| package org.apache.commons.jcs.engine.memory.behavior; |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| import org.apache.commons.jcs.engine.behavior.ICacheElement; |
| import org.apache.commons.jcs.engine.behavior.ICompositeCacheAttributes; |
| import org.apache.commons.jcs.engine.control.CompositeCache; |
| import org.apache.commons.jcs.engine.stats.behavior.IStats; |
| |
| import java.io.IOException; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** For the framework. Insures methods a MemoryCache needs to access. */ |
| public interface IMemoryCache<K, V> |
| { |
| /** |
| * Initialize the memory cache |
| * <p> |
| * @param cache The cache (region) this memory store is attached to. |
| */ |
| void initialize( CompositeCache<K, V> cache ); |
| |
| /** |
| * Destroy the memory cache |
| * <p> |
| * @throws IOException |
| */ |
| void dispose() |
| throws IOException; |
| |
| /** |
| * Get the number of elements contained in the memory store |
| * <p> |
| * @return Element count |
| */ |
| int getSize(); |
| |
| /** |
| * Returns the historical and statistical data for a region's memory cache. |
| * <p> |
| * @return Statistics and Info for the Memory Cache. |
| */ |
| IStats getStatistics(); |
| |
| /** |
| * Get a set of the keys for all elements in the memory cache. |
| * <p> |
| * @return a set of the key type |
| * TODO This should probably be done in chunks with a range passed in. This |
| * will be a problem if someone puts a 1,000,000 or so items in a |
| * region. |
| */ |
| Set<K> getKeySet(); |
| |
| /** |
| * Removes an item from the cache |
| * <p> |
| * @param key |
| * Identifies item to be removed |
| * @return Description of the Return Value |
| * @throws IOException |
| * Description of the Exception |
| */ |
| boolean remove( K key ) |
| throws IOException; |
| |
| /** |
| * Removes all cached items from the cache. |
| * <p> |
| * @throws IOException |
| * Description of the Exception |
| */ |
| void removeAll() |
| throws IOException; |
| |
| /** |
| * This instructs the memory cache to remove the <i>numberToFree</i> |
| * according to its eviction policy. For example, the LRUMemoryCache will |
| * remove the <i>numberToFree</i> least recently used items. These will be |
| * spooled to disk if a disk auxiliary is available. |
| * <p> |
| * @param numberToFree |
| * @return the number that were removed. if you ask to free 5, but there are |
| * only 3, you will get 3. |
| * @throws IOException |
| */ |
| int freeElements( int numberToFree ) |
| throws IOException; |
| |
| /** |
| * Get an item from the cache |
| * <p> |
| * @param key |
| * Description of the Parameter |
| * @return Description of the Return Value |
| * @throws IOException |
| * Description of the Exception |
| */ |
| ICacheElement<K, V> get( K key ) |
| throws IOException; |
| |
| /** |
| * Gets multiple items from the cache based on the given set of keys. |
| * <p> |
| * @param keys |
| * @return a map of K key to ICacheElement<K, V> element, or an empty map |
| * if there is no data in cache for any of these keys |
| * @throws IOException |
| */ |
| Map<K, ICacheElement<K, V>> getMultiple( Set<K> keys ) |
| throws IOException; |
| |
| /** |
| * Get an item from the cache without effecting its order or last access |
| * time |
| * <p> |
| * @param key |
| * Description of the Parameter |
| * @return The quiet value |
| * @throws IOException |
| * Description of the Exception |
| */ |
| ICacheElement<K, V> getQuiet( K key ) |
| throws IOException; |
| |
| /** |
| * Spools the item contained in the provided element to disk |
| * <p> |
| * @param ce |
| * Description of the Parameter |
| * @throws IOException |
| * Description of the Exception |
| */ |
| void waterfal( ICacheElement<K, V> ce ) |
| throws IOException; |
| |
| /** |
| * Puts an item to the cache. |
| * <p> |
| * @param ce |
| * Description of the Parameter |
| * @throws IOException |
| * Description of the Exception |
| */ |
| void update( ICacheElement<K, V> ce ) |
| throws IOException; |
| |
| /** |
| * Returns the CacheAttributes for the region. |
| * <p> |
| * @return The cacheAttributes value |
| */ |
| ICompositeCacheAttributes getCacheAttributes(); |
| |
| /** |
| * Sets the CacheAttributes of the region. |
| * <p> |
| * @param cattr |
| * The new cacheAttributes value |
| */ |
| void setCacheAttributes( ICompositeCacheAttributes cattr ); |
| |
| /** |
| * Gets the cache hub / region that uses the MemoryCache. |
| * <p> |
| * @return The cache value |
| */ |
| CompositeCache<K, V> getCompositeCache(); |
| } |