Issue 151 - [Typed objects] Implement dynamically-sized array types

lib/typedObjects/primitiveTypes.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 "use strict";
 
 let {ilog2} = require("typedObjects/utils");
+let {createArrayType} = require("typedObjects/arrayTypes");
 
 function createGetter(shift, offset, view)
 {
   shift = shift | 0;
   offset = offset | 0;
   offset >>= shift;
-  return function()
+  return function(bufferIndex, byteOffset)
   {
-    return view[this.bufferIndex][((this.byteOffset | 0) >> shift) + offset];
+    bufferIndex = bufferIndex | 0;
+    byteOffset = byteOffset | 0;
+    return view[bufferIndex][(byteOffset >> shift) + offset];
   };
 }
 
 function createSetter(shift, offset, view)
 {
   shift = shift | 0;
   offset = offset | 0;
   offset >>= shift;
-  return function(value)
+  return function(bufferIndex, byteOffset, value)
   {
-    view[this.bufferIndex][((this.byteOffset | 0) >> shift) + offset] = value;
+    bufferIndex = bufferIndex | 0;
+    byteOffset = byteOffset | 0;
+    view[bufferIndex][(byteOffset >> shift) + offset] = value;
   };
 }
 
 function PrimitiveType(viewType)
 {
   let result = Object.create(PrimitiveType.prototype);
   result.viewTypes = [viewType];
   result.byteLength = result.referenceLength = viewType.BYTES_PER_ELEMENT | 0;
 
   let offsetShift = ilog2(result.byteLength) | 0;
   result.createGetter = createGetter.bind(null, offsetShift);
   result.createSetter = createSetter.bind(null, offsetShift);
+  // Note: this is a pretty inefficient way to zero out initial values. We
+  // should consider using ArrayBuffer.fill(0) once it becomes available
+  // (https://bugzilla.mozilla.org/show_bug.cgi?id=730880).
+  result.initialValue = 0;
+  result.Array = createArrayType.bind(null, result);
   Object.freeze(result);
   return result;
 }
 
 exports.uint8 = exports.boolean = new PrimitiveType(Uint8Array);
 exports.uint8clamped = new PrimitiveType(Uint8ClampedArray);
 exports.int8 = new PrimitiveType(Int8Array);
 exports.uint16 = new PrimitiveType(Uint16Array);
 exports.int16 = new PrimitiveType(Int16Array);
 exports.uint32 = new PrimitiveType(Uint32Array);
 exports.int32 = new PrimitiveType(Int32Array);
 exports.float32 = new PrimitiveType(Float32Array);
 exports.float64 = new PrimitiveType(Float64Array);