src/java/org/apache/jcs/auxiliary/lateral/LateralCacheNoWait.java - commons-jcs - Git at Google

 package org.apache.jcs.auxiliary.lateral;

 /*
  * 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 java.io.IOException;
 import java.io.Serializable;
 import java.rmi.UnmarshalException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.jcs.auxiliary.AbstractAuxiliaryCache;
 import org.apache.jcs.auxiliary.AuxiliaryCacheAttributes;
 import org.apache.jcs.auxiliary.lateral.behavior.ILateralCacheService;
 import org.apache.jcs.engine.CacheAdaptor;
 import org.apache.jcs.engine.CacheConstants;
 import org.apache.jcs.engine.CacheEventQueueFactory;
 import org.apache.jcs.engine.behavior.ICacheElement;
 import org.apache.jcs.engine.behavior.ICacheEventQueue;
 import org.apache.jcs.engine.stats.StatElement;
 import org.apache.jcs.engine.stats.Stats;
 import org.apache.jcs.engine.stats.behavior.IStatElement;
 import org.apache.jcs.engine.stats.behavior.IStats;

 /**
  * Used to queue up update requests to the underlying cache. These requests will be processed in
  * their order of arrival via the cache event queue processor.
  */
 public class LateralCacheNoWait
     extends AbstractAuxiliaryCache
 {
     /** Don't change */
     private static final long serialVersionUID = -7251187566116178475L;

     /** The logger. */
     private final static Log log = LogFactory.getLog( LateralCacheNoWait.class );

     /** The cache */
     private final LateralCache cache;

     /** The event queue */
     private ICacheEventQueue eventQueue;

     /** times get called */
     private int getCount = 0;

     /** times remove called */
     private int removeCount = 0;

     /** times put called */
     private int putCount = 0;

     /**
      * Constructs with the given lateral cache, and fires up an event queue for aysnchronous
      * processing.
      * <p>
      * @param cache
      */
     public LateralCacheNoWait( LateralCache cache )
     {
         this.cache = cache;

         if ( log.isDebugEnabled() )
         {
             log.debug( "Constructing LateralCacheNoWait, LateralCache = [" + cache + "]" );
         }

         CacheEventQueueFactory fact = new CacheEventQueueFactory();
         this.eventQueue = fact.createCacheEventQueue( new CacheAdaptor( cache ), LateralCacheInfo.listenerId, cache
             .getCacheName(), cache.getAuxiliaryCacheAttributes().getEventQueuePoolName(), cache
             .getAuxiliaryCacheAttributes().getEventQueueType() );

         // need each no wait to handle each of its real updates and removes,
         // since there may
         // be more than one per cache? alternative is to have the cache
         // perform updates using a different method that spcifies the listener
         // this.q = new CacheEventQueue(new CacheAdaptor(this),
         // LateralCacheInfo.listenerId, cache.getCacheName());
         if ( cache.getStatus() == CacheConstants.STATUS_ERROR )
         {
             eventQueue.destroy();
         }
     }

     /**
      * @param ce
      * @throws IOException
      */
     public void update( ICacheElement ce )
         throws IOException
     {
         putCount++;
         try
         {
             eventQueue.addPutEvent( ce );
         }
         catch ( IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
     }

     /**
      * Synchronously reads from the lateral cache.
      * <p>
      * @param key
      * @return ICacheElement if found, else null
      */
     public ICacheElement get( Serializable key )
     {
         getCount++;
         if ( this.getStatus() != CacheConstants.STATUS_ERROR )
         {
             try
             {
                 return cache.get( key );
             }
             catch ( UnmarshalException ue )
             {
                 log.debug( "Retrying the get owing to UnmarshalException..." );
                 try
                 {
                     return cache.get( key );
                 }
                 catch ( IOException ex )
                 {
                     log.error( "Failed in retrying the get for the second time." );
                     eventQueue.destroy();
                 }
             }
             catch ( IOException ex )
             {
                 eventQueue.destroy();
             }
         }
         return null;
     }

