v8/src/arraybuffer.js
binji aff8ebb0eb Implement SharedArrayBuffer.
This adds a new external type (v8::SharedArrayBuffer) that uses a JSArrayBuffer
under the hood. It can be distinguished from an ArrayBuffer by the newly-added
is_shared() bit.

Currently there is no difference in functionality between a SharedArrayBuffer
and an ArrayBuffer. However, a future CL will add the Atomics API, which is
only available on an SharedArrayBuffer. All non-atomic accesses are identical
to ArrayBuffer accesses.

LOG=N
BUG=

Review URL: https://codereview.chromium.org/1136553006

Cr-Commit-Position: refs/heads/master@{#28594}
2015-05-22 13:43:17 +00:00

109 lines
2.8 KiB
JavaScript

// Copyright 2013 the V8 project 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(global, utils) {
"use strict";
%CheckIsBootstrapping();
// -------------------------------------------------------------------
// Imports
var GlobalArrayBuffer = global.ArrayBuffer;
var GlobalObject = global.Object;
var MathMax;
var MathMin;
utils.Import(function(from) {
MathMax = from.MathMax;
MathMin = from.MathMin;
});
// -------------------------------------------------------------------
function ArrayBufferConstructor(length) { // length = 1
if (%_IsConstructCall()) {
var byteLength = $toPositiveInteger(length, kInvalidArrayBufferLength);
%ArrayBufferInitialize(this, byteLength, kNotShared);
} else {
throw MakeTypeError(kConstructorNotFunction, "ArrayBuffer");
}
}
function ArrayBufferGetByteLen() {
if (!IS_ARRAYBUFFER(this)) {
throw MakeTypeError(kIncompatibleMethodReceiver,
'ArrayBuffer.prototype.byteLength', this);
}
return %_ArrayBufferGetByteLength(this);
}
// ES6 Draft 15.13.5.5.3
function ArrayBufferSlice(start, end) {
if (!IS_ARRAYBUFFER(this)) {
throw MakeTypeError(kIncompatibleMethodReceiver,
'ArrayBuffer.prototype.slice', this);
}
var relativeStart = TO_INTEGER(start);
if (!IS_UNDEFINED(end)) {
end = TO_INTEGER(end);
}
var first;
var byte_length = %_ArrayBufferGetByteLength(this);
if (relativeStart < 0) {
first = MathMax(byte_length + relativeStart, 0);
} else {
first = MathMin(relativeStart, byte_length);
}
var relativeEnd = IS_UNDEFINED(end) ? byte_length : end;
var fin;
if (relativeEnd < 0) {
fin = MathMax(byte_length + relativeEnd, 0);
} else {
fin = MathMin(relativeEnd, byte_length);
}
if (fin < first) {
fin = first;
}
var newLen = fin - first;
// TODO(dslomov): implement inheritance
var result = new GlobalArrayBuffer(newLen);
%ArrayBufferSliceImpl(this, result, first);
return result;
}
function ArrayBufferIsViewJS(obj) {
return %ArrayBufferIsView(obj);
}
// Set up the ArrayBuffer constructor function.
%SetCode(GlobalArrayBuffer, ArrayBufferConstructor);
%FunctionSetPrototype(GlobalArrayBuffer, new GlobalObject());
// Set up the constructor property on the ArrayBuffer prototype object.
%AddNamedProperty(
GlobalArrayBuffer.prototype, "constructor", GlobalArrayBuffer, DONT_ENUM);
%AddNamedProperty(GlobalArrayBuffer.prototype,
symbolToStringTag, "ArrayBuffer", DONT_ENUM | READ_ONLY);
$installGetter(GlobalArrayBuffer.prototype, "byteLength", ArrayBufferGetByteLen);
$installFunctions(GlobalArrayBuffer, DONT_ENUM, [
"isView", ArrayBufferIsViewJS
]);
$installFunctions(GlobalArrayBuffer.prototype, DONT_ENUM, [
"slice", ArrayBufferSlice
]);
})