Issue 5141 - [emscripten] Convert filter matcher to C++

lib/matcher.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 Matcher class implementing matching addresses against
- *               a list of filters.
- */
-
-const {Filter, WhitelistFilter} = require("filterClasses");
-
-/**
- * Blacklist/whitelist filter matching
- * @constructor
- */
-function Matcher()
-{
-  this.clear();
-}
+const {Matcher} = require("compiled");
 exports.Matcher = Matcher;

[sergei, 2017/12/20 09:23:23]

this Matcher is used in lib/notifications.js, so that file should be adjusted
too.

-
-Matcher.prototype = {
-  /**
-   * Lookup table for filters by their associated keyword
-   * @type {Object}
-   */
-  filterByKeyword: null,
-
-  /**
-   * Lookup table for keywords by the filter text
-   * @type {Object}
-   */
-  keywordByFilter: null,
-
-  /**
-   * Removes all known filters
-   */
-  clear()
-  {
-    this.filterByKeyword = Object.create(null);
-    this.keywordByFilter = Object.create(null);
-  },
-
-  /**
-   * Adds a filter to the matcher
-   * @param {RegExpFilter} filter
-   */
-  add(filter)
-  {
-    if (filter.text in this.keywordByFilter)
-      return;
-
-    // Look for a suitable keyword
-    let keyword = this.findKeyword(filter);
-    let oldEntry = this.filterByKeyword[keyword];
-    if (typeof oldEntry == "undefined")
-      this.filterByKeyword[keyword] = filter;
-    else if (oldEntry.length == 1)
-      this.filterByKeyword[keyword] = [oldEntry, filter];
-    else
-      oldEntry.push(filter);
-    this.keywordByFilter[filter.text] = keyword;
-  },
-
-  /**
-   * Removes a filter from the matcher
-   * @param {RegExpFilter} filter
-   */
-  remove(filter)
-  {
-    if (!(filter.text in this.keywordByFilter))
-      return;
-
-    let keyword = this.keywordByFilter[filter.text];
-    let list = this.filterByKeyword[keyword];
-    if (list.length <= 1)
-      delete this.filterByKeyword[keyword];
-    else
-    {
-      let index = list.indexOf(filter);
-      if (index >= 0)
-      {
-        list.splice(index, 1);
-        if (list.length == 1)
-          this.filterByKeyword[keyword] = list[0];
-      }
-    }
-
-    delete this.keywordByFilter[filter.text];
-  },
-
-  /**
-   * Chooses a keyword to be associated with the filter
-   * @param {Filter} filter
-   * @return {string} keyword or an empty string if no keyword could be found
-   */
-  findKeyword(filter)
-  {
-    let result = "";
-    let {text} = filter;
-    if (Filter.regexpRegExp.test(text))
-      return result;
-
-    // Remove options
-    let match = Filter.optionsRegExp.exec(text);
-    if (match)
-      text = match.input.substr(0, match.index);
-
-    // Remove whitelist marker
-    if (text.substr(0, 2) == "@@")
-      text = text.substr(2);
-
-    let candidates = text.toLowerCase().match(
-      /[^a-z0-9%*][a-z0-9%]{3,}(?=[^a-z0-9%*])/g
-    );
-    if (!candidates)
-      return result;
-
-    let hash = this.filterByKeyword;
-    let resultCount = 0xFFFFFF;
-    let resultLength = 0;
-    for (let i = 0, l = candidates.length; i < l; i++)
-    {
-      let candidate = candidates[i].substr(1);
-      let count = (candidate in hash ? hash[candidate].length : 0);
-      if (count < resultCount ||
-          (count == resultCount && candidate.length > resultLength))
-      {
-        result = candidate;
-        resultCount = count;
-        resultLength = candidate.length;
-      }
-    }
-    return result;
-  },
-
-  /**
-   * Checks whether a particular filter is being matched against.
-   * @param {RegExpFilter} filter
-   * @return {boolean}
-   */
-  hasFilter(filter)
-  {
-    return (filter.text in this.keywordByFilter);
