Issue 6923 - Only parse metadata from special comments at the top of the file

lib/synchronizer.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 18 matching lines @@
 const {filterNotifier} = require("./filterNotifier");
 const {Prefs} = require("prefs");
 const {Subscription,
        DownloadableSubscription} = require("./subscriptionClasses");
 
 const INITIAL_DELAY = 1 * MILLIS_IN_MINUTE;
 const CHECK_INTERVAL = 1 * MILLIS_IN_HOUR;
 const DEFAULT_EXPIRATION_INTERVAL = 5 * MILLIS_IN_DAY;
 
 /**
- * The object providing actual downloading functionality.
- * @type {Downloader}
+ * Downloads filter subscriptions whenever necessary.
  */
-let downloader = null;
-
-/**
- * This object is responsible for downloading filter subscriptions whenever
- * necessary.
- * @class
- */
-let Synchronizer = exports.Synchronizer =
+class Synchronizer
 {
   /**
-   * Called on module startup.
-   */
-  init()
-  {
-    downloader = new Downloader(this._getDownloadables.bind(this),
-                                INITIAL_DELAY, CHECK_INTERVAL);
+   * @hideconstructor
+   */
+  constructor()
+  {
+    /**
+     * The object providing actual downloading functionality.
+     * @type {Downloader}
+     */
+    this._downloader = new Downloader(this._getDownloadables.bind(this),
+                                      INITIAL_DELAY, CHECK_INTERVAL);
     onShutdown.add(() =>
     {
-      downloader.cancel();
+      this._downloader.cancel();
     });
 
-    downloader.onExpirationChange = this._onExpirationChange.bind(this);
-    downloader.onDownloadStarted = this._onDownloadStarted.bind(this);
-    downloader.onDownloadSuccess = this._onDownloadSuccess.bind(this);
-    downloader.onDownloadError = this._onDownloadError.bind(this);
-  },
+    this._downloader.onExpirationChange = this._onExpirationChange.bind(this);
+    this._downloader.onDownloadStarted = this._onDownloadStarted.bind(this);
+    this._downloader.onDownloadSuccess = this._onDownloadSuccess.bind(this);
+    this._downloader.onDownloadError = this._onDownloadError.bind(this);
+  }
 
   /**
    * Checks whether a subscription is currently being downloaded.
    * @param {string} url  URL of the subscription
-   * @return {boolean}
+   * @returns {boolean}
    */
   isExecuting(url)
   {
-    return downloader.isDownloading(url);
-  },
+    return this._downloader.isDownloading(url);
+  }
 
   /**
    * Starts the download of a subscription.
    * @param {DownloadableSubscription} subscription
    *   Subscription to be downloaded
    * @param {boolean} manual
-   *   true for a manually started download (should not trigger fallback
-   *   requests)
+   *   <code>true</code> for a manually started download (should not trigger
+   *   fallback requests)
    */
   execute(subscription, manual)
   {
-    downloader.download(this._getDownloadable(subscription, manual));
-  },
-
-  /**
-   * Yields Downloadable instances for all subscriptions that can be downloaded.
+    this._downloader.download(this._getDownloadable(subscription, manual));
+  }
+
+  /**
+   * Yields {@link Downloadable} instances for all subscriptions that can be
+   * downloaded.
+   * @yields {Downloadable}
    */
   *_getDownloadables()
   {
     if (!Prefs.subscriptions_autoupdate)
       return;
 
     for (let subscription of FilterStorage.subscriptions)
     {
       if (subscription instanceof DownloadableSubscription)
         yield this._getDownloadable(subscription, false);
     }
-  },
-
-  /**
-   * Creates a Downloadable instance for a subscription.
+  }
+
+  /**
+   * Creates a {@link Downloadable} instance for a subscription.
    * @param {Subscription} subscription
    * @param {boolean} manual
-   * @return {Downloadable}
+   * @returns {Downloadable}
    */
   _getDownloadable(subscription, manual)
   {
     let result = new Downloadable(subscription.url);
     if (subscription.lastDownload != subscription.lastSuccess)
       result.lastError = subscription.lastDownload * MILLIS_IN_SECOND;
     result.lastCheck = subscription.lastCheck * MILLIS_IN_SECOND;
     result.lastVersion = subscription.version;
     result.softExpiration = subscription.softExpiration * MILLIS_IN_SECOND;
     result.hardExpiration = subscription.expires * MILLIS_IN_SECOND;
     result.manual = manual;
     result.downloadCount = subscription.downloadCount;
     return result;
-  },
+  }
 
   _onExpirationChange(downloadable)
   {
     let subscription = Subscription.fromURL(downloadable.url);
     subscription.lastCheck = Math.round(
       downloadable.lastCheck / MILLIS_IN_SECOND
     );
     subscription.softExpiration = Math.round(
       downloadable.softExpiration / MILLIS_IN_SECOND
     );
     subscription.expires = Math.round(
       downloadable.hardExpiration / MILLIS_IN_SECOND
     );
-  },
+  }
 
   _onDownloadStarted(downloadable)
   {
     let subscription = Subscription.fromURL(downloadable.url);
     filterNotifier.emit("subscription.downloading", subscription);
-  },
+  }
 
   _onDownloadSuccess(downloadable, responseText, errorCallback,
                      redirectCallback)
   {
     let lines = responseText.split(/[\r\n]+/);
     let headerMatch = /\[Adblock(?:\s*Plus\s*([\d.]+)?)?\]/i.exec(lines[0]);
     if (!headerMatch)
       return errorCallback("synchronize_invalid_data");
     let minVersion = headerMatch[1];
 
@@ skipping 90 matching lines @@
         if (match[2])
           expirationInterval = interval * MILLIS_IN_HOUR;
         else
           expirationInterval = interval * MILLIS_IN_DAY;
       }
     }
 
     let [
       softExpiration,
       hardExpiration
-    ] = downloader.processExpirationInterval(expirationInterval);
+    ] = this._downloader.processExpirationInterval(expirationInterval);
     subscription.softExpiration = Math.round(softExpiration / MILLIS_IN_SECOND);
     subscription.expires = Math.round(hardExpiration / MILLIS_IN_SECOND);
 
     if (minVersion)
       subscription.requiredVersion = minVersion;
     else
       delete subscription.requiredVersion;
 
     // Process filters
     lines.shift();
     let filters = [];
     for (let line of lines)
     {
       line = Filter.normalize(line);
       if (line)
         filters.push(Filter.fromText(line));
     }
 
     FilterStorage.updateSubscriptionFilters(subscription, filters);
-  },
+  }
 
   _onDownloadError(downloadable, downloadURL, error, channelStatus,
                    responseStatus, redirectCallback)
   {
     let subscription = Subscription.fromURL(downloadable.url);
     subscription.lastDownload = Math.round(Date.now() / MILLIS_IN_SECOND);
     subscription.downloadStatus = error;
 
     // Request fallback URL if necessary - for automatic updates only
     if (!downloadable.manual)
@@ skipping 46 matching lines @@
           {
             let data = "[Adblock]\n" +
               subscription.filters.map(f => f.text).join("\n");
             redirectCallback("data:text/plain," + encodeURIComponent(data));
           }
         }, false);
         request.send(null);
       }
     }
   }
-};
-Synchronizer.init();
+}
+
+/**
+ * This object is responsible for downloading filter subscriptions whenever
+ * necessary.
+ * @type {Synchronizer}
+ */
+let synchronizer = new Synchronizer();
+
+exports.Synchronizer = synchronizer;