Revision: 4683
Author: [email protected]
Date: Wed Dec 14 15:06:47 2011
Log: faster es53 freeze
http://codereview.appspot.com/5484074
This change reduces runtime of a minimal test gadget
from 2800ms to 1800ms in Chrome Beta (16.0),
Basically, much of the cost of es53+domado startup is freeze,
and much of the cost of freeze is iterating over object properties,
which includes inherited properties which have to be ignored.
This change tries to use a native Object.keys function to do
a fast initial filtering of the properties.
[email protected]
http://code.google.com/p/google-caja/source/detail?r=4683
Modified:
/trunk/src/com/google/caja/es53.js
=======================================
--- /trunk/src/com/google/caja/es53.js Tue Nov 8 10:55:13 2011
+++ /trunk/src/com/google/caja/es53.js Wed Dec 14 15:06:47 2011
@@ -220,6 +220,17 @@
}
};
}
+
+ var hasOwnProperty = Object.prototype.hasOwnProperty;
+ var fastOwnKeys = Object.keys || function fastOwnKeys(o) {
+ // In IE<9, this will miss some keys, like an own 'toString', but that
+ // doesn't matter, because we're only using this to find ___
properties.
+ var keys = [];
+ for (var k in o) {
+ if (hasOwnProperty.call(o, k)) { keys.push(k); }
+ }
+ return keys;
+ };
Object.prototype.freeze___ = function() {
// Frozen means all the properties are neither writable nor
@@ -233,17 +244,16 @@
if (this.v___ === deferredV) {
this.v___('length');
}
- for (var i in this) {
- if (!this.hasOwnProperty(i)) { continue; }
- if (isNumericName(i)) { continue; }
- var m = i.match(endsWith_v___);
- if (!m) { continue; }
- var P = m[1];
+ var keys = fastOwnKeys(this);
+ for (var k = 0, n = keys.length; k < n; k++) {
+ var i = keys[k];
+ if (i.substr(-5) !== '_v___' || i.length < 6) { continue; }
+ var P = i.substr(0, i.length - 5);
this[P + '_c___'] = false;
this[P + '_gw___'] = false;
this[P + '_w___'] = false;
}
- if (!this.hasNumerics___()) {
+ if (!this.NUM____v___ === this) { // inline this.hasNumerics___()
this.NUM____v___ = this;
this.NUM____e___ = this;
this.NUM____g___ = void 0;