     /**
      * Gets multiple items from the cache based on the given set of keys.
      * <p>
      * @param keys
      * @return a map of Serializable key to ICacheElement element, or an empty map if there is no
      *         data in cache for any of these keys
      */
     public Map getMultiple( Set keys )
     {
         Map elements = new HashMap();

         if ( keys != null && !keys.isEmpty() )
         {
             Iterator iterator = keys.iterator();

             while ( iterator.hasNext() )
             {
                 Serializable key = (Serializable) iterator.next();

                 ICacheElement element = get( key );

                 if ( element != null )
                 {
                     elements.put( key, element );
                 }
             }
         }

         return elements;
     }

     /**
      * Synchronously reads from the lateral cache.
      * <p>
      * @param pattern
      * @return ICacheElement if found, else empty
      */
     public Map getMatching( String pattern )
     {
         getCount++;
         if ( this.getStatus() != CacheConstants.STATUS_ERROR )
         {
             try
             {
                 return cache.getMatching( pattern );
             }
             catch ( UnmarshalException ue )
             {
                 log.debug( "Retrying the get owing to UnmarshalException." );
                 try
                 {
                     return cache.getMatching( pattern );
                 }
                 catch ( IOException ex )
                 {
                     log.error( "Failed in retrying the get for the second time." );
                     eventQueue.destroy();
                 }
             }
             catch ( IOException ex )
             {
                 eventQueue.destroy();
             }
         }
         return Collections.EMPTY_MAP;
     }

     /**
      * @param groupName
      * @return Set
      */
     public Set getGroupKeys( String groupName )
     {
         return cache.getGroupKeys( groupName );
     }

     /**
      * Adds a remove request to the lateral cache.
      * <p>
      * @param key
      * @return always false
      */
     public boolean remove( Serializable key )
     {
         removeCount++;
         try
         {
             eventQueue.addRemoveEvent( key );
         }
         catch ( IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
         return false;
     }

     /** Adds a removeAll request to the lateral cache. */
     public void removeAll()
     {
         try
         {
             eventQueue.addRemoveAllEvent();
         }
         catch ( IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
     }

     /** Adds a dispose request to the lateral cache. */
     public void dispose()
     {
         try
         {
             eventQueue.addDisposeEvent();
         }
         catch ( IOException ex )
         {
             log.error( ex );
             eventQueue.destroy();
         }
     }

     /**
      * No lateral invocation.
      * <p>
      * @return The size value
      */
     public int getSize()
     {
         return cache.getSize();
     }

     /**
      * No lateral invocation.
      * <p>
      * @return The cacheType value
      */
     public int getCacheType()
     {
         return cache.getCacheType();
     }

     /**
      * Returns the asyn cache status. An error status indicates either the lateral connection is not
      * available, or the asyn queue has been unexpectedly destroyed. No lateral invokation.
      * <p>
      * @return The status value
      */
     public int getStatus()
     {
         return eventQueue.isWorking() ? cache.getStatus() : CacheConstants.STATUS_ERROR;
     }

     /**
      * Gets the cacheName attribute of the LateralCacheNoWait object
      * <p>
      * @return The cacheName value
      */
     public String getCacheName()
     {
         return cache.getCacheName();
     }

     /**
      * Replaces the lateral cache service handle with the given handle and reset the queue by
      * starting up a new instance.
      * <p>
      * @param lateral
      */
     public void fixCache( ILateralCacheService lateral )
     {
         cache.fixCache( lateral );
         resetEventQ();
         return;
     }

     /**
      * Resets the event q by first destroying the existing one and starting up new one.
      */
     public void resetEventQ()
     {
         if ( eventQueue.isWorking() )
         {
             eventQueue.destroy();
         }
         CacheEventQueueFactory fact = new CacheEventQueueFactory();
         this.eventQueue = fact.createCacheEventQueue( new CacheAdaptor( cache ), LateralCacheInfo.listenerId, cache
             .getCacheName(), cache.getAuxiliaryCacheAttributes().getEventQueuePoolName(), cache
             .getAuxiliaryCacheAttributes().getEventQueueType() );
     }

