private void checkPsiIsCorrect(final FileViewProvider key) {
    PsiFile actualPsi = key.getPsi(key.getBaseLanguage());

    PsiTreeDebugBuilder treeDebugBuilder =
        new PsiTreeDebugBuilder().setShowErrorElements(false).setShowWhiteSpaces(false);

    String actualPsiTree = treeDebugBuilder.psiToString(actualPsi);

    String fileName = key.getVirtualFile().getName();
    PsiFile psi =
        PsiFileFactory.getInstance(myProject)
            .createFileFromText(
                fileName,
                FileTypeManager.getInstance().getFileTypeByFileName(fileName),
                actualPsi.getNode().getText(),
                LocalTimeCounter.currentTime(),
                false);

    if (actualPsi.getClass().equals(psi.getClass())) {
      String expectedPsi = treeDebugBuilder.psiToString(psi);

      if (!expectedPsi.equals(actualPsiTree)) {
        myReformatElements.clear();
        assert expectedPsi.equals(actualPsiTree)
            : "Refactored psi should be the same as result of parsing";
      }
    }
  }
  private void doPostponedFormattingInner(final FileViewProvider key) {

    final List<ASTNode> astNodes = myReformatElements.remove(key);
    final Document document = key.getDocument();
    // Sort ranges by end offsets so that we won't need any offset adjustment after reformat or
    // reindent
    if (document == null) return;

    final VirtualFile virtualFile = key.getVirtualFile();
    if (!virtualFile.isValid()) return;

    final TreeSet<PostprocessFormattingTask> postProcessTasks =
        new TreeSet<PostprocessFormattingTask>();
    Collection<Disposable> toDispose = ContainerUtilRt.newArrayList();
    try {
      // process all roots in viewProvider to find marked for reformat before elements and create
      // appropriate range markers
      handleReformatMarkers(key, postProcessTasks);
      toDispose.addAll(postProcessTasks);

      // then we create ranges by changed nodes. One per node. There ranges can intersect. Ranges
      // are sorted by end offset.
      if (astNodes != null) createActionsMap(astNodes, key, postProcessTasks);

      if ("true".equals(System.getProperty("check.psi.is.valid"))
          && ApplicationManager.getApplication().isUnitTestMode()) {
        checkPsiIsCorrect(key);
      }

      while (!postProcessTasks.isEmpty()) {
        // now we have to normalize actions so that they not intersect and ordered in most
        // appropriate way
        // (free reformatting -> reindent -> formatting under reindent)
        final List<PostponedAction> normalizedActions =
            normalizeAndReorderPostponedActions(postProcessTasks, document);
        toDispose.addAll(normalizedActions);

        // only in following loop real changes in document are made
        for (final PostponedAction normalizedAction : normalizedActions) {
          CodeStyleSettings settings =
              CodeStyleSettingsManager.getSettings(myPsiManager.getProject());
          boolean old = settings.ENABLE_JAVADOC_FORMATTING;
          settings.ENABLE_JAVADOC_FORMATTING = false;
          try {
            normalizedAction.execute(key);
          } finally {
            settings.ENABLE_JAVADOC_FORMATTING = old;
          }
        }
      }
    } finally {
      for (Disposable disposable : toDispose) {
        //noinspection SSBasedInspection
        disposable.dispose();
      }
    }
  }
  @Override
  public void beforeDocumentChange(@NotNull DocumentEvent event) {
    if (myStopTrackingDocuments) return;

    final Document document = event.getDocument();
    if (!(document instanceof DocumentWindow) && !myLastCommittedTexts.containsKey(document)) {
      myLastCommittedTexts.put(
          document,
          Pair.create(document.getImmutableCharSequence(), document.getModificationStamp()));
    }

    VirtualFile virtualFile = FileDocumentManager.getInstance().getFile(document);
    boolean isRelevant = virtualFile != null && isRelevant(virtualFile);

    final FileViewProvider viewProvider = getCachedViewProvider(document);
    boolean inMyProject = viewProvider != null && viewProvider.getManager() == myPsiManager;
    if (!isRelevant || !inMyProject) {
      return;
    }

    final List<PsiFile> files = viewProvider.getAllFiles();
    PsiFile psiCause = null;
    for (PsiFile file : files) {
      if (file == null) {
        throw new AssertionError(
            "View provider "
                + viewProvider
                + " ("
                + viewProvider.getClass()
                + ") returned null in its files array: "
                + files
                + " for file "
                + viewProvider.getVirtualFile());
      }

      if (mySynchronizer.isInsideAtomicChange(file)) {
        psiCause = file;
      }
    }

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

    ((SingleRootFileViewProvider) viewProvider).beforeDocumentChanged(psiCause);
  }
  @Nullable
  @Override
  public Document getDocument(@NotNull PsiFile file) {
    if (file instanceof PsiBinaryFile) return null;

    Document document = getCachedDocument(file);
    if (document != null) {
      if (!file.getViewProvider().isPhysical() && document.getUserData(HARD_REF_TO_PSI) == null) {
        PsiUtilCore.ensureValid(file);
        cachePsi(document, file);
      }
      return document;
    }

    FileViewProvider viewProvider = file.getViewProvider();
    if (!viewProvider.isEventSystemEnabled()) return null;

    document = FileDocumentManager.getInstance().getDocument(viewProvider.getVirtualFile());
    if (document != null) {
      if (document.getTextLength() != file.getTextLength()) {
        String message =
            "Document/PSI mismatch: "
                + file
                + " ("
                + file.getClass()
                + "); physical="
                + viewProvider.isPhysical();
        if (document.getTextLength() + file.getTextLength() < 8096) {
          message +=
              "\n=== document ===\n" + document.getText() + "\n=== PSI ===\n" + file.getText();
        }
        throw new AssertionError(message);
      }

      if (!viewProvider.isPhysical()) {
        PsiUtilCore.ensureValid(file);
        cachePsi(document, file);
        file.putUserData(HARD_REF_TO_DOCUMENT, document);
      }
    }

    return document;
  }