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
/*
			 * @see IProblemRequestor#acceptProblem(IProblem)
			 */
			public void acceptProblem(IProblem problem) {
				if (isActive())
					fCollectedProblems.add(problem);
			}
			/*
			 * @see IProblemRequestor#endReporting()
			 */
			public void endReporting() {
				if (!isActive())
					return;
					
				if (fProgressMonitor != null && fProgressMonitor.isCanceled())
					return;
					
				
				boolean isCanceled= false;
				boolean temporaryProblemsChanged= false;
				
				synchronized (fAnnotations) {
					
					fPreviouslyOverlaid= fCurrentlyOverlaid;
					fCurrentlyOverlaid= new ArrayList();
					if (fGeneratedAnnotations.size() > 0) {
						temporaryProblemsChanged= true;	
						removeAnnotations(fGeneratedAnnotations, false, true);
						fGeneratedAnnotations.clear();