Commit 7c33cc7f authored by Malcolm Tredinnick's avatar Malcolm Tredinnick
Browse files

Fixed #7398 -- Allow for custom cache-backends to be used. 

Based on a patch from Lau Bech Lauritzen and Brenton Simpson.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8075 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent 7c0cf545

AUTHORS

+2 −0
Original line number Diff line number Diff line
@@ -236,6 +236,7 @@ answer newbie questions, and generally made Django that much better: 
    Stuart Langridge <http://www.kryogenix.org/>

    Paul Lanier <planier@google.com>

    Nicola Larosa <nico@teknico.net>

    Lau Bech Lauritzen

    Rune Rønde Laursen <runerl@skjoldhoej.dk>

    Eugene Lazutkin <http://lazutkin.com/blog/>

    lcordier@point45.com
@@ -341,6 +342,7 @@ answer newbie questions, and generally made Django that much better: 
    Pete Shinners <pete@shinners.org>

    Leo Shklovskii

    jason.sidabras@gmail.com

    Brenton Simpson <http://theillustratedlife.com>

    Jozko Skrablin <jozko.skrablin@gmail.com>

    Ben Slavin <benjamin.slavin@gmail.com>

    sloonz <simon.lipp@insa-lyon.fr>

django/core/cache/__init__.py

+8 −5
Original line number Diff line number Diff line
@@ -19,8 +19,10 @@ from cgi import parse_qsl 
from django.conf import settings

from django.core.cache.backends.base import InvalidCacheBackendError



# Name for use in settings file --> name of module in "backends" directory.

# Any backend scheme that is not in this dictionary is treated as a Python

# import path to a custom backend.

BACKENDS = {

    # name for use in settings file --> name of module in "backends" directory

    'memcached': 'memcached',

    'locmem': 'locmem',

    'file': 'filebased',
@@ -44,8 +46,6 @@ def get_cache(backend_uri): 
        warnings.warn("'%s' backend is deprecated. Use '%s' instead." % 

            (scheme, DEPRECATED_BACKENDS[scheme]), DeprecationWarning)

        scheme = DEPRECATED_BACKENDS[scheme]

    if scheme not in BACKENDS:

        raise InvalidCacheBackendError, "%r is not a valid cache backend" % scheme



    host = rest[2:]

    qpos = rest.find('?')
@@ -57,7 +57,10 @@ def get_cache(backend_uri): 
    if host.endswith('/'):

        host = host[:-1]



    cache_class = getattr(__import__('django.core.cache.backends.%s' % BACKENDS[scheme], {}, {}, ['']), 'CacheClass')

    return cache_class(host, params)

    if scheme in BACKENDS:

        module = __import__('django.core.cache.backends.%s' % BACKENDS[scheme], {}, {}, [''])

    else:

        module = __import__(scheme, {}, {}, [''])

    return getattr(module, 'CacheClass')(host, params)



cache = get_cache(settings.CACHE_BACKEND)

docs/cache.txt

+23 −2
Original line number Diff line number Diff line
@@ -6,8 +6,8 @@ A fundamental tradeoff in dynamic Web sites is, well, they're dynamic. Each 
time a user requests a page, the Web server makes all sorts of calculations --

from database queries to template rendering to business logic -- to create the

page that your site's visitor sees. This is a lot more expensive, from a

processing-overhead perspective, than your standard read-a-file-off-the-filesystem

server arrangement.

processing-overhead perspective, than your standard

read-a-file-off-the-filesystem server arrangement.



For most Web applications, this overhead isn't a big deal. Most Web

applications aren't washingtonpost.com or slashdot.org; they're simply small-
@@ -186,6 +186,27 @@ production environment still will. To activate dummy caching, set 


    CACHE_BACKEND = 'dummy:///'



Using a custom cache backend

----------------------------



**New in Django development version**



While Django includes support for a number of cache backends out-of-the-box,

sometimes you will want to use a customised verison or your own backend.  To

use an external cache backend with Django, use a Python import path as the

scheme portion (the part before the initial colon) of the ``CACHE_BACKEND``

URI, like so::



    CACHE_BACKEND = 'path.to.backend://'



If you're building your own backend, you can use the standard cache backends

as reference implementations. You'll find the code in the

``django/core/cache/backends/`` directory of the Django source.



Note: Without a really compelling reason, like a host that doesn't support the

them, you should stick to the cache backends included with Django. They've

been really well-tested and are quite easy to use.



CACHE_BACKEND arguments

-----------------------