Issue 537 - Mark first few downloads

lib/downloader.js

Index: lib/downloader.js
===================================================================
--- a/lib/downloader.js
+++ b/lib/downloader.js
@@ -191,13 +191,18 @@
       url += "&";
     else
       url += "?";
+    // We limit the download count to 4+ to keep the request anonymized
+    let downloadCount = downloadable.downloadCount;
+    if (downloadCount > 4)
+      downloadCount = "4+";
     url += "addonName=" + encodeURIComponent(addonName) +
         "&addonVersion=" + encodeURIComponent(addonVersion) +
         "&application=" + encodeURIComponent(application) +
         "&applicationVersion=" + encodeURIComponent(applicationVersion) +
         "&platform=" + encodeURIComponent(platform) +
         "&platformVersion=" + encodeURIComponent(platformVersion) +
-        "&lastVersion=" + encodeURIComponent(downloadable.lastVersion);
+        "&lastVersion=" + encodeURIComponent(downloadable.lastVersion) +
+        "&downloadCount=" + encodeURIComponent(downloadCount);
     return url;
   },
 
@@ -291,6 +296,8 @@
         return;
       }
 
+      downloadable.downloadCount++;
+
       this.onDownloadSuccess(downloadable, request.responseText, errorCallback, function redirectCallback(url)
       {
         if (redirects >= this.maxRedirects)
@@ -378,4 +385,10 @@
    * @type Integer
    */
   hardExpiration: 0,
+  
+  /**
+   * Number indicating how often the object was downloaded.
+   * @type Integer
+   */
+  downloadCount: 0,
 };