WebUI: Fix increasing frequency of XHR requests

ajaxfn() is called every time the torrent list is filtered. This function
calls itself after a predefined amount of time by setting a timer. If
the function is called manually without destroying the timer, the
frequency of the XHR requests will increase.

Fix this by saving a reference to each timer that is created so that
they can be later destroyed.

Add also two helper functions to request updated data safely.

src/webui/www/public/scripts/client.js

@@ -23,7 +23,6 @@
  */
 
 myTable = new dynamicTable();
-ajaxfn = function () {};
 
 window.addEvent('load', function () {
 
@@ -77,8 +76,6 @@ window.addEvent('load', function () {
     });
     initializeWindows();
     var r = 0;
-    var waiting = false;
-    var waitingTrInfo = false;
 
     var stateToImg = function (state) {
         if (state == "pausedUP" || state == "pausedDL") {
@@ -94,18 +91,17 @@ window.addEvent('load', function () {
         }
         return 'images/skin/' + state + '.png';
     };
+
+    var loadTransferInfoTimer;
     var loadTransferInfo = function () {
         var url = 'json/transferInfo';
-        if (!waitingTrInfo) {
-            waitingTrInfo = true;
         var request = new Request.JSON({
             url : url,
             noCache : true,
             method : 'get',
             onFailure : function () {
                 $('error_div').set('html', '_(qBittorrent client is not reachable)');
-                        waitingTrInfo = false;
-                        loadTransferInfo.delay(4000);
+                loadTransferInfoTimer = loadTransferInfo.delay(4000);
             },
             onSuccess : function (info) {
                 if (info) {
@@ -119,32 +115,37 @@ window.addEvent('load', function () {
                         document.title = "_(D:%1 U:%2)".replace("%1", friendlyUnit(info.dl_info_speed, true)).replace("%2", friendlyUnit(info.up_info_speed, true));
                     else
                         document.title = "_(qBittorrent web User Interface)";
-                            waitingTrInfo = false;
-                            loadTransferInfo.delay(3000);
+                    loadTransferInfoTimer = loadTransferInfo.delay(3000);
                 }
             }
         }).send();
-        }
     };
+
+    var updateTransferInfo = function() {
+        clearTimeout(loadTransferInfoTimer);
+        loadTransferInfoTimer = loadTransferInfo();
+    }
+
+    // Start fetching data now
+    loadTransferInfo();
+
     $('DlInfos').addEvent('click', globalDownloadLimitFN);
     $('UpInfos').addEvent('click', globalUploadLimitFN);
 
+    var ajaxfnTimer;
     var ajaxfn = function () {
         var queueing_enabled = false;
         var url = new URI('json/torrents');
         url.setData('filter', filter);
         url.setData('sort', myTable.table.sortedColumn);
         url.setData('reverse', myTable.table.reverseSort);
-        if (!waiting) {
-            waiting = true;
         var request = new Request.JSON({
             url : url,
             noCache : true,
             method : 'get',
             onFailure : function () {
                 $('error_div').set('html', '_(qBittorrent client is not reachable)');
-                        waiting = false;
-                        ajaxfn.delay(2000);
+                ajaxfnTimer = ajaxfn.delay(2000);
             },
             onSuccess : function (events) {
                 $('error_div').set('html', '');
@@ -217,17 +218,19 @@ window.addEvent('load', function () {
                     
                     myTable.altRow();
                 }
-                        waiting = false;
-                        ajaxfn.delay(1500);
+                ajaxfnTimer = ajaxfn.delay(1500);
             }
         }).send();
-        }
     };
 
+    var updateTransferList = function() {
+        clearTimeout(ajaxfnTimer);
+        ajaxfnTimer = ajaxfn();
+    }
+
     setSortedColumn = function (column) {
         myTable.setSortedColumn(column);
-        // reload torrents
-        ajaxfn();
+        updateTransferList();
     };
 
     new MochaUI.Panel({
@@ -243,7 +246,7 @@ window.addEvent('load', function () {
         loadMethod : 'xhr',
         contentURL : 'transferlist.html',
         onContentLoaded : function () {
-            ajaxfn();
+            updateTransferList();
         },
         column : 'mainColumn',
         onResize : saveColumnSizes,
@@ -272,8 +275,6 @@ window.addEvent('load', function () {
         column : 'mainColumn',
         height : prop_h
     });
-    //ajaxfn();
-    loadTransferInfo();
 
     setFilter = function (f) {
         // Visually Select the right filter
@@ -287,7 +288,7 @@ window.addEvent('load', function () {
         filter = f;
         localStorage.setItem('selected_filter', f);
         // Reload torrents
-        ajaxfn();
+        updateTransferList();
     }
 
 });