Issue 7016 - Convert serialization functions into generators

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
@@ skipping 107 matching lines @@
     if (value != this._disabled)
     {
       let oldValue = this._disabled;
       this._disabled = value;
       filterNotifier.emit("subscription.disabled", this, value, oldValue);
     }
     return this._disabled;
   },
 
   /**
-   * Serializes the subscription for writing

[Manish Jethani, 2018/10/22 20:18:01]

Nit: We could wrap this.

[Jon Sonesen, 2018/10/22 22:59:36]

Acknowledged.

-   * out on the disk.
+   * Serializes the subscription for writing out on disk.
    * @yields {string}
    */
   *serialize()
   {
     let {url, type, _title, _fixedTitle, _disabled} = this;
 
     yield "[Subscription]";
     yield "url=" + url;
 
     if (type)
       yield "type=" + type;
     if (_title)
       yield "title=" + _title;
     if (_fixedTitle)
       yield "fixedTitle=true";
     if (_disabled)
       yield "disabled=true";
   },
 
   *serializeFilters()
   {
     let {filters} = this;
 
     yield "[Subscription filters]";
+
     for (let filter of filters)
       yield filter.text.replace(/\[/g, "\\[");
   },
 
   toString()
   {
     return [...this.serialize()].join("\n");

[Jon Sonesen, 2018/10/22 22:59:36]

This may be unrelated, but I was reading about how spread operators prevent
functions from being optimized by the engine. If I recall correctly this method
is used in a couple performant reliant functions, no?

[Manish Jethani, 2018/10/22 23:01:29]

I don't know (where is this method called?), but I also don't see a better way
of doing it. `Array.from` is even worse.

[Jon Sonesen, 2018/10/23 02:04:24]

Acknowledged.

   }
 };
 
 /**
  * Cache for known filter subscriptions, maps URL to subscription objects.
  * @type {Map.<string,Subscription>}
  */
 Subscription.knownSubscriptions = new Map();
 
 /**
@@ skipping 113 matching lines @@
   /**
    * See Subscription.serialize()
    * @inheritdoc
    */
   *serialize()
   {
     let {defaults, _lastDownload} = this;
 
     yield* Subscription.prototype.serialize.call(this);
 
-    if (defaults && defaults.length)
+    if (defaults)
     {
       yield "defaults=" +
             defaults.filter(
               type => SpecialSubscription.defaultsMap.has(type)
             ).join(" ");
     }
     if (_lastDownload)
       yield "lastDownload=" + _lastDownload;
   }
 });
@@ skipping 277 matching lines @@
     if (errors)
       yield "errors=" + errors;
     if (version)
       yield "version=" + version;
     if (requiredVersion)
       yield "requiredVersion=" + requiredVersion;
     if (downloadCount)
       yield "downloadCount=" + downloadCount;
   }
 });