[platform-team-dev] Problem with decorator performance

["Bursian, Achim" <achim.bursian@xxxxxxxxxxx>]

Hello everybody,

I'm new to this list, and I hope this is the right place to get advice :-)

 

Recently I joined the dev team for the Eclipse ClearCase team provider http://sourceforge.net/projects/eclipse-ccase/, mainly to improve the really bad performance of this provider. ClearCase access is really slow on some platforms. We improved a lot already, but there is one major problem where I'm stuck:

 

When a project gets associated with ClearCase (this is done manually via a menu entry), I want the CC decorators to get activated. Basically I do a LabelProviderChangedEvent for all the resources in the project. This is taken almost directly from the CVS code:

 

 public void refresh(IProject project) {
  final List<IResource> resources = new ArrayList<IResource>();
  try {
   project.accept(new IResourceVisitor() {
    public boolean visit(IResource resource) {
     resources.add(resource);
     return true;
    }
   });
   fireLabelProviderChanged(new LabelProviderChangedEvent(this, resources.toArray()));
  } catch (CoreException e) {
   handleException(e);
  }
 }

In turn, the platform calls the decorate() for every resource. In the decorate() method, I ask ClearCase for the file state (checkd in/out, private etc...) which takes around 50ms, and then I decorate the icon correspondingly. Additionally, that CC state information is cached, to speed up later processing.

 

The problem shows with projects of several thousnad files and folders, which is quite common for CC users. It takes several minutes (one user reported 20min) until the decorators show. That is clearly unacceptable. ("...One of our projects has currently about 17000 Files in 2000 folders (90 folders in the first project level).The fist association process takes about 15 to 20 minutes...")

 

Even worse: There is no sign to the user when this process has finished or what's going on at all. To improve the user experience, I am gathering the CC state in advance now and fill the cache, shown with a progress monitor. That doesn't make it any faster, but at least the user knows what's going on.

 

I'm searching for a way to ask the platform to update only the labels for elements that are currently shown in the UI. If, for example, a project is opened and only the first level of folders is currently shown in the package explorer, only these labels should be refreshed during the associate action. Then, whenever another folder is opened by the user, the contained elements should update their labels. (I hope that's clear? English is not my native language)

 

That way the delay for the CC operations would be almost unnoticable.

 

Is there any way to achieve this? Any help or pointer are greatly appreciated. Thanks.

  Achim