Fixed #29864 -- Added link targets for low-level cache API.

This commit is contained in:
Prabakaran Kumaresshan 2018-10-26 22:24:01 +05:30 committed by Tim Graham
parent 26bb2611a5
commit 8250538bfc
2 changed files with 31 additions and 6 deletions

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@ -115,8 +115,8 @@ Cache
* The :ref:`local-memory cache backend <local-memory-caching>` now uses a * The :ref:`local-memory cache backend <local-memory-caching>` now uses a
least-recently-used (LRU) culling strategy rather than a pseudo-random one. least-recently-used (LRU) culling strategy rather than a pseudo-random one.
* The new ``touch()`` method of the :ref:`low-level cache API * The new :meth:`~django.core.caches.cache.touch` method of the :ref:`low-level
<low-level-cache-api>` updates the timeout of cache keys. cache API <low-level-cache-api>` updates the timeout of cache keys.
CSRF CSRF
~~~~ ~~~~

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@ -788,9 +788,16 @@ Accessing the cache
Basic usage Basic usage
----------- -----------
The basic interface is ``set(key, value, timeout)`` and ``get(key)``:: .. currentmodule:: django.core.caches
The basic interface is:
.. method:: cache.set(key, value, timeout=DEFAULT_TIMEOUT, version=None)
>>> cache.set('my_key', 'hello, world!', 30) >>> cache.set('my_key', 'hello, world!', 30)
.. method:: cache.get(key, default=None, version=None)
>>> cache.get('my_key') >>> cache.get('my_key')
'hello, world!' 'hello, world!'
@ -818,6 +825,8 @@ return if the object doesn't exist in the cache::
>>> cache.get('my_key', 'has expired') >>> cache.get('my_key', 'has expired')
'has expired' 'has expired'
.. method:: cache.add(key, value, timeout=DEFAULT_TIMEOUT, version=None)
To add a key only if it doesn't already exist, use the ``add()`` method. To add a key only if it doesn't already exist, use the ``add()`` method.
It takes the same parameters as ``set()``, but it will not attempt to It takes the same parameters as ``set()``, but it will not attempt to
update the cache if the key specified is already present:: update the cache if the key specified is already present::
@ -831,6 +840,8 @@ If you need to know whether ``add()`` stored a value in the cache, you can
check the return value. It will return ``True`` if the value was stored, check the return value. It will return ``True`` if the value was stored,
``False`` otherwise. ``False`` otherwise.
.. method:: cache.get_or_set(key, default, timeout=DEFAULT_TIMEOUT, version=None)
If you want to get a key's value or set a value if the key isn't in the cache, If you want to get a key's value or set a value if the key isn't in the cache,
there is the ``get_or_set()`` method. It takes the same parameters as ``get()`` there is the ``get_or_set()`` method. It takes the same parameters as ``get()``
but the default is set as the new cache value for that key, rather than simply but the default is set as the new cache value for that key, rather than simply
@ -846,6 +857,8 @@ You can also pass any callable as a *default* value::
>>> cache.get_or_set('some-timestamp-key', datetime.datetime.now) >>> cache.get_or_set('some-timestamp-key', datetime.datetime.now)
datetime.datetime(2014, 12, 11, 0, 15, 49, 457920) datetime.datetime(2014, 12, 11, 0, 15, 49, 457920)
.. method:: cache.get_many(keys, version=None)
There's also a ``get_many()`` interface that only hits the cache once. There's also a ``get_many()`` interface that only hits the cache once.
``get_many()`` returns a dictionary with all the keys you asked for that ``get_many()`` returns a dictionary with all the keys you asked for that
actually exist in the cache (and haven't expired):: actually exist in the cache (and haven't expired)::
@ -856,6 +869,8 @@ actually exist in the cache (and haven't expired)::
>>> cache.get_many(['a', 'b', 'c']) >>> cache.get_many(['a', 'b', 'c'])
{'a': 1, 'b': 2, 'c': 3} {'a': 1, 'b': 2, 'c': 3}
.. method:: cache.set_many(dict, timeout)
To set multiple values more efficiently, use ``set_many()`` to pass a dictionary To set multiple values more efficiently, use ``set_many()`` to pass a dictionary
of key-value pairs:: of key-value pairs::
@ -868,22 +883,32 @@ Like ``cache.set()``, ``set_many()`` takes an optional ``timeout`` parameter.
On supported backends (memcached), ``set_many()`` returns a list of keys that On supported backends (memcached), ``set_many()`` returns a list of keys that
failed to be inserted. failed to be inserted.
.. method:: cache.delete(key, version=None)
You can delete keys explicitly with ``delete()``. This is an easy way of You can delete keys explicitly with ``delete()``. This is an easy way of
clearing the cache for a particular object:: clearing the cache for a particular object::
>>> cache.delete('a') >>> cache.delete('a')
.. method:: cache.delete_many(keys, version=None)
If you want to clear a bunch of keys at once, ``delete_many()`` can take a list If you want to clear a bunch of keys at once, ``delete_many()`` can take a list
of keys to be cleared:: of keys to be cleared::
>>> cache.delete_many(['a', 'b', 'c']) >>> cache.delete_many(['a', 'b', 'c'])
.. method:: cache.clear()
Finally, if you want to delete all the keys in the cache, use Finally, if you want to delete all the keys in the cache, use
``cache.clear()``. Be careful with this; ``clear()`` will remove *everything* ``cache.clear()``. Be careful with this; ``clear()`` will remove *everything*
from the cache, not just the keys set by your application. :: from the cache, not just the keys set by your application. ::
>>> cache.clear() >>> cache.clear()
.. method:: cache.touch(key, timeout=DEFAULT_TIMEOUT, version=None)
.. versionadded:: 2.1
``cache.touch()`` sets a new expiration for a key. For example, to update a key ``cache.touch()`` sets a new expiration for a key. For example, to update a key
to expire 10 seconds from now:: to expire 10 seconds from now::
@ -896,9 +921,8 @@ Like other methods, the ``timeout`` argument is optional and defaults to the
``touch()`` returns ``True`` if the key was successfully touched, ``False`` ``touch()`` returns ``True`` if the key was successfully touched, ``False``
otherwise. otherwise.
.. versionchanged:: 2.1 .. method:: cache.incr(key, delta=1, version=None)
.. method:: cache.decr(key, delta=1, version=None)
The ``cache.touch()`` method was added.
You can also increment or decrement a key that already exists using the You can also increment or decrement a key that already exists using the
``incr()`` or ``decr()`` methods, respectively. By default, the existing cache ``incr()`` or ``decr()`` methods, respectively. By default, the existing cache
@ -925,6 +949,7 @@ nonexistent cache key.::
However, if the backend doesn't natively provide an increment/decrement However, if the backend doesn't natively provide an increment/decrement
operation, it will be implemented using a two-step retrieve/update. operation, it will be implemented using a two-step retrieve/update.
.. method:: cache.close()
You can close the connection to your cache with ``close()`` if implemented by You can close the connection to your cache with ``close()`` if implemented by
the cache backend. the cache backend.