-  },
-
-  /**
-   * Returns the keyword used for a filter, null for unknown filters.
-   * @param {RegExpFilter} filter
-   * @return {string}
-   */
-  getKeywordForFilter(filter)
-  {
-    if (filter.text in this.keywordByFilter)
-      return this.keywordByFilter[filter.text];
-    return null;
-  },
-
-  /**
-   * Checks whether the entries for a particular keyword match a URL
-   * @param {string} keyword
-   * @param {string} location
-   * @param {number} typeMask
-   * @param {string} docDomain
-   * @param {boolean} thirdParty
-   * @param {string} sitekey
-   * @param {boolean} specificOnly
-   * @return {?Filter}
-   */
-  _checkEntryMatch(keyword, location, typeMask, docDomain, thirdParty, sitekey,
-                   specificOnly)
-  {
-    let list = this.filterByKeyword[keyword];
-    for (let i = 0; i < list.length; i++)
-    {
-      let filter = list[i];
-
-      if (specificOnly && filter.isGeneric() &&
-          !(filter instanceof WhitelistFilter))
-        continue;
-
-      if (filter.matches(location, typeMask, docDomain, thirdParty, sitekey))
-        return filter;
-    }
-    return null;
-  },
-
-  /**
-   * Tests whether the URL matches any of the known filters
-   * @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
-   * @param {boolean} specificOnly
-   *   should be true if generic matches should be ignored
-   * @return {?RegExpFilter}
-   *   matching filter or null
-   */
-  matchesAny(location, typeMask, docDomain, thirdParty, sitekey, specificOnly)
-  {
-    let candidates = location.toLowerCase().match(/[a-z0-9%]{3,}/g);
-    if (candidates === null)
-      candidates = [];
-    candidates.push("");
-    for (let i = 0, l = candidates.length; i < l; i++)
-    {
-      let substr = candidates[i];
-      if (substr in this.filterByKeyword)
-      {
-        let result = this._checkEntryMatch(substr, location, typeMask,
-                                           docDomain, thirdParty, sitekey,
-                                           specificOnly);
-        if (result)
-          return result;
-      }
-    }
-
-    return null;
-  }
-};
-
-/**
- * Combines a matcher for blocking and exception rules, automatically sorts
- * rules into two Matcher instances.
- * @constructor
- * @augments Matcher
- */
-function CombinedMatcher()
-{
-  this.blacklist = new Matcher();
-  this.whitelist = new Matcher();
-  this.resultCache = Object.create(null);
-}
-exports.CombinedMatcher = CombinedMatcher;
-
-/**
- * Maximal number of matching cache entries to be kept
- * @type {number}
- */
-CombinedMatcher.maxCacheEntries = 1000;
-
-CombinedMatcher.prototype =
-{
-  /**
-   * Matcher for blocking rules.
-   * @type {Matcher}
-   */
-  blacklist: null,
-
-  /**
-   * Matcher for exception rules.
-   * @type {Matcher}
-   */
-  whitelist: null,
-
-  /**
-   * Lookup table of previous matchesAny results
-   * @type {Object}
-   */
-  resultCache: null,
-
-  /**
-   * Number of entries in resultCache
-   * @type {number}
-   */
-  cacheEntries: 0,
-
-  /**
-   * @see Matcher#clear
-   */
-  clear()
-  {
-    this.blacklist.clear();
-    this.whitelist.clear();
-    this.resultCache = Object.create(null);
-    this.cacheEntries = 0;
-  },
-
-  /**
-   * @see Matcher#add
-   * @param {Filter} filter
-   */
-  add(filter)
-  {
-    if (filter instanceof WhitelistFilter)
-      this.whitelist.add(filter);
-    else
-      this.blacklist.add(filter);
-
-    if (this.cacheEntries > 0)
-    {
-      this.resultCache = Object.create(null);
-      this.cacheEntries = 0;
-    }
-  },
-
-  /**
-   * @see Matcher#remove
-   * @param {Filter} filter
-   */
-  remove(filter)
-  {
-    if (filter instanceof WhitelistFilter)
