@Override
  public void beforeDocumentChange(DocumentEvent event) {
    final Document document = event.getDocument();

    final FileViewProvider viewProvider = getCachedViewProvider(document);
    if (viewProvider == null) return;
    if (!isRelevant(viewProvider)) return;

    VirtualFile virtualFile = viewProvider.getVirtualFile();
    if (virtualFile.getFileType().isBinary()) return;

    final List<PsiFile> files = viewProvider.getAllFiles();
    PsiFile psiCause = null;
    for (PsiFile file : files) {
      mySmartPointerManager.fastenBelts(file, event.getOffset(), null);

      if (TextBlock.get(file).isLocked()) {
        psiCause = file;
      }
    }

    if (psiCause == null) {
      beforeDocumentChangeOnUnlockedDocument(viewProvider);
    }

    ((SingleRootFileViewProvider) viewProvider).beforeDocumentChanged(psiCause);
  }
  @Override
  public void documentChanged(DocumentEvent event) {
    final Document document = event.getDocument();
    final FileViewProvider viewProvider = getCachedViewProvider(document);
    if (viewProvider == null) return;
    if (!isRelevant(viewProvider)) return;

    ApplicationManager.getApplication().assertWriteAccessAllowed();
    final List<PsiFile> files = viewProvider.getAllFiles();
    boolean commitNecessary = true;
    for (PsiFile file : files) {
      mySmartPointerManager.unfastenBelts(file, event.getOffset());

      final TextBlock textBlock = TextBlock.get(file);
      if (textBlock.isLocked()) {
        commitNecessary = false;
        continue;
      }

      textBlock.documentChanged(event);
      assert file instanceof PsiFileImpl
              || "mock.file".equals(file.getName())
                  && ApplicationManager.getApplication().isUnitTestMode()
          : event + "; file=" + file + "; allFiles=" + files + "; viewProvider=" + viewProvider;
    }

    boolean forceCommit =
        ApplicationManager.getApplication().hasWriteAction(ExternalChangeAction.class)
            && (SystemProperties.getBooleanProperty("idea.force.commit.on.external.change", false)
                || ApplicationManager.getApplication().isHeadlessEnvironment());

    // Consider that it's worth to perform complete re-parse instead of merge if the whole document
    // text is replaced and
    // current document lines number is roughly above 5000. This makes sense in situations when
    // external change is performed
    // for the huge file (that causes the whole document to be reloaded and 'merge' way takes a
    // while to complete).
    if (event.isWholeTextReplaced() && document.getTextLength() > 100000) {
      document.putUserData(BlockSupport.DO_NOT_REPARSE_INCREMENTALLY, Boolean.TRUE);
    }

    if (commitNecessary) {
      myUncommittedDocuments.add(document);
      if (forceCommit) {
        commitDocument(document);
      } else if (!((DocumentEx) document).isInBulkUpdate()) {
        myDocumentCommitProcessor.commitAsynchronously(myProject, document, event);
      }
    }
  }