     /**
      * @return Returns the AuxiliaryCacheAttributes.
      */
     public AuxiliaryCacheAttributes getAuxiliaryCacheAttributes()
     {
         return cache.getAuxiliaryCacheAttributes();
     }

     /**
      * getStats
      * @return String
      */
     public String getStats()
     {
         return getStatistics().toString();
     }

     /**
      * this won't be called since we don't do ICache logging here.
      * <p>
      * @return String
      */
     public String getEventLoggingExtraInfo()
     {
         return "Lateral Cache No Wait";
     }

     /**
      * @return statistics about this communication
      */
     public IStats getStatistics()
     {
         IStats stats = new Stats();
         stats.setTypeName( "Lateral Cache No Wait" );

         ArrayList elems = new ArrayList();

         // IStatElement se = null;
         // no data gathered here

         // get the stats from the event queue too
         // get as array, convert to list, add list to our outer list
         IStats eqStats = this.eventQueue.getStatistics();

         IStatElement[] eqSEs = eqStats.getStatElements();
         List eqL = Arrays.asList( eqSEs );
         elems.addAll( eqL );

         IStatElement se = null;

         se = new StatElement();
         se.setName( "Get Count" );
         se.setData( "" + this.getCount );
         elems.add( se );

         se = new StatElement();
         se.setName( "Remove Count" );
         se.setData( "" + this.removeCount );
         elems.add( se );

         se = new StatElement();
         se.setName( "Put Count" );
         se.setData( "" + this.putCount );
         elems.add( se );

         // get an array and put them in the Stats object
         IStatElement[] ses = (IStatElement[]) elems.toArray( new StatElement[elems.size()] );
         stats.setStatElements( ses );

         return stats;
     }

     /**
      * @return debugging info.
      */
     public String toString()
     {
         StringBuffer buf = new StringBuffer();
         buf.append( " LateralCacheNoWait " );
         buf.append( " Status = " + this.getStatus() );
         buf.append( " cache = [" + cache.toString() + "]" );
         return buf.toString();
     }
 }
	package org.apache.jcs.auxiliary.lateral;

	/*
	* 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 java.io.IOException;
	import java.io.Serializable;
	import java.rmi.UnmarshalException;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.jcs.auxiliary.AbstractAuxiliaryCache;
	import org.apache.jcs.auxiliary.AuxiliaryCacheAttributes;
	import org.apache.jcs.auxiliary.lateral.behavior.ILateralCacheService;
	import org.apache.jcs.engine.CacheAdaptor;
	import org.apache.jcs.engine.CacheConstants;
	import org.apache.jcs.engine.CacheEventQueueFactory;
	import org.apache.jcs.engine.behavior.ICacheElement;
	import org.apache.jcs.engine.behavior.ICacheEventQueue;
	import org.apache.jcs.engine.stats.StatElement;
	import org.apache.jcs.engine.stats.Stats;
	import org.apache.jcs.engine.stats.behavior.IStatElement;
	import org.apache.jcs.engine.stats.behavior.IStats;

	/**
	* Used to queue up update requests to the underlying cache. These requests will be processed in
	* their order of arrival via the cache event queue processor.
	*/
	public class LateralCacheNoWait
	extends AbstractAuxiliaryCache
	{
	/** Don't change */
	private static final long serialVersionUID = -7251187566116178475L;

	/** The logger. */
	private final static Log log = LogFactory.getLog( LateralCacheNoWait.class );

	/** The cache */
	private final LateralCache cache;

	/** The event queue */
	private ICacheEventQueue eventQueue;

	/** times get called */
	private int getCount = 0;

	/** times remove called */
	private int removeCount = 0;

	/** times put called */
	private int putCount = 0;

	/**
	* Constructs with the given lateral cache, and fires up an event queue for aysnchronous
	* processing.
	* <p>
	* @param cache
	*/
	public LateralCacheNoWait( LateralCache cache )
	{
	this.cache = cache;

	if ( log.isDebugEnabled() )
	{
	log.debug( "Constructing LateralCacheNoWait, LateralCache = [" + cache + "]" );
	}

