Metadata-Version: 1.0
Name: dogpile.core
Version: 0.4.0
Summary: A 'dogpile' lock, typically used as a component of a larger caching solution
Home-page: http://bitbucket.org/zzzeek/dogpile.core
Author: Mike Bayer
Author-email: mike_mp@zzzcomputing.com
License: BSD
Description: dogpile.core
        ============
        
        A "dogpile" lock, one which allows a single thread to generate
        an expensive resource while other threads use the "old" value, until the
        "new" value is ready.
        
        Dogpile is basically the locking code extracted from the
        Beaker package, for simple and generic usage.
        
        Usage
        -----
        
        A simple example::
        
            from dogpile.core import Dogpile
        
            # store a reference to a "resource", some 
            # object that is expensive to create.
            the_resource = [None]
        
            def some_creation_function():
                # create the resource here
                the_resource[0] = create_some_resource()
        
            def use_the_resource():
                # some function that uses
                # the resource.  Won't reach
                # here until some_creation_function()
                # has completed at least once.
                the_resource[0].do_something()
        
            # create Dogpile with 3600 second
            # expiry time
            dogpile = Dogpile(3600)
        
            with dogpile.acquire(some_creation_function):
                use_the_resource()
        
        Above, ``some_creation_function()`` will be called
        when ``Dogpile.acquire()`` is first called.  The 
        remainder of the ``with`` block then proceeds.   Concurrent threads which 
        call ``Dogpile.acquire()`` during this initial period
        will be blocked until ``some_creation_function()`` completes.
        
        Once the creation function has completed successfully the first time,
        new calls to ``Dogpile.acquire()`` will call ``some_creation_function()`` 
        each time the "expiretime" has been reached, allowing only a single
        thread to call the function.  Concurrent threads
        which call ``Dogpile.acquire()`` during this period will
        fall through, and not be blocked.  It is expected that
        the "stale" version of the resource remain available at this
        time while the new one is generated.
        
        dogpile.core is at the core of the `dogpile.cache <http://bitbucket.org/zzzeek/dogpile.cache>`_ package
        which provides for a basic cache API and sample backends based on the dogpile concept.
        
        Development Status
        -------------------
        
        dogpile.core has been in use in a small number of production environments for a period of
        months, and as of 0.3.2 has entered beta status.  No issues have been reported yet with its
        core synchronization model, and overall the project hasn't seen many changes. 
        Most development continues within dogpile.cache.   
        
        
        
        
Keywords: caching
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: BSD License
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
