# -*- coding: utf-8 -*-
"""Fake (in-memory only) storage writer for testing."""
from plaso.lib import definitions
from plaso.storage import writer
from plaso.storage.fake import fake_store
[docs]
class FakeStorageWriter(writer.StorageWriter):
"""Fake (in-memory only) storage writer object.
Attributes:
task_completion (TaskCompletion): task completion attribute container.
task_start (TaskStart): task start attribute container.
"""
[docs]
def __init__(self, storage_type=definitions.STORAGE_TYPE_SESSION):
"""Initializes a storage writer object.
Args:
storage_type (Optional[str]): storage type.
"""
super(FakeStorageWriter, self).__init__(storage_type=storage_type)
self._first_written_event_data_index = 0
self._first_written_event_source_index = 0
self._written_event_data_index = 0
self._written_event_source_index = 0
self.task_completion = None
self.task_start = None
[docs]
def GetFirstWrittenEventData(self):
"""Retrieves the first event data that was written after open.
Using GetFirstWrittenEventData and GetNextWrittenEventData newly
added event data can be retrieved in order of addition.
Returns:
EventData: event data or None if there are no newly written ones.
Raises:
IOError: when the storage writer is closed.
OSError: when the storage writer is closed.
"""
if not self._store:
raise IOError('Unable to read from closed storage writer.')
event_data = self._store.GetAttributeContainerByIndex(
self._CONTAINER_TYPE_EVENT_DATA, self._first_written_event_data_index)
self._written_event_data_index = self._first_written_event_data_index + 1
return event_data
[docs]
def GetNextWrittenEventData(self):
"""Retrieves the next event data that was written after open.
Returns:
EventData: event data or None if there are no newly written ones.
Raises:
IOError: when the storage writer is closed.
OSError: when the storage writer is closed.
"""
if not self._store:
raise IOError('Unable to read from closed storage writer.')
event_data = self._store.GetAttributeContainerByIndex(
self._CONTAINER_TYPE_EVENT_DATA, self._written_event_data_index)
self._written_event_data_index += 1
return event_data
[docs]
def GetFirstWrittenEventSource(self):
"""Retrieves the first event source that was written after open.
Using GetFirstWrittenEventSource and GetNextWrittenEventSource newly
added event sources can be retrieved in order of addition.
Returns:
EventSource: event source or None if there are no newly written ones.
Raises:
IOError: when the storage writer is closed.
OSError: when the storage writer is closed.
"""
if not self._store:
raise IOError('Unable to read from closed storage writer.')
event_source = self._store.GetAttributeContainerByIndex(
self._CONTAINER_TYPE_EVENT_SOURCE,
self._first_written_event_source_index)
self._written_event_source_index = (
self._first_written_event_source_index + 1)
return event_source
[docs]
def GetNextWrittenEventSource(self):
"""Retrieves the next event source that was written after open.
Returns:
EventSource: event source or None if there are no newly written ones.
Raises:
IOError: when the storage writer is closed.
OSError: when the storage writer is closed.
"""
if not self._store:
raise IOError('Unable to read from closed storage writer.')
event_source = self._store.GetAttributeContainerByIndex(
self._CONTAINER_TYPE_EVENT_SOURCE, self._written_event_source_index)
self._written_event_source_index += 1
return event_source
[docs]
def Open(self, **unused_kwargs):
"""Opens the storage writer.
Raises:
IOError: if the storage writer is already opened.
OSError: if the storage writer is already opened.
"""
if self._store:
raise IOError('Storage writer already opened.')
self._store = fake_store.FakeStore()
self._store.Open()
self._first_written_event_data_index = 0
self._first_written_event_source_index = 0
self._written_event_data_index = 0
self._written_event_source_index = 0