# Poco

# template < class TKey, class TValue, class TMutex = FastMutex, class TEventMutex = FastMutex >

# class UniqueExpireLRUCache

Library: Foundation
Package: Cache
Header: Poco/UniqueExpireLRUCache.h

## Description

A UniqueExpireLRUCache combines LRU caching and time based per entry expire caching. One can define for each cache entry a separate timepoint but also limit the size of the cache (per default: 1024). Each TValue object must thus offer the following method:

    const Poco::Timestamp& getExpiration() const;

which returns the absolute timepoint when the entry will be invalidated. Accessing an object will NOT update this absolute expire timepoint. You can use the Poco::ExpirationDecorator to add the getExpiration method to values that do not have a getExpiration function.

## Inheritance

Direct Base Classes: AbstractCache < TKey, TValue, StrategyCollection < TKey, TValue >, TMutex, TEventMutex >

All Base Classes: AbstractCache < TKey, TValue, StrategyCollection < TKey, TValue >, TMutex, TEventMutex >

## Constructors

### UniqueExpireLRUCache

UniqueExpireLRUCache(
std::size_t cacheSize = 1024
);

## Destructor

### ~UniqueExpireLRUCache

~UniqueExpireLRUCache();