com.facebook.presto.hive.$internal.jodd.cache.Cache Maven / Gradle / Ivy
// Copyright (c) 2003-2014, Jodd Team (com.facebook.presto.hive.$internal.jodd.org). All Rights Reserved.
package com.facebook.presto.hive.$internal.jodd.cache;
import java.util.Iterator;
/**
* Cache interface.
*/
public interface Cache {
/**
* Returns cache size or 0 if there is no size limit.
*/
int getCacheSize();
/**
* Returns default timeout or 0 if it is not set.
*/
long getCacheTimeout();
/**
* Adds an object to the cache with default timeout.
* @see Cache#put(Object, Object, long)
*/
void put(K key, V object);
/**
* Adds an object to the cache with specified timeout after which it becomes expired.
* If cache is full, {@link #prune()} is invoked to make room for new object.
*/
void put(K key, V object, long timeout);
/**
* Retrieves an object from the cache. Returns null if object
* is not longer in cache or if it is expired.
*/
V get(K key);
/**
* Returns iterator over non-expired values.
*/
Iterator iterator();
/**
* Prunes objects from cache and returns the number of removed objects.
* Used strategy depends on cache implementation.
*/
int prune();
/**
* Returns true if max cache capacity has been reached
* only if cache is size limited.
*/
boolean isFull();
/**
* Removes an object from the cache.
*/
void remove(K key);
/**
* Clears current cache.
*/
void clear();
/**
* Returns current cache size.
*/
int size();
/**
* Returns true if cache is empty.
*/
boolean isEmpty();
}