Metadata-Version: 2.1
Name: portalocker
Version: 2.2.1
Summary: Wraps the portalocker recipe for easy usage
Home-page: https://github.com/WoLpH/portalocker
Author: Rick van Hattem
Author-email: wolph@wol.ph
License: PSF
Description: ############################################
        portalocker - Cross-platform locking library
        ############################################
        
        .. image:: https://travis-ci.com/WoLpH/portalocker.svg?branch=master
            :alt: Linux Test Status
            :target: https://travis-ci.com/WoLpH/portalocker
        
        .. image:: https://ci.appveyor.com/api/projects/status/mgqry98hgpy4prhh?svg=true
            :alt: Windows Tests Status
            :target: https://ci.appveyor.com/project/WoLpH/portalocker
        
        .. image:: https://coveralls.io/repos/WoLpH/portalocker/badge.svg?branch=master
            :alt: Coverage Status
            :target: https://coveralls.io/r/WoLpH/portalocker?branch=master
        
        Overview
        --------
        
        Portalocker is a library to provide an easy API to file locking.
        
        An important detail to note is that on Linux and Unix systems the locks are
        advisory by default. By specifying the `-o mand` option to the mount command it
        is possible to enable mandatory file locking on Linux. This is generally not
        recommended however. For more information about the subject:
        
         - https://en.wikipedia.org/wiki/File_locking
         - http://stackoverflow.com/questions/39292051/portalocker-does-not-seem-to-lock
         - https://stackoverflow.com/questions/12062466/mandatory-file-lock-on-linux
        
        The module is currently maintained by Rick van Hattem <Wolph@wol.ph>.
        The project resides at https://github.com/WoLpH/portalocker . Bugs and feature
        requests can be submitted there. Patches are also very welcome.
        
        Redis Locks
        -----------
        
        This library now features a lock based on Redis which allows for locks across
        multiple threads, processes and even distributed locks across multiple
        computers.
        
        It is an extremely reliable Redis lock that is based on pubsub.
        
        As opposed to most Redis locking systems based on key/value pairs,
        this locking method is based on the pubsub system. The big advantage is
        that if the connection gets killed due to network issues, crashing
        processes or otherwise, it will still immediately unlock instead of
        waiting for a lock timeout.
        
        Usage is really easy:
        
        ::
        
            import portalocker
        
            lock = portalocker.RedisLock('some_lock_channel_name')
        
            with lock:
                print('do something here')
        
        The API is essentially identical to the other ``Lock`` classes so in addition
        to the ``with`` statement you can also use ``lock.acquire(...)``.
        
        Python 2
        --------
        
        Python 2 was supported in versions before Portalocker 2.0. If you are still
        using
        Python 2,
        you can run this to install:
        
        ::
        
            pip install "portalocker<2"
        
        Tips
        ----
        
        On some networked filesystems it might be needed to force a `os.fsync()` before
        closing the file so it's actually written before another client reads the file.
        Effectively this comes down to:
        
        ::
        
           with portalocker.Lock('some_file', 'rb+', timeout=60) as fh:
               # do what you need to do
               ...
        
               # flush and sync to filesystem
               fh.flush()
               os.fsync(fh.fileno())
        
        Links
        -----
        
        * Documentation
            - http://portalocker.readthedocs.org/en/latest/
        * Source
            - https://github.com/WoLpH/portalocker
        * Bug reports
            - https://github.com/WoLpH/portalocker/issues
        * Package homepage
            - https://pypi.python.org/pypi/portalocker
        * My blog
            - http://w.wol.ph/
        
        Examples
        --------
        
        To make sure your cache generation scripts don't race, use the `Lock` class:
        
        >>> import portalocker
        >>> with portalocker.Lock('somefile', timeout=1) as fh:
        ...     print >>fh, 'writing some stuff to my cache...'
        
        To customize the opening and locking a manual approach is also possible:
        
        >>> import portalocker
        >>> file = open('somefile', 'r+')
        >>> portalocker.lock(file, portalocker.EXCLUSIVE)
        >>> file.seek(12)
        >>> file.write('foo')
        >>> file.close()
        
        Explicitly unlocking is not needed in most cases but omitting it has been known
        to cause issues:
        
        >>> import portalocker
        >>> with portalocker.Lock('somefile', timeout=1) as fh:
        ...     print >>fh, 'writing some stuff to my cache...'
        
        To customize the opening and locking a manual approach is also possible:
        
        >>> import portalocker
        >>> file = open('somefile', 'r+')
        >>> portalocker.lock(file, portalocker.EXCLUSIVE)
        >>> file.seek(12)
        >>> file.write('foo')
        >>> file.close()
        
        Explicitly unlocking is not needed in most cases but omitting it has been known
        to cause issues:
        
        >>> import portalocker
        >>> with portalocker.Lock('somefile', timeout=1) as fh:
        ...     print >>fh, 'writing some stuff to my cache...'
        
        To customize the opening and locking a manual approach is also possible:
        
        >>> import portalocker
        >>> file = open('somefile', 'r+')
        >>> portalocker.lock(file, portalocker.LOCK_EX)
        >>> file.seek(12)
        >>> file.write('foo')
        >>> file.close()
        
        Explicitly unlocking is not needed in most cases but omitting it has been known
        to cause issues:
        https://github.com/AzureAD/microsoft-authentication-extensions-for-python/issues/42#issuecomment-601108266
        
        If needed, it can be done through:
        
        >>> portalocker.unlock(file)
        
        Do note that your data might still be in a buffer so it is possible that your
        data is not available until you `flush()` or `close()`.
        
        To create a cross platform bounded semaphore across multiple processes you can
        use the `BoundedSemaphore` class which functions somewhat similar to
        `threading.BoundedSemaphore`:
        
        >>> import portalocker
        >>> n = 2
        >>> timeout = 0.1
        
        >>> semaphore_a = portalocker.BoundedSemaphore(n, timeout=timeout)
        >>> semaphore_b = portalocker.BoundedSemaphore(n, timeout=timeout)
        >>> semaphore_c = portalocker.BoundedSemaphore(n, timeout=timeout)
        
        >>> semaphore_a.acquire()
        <portalocker.utils.Lock object at ...>
        >>> semaphore_b.acquire()
        <portalocker.utils.Lock object at ...>
        >>> semaphore_c.acquire()
        Traceback (most recent call last):
          ...
        portalocker.exceptions.AlreadyLocked
        
        
        More examples can be found in the
        `tests <http://portalocker.readthedocs.io/en/latest/_modules/tests/tests.html>`_.
        
        Changelog
        ---------
        
        Every release has a ``git tag`` with a commit message for the tag
        explaining what was added and/or changed. The list of tags/releases
        including the commit messages can be found here:
        https://github.com/WoLpH/portalocker/releases
        
        License
        -------
        
        See the `LICENSE <https://github.com/WoLpH/portalocker/blob/develop/LICENSE>`_ file.
        
        
Keywords: locking,locks,with statement,windows,linux,unix
Platform: any
Classifier: Intended Audience :: Developers
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3.3
Classifier: Programming Language :: Python :: 3.4
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Provides-Extra: docs
Provides-Extra: tests
Provides-Extra: redis
