Issue 3780 - wait for the loading of filters and only afterwards start to fetch pages

lib/crawler.js

 /*
  * This Source Code is subject to the terms of the Mozilla Public License
  * version 2.0 (the "License"). You can obtain a copy of the License at
  * http://mozilla.org/MPL/2.0/.
  */
 
 /**
  * @module crawler
  */
 
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/Task.jsm");
 Cu.import("resource://gre/modules/Promise.jsm");
 
 function abprequire(module)
 {
   let result = {};
   result.wrappedJSObject = result;
   Services.obs.notifyObservers(result, "adblockplus-require", module);
   return result.exports;
 }
 
 let {RequestNotifier} = abprequire("requestNotifier");
 

[Wladimir Palant, 2016/03/15 13:44:22]

Nit: Why the empty line here?

[sergei, 2016/03/15 14:44:25]

Done.

+let {FilterNotifier} = abprequire("filterNotifier");
+let {FilterStorage} = abprequire("filterStorage");
 
 /**
  * Creates a pool of tabs and allocates them to tasks on request.
  *
  * @param {tabbrowser} browser
  *    The tabbed browser where tabs should be created
  * @param {int} maxtabs
  *    The maximum number of tabs to be allocated
  * @constructor
  */
@@ skipping 177 matching lines @@
   {
     running--;
     if (running <= 0)
     {
       loadListener.stop();
       windowCloser.stop();
       onDone();
     }
   };
 
-  for (let url of urls)
+  let crawl_urls = () =>

[Wladimir Palant, 2016/03/15 13:44:22]

I really meant having crawl_urls as a regular function - |function
clawl_urls(urls)|, just above |function* crawl_url|.

[sergei, 2016/03/15 14:44:25]

Done.

   {
-    running++;
-    Task.spawn(crawl_url.bind(null, url, tabAllocator, loadListener)).then(function(result)
+    for (let url of urls)
     {
-      let request = new XMLHttpRequest();
-      request.open("POST", targetURL);
-      request.addEventListener("load", taskDone, false);
-      request.addEventListener("error", taskDone, false);
-      request.send(JSON.stringify(result));
-    }, function(url, exception)
+      running++;
+      Task.spawn(crawl_url.bind(null, url, tabAllocator, loadListener)).then(function(result)
+      {
+        let request = new XMLHttpRequest();
+        request.open("POST", targetURL);
+        request.addEventListener("load", taskDone, false);
+        request.addEventListener("error", taskDone, false);
+        request.send(JSON.stringify(result));
+      }, function(url, exception)
+      {
+        reportException(exception);
+
+        let request = new XMLHttpRequest();
+        request.open("POST", targetURL);
+        request.addEventListener("load", taskDone, false);
+        request.addEventListener("error", taskDone, false);
+        request.send(JSON.stringify({
+          url: url,
+          startTime: Date.now(),
+          error: String(exception)
+        }));
+      }.bind(null, url));
+    }
+  };
+  new Promise((resolve, reject) =>
+  {
+    if (FilterStorage.subscriptions.length > 0 && !FilterStorage._loading)
     {
-      reportException(exception);
-
-      let request = new XMLHttpRequest();
-      request.open("POST", targetURL);
-      request.addEventListener("load", taskDone, false);
-      request.addEventListener("error", taskDone, false);
-      request.send(JSON.stringify({
-        url: url,
-        startTime: Date.now(),
-        error: String(exception)
-      }));
-    }.bind(null, url));
-  }
+      resolve();
+      return;
+    }
+    FilterNotifier.addListener((action, item, newValue, oldValue) =>
+    {
+      if (action == "load")
+      {
+        resolve();
+      }
+    });
+  }).then(crawl_urls)
+  .catch(reportException);

[Wladimir Palant, 2016/03/15 13:44:22]

Nit: put catch() on the same line as then()?

[sergei, 2016/03/15 14:44:25]

Done.

 }
 exports.run = run;
 
 /**
  * Crawls a URL. This is a generator meant to be used via a Task object.
  *
  * @param {String} url
  * @param {TabAllocator} tabAllocator
  * @param {loadListener} loadListener
  * @result {Object}
@@ skipping 56 matching lines @@
 
 function reportException(e)
 {
   let stack = "";
   if (e && typeof e == "object" && "stack" in e)
     stack = e.stack + "\n";
 
   Cu.reportError(e);
   dump(e + "\n" + stack + "\n");
 }