Bug 43766 [reconciling] ResourceMarkerAnnotationModel listener taking a long time
Build: I20030925 I was investigating a situation where adding breakpoints to a large file was very slow. It can take up to a second to add a breakpoint to a file such as Workspace.java (2000 lines). Almost all of this time is in the resource change listener added by ResourceMarkerAnnotationModel. First, a minor issue: Instead of adding a resource change listener that traverses the entire delta, you can locate a given resource delta within the resource change delta very quickly using IResourceDelta.findMember(): public void resourceChanged(IResourceChangeEvent e) { IResourceDelta delta= e.getDelta(); if (delta != null) { IResourceDelta child = delta.findMember(fResource.getFullPath()); if (child != null) update(child.getMarkerDeltas()); } } However, this was only a small speed improvement. The main problem is that the entire compilation unit is reparsed every time a breakpoint is added. I have added a profiler trace of where the time is going for adding a single breakpoint.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/filebuffers/CompilationUnitDocumentProvider2.java
protected void disposeFileInfo(Object element, FileInfo info) {
		if (info instanceof CompilationUnitInfo) {
			CompilationUnitInfo cuInfo= (CompilationUnitInfo) info;
			
			if (JavaPlugin.USE_WORKING_COPY_OWNERS)  {
				
				try  {
					cuInfo.fCopy.discardWorkingCopy();
				} catch (JavaModelException x)  {
					handleCoreException(x, x.getMessage());
				}
			
			} else  {
				cuInfo.fCopy.destroy();
			}
			
			cuInfo.fModel.removeAnnotationModelListener(fGlobalAnnotationModelListener);
		}
		super.disposeFileInfo(element, info);
	}
	
	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#saveDocument(org.eclipse.core.runtime.IProgressMonitor, java.lang.Object, org.eclipse.jface.text.IDocument, boolean)
	 */
	public void saveDocument(IProgressMonitor monitor, Object element, IDocument ignore, boolean overwrite) throws CoreException {
		
		FileInfo fileInfo= getFileInfo(element);
		
		if (fileInfo instanceof CompilationUnitInfo) {
			CompilationUnitInfo info= (CompilationUnitInfo) fileInfo;