:py:mod:`dissect.database.sqlite3.wal`
======================================

.. py:module:: dissect.database.sqlite3.wal




Module Contents
---------------

Classes
~~~~~~~

.. autoapisummary::

   dissect.database.sqlite3.wal.WAL
   dissect.database.sqlite3.wal.Frame
   dissect.database.sqlite3.wal.Checkpoint
   dissect.database.sqlite3.wal.Commit



Functions
~~~~~~~~~

.. autoapisummary::
   :nosignatures:

   dissect.database.sqlite3.wal.checksum



Attributes
~~~~~~~~~~

.. autoapisummary::

   dissect.database.sqlite3.wal.log
   dissect.database.sqlite3.wal.WAL_HEADER_MAGIC_LE
   dissect.database.sqlite3.wal.WAL_HEADER_MAGIC_BE
   dissect.database.sqlite3.wal.WAL_HEADER_MAGIC


.. py:data:: log

.. py:data:: WAL_HEADER_MAGIC_LE
   :value: 931071618


.. py:data:: WAL_HEADER_MAGIC_BE
   :value: 931071619


.. py:data:: WAL_HEADER_MAGIC

.. py:class:: WAL(fh: pathlib.Path | BinaryIO)

   .. py:attribute:: fh


   .. py:attribute:: path


   .. py:attribute:: header


   .. py:attribute:: checksum_endian
      :value: '<'



   .. py:attribute:: highest_page_num


   .. py:attribute:: frame


   .. py:method:: close() -> None

      Close the WAL.



   .. py:method:: frames() -> collections.abc.Iterator[Frame]


   .. py:property:: commits
      :type: list[Commit]


      Return all commits in the WAL file.

      Commits are frames where ``header.page_count`` specifies the size of the
      database file in pages after the commit. For all other frames it is 0.

      .. rubric:: References

      - https://sqlite.org/fileformat2.html#wal_file_format


   .. py:property:: checkpoints
      :type: list[Checkpoint]


      Return deduplicated checkpoints, oldest first.

      Deduplicate commits by the ``salt1`` value of their first frame. Later
      commits overwrite earlier ones so the returned list contains the most
      recent commit for each ``salt1``, sorted ascending.

      .. rubric:: References

      - https://sqlite.org/fileformat2.html#wal_file_format
      - https://sqlite.org/wal.html#checkpointing


.. py:class:: Frame(wal: WAL, offset: int)

   .. py:attribute:: wal


   .. py:attribute:: offset


   .. py:attribute:: fh


   .. py:attribute:: header


   .. py:method:: __repr__() -> str


   .. py:property:: valid
      :type: bool



   .. py:property:: data
      :type: bytes



   .. py:property:: page_number
      :type: int



   .. py:property:: page_count
      :type: int



.. py:class:: Checkpoint(wal: WAL, frames: list[Frame])

   Bases: :py:obj:`_FrameCollection`


   A checkpoint is an operation that transfers all committed transactions from
   the WAL file back into the main database file.

   .. rubric:: References

   - https://sqlite.org/fileformat2.html#wal_file_format


.. py:class:: Commit(wal: WAL, frames: list[Frame])

   Bases: :py:obj:`_FrameCollection`


   A commit is a collection of frames that were committed together.

   .. rubric:: References

   - https://sqlite.org/fileformat2.html#wal_file_format


.. py:function:: checksum(buf: bytes, endian: str = '>') -> tuple[int, int]