Issue 6994 - Use shortcut matching for location only filters

lib/filterClasses.js

Index: lib/filterClasses.js
===================================================================
--- a/lib/filterClasses.js
+++ b/lib/filterClasses.js
@@ -803,16 +803,26 @@
 
     Object.defineProperty(
       this, "sitekeys", {value: sitekeys, enumerable: true}
     );
     return this.sitekeys;
   },
 
   /**
+   * Tests whether the filter only has a location.
+   * @return {boolean}
+   */
+  isLocationOnly()
+  {
+    return this.contentType == RegExpFilter.prototype.contentType &&

[Manish Jethani, 2018/10/24 21:35:28]

I haven't run this code, but I'm pretty sure that this would cause the initial
memory footprint to go up, because we would end up creating the domain maps for
all the blocking/whitelist filters.

We could change the check to this:

  return this.contentType == RegExpFilter.prototype.contentType &&
         this.thirdParty == null && !this.domainSource && !this.sitekeySource &&
         !this.domains && !this.sitekeys;

For filters that do have domains, it would short-circuit at `!this.domainSource`
and thus avoid the creation of the domain map. If the domain map has already
been created, it would fail at `!this.domains`. For filters that do not have
domains, both tests would pass.

[Jon Sonesen, 2018/10/24 21:46:51]

Ah, I see what you mean there. I didn't look deep enough in the docs/source to
properly see or understand domainSource and sitekeySource

+           this.thirdParty == null && !this.domains && !this.sitekeys;
+  },
+
+  /**
    * Tests whether the URL matches this filter
    * @param {string} location URL to be tested
    * @param {number} typeMask bitmask of content / request types to match
    * @param {string} [docDomain] domain name of the document that loads the URL
    * @param {boolean} [thirdParty] should be true if the URL is a third-party
    *                               request
    * @param {string} [sitekey] public key provided by the document
    * @return {boolean} true in case of a match