Issue 147 - [Typed objects] Implement object types

lib/typedObjects/utils.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";
 
 /**
  * Calculates the binary logarithm (position of highest bit) of an integer.
  * Source: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious
  */
-exports.log2 = function log2(/**Integer*/ num) /**Integer*/

[René Jeschke, 2014/04/21 17:24:12]

I'm not really sure is this is the right name for this method. 'log2' implies
that it works on and returns floating point values (like Math.log). Maybe we
should add something to indicate that this works with integers only (like
'ilog2'). 

Also: this method will run into an endless loop for negative values, which will
not occur when called from the creator methods but as it is exported it may be a
good idea to capture that case and throw an error.

[Wladimir Palant, 2014/04/22 15:25:05]

Changed name into ilog2 but I didn't really feel like introducing an additional
check/branch to this function.

[René Jeschke, 2014/04/22 15:40:34]

Alright then.

+exports.ilog2 = function ilog2(/**Integer*/ num) /**Integer*/
 {
   num = num | 0;
   let result = 0;
-  while (num >>= 1)
+  while ((num >>= 1) > 0)
     result++;
   return result;
 };
 
 /**
  * Round up a 32-bit integer to the next power of two.
  * Source: See http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
  */
-exports.ceilLog2 = function ceilLog2(/**Integer*/ num) /**Integer*/

[René Jeschke, 2014/04/21 17:24:12]

See above for naming issues, maybe just call it 'nextPowerOf2'?

[Wladimir Palant, 2014/04/22 15:25:05]

Renamed into nextPow2

+exports.nextPow2 = function nextPow2(/**Integer*/ num) /**Integer*/
 {
   num = num | 0;
   num--;
   num |= num >> 1;
   num |= num >> 2;
   num |= num >> 4;
   num |= num >> 8;
   num |= num >> 16;
   return num + 1;
 };
@@ skipping 74 matching lines @@
       enumerable: true
     };
     offset += type.referenceLength;
   }
 
   // Define properties
   Object.defineProperties(obj, descriptors);
 
   return offset;
 };