langacore.kit.django.cache

A drop-in substitute for the default django.core.cache object. This implementation is using a modified mint cache approach based on http://www.djangosnippets.org/snippets/793/.

This implementation does not support specifying fallback values for the get() function since it would not be possible to otherwise reliably communicate that the value is stale and has to be updated.

Configured by three values in settings.py:

• CACHE_DEFAULT_TIMEOUT - how long a set value should be considered valid (in seconds). After this period the value is considered stale, a single request starts to update it, and subsequent requests get the old value until the value gets updated. Default: 300 seconds.
• CACHE_FILELOCK_PATH - path to a non-existant file which will work as an interprocess lock to make cache access atomic. Default: /tmp/langacore_django_cache.lock
• CACHE_MINT_DELAY - an upper bound on how long a value should take to be generated (in seconds). This value is used for stale keys and is the real time after which the key is completely removed from the cache. Default: 30 seconds.

Functions

get(*args, **kwargs)

Get a value from the cache.

Parameters:key – the key for which to return the value

set(*args, **kwargs)

Set a value in the cache.

Parameters:

• key – the key under which to set the value
• val – the value to set
• timeout – how long should this value be valid, by default CACHE_DEFAULT_TIMEOUT
• _is_stale – boolean, used internally to set a stale value in the cache back-end. Don’t use on your own.

delete(*args, **kwargs)

Removes a value from the cache.

Parameters:key – the key to delete from the cache