@Override
  @Nullable
  public Document getDocument(@NotNull final VirtualFile file) {
    DocumentEx document = (DocumentEx) getCachedDocument(file);
    if (document == null) {
      if (file.isDirectory()
          || isBinaryWithoutDecompiler(file)
          || SingleRootFileViewProvider.isTooLargeForContentLoading(file)) {
        return null;
      }
      final CharSequence text = LoadTextUtil.loadText(file);

      synchronized (lock) {
        document = (DocumentEx) getCachedDocument(file);
        if (document != null) return document; // Double checking

        document = (DocumentEx) createDocument(text);
        document.setModificationStamp(file.getModificationStamp());
        final FileType fileType = file.getFileType();
        document.setReadOnly(!file.isWritable() || fileType.isBinary());
        file.putUserData(DOCUMENT_KEY, new WeakReference<Document>(document));
        document.putUserData(FILE_KEY, file);

        if (!(file instanceof LightVirtualFile
            || file.getFileSystem() instanceof DummyFileSystem)) {
          document.addDocumentListener(
              new DocumentAdapter() {
                @Override
                public void documentChanged(DocumentEvent e) {
                  final Document document = e.getDocument();
                  myUnsavedDocuments.add(document);
                  final Runnable currentCommand =
                      CommandProcessor.getInstance().getCurrentCommand();
                  Project project =
                      currentCommand == null
                          ? null
                          : CommandProcessor.getInstance().getCurrentCommandProject();
                  String lineSeparator = CodeStyleFacade.getInstance(project).getLineSeparator();
                  document.putUserData(LINE_SEPARATOR_KEY, lineSeparator);

                  // avoid documents piling up during batch processing
                  if (areTooManyDocumentsInTheQueue(myUnsavedDocuments)) {
                    saveAllDocumentsLater();
                  }
                }
              });
        }
      }

      myMultiCaster.fileContentLoaded(file, document);
    }

    return document;
  }
  private static boolean isSaveNeeded(@NotNull Document document, @NotNull VirtualFile file)
      throws IOException {
    if (file.getFileType().isBinary()
        || document.getTextLength() > 1000 * 1000) { // don't compare if the file is too big
      return true;
    }

    byte[] bytes = file.contentsToByteArray();
    CharSequence loaded = LoadTextUtil.getTextByBinaryPresentation(bytes, file, false, false);

    return !Comparing.equal(document.getCharsSequence(), loaded);
  }
 @Override
 public boolean requestWriting(@NotNull Document document, Project project) {
   final VirtualFile file = getInstance().getFile(document);
   if (project != null && file != null && file.isValid()) {
     return !file.getFileType().isBinary()
         && ReadonlyStatusHandler.ensureFilesWritable(project, file);
   }
   if (document.isWritable()) {
     return true;
   }
   document.fireReadOnlyModificationAttempt();
   return false;
 }
 // returns number of hits
 static int processUsagesInFile(
     @NotNull final PsiFile psiFile,
     @NotNull final FindModel findModel,
     @NotNull final Processor<UsageInfo> consumer) {
   if (findModel.getStringToFind().isEmpty()) {
     if (!ApplicationManager.getApplication()
         .runReadAction((Computable<Boolean>) () -> consumer.process(new UsageInfo(psiFile)))) {
       throw new ProcessCanceledException();
     }
     return 1;
   }
   final VirtualFile virtualFile = psiFile.getVirtualFile();
   if (virtualFile == null) return 0;
   if (virtualFile.getFileType().isBinary()) return 0; // do not decompile .class files
   final Document document =
       ApplicationManager.getApplication()
           .runReadAction(
               (Computable<Document>)
                   () ->
                       virtualFile.isValid()
                           ? FileDocumentManager.getInstance().getDocument(virtualFile)
                           : null);
   if (document == null) return 0;
   final int[] offset = {0};
   int count = 0;
   int found;
   ProgressIndicator indicator =
       ProgressWrapper.unwrap(ProgressManager.getInstance().getProgressIndicator());
   TooManyUsagesStatus tooManyUsagesStatus = TooManyUsagesStatus.getFrom(indicator);
   do {
     tooManyUsagesStatus.pauseProcessingIfTooManyUsages(); // wait for user out of read action
     found =
         ApplicationManager.getApplication()
             .runReadAction(
                 (Computable<Integer>)
                     () -> {
                       if (!psiFile.isValid()) return 0;
                       return addToUsages(
                           document, consumer, findModel, psiFile, offset, USAGES_PER_READ_ACTION);
                     });
     count += found;
   } while (found != 0);
   return count;
 }
 private static boolean isBinaryWithoutDecompiler(VirtualFile file) {
   final FileType ft = file.getFileType();
   return ft.isBinary() && BinaryFileTypeDecompilers.INSTANCE.forFileType(ft) == null;
 }