Overview
********


The Metadata class can be used in order to organize lot's of Buffer files. 
For example you might have a project generated by the Analyzer4D Software and you want to search through all buffer files
in order to find all buffers with a certain compression.
You could go through each file and check out if the compression matches your requirement which takes a lot of time.
The cache creates a database that caches all the metadata available in the :class:`qass.tools.analyzer.buffer_parser.Buffer` class.
You can then query the cache very fast and programmatically in Python!

Example
*******

In this example we create an instance of the cache and synchronize it with the directory `my/directory`.
We then create a template `BufferMetadata` object and use it with the cache to query for all buffers with a compression_frq = 8.
You can use all properties that are in :py:attr:`BufferMetadata.properties`.
The :py:meth:`BufferMetadataCache.get_matching_buffers` method returns a list of :class:`Buffer` objects
that are in this case sorted by their process number (as specified in the `sort_key`).

.. code-block:: python
    :linenos:
	
    from qass.tools.analyzer.buffer_metadata_cache import BufferMetadataCache as BMC, BufferMetadata as BM, select

    cache = BMC()
    cache.synchronize_directory("my/directory")

    results = cache.get_matching_buffers(query=select(BM).filter(BM.compression_frq==8).order_by(BM.process))


Example (Deprecated)
********************

.. code-block:: python
    :linenos:
	
    from qass.tools.analyzer.buffer_metadata_cache import BufferMetadataCache as BMC, BufferMetadata as BM
    from qass.tools.analyzer.buffer_parser import Buffer

    cache = BMC(BMC.create_session(), Buffer)
    cache.synchronize_directory("my/directory")

    buffer_metadata = BM(compression_frq = 8)
    results = cache.get_matching_buffers(buffer_metadata, sort_key = lambda bm: bm.process)


BufferMetadataCache
*******************

.. autoclass:: qass.tools.analyzer.buffer_metadata_cache.BufferMetadataCache
    :members:



BufferMetadata
**************

.. autoclass:: qass.tools.analyzer.buffer_metadata_cache.BufferMetadata
    :members:

.. autofunction:: qass.tools.analyzer.buffer_metadata_cache.get_declarative_base