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Diffstat (limited to 'mojo/public/js/new_bindings/buffer.js')
-rw-r--r--mojo/public/js/new_bindings/buffer.js155
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
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+++ b/mojo/public/js/new_bindings/buffer.js
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+// 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;
+})();