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
List list= (List) cached;
					list.add(annotation);
				} else if (cached instanceof Annotation) {
					List list= new ArrayList(2);
					list.add(cached);
					list.add(annotation);
					fReverseMap.put(position, list);
				}
			}
			
			/*
			 * @see AnnotationModel#removeAllAnnotations(boolean)
			 */
			protected void removeAllAnnotations(boolean fireModelChanged) {
				for (Iterator iter= getAnnotationIterator(); iter.hasNext();) {
					fCurrentEvent.annotationRemoved((Annotation) iter.next());
				}
				super.removeAllAnnotations(fireModelChanged);
				fReverseMap.clear();
			}
			
			/*
			 * @see AnnotationModel#removeAnnotation(Annotation, boolean)
			 */
			protected void removeAnnotation(Annotation annotation, boolean fireModelChanged) {
				fCurrentEvent.annotationRemoved(annotation);
				
				Position position= getPosition(annotation);
				Object cached= fReverseMap.get(position);
				if (cached instanceof List) {