locked_async library

A class which allows running a task with a lock and cancelling the previous task when a new task is run. Useful for file watching, search-as-you-type, etc.

Example:

final task = LockedAsync();

void downloadFile(String url, String filename) {
  task.run((state) async {
    state.guard();

    // Download file from internet
    final response = await state.wait(() => http.get(Uri.parse(url)));

    await File(filename).writeAsString(response.body);
  });
}

downloadFile('https://example.com/file1.txt', 'file1.txt'); // Starts
downloadFile('https://example.com/file2.txt', 'file2.txt'); // Cancels file1, starts file2