pyzim.cache.NoOpCache

class documentation

class NoOpCache(BaseCache):

Constructor: NoOpCache(on_leave)

A BaseCache implementation that does not cache.

Method	`clear`	Empty this cache.
Method	`get`	Return the element that has been cached for this key.
Method	`has`	Return True if an element is cached for the specific key.
Method	`push`	Push an element for this key into this cache.
Method	`remove`	If an element is cached for key, remove it from the cache.

Inherited from BaseCache:

Method	`__init__`	The default constructor.
Instance Variable	`on_leave`	a callable expecting two arguments (key, value) that will be called when an element leaves the cache

def clear(self, call_on_leave=True): ¶

overrides pyzim.cache.BaseCache.clear

Empty this cache.

Parameters
call_on_leave:`bool`	if nonzero (default), call `BaseCache.on_leave` for each element cleared

def get(self, key): ¶

overrides pyzim.cache.BaseCache.get

Return the element that has been cached for this key.

Parameters
key:hashable	key for the element that should be returned

Returns
same as passed to `BaseCache.push`	the element

Raises
`KeyError`	if no element was cached for this key

def has(self, key): ¶

overrides pyzim.cache.BaseCache.has

Return True if an element is cached for the specific key.

Parameters
key:hashable	key of element that should be checked

Returns
`bool`	True if an element has been cached for this key

def push(self, key, element, allow_replacement=True): ¶

overrides pyzim.cache.BaseCache.push

Push an element for this key into this cache.

It is up for the cache to decide whether the element will actually be cached or not. If allow_replacement=False is set, no other element should be kicked from the cache.

Re-pushing an already cached element will not update the cached element.

Parameters
key:hashable	key which will be used to identify the element
element:any	element to cache
allow_replacement:`bool`	if this value is false, do not cache if this would kick another element from the cache

Returns
`bool`	True if the element is now cached, False otherwise

def remove(self, key, call_on_leave=True): ¶

overrides pyzim.cache.BaseCache.remove

If an element is cached for key, remove it from the cache.

Parameters
key:hashable	key of element to remove
call_on_leave:`bool`	if nonzero (default), call `BaseCache.on_leave` on the removed element