# Buggy code
def _Open(
    self,
    path,
    access_mode="r",
    serializer_format=definitions.SERIALIZER_FORMAT_PROTOBUF,
):
    """Opens the storage file.

    Args:
      path: string containing the path of the storage file.
      access_mode: optional string indicating the access mode.
      serializer_format: Optional storage serializer format.

    Raises:
      IOError: if the file is opened in read only mode and the file does
               not exist.
    """
    super(StorageFile, self)._Open(path, access_mode=access_mode)

    serializer_stream_name = "serializer.txt"
    has_serializer_stream = self._HasStream(serializer_stream_name)
    if has_serializer_stream:
        stored_serializer_format = self._ReadStream(serializer_stream_name)
        if stored_serializer_format:
            serializer_format = stored_serializer_format

    self._SetSerializerFormat(serializer_format)

    if access_mode != "r" and not has_serializer_stream:
        # Note that _serializer_format_string is set by _SetSerializerFormat().
        self._WriteStream(serializer_stream_name, self._serializer_format_string)

    if not self._read_only:
        logging.debug(
            "Writing to ZIP file with buffer size: {0:d}".format(self._max_buffer_size)
        )

        if self._pre_obj:
            self._pre_obj.counter = collections.Counter()
            self._pre_obj.plugin_counter = collections.Counter()

        # Start up a counter for modules in buffer.
        self._count_data_type = collections.Counter()
        self._count_parser = collections.Counter()

        # Need to get the last number in the list.
        for stream_name in self._GetStreamNames():
            if stream_name.startswith("plaso_meta."):
                _, _, file_number = stream_name.partition(".")

                try:
                    file_number = int(file_number, 10)
                    if file_number >= self._file_number:
                        self._file_number = file_number + 1
                except ValueError:
                    # Ignore invalid metadata stream names.
                    pass

        self._first_file_number = self._file_number


# Traceback (MemoryError)
2015-10-14 12:58:53,921 [WARNING] (StorageWriter) PID:2384 <multi_process> Unhandled exception in storage writer (PID: 2384).
2015-10-14 12:58:53,926 [ERROR] (StorageWriter) PID:2384 <multi_process>
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/plaso/multi_processing/multi_process.py", line 1184, in _Main
self._storage_writer.WriteEventObjects()
File "/usr/lib/python2.7/dist-packages/plaso/lib/storage.py", line 1645, in WriteEventObjects
self._Close()
File "/usr/lib/python2.7/dist-packages/plaso/lib/storage.py", line 1675, in _Close
self._storage_file.Close()
File "/usr/lib/python2.7/dist-packages/plaso/lib/storage.py", line 874, in Close
self._FlushBuffer()
File "/usr/lib/python2.7/dist-packages/plaso/lib/storage.py", line 431, in _FlushBuffer
self._WriteStream(stream_name, b''.join(proto_str))
MemoryError
2015-10-14 12:59:17,026 [WARNING] (MainProcess) PID:2379 <multi_process> Killing process: Worker_00 (PID: 2385).
2015-10-14 12:59:17,026 [WARNING] (MainProcess) PID:2379 <multi_process> Killing process: Worker_04 (PID: 2392).
Processing completed with errors.

# Fixed code
def _Open(
    self,
    path,
    access_mode="r",
    serializer_format=definitions.SERIALIZER_FORMAT_PROTOBUF,
):
    """Opens the storage file.

    Args:
      path: string containing the path of the storage file.
      access_mode: optional string indicating the access mode.
      serializer_format: Optional storage serializer format.

    Raises:
      IOError: if the file is opened in read only mode and the file does
               not exist.
    """
    super(StorageFile, self)._Open(path, access_mode=access_mode)

    serializer_stream_name = "serializer.txt"
    has_serializer_stream = self._HasStream(serializer_stream_name)
    if has_serializer_stream:
        stored_serializer_format = self._ReadStream(serializer_stream_name)
        if stored_serializer_format:
            serializer_format = stored_serializer_format

    self._SetSerializerFormat(serializer_format)

    if access_mode != "r" and not has_serializer_stream:
        # Note that _serializer_format_string is set by _SetSerializerFormat().
        self._WriteStream(serializer_stream_name, self._serializer_format_string)

    if not self._read_only:
        logging.debug(
            "Writing to ZIP file with buffer size: {0:d}".format(self._max_buffer_size)
        )

        if self._pre_obj:
            self._pre_obj.counter = collections.Counter()
            self._pre_obj.plugin_counter = collections.Counter()

        # Start up a counter for modules in buffer.
        self._count_data_type = collections.Counter()
        self._count_parser = collections.Counter()

        # Need to get the last number in the list.
        for stream_name in self._GetStreamNames():
            if stream_name.startswith("plaso_meta."):
                _, _, file_number = stream_name.partition(".")

                try:
                    file_number = int(file_number, 10)
                    if file_number >= self._file_number:
                        self._file_number = file_number + 1
                except ValueError:
                    # Ignore invalid metadata stream names.
                    pass

        self._first_file_number = self._file_number