	CacheEventQueueFactory fact = new CacheEventQueueFactory();
	this.eventQueue = fact.createCacheEventQueue( new CacheAdaptor( cache ), LateralCacheInfo.listenerId, cache
	.getCacheName(), cache.getAuxiliaryCacheAttributes().getEventQueuePoolName(), cache
	.getAuxiliaryCacheAttributes().getEventQueueType() );

	// need each no wait to handle each of its real updates and removes,
	// since there may
	// be more than one per cache? alternative is to have the cache
	// perform updates using a different method that spcifies the listener
	// this.q = new CacheEventQueue(new CacheAdaptor(this),
	// LateralCacheInfo.listenerId, cache.getCacheName());
	if ( cache.getStatus() == CacheConstants.STATUS_ERROR )
	{
	eventQueue.destroy();
	}
	}

	/**
	* @param ce
	* @throws IOException
	*/
	public void update( ICacheElement ce )
	throws IOException
	{
	putCount++;
	try
	{
	eventQueue.addPutEvent( ce );
	}
	catch ( IOException ex )
	{
	log.error( ex );
	eventQueue.destroy();
	}
	}

	/**
	* Synchronously reads from the lateral cache.
	* <p>
	* @param key
	* @return ICacheElement if found, else null
	*/
	public ICacheElement get( Serializable key )
	{
	getCount++;
	if ( this.getStatus() != CacheConstants.STATUS_ERROR )
	{
	try
	{
	return cache.get( key );
	}
	catch ( UnmarshalException ue )
	{
	log.debug( "Retrying the get owing to UnmarshalException..." );
	try
	{
	return cache.get( key );
	}
	catch ( IOException ex )
	{
	log.error( "Failed in retrying the get for the second time." );
	eventQueue.destroy();
	}
	}
	catch ( IOException ex )
	{
	eventQueue.destroy();
	}
	}
	return null;
	}

	/**
	* Gets multiple items from the cache based on the given set of keys.
	* <p>
	* @param keys
	* @return a map of Serializable key to ICacheElement element, or an empty map if there is no
	* data in cache for any of these keys
	*/
	public Map getMultiple( Set keys )
	{
	Map elements = new HashMap();

	if ( keys != null && !keys.isEmpty() )
	{
	Iterator iterator = keys.iterator();

	while ( iterator.hasNext() )
	{
	Serializable key = (Serializable) iterator.next();

	ICacheElement element = get( key );

	if ( element != null )
	{
	elements.put( key, element );
	}
	}
	}

	return elements;
	}

	/**
	* Synchronously reads from the lateral cache.
	* <p>
	* @param pattern
	* @return ICacheElement if found, else empty
	*/
	public Map getMatching( String pattern )
	{
	getCount++;
	if ( this.getStatus() != CacheConstants.STATUS_ERROR )
	{
	try
	{
	return cache.getMatching( pattern );
	}
	catch ( UnmarshalException ue )
	{
	log.debug( "Retrying the get owing to UnmarshalException." );
	try
	{
	return cache.getMatching( pattern );
	}
	catch ( IOException ex )
	{
	log.error( "Failed in retrying the get for the second time." );
	eventQueue.destroy();
	}
	}
	catch ( IOException ex )
	{
	eventQueue.destroy();
	}
	}
	return Collections.EMPTY_MAP;
	}

	/**
	* @param groupName
	* @return Set
	*/
	public Set getGroupKeys( String groupName )
	{
	return cache.getGroupKeys( groupName );
	}

	/**
	* Adds a remove request to the lateral cache.
	* <p>
	* @param key
	* @return always false
	*/
	public boolean remove( Serializable key )
	{
	removeCount++;
	try
	{
	eventQueue.addRemoveEvent( key );
	}
	catch ( IOException ex )
	{
	log.error( ex );
	eventQueue.destroy();
	}
	return false;
	}

	/** Adds a removeAll request to the lateral cache. */
	public void removeAll()
	{
	try
	{
	eventQueue.addRemoveAllEvent();
	}
	catch ( IOException ex )
	{
	log.error( ex );
	eventQueue.destroy();
	}
	}

