Issue 6665 - Optimize element hiding emulation filter lookups

lib/elemHideEmulation.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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";
 
 /**
  * @fileOverview Element hiding emulation implementation.
  */
 
 const {ElemHide} = require("./elemHide");
-const {regExpIt} = require("./coreUtils");
+const {subdomains} = require("./common");
 
 /**
  * Map of element hiding emulation filters by domain
  * @type {Map.<string,Map.<ElemHideEmulationFilter,boolean>>}
  */
 let filtersByDomain = new Map();
 
 /**
  * Set containing known element hiding emulation filters
  * @type {Set.<ElemHideEmulation>}
  */
 let knownFilters = new Set();
 
 /**
  * Yields the domains associated with a filter, along with whether the filter
  * should be included on the domain and the set of filters associated with the
  * domain
  * @param {ElemHideEmulationFilter} filter
  * @yields {Array.<string,boolean,?Set.<ElemHideEmulationFilter>>}
  */
 function* filterDomains(filter)
 {
   for (let [domain, include] of filter.domains || [])
   {
     if (domain != "")
       yield [domain, include, filtersByDomain.get(domain)];
-  }
-}
-
-/**
- * Yields subdomains of a domain
- * @param {string} domain
- * @yields {string}
- */
-function* subdomains(domain)
-{
-  for (let [, subdomain] of
-       regExpIt(/([^|]*)\|/g, domain.replace(/([^.]+\.)/g, "$'|")))
-  {
-    yield subdomain;
   }
 }
 
 /**
  * Yields the filters for a domain and its subdomains, along with whether the
  * filter should be included on its corresponding domain
  * @param {string} domain
  * @yields {Array.<ElemHideEmulationFilter,boolean>}
  */
 function* filtersForDomain(domain)
@@ skipping 80 matching lines @@
                !ElemHide.getException(filter, domain))
       {
         result.push(filter);
       }
     }
 
     return result;
   }
 };
 exports.ElemHideEmulation = ElemHideEmulation;