Beaker 0.7

A Session and Caching library with WSGI Middleware

About

Beaker 0.7 is a new and refactored update to Beaker built on code from the package MyghtyUtils, originally used in the Myghty project. It implements a full set of cache functionality along with sessions that can utilize the caches.

Beaker includes Cache and Session WSGI middleware to ease integration with WSGI capable frameworks, and is automatically used by Pylons.

Features

• Fast, robust performance

• Multiple reader/single writer lock system to avoid duplicate simultaneous cache creation

• Cache back-ends include dbm, file, memory, memcached, and database (Using SQLAlchemy for multiple-db vendor support)

• Signed cookie’s to prevent session hijacking/spoofing

• Extensible Container object to support new back-ends

• Cache’s can be divided into namespaces (to represent templates, objects, etc.) then keyed for different copies

• Create functions for automatic call-backs to create new cache copies after expiration

• Fine-grained toggling of back-ends, keys, and expiration per Cache object

Usage

Caching

Basic Example:

from beaker.cache import CacheManager
cm = CacheManager(type='dbm', data_dir='./cache')

cache = cm.get_cache('mytemplate')

def somethingslow():
    # slow stuff
    db_lookups()

# Get the value, this will create the cache copy the first time
# and any time it expires (in seconds, so 3600 = one hour)
result = mycache.get_value(day, createfunc=somethingslow, expiretime=3600)

Using WSGI:

from beaker.middleware import CacheMiddleware

def simple_app(environ, start_response):
    cache = environ['beaker.cache'].get_cache('testcache')
    try:
        value = cache.get_value('value')
    except KeyError:
        value = 0
    cache.set_value('value', value+1)
    start_response('200 OK', [('Content-type', 'text/plain')])
    return ['The current value is: %s' % cache.get_value('value')]

app = CacheMiddleware(simple_app, type='dbm', data_dir='./cache')

Sessions

Using WSGI:

from beaker.middleware import SessionMiddleware

def simple_app(environ, start_response):
    session = environ['beaker.session']
    if not session.has_key('value'):
        session['value'] = 0
    session['value'] += 1
    session.save()
    start_response('200 OK', [('Content-type', 'text/plain')])
    return ['The current value is: %d' % session['value']]

wsgi_app = SessionMiddleware(simple_app, type='dbm', data_dir='./cache')

Source

The latest developer version is available in a Subversion repository.