ExpiringLRUCache

Data cache class template with element life time limitation. Stores items of raw data, either of fixed or dynamic size. When the life time of an item, which is the difference between its creation time and the current wall clock time, has expired, it is removed automatically on the next getAndRefreshValue()/exists() access.

class ExpiringLRUCache : LRUCache!(T, true), IExpiringCacheInfo (

T = void[]

) {

import ocean.core.Verify;;

time_t lifetime;

protected

uint n_expired;

this(size_t max_items, time_t lifetime);

T* getAndRefresh(hash_t key);

alias getAndRefresh = LRUCache!(T, true).getAndRefresh;

T* getAndRefresh(hash_t key, bool expired);

T* getRefreshOrCreate(hash_t key, bool existed);

alias getRefreshOrCreate = LRUCache!(T, true).getRefreshOrCreate;

bool exists(hash_t key, bool expired);

bool exists(hash_t key);

uint num_expired();

void resetStats();

}

Constructors

this this(size_t max_items, time_t lifetime): Constructor.

Members

Aliases

getAndRefresh alias getAndRefresh = LRUCache!(T, true).getAndRefresh: Gets an item from the cache. If the item was found in the cache, its access time is updated. If the item life time has expired, it is automatically removed.
getRefreshOrCreate alias getRefreshOrCreate = LRUCache!(T, true).getRefreshOrCreate: Imports the super class overloaded methods which were hidden by the getOrCreate() override implementation.

Functions

exists bool exists(hash_t key, bool expired): Checks whether an item exists in the cache and updates its access time. If the life time of the item has expired, it is removed.
exists bool exists(hash_t key): Checks whether an item exists in the cache and updates its access time. If the life time of the item has expired, it is removed.
getAndRefresh T* getAndRefresh(hash_t key): Gets an item from the cache. If the item was found in the cache, its access time is updated. If the item life time has expired, it is automatically removed.
getAndRefresh T* getAndRefresh(hash_t key, bool expired): Gets an item from the cache. If the item was found in the cache, its access time is updated. If the item life time has expired, it is automatically removed.
getRefreshOrCreate T* getRefreshOrCreate(hash_t key, bool existed): Gets an item from the cache or creates it if not already existing. If the item was found in the cache, its access time is updated, otherwise its create time is set. If the item was found but was expired, the effect is the same as if the item was not found.
num_expired uint num_expired()
resetStats void resetStats(): Resets the statistics counter values.

Variables

lifetime time_t lifetime;: Life time for all items in seconds; may be changed at any time. This value must be at least 1.
n_expired uint n_expired;: Counts the number of lookups where an existing element was expired.

ExpiringLRUCache

Constructors

Members

Aliases

Functions

Variables

Inherited Members

From IExpiringCacheInfo

Parameters

Meta

Source