diff options
Diffstat (limited to 'app/static/doc/flask-docs/_sources/patterns/caching.txt')
| -rw-r--r-- | app/static/doc/flask-docs/_sources/patterns/caching.txt | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/app/static/doc/flask-docs/_sources/patterns/caching.txt b/app/static/doc/flask-docs/_sources/patterns/caching.txt deleted file mode 100644 index 5817aa2..0000000 --- a/app/static/doc/flask-docs/_sources/patterns/caching.txt +++ /dev/null @@ -1,69 +0,0 @@ -.. _caching-pattern: - -Caching -======= - -When your application runs slow, throw some caches in. Well, at least -it's the easiest way to speed up things. What does a cache do? Say you -have a function that takes some time to complete but the results would -still be good enough if they were 5 minutes old. So then the idea is that -you actually put the result of that calculation into a cache for some -time. - -Flask itself does not provide caching for you, but Werkzeug, one of the -libraries it is based on, has some very basic cache support. It supports -multiple cache backends, normally you want to use a memcached server. - -Setting up a Cache ------------------- - -You create a cache object once and keep it around, similar to how -:class:`~flask.Flask` objects are created. If you are using the -development server you can create a -:class:`~werkzeug.contrib.cache.SimpleCache` object, that one is a simple -cache that keeps the item stored in the memory of the Python interpreter:: - - from werkzeug.contrib.cache import SimpleCache - cache = SimpleCache() - -If you want to use memcached, make sure to have one of the memcache modules -supported (you get them from `PyPI <http://pypi.python.org/>`_) and a -memcached server running somewhere. This is how you connect to such an -memcached server then:: - - from werkzeug.contrib.cache import MemcachedCache - cache = MemcachedCache(['127.0.0.1:11211']) - -If you are using App Engine, you can connect to the App Engine memcache -server easily:: - - from werkzeug.contrib.cache import GAEMemcachedCache - cache = GAEMemcachedCache() - -Using a Cache -------------- - -Now how can one use such a cache? There are two very important -operations: :meth:`~werkzeug.contrib.cache.BaseCache.get` and -:meth:`~werkzeug.contrib.cache.BaseCache.set`. This is how to use them: - -To get an item from the cache call -:meth:`~werkzeug.contrib.cache.BaseCache.get` with a string as key name. -If something is in the cache, it is returned. Otherwise that function -will return `None`:: - - rv = cache.get('my-item') - -To add items to the cache, use the :meth:`~werkzeug.contrib.cache.BaseCache.set` -method instead. The first argument is the key and the second the value -that should be set. Also a timeout can be provided after which the cache -will automatically remove item. - -Here a full example how this looks like normally:: - - def get_my_item(): - rv = cache.get('my-item') - if rv is None: - rv = calculate_value() - cache.set('my-item', rv, timeout=5 * 60) - return rv |