Issue 7094 - Encapsulate management of subscription filters

lib/subscriptionClasses.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 Definition of Subscription class and its subclasses.
  */
 
-const {Filter, ActiveFilter, BlockingFilter,
+const {ActiveFilter, BlockingFilter,
        WhitelistFilter, ElemHideBase} = require("./filterClasses");
 const {filterNotifier} = require("./filterNotifier");
 const {extend} = require("./coreUtils");
 
 /**
  * Abstract base class for filter subscriptions
  *
  * @param {string} url    download location of the subscription
  * @param {string} [title]  title of the filter subscription
  * @constructor
  */
 function Subscription(url, title)
 {
   this.url = url;
+
   this._filterText = [];
   this._filters = [];
+
   if (title)
     this._title = title;
+
   Subscription.knownSubscriptions.set(url, this);
 }
 exports.Subscription = Subscription;
 
 Subscription.prototype =
 {
   /**
    * Download location of the subscription
    * @type {string}
    */
   url: null,
 
   /**
    * Type of the subscription
    * @type {?string}
    */
   type: null,
 
   /**
    * Filter text contained in the filter subscription.
    * @type {Array.<string>}
    * @private
    */
   _filterText: null,

[hub, 2018/11/19 17:47:49]

shouldn't this be named `_filtersText` since it is many filters?

Also would be consistent with `_filters`

[Manish Jethani, 2018/11/20 00:19:39]

I thought about calling it _filtersText but that sounds wrong in English. Maybe
_filterTextList or _filterTextArray? Though I find it clear enough to just call
it _filterText, since text is both singular and plural and it maps nicely to the
generator function filterText()

[hub, 2018/11/20 19:30:19]

my bad. let's leave it at that.

 
   /**
-   * Optional {@link Filter} objects corresponding to the subscription's filter
-   * text.
-   * @type {Array.<?Filter>}
+   * {@link Filter} objects corresponding to the subscription's filter text.
+   * @type {Array.<Filter>}
    * @private
    */
   _filters: null,
 
   _title: null,
   _fixedTitle: false,
   _disabled: false,
 
   /**
    * Title of the filter subscription
@@ skipping 69 matching lines @@
   {
     yield* this._filterText;
   },
 
   /**
    * Yields the {@link Filter} object for each filter in the subscription.
    * @yields {Filter}
    */
   *filters()
   {
-    for (let i = 0; i < this._filters.length; i++)
-      yield this._filters[i] || Filter.fromText(this._filterText[i]);
+    yield* this._filters;
   },
 
   /**
    * Returns the {@link Filter} object at the given 0-based index.
    * @param {number} index
    * @returns {?Filter}
    */
   filterAt(index)
   {
-    return this._filters[index] ||
-           (index < this._filters.length ?
-              Filter.fromText(this._filterText[index]) : null);
+    return this._filters[index] || null;
   },
 
   /**
    * Returns the 0-based index of the given filter.
    * @param {Filter} filter
    * @param {number} [fromIndex] The index from which to start the search.
    * @return {number}
    */
   searchFilter(filter, fromIndex = 0)
   {
     return this._filterText.indexOf(filter.text, fromIndex);
   },
 
   /**
    * Removes all filters from the subscription.
    */
   clearFilters()
   {
     this._filterText = [];
     this._filters = [];
   },
 
   /**
    * Adds a filter to the subscription.
    * @param {Filter} filter
-   * @param {boolean} [forceCache] If set to <code>true</code>, the
-   *   {@link Filter} object is cached regardless of whether it's lightweight.
-   *   By default lightweight objects are not cached but are recreated on
-   *   demand.
-   */
-  addFilter(filter, forceCache = false)
+   */
+  addFilter(filter)
   {
     this._filterText.push(filter.text);
-    this._filters.push(!forceCache && filter.lightweight ? null : filter);
+    this._filters.push(filter);
   },
 
   /**
    * Inserts a filter into the subscription.
    * @param {Filter} filter
-   * @param {number} [index] The index at which to insert the filter.
+   * @param {number} index The index at which to insert the filter.
    */
   insertFilterAt(filter, index)
   {
     this._filterText.splice(index, 0, filter.text);
-    this._filters.splice(index, 0, filter.lightweight ? null : filter);
+    this._filters.splice(index, 0, filter);
   },
 
   /**
    * Deletes a filter from the subscription.
-   * @param {number} [index] The index at which to delete the filter.
+   * @param {number} index The index at which to delete the filter.
    */
   deleteFilterAt(index)
   {
+    // Ignore index if out of bounds on the negative side, for consistency.
+    if (index < 0)
+      return;
+
     this._filterText.splice(index, 1);
     this._filters.splice(index, 1);
-  },
-
-  /**
-   * Frees up any force-cached {@link Filter} objects.
-   * @see #addFilter
-   */
-  freeFilters()
-  {
-    for (let i = 0; i < this._filters.length; i++)
-    {
-      let filter = this._filters[i];
-      if (filter && filter.lightweight)
-        this._filters[i] = null;
-    }
   },
 
   /**
    * Serializes the subscription for writing out on disk.
    * @yields {string}
    */
   *serialize()
   {
     let {url, type, _title, _fixedTitle, _disabled} = this;
 
@@ skipping 447 matching lines @@
     if (errors)
       yield "errors=" + errors;
     if (version)
       yield "version=" + version;
     if (requiredVersion)
       yield "requiredVersion=" + requiredVersion;
     if (downloadCount)
       yield "downloadCount=" + downloadCount;
   }
 });