	/** Adds a dispose request to the lateral cache. */
	public void dispose()
	{
	try
	{
	eventQueue.addDisposeEvent();
	}
	catch ( IOException ex )
	{
	log.error( ex );
	eventQueue.destroy();
	}
	}

	/**
	* No lateral invocation.
	* <p>
	* @return The size value
	*/
	public int getSize()
	{
	return cache.getSize();
	}

	/**
	* No lateral invocation.
	* <p>
	* @return The cacheType value
	*/
	public int getCacheType()
	{
	return cache.getCacheType();
	}

	/**
	* Returns the asyn cache status. An error status indicates either the lateral connection is not
	* available, or the asyn queue has been unexpectedly destroyed. No lateral invokation.
	* <p>
	* @return The status value
	*/
	public int getStatus()
	{
	return eventQueue.isWorking() ? cache.getStatus() : CacheConstants.STATUS_ERROR;
	}

	/**
	* Gets the cacheName attribute of the LateralCacheNoWait object
	* <p>
	* @return The cacheName value
	*/
	public String getCacheName()
	{
	return cache.getCacheName();
	}

	/**
	* Replaces the lateral cache service handle with the given handle and reset the queue by
	* starting up a new instance.
	* <p>
	* @param lateral
	*/
	public void fixCache( ILateralCacheService lateral )
	{
	cache.fixCache( lateral );
	resetEventQ();
	return;
	}

	/**
	* Resets the event q by first destroying the existing one and starting up new one.
	*/
	public void resetEventQ()
	{
	if ( eventQueue.isWorking() )
	{
	eventQueue.destroy();
	}
	CacheEventQueueFactory fact = new CacheEventQueueFactory();
	this.eventQueue = fact.createCacheEventQueue( new CacheAdaptor( cache ), LateralCacheInfo.listenerId, cache
	.getCacheName(), cache.getAuxiliaryCacheAttributes().getEventQueuePoolName(), cache
	.getAuxiliaryCacheAttributes().getEventQueueType() );
	}

	/**
	* @return Returns the AuxiliaryCacheAttributes.
	*/
	public AuxiliaryCacheAttributes getAuxiliaryCacheAttributes()
	{
	return cache.getAuxiliaryCacheAttributes();
	}

	/**
	* getStats
	* @return String
	*/
	public String getStats()
	{
	return getStatistics().toString();
	}

	/**
	* this won't be called since we don't do ICache logging here.
	* <p>
	* @return String
	*/
	public String getEventLoggingExtraInfo()
	{
	return "Lateral Cache No Wait";
	}

	/**
	* @return statistics about this communication
	*/
	public IStats getStatistics()
	{
	IStats stats = new Stats();
	stats.setTypeName( "Lateral Cache No Wait" );

	ArrayList elems = new ArrayList();

	// IStatElement se = null;
	// no data gathered here

	// get the stats from the event queue too
	// get as array, convert to list, add list to our outer list
	IStats eqStats = this.eventQueue.getStatistics();

	IStatElement[] eqSEs = eqStats.getStatElements();
	List eqL = Arrays.asList( eqSEs );
	elems.addAll( eqL );

	IStatElement se = null;

	se = new StatElement();
	se.setName( "Get Count" );
	se.setData( "" + this.getCount );
	elems.add( se );

	se = new StatElement();
	se.setName( "Remove Count" );
	se.setData( "" + this.removeCount );
	elems.add( se );

	se = new StatElement();
	se.setName( "Put Count" );
	se.setData( "" + this.putCount );
	elems.add( se );

	// get an array and put them in the Stats object
	IStatElement[] ses = (IStatElement[]) elems.toArray( new StatElement[elems.size()] );
	stats.setStatElements( ses );

	return stats;
	}

	/**
	* @return debugging info.
	*/
	public String toString()
	{
	StringBuffer buf = new StringBuffer();
	buf.append( " LateralCacheNoWait " );
	buf.append( " Status = " + this.getStatus() );
	buf.append( " cache = [" + cache.toString() + "]" );
	return buf.toString();
	}
	}