132013 - remove from list should be batched. r=hewitt sr=ben

xpfe/components/download-manager/public/nsIDownloadManager.idl

@@ -144,7 +144,19 @@ interface nsIDownloadManager : nsISupports {
   * third party managers to let us know when they've closed.
   */
 
-  void onClose(); 
+  void onClose();
+  
+  /**
+  * Indicate that a batch update (e.g. mass removal) is about to start.
+  */
+
+  void startBatchUpdate();
+  
+  /**
+  * Indicate that a batch update is ending.
+  */
+  
+  void endBatchUpdate();
 };
 
 

xpfe/components/download-manager/resources/downloadmanager.js

@@ -199,8 +199,12 @@ var downloadViewController = {
       break;
     case "cmd_remove":
       selectedItems = getSelectedItems();
-      for (i = 0; i < selectedItems.length; i++)
+      gDownloadManager.startBatchUpdate();
+      for (i = 0; i < selectedItems.length; i++) {
+        if (i == selectedItems.length - 1)
+          gDownloadManager.endBatchUpdate();
         gDownloadManager.removeDownload(selectedItems[i].id);
+      }
       window.updateCommands("tree-select");
       break;
     case "cmd_selectAll":

xpfe/components/download-manager/src/nsDownloadManager.cpp

@@ -84,7 +84,8 @@ nsIRDFService* gRDFService;
 
 NS_IMPL_ISUPPORTS3(nsDownloadManager, nsIDownloadManager, nsIDOMEventListener, nsIObserver)
 
-nsDownloadManager::nsDownloadManager() : mCurrDownloads(nsnull)
+nsDownloadManager::nsDownloadManager() : mCurrDownloads(nsnull),
+                                         mBatches(0)
 {
   NS_INIT_ISUPPORTS();
 }
@@ -627,10 +628,27 @@ nsDownloadManager::RemoveDownload(const char* aPath)
   rv = downloads->RemoveElementAt(itemIndex, PR_TRUE, getter_AddRefs(node));
   if (NS_FAILED(rv)) return rv;
   
+  // if a mass removal is being done, we don't want to flush every time
+  if (mBatches) return rv;
+
   nsCOMPtr<nsIRDFRemoteDataSource> remote = do_QueryInterface(mDataSource);
   return remote->Flush();
 }  
 
+NS_IMETHODIMP
+nsDownloadManager::StartBatchUpdate()
+{
+  ++mBatches;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDownloadManager::EndBatchUpdate()
+{
+  --mBatches;
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDownloadManager::Open(nsIDOMWindow* aParent)
 {

xpfe/components/download-manager/src/nsDownloadManager.h

@@ -93,6 +93,7 @@ private:
   nsCOMPtr<nsIDownloadProgressListener> mListener;
   nsCOMPtr<nsIRDFContainerUtils> mRDFContainerUtils;
   nsCOMPtr<nsIStringBundle> mBundle;
+  PRInt32 mBatches;
   nsHashtable* mCurrDownloads;
 
   friend class nsDownload;