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
JavaMarkerAnnotation annotation= (JavaMarkerAnnotation) value;
					if (annotation.isProblem()) {
						annotation.setOverlay(problemAnnotation);
						fPreviouslyOverlaid.remove(annotation);
						fCurrentlyOverlaid.add(annotation);
					}
				}
			}
			
			private void  overlayMarkers(Position position, ProblemAnnotation problemAnnotation) {
				Object value= getAnnotations(position);
				if (value instanceof List) {
					List list= (List) value;
					for (Iterator e = list.iterator(); e.hasNext();)
						setOverlay(e.next(), problemAnnotation);
				} else {
					setOverlay(value, problemAnnotation);
				}
			}
			
			/**
			 * Tells this annotation model to collect temporary problems from now on.
			 */
			private void startCollectingProblems() {
				fCollectedProblems= new ArrayList();
				fGeneratedAnnotations= new ArrayList();  
			}
			
			/**
			 * Tells this annotation model to no longer collect temporary problems.