Skip to main content

memcache-based session storage

Project description

===========================
Session Data Using memcache
===========================

This package provides a session data manager which stores it's data in
memcache. The package uses lovely.memcached to store it's data.

IMPORTANT:

This test expects a memcache server running on local port 11211 which
is the default port for memcached.

This test runs in level 2 because it needs external resources to work. If you
want to run this test you need to use --all as parameter to your test.

Start a memcache instance with : memcached <optional options>


Once memcached is running, we can start testing:

>>> from zope import component
>>> from lovely.memcached.interfaces import IMemcachedClient
>>> from lovely.memcached.utility import MemcachedClient
>>> util = MemcachedClient()
>>> component.provideUtility(util, IMemcachedClient, name='session')
>>> util.invalidateAll()


Import the container we will use for caching tests.

>>> from lovely.session.memcached import MemCachedSessionDataContainer

Timeout behavior
~~~~~~~~~~~~~~~~

We need to test the timeout capability of the container. We can do this by simulating the passage of time while minimizing the timeout period.

Create a new session data that we will cause to timeout.

>>> timeoutSessionData = MemCachedSessionDataContainer()
>>> timeoutSessionData.cacheName = u'session'
>>> timeoutSessionData.__name__ = 'MemCacheSession'

>>> timeoutSession = timeoutSessionData['mySessionId']
>>> timeoutSession
{}

So we expect it is empty at this point. Get a new session from it.

>>> timeoutData = timeoutSession['myData1']
>>> timeoutData
{}

Okay, so now add some data to that session.

>>> timeoutData['info'] = 'stored in memcache'
>>> timeoutData
{'info': 'stored in memcache'}

Now get that sessionData from the session. It should just give it to us and the sessionData should have data.

>>> timeoutData = timeoutSession['myData1']
>>> timeoutData
{'info': 'stored in memcache'}

Now simulate the effect of a timeout by forcing one.

>>> timeoutSessionData.timeout=1
>>> timeoutSessionData.lastAccessTime=0

Now ask the sessionData for the session again. If the timeout worked, the session will be empty.

>>> timeoutSession = timeoutSessionData['mySessionId']
>>> timeoutSession
{}

Attempt to get the data from the session anyway and it will also be empty.

>>> timeoutData = timeoutSession['myData1']
>>> timeoutData
{}


Normal memcache access
~~~~~~~~~~~~~~~~~~~~~~

Now we create a memcache session and connect it to the memcached client.

>>> sessionData = MemCachedSessionDataContainer()
>>> sessionData.cacheName = u'session'

We need to provide a name for the session data manager because it is used to
identify the cache entry in memcache.

>>> sessionData.__name__ = 'MemCacheSession'

>>> session = sessionData['mySessionId']
>>> session
{}
>>> type(session)
<class 'lovely.session.memcached.MemCacheSessionData'>

We can now get data from the session.

>>> data = session['myData']
>>> data
{}
>>> type(data)
<class 'lovely.session.memcached.MemCachePkgData'>

>>> data['info'] = 'stored in memcache'
>>> data
{'info': 'stored in memcache'}


Transaction support
~~~~~~~~~~~~~~~~~~~

Because the MemCacheSession is transaction aware we need to commit the
transaction to store data in the memcache.

>>> import transaction

>>> transaction.commit()

If we now read session data it is read back from the memcache.

>>> session = sessionData['mySessionId']
>>> session['myData']
{'info': 'stored in memcache'}

>>> sessionData.items()
[('mySessionId', <lovely.session.memcached.DataManager object at ...>)]


MemCacheSession is now also savepoint aware, let's check how that works:

We first set some data:

>>> session = sessionData['mySessionId']
>>> data = session['myData']
>>> data['info'] = 'we want to keep this'

Set a savepoint:

>>> savepoint = transaction.savepoint()

Change the data:

>>> data['info'] = 'this should be dumped'

Rollback to the previous value:

>>> savepoint.rollback()

And here it is, the before value:

>>> data['info']
'we want to keep this'

Newly added data must also go away:

We add a new data:

>>> data['newinfo'] = 'go away'

And a new container:

>>> newdata = session['myNewData']
>>> newdata['foo'] = 'bar'

Roll it back to the previous savepoint:

>>> savepoint.rollback()

The data is gone:

>>> data['newinfo']
Traceback (most recent call last):
...
KeyError: 'newinfo'

The container is empty, because it gets always created on retrieval:

>>> session['myNewData']
{}

Let's see what happens on commit:

>>> transaction.commit()

If we now read session data it is read back from the memcache.

>>> session = sessionData['mySessionId']
>>> session['myData']
{'info': 'we want to keep this'}

The data is not present:

>>> data['newinfo']
Traceback (most recent call last):
...
KeyError: 'newinfo'

The container is empty, because it gets always created on retrieval:

>>> session['myNewData']
{}


=======
CHANGES
=======

0.3.0 (12-11-2009)
------------------

- Use zope.container instead of zope.app.container

- Removed unused dependencies


0.2.2 (2009-08-14)
------------------

- Add 'lastAccessTime' class attribute (fix old instances)


0.2.1 (2009-08-14)
------------------

- Correctly implemented timeout behavior of session data.

- Remove duplicate extras_require (python2.4 compatibility)


0.2.0 (2008-09-25)
------------------

- Made the DataManager savepoint aware.


0.1.4 (2008-07-31)
------------------

- Fixed ZCML to avoid deprecation warnings, since the session API was moved to
``zope.session``. *Sigh*


0.1.3 (2008-07-31)
------------------

- Fixed `setup.py` to be on par with the latest layout.

- Fixed deprecation warnings, since the session API was moved to
``zope.session``.


0.1.2 (2007-08-13)
------------------

- Move source to svn.zope.org.


0.1.1 (2007-08-13)
------------------

- Fixed dependency on `lovely.memcached`.


========
Download
========

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

lovely.session-0.3.0.tar.gz (10.0 kB view hashes)

Uploaded Source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page