Issue 6856 - Remove FilterStorage.moveSubscription

lib/filterStorage.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
@@ skipping 62 matching lines @@
    */
   firstRun: false,
 
   /**
    * Map of properties listed in the filter storage file before the sections
    * start. Right now this should be only the format version.
    */
   fileProperties: Object.create(null),
 
   /**
-   * List of filter subscriptions containing all filters
-   * @type {Subscription[]}
+   * Generator for filter subscriptions containing all filters

[Manish Jethani, 2018/09/21 09:21:58]

We could just say "Yields filter subscriptions containing all filters."

[Jon Sonesen, 2018/09/27 15:14:05]

Done.

+   * @type {Subscription.Generator}

[Manish Jethani, 2018/09/21 09:21:58]

This is a function now rather than a property, so we don't use `@type` but
rather `@returns`, or in this case `@yields` (since it's a generator function).

  @yields {Subscription}

[Jon Sonesen, 2018/09/27 15:14:04]

Done.

    */
-  subscriptions: [],
+  *subscriptions()
+  {
+    for (let subscription of this.knownSubscriptions.values())

[Manish Jethani, 2018/09/21 09:21:58]

We could replace the body of this function with this:

  yield* this.knownSubscriptions.values();

`yield*` is essentially syntactic sugar, it does what a `for` loop does above
but with one line of code. We use `yield*` in other places so compatibility is
not an issue.

[Jon Sonesen, 2018/09/27 15:14:05]

Done.

+      yield subscription;
+  },
+
+  subscriptionCount()

[Manish Jethani, 2018/09/21 09:21:58]

This needs JSDoc.

How about:

  Number of known subscriptions.
  @type {number}

Also this should be a property rather than a function, so we should replace
`subscriptionCount()` with `get subscriptionCount()` here.

[Jon Sonesen, 2018/09/27 15:14:04]

Done.

+  {
+    return this.knownSubscriptions.size;
+  },
 
   /**
    * Map of subscriptions already on the list, by their URL/identifier
    * @type {Map.<string,Subscription>}
    */
   knownSubscriptions: new Map(),
 
   /**
    * Finds the filter group that a filter should be added to by default. Will
    * return null if this group doesn't exist yet.
    * @param {Filter} filter
    * @return {?SpecialSubscription}
    */
   getGroupForFilter(filter)
   {
     let generalSubscription = null;
-    for (let subscription of FilterStorage.subscriptions)
+    for (let subscription of FilterStorage.subscriptions())
     {
       if (subscription instanceof SpecialSubscription && !subscription.disabled)
       {
         // Always prefer specialized subscriptions
         if (subscription.isDefaultFor(filter))
           return subscription;
 
         // If this is a general subscription - store it as fallback
         if (!generalSubscription &&
             (!subscription.defaults || !subscription.defaults.length))
         {
           generalSubscription = subscription;
         }
       }
     }
     return generalSubscription;
   },
 
   /**
    * Adds a filter subscription to the list
    * @param {Subscription} subscription filter subscription to be added
    */
   addSubscription(subscription)
   {
     if (FilterStorage.knownSubscriptions.has(subscription.url))
       return;
 
-    FilterStorage.subscriptions.push(subscription);
     FilterStorage.knownSubscriptions.set(subscription.url, subscription);
     addSubscriptionFilters(subscription);
 
     filterNotifier.emit("subscription.added", subscription);
   },
 
   /**
    * Removes a filter subscription from the list
    * @param {Subscription} subscription filter subscription to be removed
    */
   removeSubscription(subscription)
   {
-    for (let i = 0; i < FilterStorage.subscriptions.length; i++)
-    {
-      if (FilterStorage.subscriptions[i].url == subscription.url)
-      {
-        removeSubscriptionFilters(subscription);
+    if (!FilterStorage.knownSubscriptions.has(subscription.url))
+      return;

[Manish Jethani, 2018/09/21 09:21:59]

It seems when we have a check like this we normally leave a blank line after it.

[Jon Sonesen, 2018/09/27 15:14:04]

Done.