-      this.whitelist.remove(filter);
-    else
-      this.blacklist.remove(filter);
-
-    if (this.cacheEntries > 0)
-    {
-      this.resultCache = Object.create(null);
-      this.cacheEntries = 0;
-    }
-  },
-
-  /**
-   * @see Matcher#findKeyword
-   * @param {Filter} filter
-   * @return {string} keyword
-   */
-  findKeyword(filter)
-  {
-    if (filter instanceof WhitelistFilter)
-      return this.whitelist.findKeyword(filter);
-    return this.blacklist.findKeyword(filter);
-  },
-
-  /**
-   * @see Matcher#hasFilter
-   * @param {Filter} filter
-   * @return {boolean}
-   */
-  hasFilter(filter)
-  {
-    if (filter instanceof WhitelistFilter)
-      return this.whitelist.hasFilter(filter);
-    return this.blacklist.hasFilter(filter);
-  },
-
-  /**
-   * @see Matcher#getKeywordForFilter
-   * @param {Filter} filter
-   * @return {string} keyword
-   */
-  getKeywordForFilter(filter)
-  {
-    if (filter instanceof WhitelistFilter)
-      return this.whitelist.getKeywordForFilter(filter);
-    return this.blacklist.getKeywordForFilter(filter);
-  },
-
-  /**
-   * Checks whether a particular filter is slow
-   * @param {RegExpFilter} filter
-   * @return {boolean}
-   */
-  isSlowFilter(filter)
-  {
-    let matcher = (
-      filter instanceof WhitelistFilter ? this.whitelist : this.blacklist
-    );
-    if (matcher.hasFilter(filter))
-      return !matcher.getKeywordForFilter(filter);
-    return !matcher.findKeyword(filter);
-  },
-
-  /**
-   * Optimized filter matching testing both whitelist and blacklist matchers
-   * simultaneously. For parameters see Matcher.matchesAny().
-   * @see Matcher#matchesAny
-   * @inheritdoc
-   */
-  matchesAnyInternal(location, typeMask, docDomain, thirdParty, sitekey,
-                     specificOnly)
-  {
-    let candidates = location.toLowerCase().match(/[a-z0-9%]{3,}/g);
-    if (candidates === null)
-      candidates = [];
-    candidates.push("");
-
-    let blacklistHit = null;
-    for (let i = 0, l = candidates.length; i < l; i++)
-    {
-      let substr = candidates[i];
-      if (substr in this.whitelist.filterByKeyword)
-      {
-        let result = this.whitelist._checkEntryMatch(
-          substr, location, typeMask, docDomain, thirdParty, sitekey
-        );
-        if (result)
-          return result;
-      }
-      if (substr in this.blacklist.filterByKeyword && blacklistHit === null)
-      {
-        blacklistHit = this.blacklist._checkEntryMatch(
-          substr, location, typeMask, docDomain, thirdParty, sitekey,
-          specificOnly
-        );
-      }
-    }
-    return blacklistHit;
-  },
-
-  /**
-   * @see Matcher#matchesAny
-   * @inheritdoc
-   */
-  matchesAny(location, typeMask, docDomain, thirdParty, sitekey, specificOnly)
-  {
-    let key = location + " " + typeMask + " " + docDomain + " " + thirdParty +
-      " " + sitekey + " " + specificOnly;
-    if (key in this.resultCache)
-      return this.resultCache[key];
-
-    let result = this.matchesAnyInternal(location, typeMask, docDomain,
-                                         thirdParty, sitekey, specificOnly);
-
-    if (this.cacheEntries >= CombinedMatcher.maxCacheEntries)
-    {
-      this.resultCache = Object.create(null);
-      this.cacheEntries = 0;
-    }
-
-    this.resultCache[key] = result;
-    this.cacheEntries++;
-
-    return result;
-  }
-};
-
-/**
- * Shared CombinedMatcher instance that should usually be used.
- * @type {CombinedMatcher}
- */
-exports.defaultMatcher = new CombinedMatcher();
+exports.defaultMatcher = Matcher.create();

[sergei, 2017/10/18 10:58:43]

BTW, just for reference, currently it's not deleted.