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
return null;
	}
	
	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#createEmptyFileInfo()
	 */
	protected FileInfo createEmptyFileInfo() {
		return new CompilationUnitInfo();
	}
	
	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#createAnnotationModel(org.eclipse.core.resources.IFile)
	 */
	protected IAnnotationModel createAnnotationModel(IFile file) {
		return new CompilationUnitAnnotationModel(file);
	}
	
	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#createFileInfo(java.lang.Object)
	 */
	protected FileInfo createFileInfo(Object element) throws CoreException {
		if (!(element instanceof IFileEditorInput))
			return null;
			
		IFileEditorInput input= (IFileEditorInput) element;
		ICompilationUnit original= createCompilationUnit(input.getFile());
		if (original == null)
			return null;
		
		FileInfo info= super.createFileInfo(element);