compressed-deque 0.1.2
Compressed Deque
License: MIT License

Copyright (c) 2016, Pedro Lopes

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Description: Compressed Deque
        ================
        
        A deque which compresses its items for a decreased volatile and persistent memory footprint.
        
        Installation
        ------------
        
        .. code-block:: bash
        
            $ pip install compressed-deque
        
        
        How to Use it
        -------------
        
        .. code-block:: python
        
            from compdeque import CompressedDeque
        
            # Instantiate the Deque
            collection = CompressedDeque()
        
            # Use it as a normal deque
            collection.append(1)
        
            # Persist to a file
            CompressedDeque.save_to_file(collection, file_path="/path/to/collection.dat")
        
            # ...
        
            # and load it when you need it later
            loaded_collection = CompressedDeque.load_from_file("/path/to/collection.dat")
        
        Tests and documentation
        -----------------------
        
        On the project's root folder:
        
        .. code-block:: bash
        
            # Run all tests
            $ make test
        
            # Generate documentation
            $ make docs
        
        Structure
        ---------
        
        Compressed Deque inherits from `deque <https://docs.python.org/2/library/collections.html#collections.deque>`_ and stores its items as zlib compressed pickles. The middle pickle layer only serves as a generic serialization method which can provide a serialized object string for zlib to compress. Although pickle can compress objects, its compression rate does not match zlib's, even using `higher protocols <https://docs.python.org/2/library/pickle.html#data-stream-format>`_.
        
        .. image:: docs/images/value_layers.png
        
        ``save_to_file()`` and ``load_from_file()`` static methods are provided to persist the collection directly into disk in its compressed representation, without much overhead.
        
        The persisted file contains a sequence of header/compressed_value pairs: the header is a 4 byte integer description of the compressed value's length and the compressed value is similiar to its in-memory representation.
        
        .. image:: docs/images/persisted_values.png
Keywords: compressed deque zipped zlib
Platform: UNKNOWN
Classifier: Development Status :: 3 - Alpha
Classifier: Intended Audience :: Developers
Classifier: Topic :: Software Development :: Build Tools
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.6
Classifier: Programming Language :: Python :: 2.7