@NotNull
  private VirtualFilePointer create(
      @Nullable VirtualFile file,
      @NotNull String url,
      @NotNull final Disposable parentDisposable,
      @Nullable VirtualFilePointerListener listener) {
    String protocol;
    VirtualFileSystem fileSystem;
    if (file == null) {
      protocol = VirtualFileManager.extractProtocol(url);
      fileSystem = myVirtualFileManager.getFileSystem(protocol);
    } else {
      protocol = null;
      fileSystem = file.getFileSystem();
    }
    if (fileSystem == TempFileSystem.getInstance()) {
      // for tests, recreate always since
      VirtualFile found =
          fileSystem == null
              ? null
              : file != null ? file : VirtualFileManager.getInstance().findFileByUrl(url);
      return new IdentityVirtualFilePointer(found, url);
    }
    if (fileSystem != LocalFileSystem.getInstance() && fileSystem != JarFileSystem.getInstance()) {
      // we are unable to track alien file systems for now
      VirtualFile found =
          fileSystem == null
              ? null
              : file != null ? file : VirtualFileManager.getInstance().findFileByUrl(url);
      // if file is null, this pointer will never be alive
      return getOrCreateIdentity(url, found);
    }

    String path;
    if (file == null) {
      path = VirtualFileManager.extractPath(url);
      path = cleanupPath(path, protocol);
      url = VirtualFileManager.constructUrl(protocol, path);
    } else {
      path = file.getPath();
      // url has come from VirtualFile.getUrl() and is good enough
    }

    VirtualFilePointerImpl pointer = getOrCreate(file, url, parentDisposable, listener, path);

    int newCount = pointer.incrementUsageCount();

    if (newCount == 1) {
      Disposer.register(parentDisposable, pointer);
    } else {
      // already registered
      register(parentDisposable, pointer);
    }

    return pointer;
  }
 @Override
 @NotNull
 public synchronized VirtualFilePointer create(
     @NotNull VirtualFile file,
     @NotNull Disposable parent,
     @Nullable VirtualFilePointerListener listener) {
   return create(file, file.getUrl(), parent, listener);
 }
    @Override
    public void before(@NotNull final List<? extends VFileEvent> events) {
      cleanContainerCaches();
      List<VirtualFilePointer> toFireEvents = new ArrayList<VirtualFilePointer>();
      List<String> toUpdateUrl = new ArrayList<String>();

      synchronized (VirtualFilePointerManagerImpl.this) {
        for (VFileEvent event : events) {
          if (event instanceof VFileDeleteEvent) {
            final VFileDeleteEvent deleteEvent = (VFileDeleteEvent) event;
            String url = deleteEvent.getFile().getPath();
            addPointersUnder(url, true, toFireEvents);
          } else if (event instanceof VFileCreateEvent) {
            final VFileCreateEvent createEvent = (VFileCreateEvent) event;
            String url = createEvent.getPath();
            addPointersUnder(url, false, toFireEvents);
          } else if (event instanceof VFileCopyEvent) {
            final VFileCopyEvent copyEvent = (VFileCopyEvent) event;
            String url = copyEvent.getNewParent().getPath() + "/" + copyEvent.getFile().getName();
            addPointersUnder(url, false, toFireEvents);
          } else if (event instanceof VFileMoveEvent) {
            final VFileMoveEvent moveEvent = (VFileMoveEvent) event;
            List<VirtualFilePointer> pointers = new ArrayList<VirtualFilePointer>();
            addPointersUnder(moveEvent.getFile().getPath(), false, pointers);
            for (VirtualFilePointer pointer : pointers) {
              VirtualFile file = pointer.getFile();
              if (file != null) {
                toUpdateUrl.add(file.getPath());
              }
            }
          } else if (event instanceof VFilePropertyChangeEvent) {
            final VFilePropertyChangeEvent change = (VFilePropertyChangeEvent) event;
            if (VirtualFile.PROP_NAME.equals(change.getPropertyName())) {
              List<VirtualFilePointer> pointers = new ArrayList<VirtualFilePointer>();
              addPointersUnder(change.getFile().getPath(), false, pointers);
              for (VirtualFilePointer pointer : pointers) {
                VirtualFile file = pointer.getFile();
                if (file != null) {
                  toUpdateUrl.add(file.getPath());
                }
              }
            }
          }
        }

        myEvents = new ArrayList<EventDescriptor>();
        for (VirtualFilePointerListener listener : myUrlToPointerMaps.keySet()) {
          if (listener == null) continue;
          EventDescriptor event = new EventDescriptor(listener, toFireEvents);
          myEvents.add(event);
        }
      }

      for (EventDescriptor event : myEvents) {
        event.fireBefore();
      }

      if (!toFireEvents.isEmpty()) {
        VirtualFilePointer[] arr =
            toFireEvents.toArray(new VirtualFilePointer[toFireEvents.size()]);
        myBus.syncPublisher(VirtualFilePointerListener.TOPIC).beforeValidityChanged(arr);
      }

      myPointersToUpdate = toFireEvents;
      myUrlsToUpdate = toUpdateUrl;
    }