package org.apache.stratum.jcs.auxiliary.remote;
import java.io.IOException;
import java.io.Serializable;
import java.rmi.UnmarshalException;
import org.apache.stratum.jcs.auxiliary.remote.behavior.IRemoteCacheService;
import org.apache.stratum.jcs.engine.behavior.IElementAttributes;
import org.apache.stratum.jcs.engine.CacheAdaptor;
import org.apache.stratum.jcs.engine.CacheElement;
import org.apache.stratum.jcs.engine.CacheEventQueue;
import org.apache.stratum.jcs.engine.behavior.ICache;
import org.apache.stratum.jcs.engine.behavior.ICacheElement;
import org.apache.stratum.jcs.engine.behavior.ICacheEventQueue;
import org.apache.stratum.jcs.engine.behavior.ICacheType;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* 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.
*
* @author asmuts
* @created January 15, 2002
*/
public class RemoteCacheNoWait implements ICache
{
private final static Log log =
LogFactory.getLog( RemoteCacheNoWait.class );
private final RemoteCache cache;
private ICacheEventQueue q;
/**
* Constructs with the given remote cache, and fires up an event queue for
* aysnchronous processing.
*
* @param cache
*/
public RemoteCacheNoWait( RemoteCache cache )
{
this.cache = cache;
this.q = new CacheEventQueue( new CacheAdaptor( cache ), RemoteCacheInfo.listenerId, cache.getCacheName() );
if ( cache.getStatus() == cache.STATUS_ERROR )
{
q.destroy();
}
}
/** Adds a put request to the remote cache. */
public void put( Serializable key, Serializable value )
throws IOException
{
put( key, value, null );
}
/** Description of the Method */
public void put( Serializable key, Serializable value, IElementAttributes attr )
throws IOException
{
try
{
CacheElement ce = new CacheElement( cache.getCacheName(), key, value );
ce.setElementAttributes( attr );
update( ce );
}
catch ( IOException ex )
{
log.error( ex );
q.destroy();
throw ex;
}
}
/** Description of the Method */
public void update( ICacheElement ce )
throws IOException
{
try
{
q.addPutEvent( ce );
}
catch ( IOException ex )
{
log.error( ex );
q.destroy();
throw ex;
}
}
/** Synchronously reads from the remote cache. */
public Serializable get( Serializable key )
throws IOException
{
return get( key, true );
}
/** Description of the Method */
public Serializable get( Serializable key, boolean container )
throws IOException
{
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.debug( "Failed in retrying the get for the second time." );
q.destroy();
}
}
catch ( IOException ex )
{
q.destroy();
throw ex;
}
return null;
}
/** Adds a remove request to the remote cache. */
public boolean remove( Serializable key )
throws IOException
{
try
{
q.addRemoveEvent( key );
}
catch ( IOException ex )
{
log.error( ex );
q.destroy();
throw ex;
}
return false;
}
/** Adds a removeAll request to the remote cache. */
public void removeAll()
throws IOException
{
try
{
q.addRemoveAllEvent();
}
catch ( IOException ex )
{
log.error( ex );
q.destroy();
throw ex;
}
}
/** Adds a dispose request to the remote cache. */
public void dispose()
{
try
{
q.addDisposeEvent();
}
catch ( IOException ex )
{
log.error( ex );
q.destroy();
}
}
/**
* No remote invokation.
*
* @return The stats value
*/
public String getStats()
{
return cache.getStats();
}
/**
* No remote invokation.
*
* @return The size value
*/
public int getSize()
{
return cache.getSize();
}
/**
* No remote invokation.
*
* @return The cacheType value
*/
public int getCacheType()
{
return ICacheType.REMOTE_CACHE;
//return cache.getCacheType();
}
/**
* Returns the asyn cache status. An error status indicates either the
* remote connection is not available, or the asyn queue has been
* unexpectedly destroyed. No remote invokation.
*
* @return The status value
*/
public int getStatus()
{
return q.isAlive() ? cache.getStatus() : cache.STATUS_ERROR;
}
/**
* Gets the cacheName attribute of the RemoteCacheNoWait object
*
* @return The cacheName value
*/
public String getCacheName()
{
return cache.getCacheName();
}
/**
* Replaces the remote cache service handle with the given handle and reset
* the event queue by starting up a new instance.
*/
public void fixCache( IRemoteCacheService remote )
{
cache.fixCache( remote );
resetEventQ();
return;
}
/**
* Resets the event q by first destroying the existing one and starting up
* new one.
*/
public void resetEventQ()
{
if ( q.isAlive() )
{
q.destroy();
}
this.q = new CacheEventQueue( new CacheAdaptor( cache ), RemoteCacheInfo.listenerId, cache.getCacheName() );
}
/** Description of the Method */
public String toString()
{
return "RemoteCacheNoWait: " + cache.toString();
}
}