diff options
Diffstat (limited to 'mojo/public/js/new_bindings/buffer.js')
-rw-r--r-- | mojo/public/js/new_bindings/buffer.js | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/mojo/public/js/new_bindings/buffer.js b/mojo/public/js/new_bindings/buffer.js new file mode 100644 index 0000000000..c44058bd0f --- /dev/null +++ b/mojo/public/js/new_bindings/buffer.js @@ -0,0 +1,155 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +(function() { + var internal = mojo.internal; + + var kHostIsLittleEndian = (function () { + var endianArrayBuffer = new ArrayBuffer(2); + var endianUint8Array = new Uint8Array(endianArrayBuffer); + var endianUint16Array = new Uint16Array(endianArrayBuffer); + endianUint16Array[0] = 1; + return endianUint8Array[0] == 1; + })(); + + var kHighWordMultiplier = 0x100000000; + + function Buffer(sizeOrArrayBuffer) { + if (sizeOrArrayBuffer instanceof ArrayBuffer) + this.arrayBuffer = sizeOrArrayBuffer; + else + this.arrayBuffer = new ArrayBuffer(sizeOrArrayBuffer); + + this.dataView = new DataView(this.arrayBuffer); + this.next = 0; + } + + Object.defineProperty(Buffer.prototype, "byteLength", { + get: function() { return this.arrayBuffer.byteLength; } + }); + + Buffer.prototype.alloc = function(size) { + var pointer = this.next; + this.next += size; + if (this.next > this.byteLength) { + var newSize = (1.5 * (this.byteLength + size)) | 0; + this.grow(newSize); + } + return pointer; + }; + + function copyArrayBuffer(dstArrayBuffer, srcArrayBuffer) { + (new Uint8Array(dstArrayBuffer)).set(new Uint8Array(srcArrayBuffer)); + } + + Buffer.prototype.grow = function(size) { + var newArrayBuffer = new ArrayBuffer(size); + copyArrayBuffer(newArrayBuffer, this.arrayBuffer); + this.arrayBuffer = newArrayBuffer; + this.dataView = new DataView(this.arrayBuffer); + }; + + Buffer.prototype.trim = function() { + this.arrayBuffer = this.arrayBuffer.slice(0, this.next); + this.dataView = new DataView(this.arrayBuffer); + }; + + Buffer.prototype.getUint8 = function(offset) { + return this.dataView.getUint8(offset); + } + Buffer.prototype.getUint16 = function(offset) { + return this.dataView.getUint16(offset, kHostIsLittleEndian); + } + Buffer.prototype.getUint32 = function(offset) { + return this.dataView.getUint32(offset, kHostIsLittleEndian); + } + Buffer.prototype.getUint64 = function(offset) { + var lo, hi; + if (kHostIsLittleEndian) { + lo = this.dataView.getUint32(offset, kHostIsLittleEndian); + hi = this.dataView.getUint32(offset + 4, kHostIsLittleEndian); + } else { + hi = this.dataView.getUint32(offset, kHostIsLittleEndian); + lo = this.dataView.getUint32(offset + 4, kHostIsLittleEndian); + } + return lo + hi * kHighWordMultiplier; + } + + Buffer.prototype.getInt8 = function(offset) { + return this.dataView.getInt8(offset); + } + Buffer.prototype.getInt16 = function(offset) { + return this.dataView.getInt16(offset, kHostIsLittleEndian); + } + Buffer.prototype.getInt32 = function(offset) { + return this.dataView.getInt32(offset, kHostIsLittleEndian); + } + Buffer.prototype.getInt64 = function(offset) { + var lo, hi; + if (kHostIsLittleEndian) { + lo = this.dataView.getUint32(offset, kHostIsLittleEndian); + hi = this.dataView.getInt32(offset + 4, kHostIsLittleEndian); + } else { + hi = this.dataView.getInt32(offset, kHostIsLittleEndian); + lo = this.dataView.getUint32(offset + 4, kHostIsLittleEndian); + } + return lo + hi * kHighWordMultiplier; + } + + Buffer.prototype.getFloat32 = function(offset) { + return this.dataView.getFloat32(offset, kHostIsLittleEndian); + } + Buffer.prototype.getFloat64 = function(offset) { + return this.dataView.getFloat64(offset, kHostIsLittleEndian); + } + + Buffer.prototype.setUint8 = function(offset, value) { + this.dataView.setUint8(offset, value); + } + Buffer.prototype.setUint16 = function(offset, value) { + this.dataView.setUint16(offset, value, kHostIsLittleEndian); + } + Buffer.prototype.setUint32 = function(offset, value) { + this.dataView.setUint32(offset, value, kHostIsLittleEndian); + } + Buffer.prototype.setUint64 = function(offset, value) { + var hi = (value / kHighWordMultiplier) | 0; + if (kHostIsLittleEndian) { + this.dataView.setInt32(offset, value, kHostIsLittleEndian); + this.dataView.setInt32(offset + 4, hi, kHostIsLittleEndian); + } else { + this.dataView.setInt32(offset, hi, kHostIsLittleEndian); + this.dataView.setInt32(offset + 4, value, kHostIsLittleEndian); + } + } + + Buffer.prototype.setInt8 = function(offset, value) { + this.dataView.setInt8(offset, value); + } + Buffer.prototype.setInt16 = function(offset, value) { + this.dataView.setInt16(offset, value, kHostIsLittleEndian); + } + Buffer.prototype.setInt32 = function(offset, value) { + this.dataView.setInt32(offset, value, kHostIsLittleEndian); + } + Buffer.prototype.setInt64 = function(offset, value) { + var hi = Math.floor(value / kHighWordMultiplier); + if (kHostIsLittleEndian) { + this.dataView.setInt32(offset, value, kHostIsLittleEndian); + this.dataView.setInt32(offset + 4, hi, kHostIsLittleEndian); + } else { + this.dataView.setInt32(offset, hi, kHostIsLittleEndian); + this.dataView.setInt32(offset + 4, value, kHostIsLittleEndian); + } + } + + Buffer.prototype.setFloat32 = function(offset, value) { + this.dataView.setFloat32(offset, value, kHostIsLittleEndian); + } + Buffer.prototype.setFloat64 = function(offset, value) { + this.dataView.setFloat64(offset, value, kHostIsLittleEndian); + } + + internal.Buffer = Buffer; +})(); |