:py:mod:`dissect.evidence.asdf.streams`
=======================================

.. py:module:: dissect.evidence.asdf.streams


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

Classes
~~~~~~~

.. autoapisummary::

   dissect.evidence.asdf.streams.SubStreamBase
   dissect.evidence.asdf.streams.Crc32Stream
   dissect.evidence.asdf.streams.HashedStream
   dissect.evidence.asdf.streams.CompressedStream




.. py:class:: SubStreamBase(fh: BinaryIO)


   Bases: :py:obj:`io.RawIOBase`

   Convenience class for easy sub stream subclassing.

   Additionally adds the `finalize` method.

   :param fh: The file-like object to wrap.

   .. py:method:: write(b: bytes) -> int


   .. py:method:: tell() -> int

      Return current stream position.


   .. py:method:: seek(pos: int, whence: int = io.SEEK_CUR) -> int

      Change stream position.

      Change the stream position to the given byte offset. The offset is
      interpreted relative to the position indicated by whence.  Values
      for whence are:

      * 0 -- start of stream (the default); offset should be zero or positive
      * 1 -- current stream position; offset may be negative
      * 2 -- end of stream; offset is usually negative

      Return the new absolute position.


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

      Flush and close the IO object.

      This method has no effect if the file is already closed.


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



.. py:class:: Crc32Stream(fh: BinaryIO)


   Bases: :py:obj:`SubStreamBase`

   Compute a CRC32 over all written data.

   This assumes that all data is written as a continuous stream.

   :param fh: The file-like object to wrap.

   .. py:method:: write(b: bytes) -> int


   .. py:method:: digest() -> bytes


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



.. py:class:: HashedStream(fh: BinaryIO, alg: str = 'sha256')


   Bases: :py:obj:`SubStreamBase`

   Compute a hash over all written data.

   This assumes that all data is written as a continuous stream.

   :param fh: The file-like object to wrap.
   :param alg: The hashing algorithm to use. Must be supported by hashlib.

   .. py:method:: write(b: bytes) -> int


   .. py:method:: digest() -> bytes


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


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

      Flush and close the IO object.

      This method has no effect if the file is already closed.



.. py:class:: CompressedStream(fh: BinaryIO)


   Bases: :py:obj:`SubStreamBase`

   Compress data as it's being written.

   This assumes that all data is written as a continuous stream.

   :param fh: The file-like object to wrap.

   .. py:method:: write(b: bytes) -> int


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