net.sf.ehcache.hibernate.EhCache Maven / Gradle / Ivy
/**
* Copyright 2003-2009 Terracotta, Inc.
*
* Licensed 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.
*/
package net.sf.ehcache.hibernate;
import net.sf.ehcache.Element;
import org.hibernate.cache.Cache;
import org.hibernate.cache.CacheException;
import org.hibernate.cache.Timestamper;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* EHCache plugin for Hibernate.
*
* EHCache uses a {@link net.sf.ehcache.store.MemoryStore} and a
* {@link net.sf.ehcache.store.DiskStore}.
*
* The {@link net.sf.ehcache.store.DiskStore} requires that both keys and values be {@link java.io.Serializable}.
* However the MemoryStore does not and in ehcache-1.2 nonSerializable Objects are permitted. They are discarded
* if an attempt it made to overflow them to Disk or to replicate them to remote cache peers.
*
*
* @author Greg Luck
* @author Emmanuel Bernard
* @version $Id: EhCache.java 1406 2009-11-06 11:43:02Z gluck $
*/
public final class EhCache implements Cache {
private static final Logger LOG = LoggerFactory.getLogger(EhCache.class.getName());
private static final int SIXTY_THOUSAND_MS = 60000;
private final net.sf.ehcache.Ehcache cache;
/**
* Creates a new Hibernate pluggable cache by name.
*
* ehcache will look in ehcache.xml to load the configuration for the cache.
* If the cache is not there, it will use the defaultCache settings. It is
* always a good idea to specifically configure each cache.
*
* @param cache The backing ehcache cache.
*/
public EhCache(net.sf.ehcache.Ehcache cache) {
this.cache = cache;
}
/**
* Gets a value of an element which matches the given key.
*
* @param key the key of the element to return.
* @return The value placed into the cache with an earlier put, or null if not found or expired
* @throws org.hibernate.cache.CacheException
*
*/
public final Object get(Object key) throws CacheException {
try {
LOG.debug("key: {}", key);
if (key == null) {
return null;
} else {
Element element = cache.get(key);
if (element == null) {
LOG.debug("Element for key {} is null", key);
return null;
} else {
return element.getObjectValue();
}
}
} catch (net.sf.ehcache.CacheException e) {
throw new CacheException(e);
}
}
/**
* Gets an object from the cache.
*
* @param key an Object value
* @return the Object, or null if not found
* @throws CacheException
*/
public final Object read(Object key) throws CacheException {
return get(key);
}
/**
* Updates an object in the cache, or if it does not exist, inserts it.
*
* @param key an Object key
* @param value an Object value
* @throws CacheException if the {@link net.sf.ehcache.CacheManager} is shutdown or another {@link Exception} occurs.
*/
public final void update(Object key, Object value) throws CacheException {
put(key, value);
}
/**
* Puts an object into the cache.
*
* @param key an Object key
* @param value an Object value
* @throws CacheException if the {@link net.sf.ehcache.CacheManager} is shutdown or another {@link Exception} occurs.
*/
public final void put(Object key, Object value) throws CacheException {
LOG.debug("key: {} value: {}", key, value);
try {
Element element = new Element(key, value);
cache.put(element);
} catch (IllegalArgumentException e) {
throw new CacheException(e);
} catch (IllegalStateException e) {
throw new CacheException(e);
}
}
/**
* Removes the element which matches the key.
*
* If no element matches, nothing is removed and no Exception is thrown.
*
* @param key the key of the element to remove
* @throws CacheException
*/
public final void remove(Object key) throws CacheException {
try {
cache.remove(key);
} catch (ClassCastException e) {
throw new CacheException(e);
} catch (IllegalStateException e) {
throw new CacheException(e);
}
}
/**
* Remove all elements in the cache, but leave the cache in a useable state.
*
* @throws CacheException
*/
public final void clear() throws CacheException {
try {
cache.removeAll();
} catch (IllegalStateException e) {
throw new CacheException(e);
}
}
/**
* Remove the cache and make it unuseable.
*
*
* @throws CacheException
*/
public final void destroy() throws CacheException {
try {
cache.getCacheManager().removeCache(cache.getName());
} catch (IllegalStateException e) {
//When Spring and Hibernate are both involved this will happen in normal shutdown operation.
//Do not throw an exception, simply log this one.
LOG.debug("This can happen if multiple frameworks both try to shutdown ehcache", e);
} catch (net.sf.ehcache.CacheException e) {
throw new CacheException(e);
}
}
/**
* Calls to this method should perform their own synchronization.
* It is provided for distributed caches.
*
* ehcache does not support distributed locking and therefore this method does nothing.
*/
public final void lock(Object key) throws CacheException {
//noop
}
/**
* Calls to this method should perform their own synchronization.
*
* ehcache does not support distributed locking and therefore this method does nothing.
*/
public final void unlock(Object key) throws CacheException {
//noop
}
/**
* Gets the next timestamp;
*/
public final long nextTimestamp() {
return Timestamper.next();
}
/**
* Returns the lock timeout for this cache, which is 60s
*/
public final int getTimeout() {
// 60 second lock timeout
return Timestamper.ONE_MS * SIXTY_THOUSAND_MS;
}
/**
* @return the region name of the cache, which is the cache name in ehcache
*/
public final String getRegionName() {
return cache.getName();
}
/**
* Warning: This method can be very expensive to run. Allow approximately 1 second
* per 1MB of entries. Running this method could create liveness problems
* because the object lock is held for a long period
*
*
* @return the approximate size of memory ehcache is using for the MemoryStore for this cache
*/
public final long getSizeInMemory() {
try {
return cache.calculateInMemorySize();
} catch (Throwable t) {
return -1;
}
}
/**
* @return the number of elements in ehcache's MemoryStore
*/
public final long getElementCountInMemory() {
try {
return cache.getMemoryStoreSize();
} catch (net.sf.ehcache.CacheException ce) {
throw new CacheException(ce);
}
}
/**
* @return the number of elements in ehcache's DiskStore. 0 is there is no DiskStore
*/
public final long getElementCountOnDisk() {
return cache.getDiskStoreSize();
}
/**
* @return a copy of the cache Elements as a Map
*/
public final Map toMap() {
try {
Map result = new HashMap();
Iterator iter = cache.getKeys().iterator();
while (iter.hasNext()) {
Object key = iter.next();
result.put(key, cache.get(key).getObjectValue());
}
return result;
} catch (Exception e) {
throw new CacheException(e);
}
}
/**
* @return the region name, which is the cache name in ehcache
*/
public final String toString() {
return "EHCache(" + getRegionName() + ')';
}
/**
* Package protected method used for testing
*/
final net.sf.ehcache.Ehcache getBackingCache() {
return cache;
}
}