+    removeSubscriptionFilters(subscription);
+    FilterStorage.knownSubscriptions.delete(subscription.url);
 
-        FilterStorage.subscriptions.splice(i--, 1);
-        FilterStorage.knownSubscriptions.delete(subscription.url);
+    // This should be the last remaining reference to the Subscription
+    // object.
+    Subscription.knownSubscriptions.delete(subscription.url);
 
-        // This should be the last remaining reference to the Subscription
-        // object.
-        Subscription.knownSubscriptions.delete(subscription.url);
-
-        filterNotifier.emit("subscription.removed", subscription);
-        return;
-      }
-    }
-  },
-
-  /**
-   * Moves a subscription in the list to a new position.
-   * @param {Subscription} subscription filter subscription to be moved
-   * @param {Subscription} [insertBefore] filter subscription to insert before
-   *        (if omitted the subscription will be put at the end of the list)
-   */
-  moveSubscription(subscription, insertBefore)
-  {
-    let currentPos = FilterStorage.subscriptions.indexOf(subscription);
-    if (currentPos < 0)
-      return;
-
-    let newPos = -1;
-    if (insertBefore)
-      newPos = FilterStorage.subscriptions.indexOf(insertBefore);
-
-    if (newPos < 0)
-      newPos = FilterStorage.subscriptions.length;
-
-    if (currentPos < newPos)
-      newPos--;
-    if (currentPos == newPos)
-      return;
-
-    FilterStorage.subscriptions.splice(currentPos, 1);
-    FilterStorage.subscriptions.splice(newPos, 0, subscription);
-    filterNotifier.emit("subscription.moved", subscription);
+    filterNotifier.emit("subscription.removed", subscription);
   },
 
   /**
    * Replaces the list of filters in a subscription by a new list
    * @param {Subscription} subscription filter subscription to be updated
    * @param {Filter[]} filters new filter list
    */
   updateSubscriptionFilters(subscription, filters)
   {
     removeSubscriptionFilters(subscription);
@@ skipping 166 matching lines @@
     return line =>
     {
       parser.process(line);
       if (line === null)
       {
         let knownSubscriptions = new Map();
         for (let subscription of parser.subscriptions)
           knownSubscriptions.set(subscription.url, subscription);
 
         this.fileProperties = parser.fileProperties;
-        this.subscriptions = parser.subscriptions;
         this.knownSubscriptions = knownSubscriptions;
         Filter.knownFilters = parser.knownFilters;
         Subscription.knownSubscriptions = parser.knownSubscriptions;
 
         if (!silent)
           filterNotifier.emit("load");
       }
     };
   },
 
   /**
    * Loads all subscriptions from the disk.
    * @return {Promise} promise resolved or rejected when loading is complete
    */
   loadFromDisk()
   {
     let tryBackup = backupIndex =>
     {
       return this.restoreBackup(backupIndex, true).then(() =>
       {
-        if (this.subscriptions.length == 0)
+        if (this.subscriptionCount == 0)
           return tryBackup(backupIndex + 1);
       }).catch(error =>
       {
         // Give up
       });
     };
 
     return IO.statFile(this.sourceFile).then(statData =>
     {
       if (!statData.exists)
       {
         this.firstRun = true;
         return;
       }
 
       let parser = this.importData(true);
       return IO.readFromFile(this.sourceFile, parser).then(() =>
       {
         parser(null);
-        if (this.subscriptions.length == 0)
+        if (this.subscriptionCount == 0)
         {
           // No filter subscriptions in the file, this isn't right.
           throw new Error("No data in the file");
         }
       });
     }).catch(error =>
     {
       Cu.reportError(error);
       return tryBackup(1);
     }).then(() =>
@@ skipping 33 matching lines @@
       return this.saveToDisk();
     });
   },
 
   /**
    * Generator serializing filter data and yielding it line by line.
    */
   *exportData()
   {
     // Do not persist external subscriptions
-    let subscriptions = this.subscriptions.filter(
+    let subscriptions = [...this.subscriptions()].filter(
       s => !(s instanceof ExternalSubscription)
     );
 
     yield "# Adblock Plus preferences";
     yield "version=" + formatVersion;
 
     let saved = new Set();
     let buf = [];
 
     // Save subscriptions
@@ skipping 189 matching lines @@
  * @param {Subscription} subscription filter subscription to be removed
  */
 function removeSubscriptionFilters(subscription)
 {
   if (!FilterStorage.knownSubscriptions.has(subscription.url))
     return;
 
   for (let filter of subscription.filters)
     filter.removeSubscription(subscription);
 }