this, value, offset, byteLength, Math.pow(2, 8 * byteLength - 1) - 1, -Math.pow(2, 8 * byteLength - 1)); } var i = byteLength - 1; var mul = 1; var sub = value < 0 ? 1 : 0; this[offset + i] = value; while (--i >= 0 && (mul *= 0x100)) this[offset + i] = ((value / mul) >> 0) - sub; return offset + byteLength; }; Buffer.prototype.writeInt8 = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 1, 0x7f, -0x80); this[offset] = value; return offset + 1; }; Buffer.prototype.writeInt16LE = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000); this[offset] = value; this[offset + 1] = (value >>> 8); return offset + 2; }; Buffer.prototype.writeInt16BE = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000); this[offset] = (value >>> 8); this[offset + 1] = value; return offset + 2; }; Buffer.prototype.writeInt32LE = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000); this[offset] = value; this[offset + 1] = (value >>> 8); this[offset + 2] = (value >>> 16); this[offset + 3] = (value >>> 24); return offset + 4; }; Buffer.prototype.writeInt32BE = function(value, offset, noAssert) { value = +value; offset = offset >>> 0; if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000); this[offset] = (value >>> 24); this[offset + 1] = (value >>> 16); this[offset + 2] = (value >>> 8); this[offset + 3] = value; return offset + 4; }; function checkFloat(buffer, value, offset, ext) { if (!(buffer instanceof Buffer)) throw new TypeError('buffer must be a Buffer instance'); if (offset + ext > buffer.length) throw new RangeError('index out of range'); } Buffer.prototype.writeFloatLE = function writeFloatLE(val, offset, noAssert) { val = +val; offset = offset >>> 0; if (!noAssert) checkFloat(this, val, offset, 4); binding.writeFloatLE(this, val, offset); return offset + 4; }; Buffer.prototype.writeFloatBE = function writeFloatBE(val, offset, noAssert) { val = +val; offset = offset >>> 0; if (!noAssert) checkFloat(this, val, offset, 4); binding.writeFloatBE(this, val, offset); return offset + 4; }; Buffer.prototype.writeDoubleLE = function writeDoubleLE(val, offset, noAssert) { val = +val; offset = offset >>> 0; if (!noAssert) checkFloat(this, val, offset, 8); binding.writeDoubleLE(this, val, offset); return offset + 8; }; Buffer.prototype.writeDoubleBE = function writeDoubleBE(val, offset, noAssert) { val = +val; offset = offset >>> 0; if (!noAssert) checkFloat(this, val, offset, 8); binding.writeDoubleBE(this, val, offset); return offset + 8; }; // ES6 iterator var ITERATOR_KIND_KEYS = 1; var ITERATOR_KIND_ENTRIES = 3; function BufferIteratorResult(value, done) { this.value = value; this.done = done; } var resultCache = new Array(256); for (var i = 0; i < 256; i++) resultCache[i] = Object.freeze(new BufferIteratorResult(i, false)); var finalResult = Object.freeze(new BufferIteratorResult(undefined, true)); function BufferIterator(buffer, kind) { this._buffer = buffer; this._kind = kind; this._index = 0; } BufferIterator.prototype.next = function() { var buffer = this._buffer; var kind = this._kind; var index = this._index; if (index >= buffer.length) return finalResult; this._index++; if (kind === ITERATOR_KIND_ENTRIES) return new BufferIteratorResult([index, buffer[index]], false); return new BufferIteratorResult(index, false); }; function BufferValueIterator(buffer) { BufferIterator.call(this, buffer, null); } BufferValueIterator.prototype.next = function() { var buffer = this._buffer; var index = this._index; if (index >= buffer.length) return finalResult; this._index++; return resultCache[buffer[index]]; }; BufferIterator.prototype[Symbol.iterator] = function() { return this; }; BufferValueIterator.prototype[Symbol.iterator] = BufferIterator.prototype[Symbol.iterator]; Buffer.prototype.keys = function() { return new BufferIterator(this, ITERATOR_KIND_KEYS); }; Buffer.prototype.entries = function() { return new BufferIterator(this, ITERATOR_KIND_ENTRIES); }; Buffer.prototype.values = function() { return new BufferValueIterator(this); }; Buffer.prototype[Symbol.iterator] = Buffer.prototype.values;