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
fCollectedProblems.clear();
					}
					
					removeMarkerOverlays(isCanceled);
					fPreviouslyOverlaid.clear();
					fPreviouslyOverlaid= null;
				}
					
				if (temporaryProblemsChanged)
					fireModelChanged();
			}
			
			private void removeMarkerOverlays(boolean isCanceled) {
				if (isCanceled) {
					fCurrentlyOverlaid.addAll(fPreviouslyOverlaid);
				} else if (fPreviouslyOverlaid != null) {
					Iterator e= fPreviouslyOverlaid.iterator();
					while (e.hasNext()) {
						JavaMarkerAnnotation annotation= (JavaMarkerAnnotation) e.next();
						annotation.setOverlay(null);
					}
				}			
			}
			
			/**
			 * Overlays value with problem annotation.
			 * @param problemAnnotation
			 */
			private void setOverlay(Object value, ProblemAnnotation problemAnnotation) {
				if (value instanceof  JavaMarkerAnnotation) {