src.openwfe.org.engine.impl.expool.CachedExpressionPool Maven / Gradle / Ivy
/*
* Copyright (c) 2001-2006, John Mettraux, OpenWFE.org
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* . Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* . Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* . Neither the name of the "OpenWFE" nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* $Id: CachedExpressionPool.java 2717 2006-06-01 15:26:06Z jmettraux $
*/
//
// CachedExpressionPool.java
//
// [email protected]
//
// generated with
// jtmpl 1.0.04 20.11.2001 John Mettraux ([email protected])
//
package openwfe.org.engine.impl.expool;
import openwfe.org.MapUtils;
import openwfe.org.engine.Definitions;
import openwfe.org.ApplicationContext;
import openwfe.org.ServiceException;
import openwfe.org.misc.Cache;
import openwfe.org.engine.expool.PoolException;
import openwfe.org.engine.history.History;
import openwfe.org.engine.workitem.InFlowWorkItem;
import openwfe.org.engine.dispatch.DispatchingException;
import openwfe.org.engine.expressions.FlowExpression;
import openwfe.org.engine.expressions.ApplyException;
import openwfe.org.engine.expressions.ReplyException;
import openwfe.org.engine.expressions.FlowExpressionId;
import openwfe.org.engine.expressions.CompositeFlowExpression;
import openwfe.org.engine.participants.Participant;
import openwfe.org.engine.participants.ParticipantMap;
/**
* This is the best available expression pool : it has a bounded capacity
* (unlike the InMemoryExpressionPool), and the performance price for this is
* small.
*
* CVS Info :
*
$Author: jmettraux $
*
$Date: 2006-06-01 17:26:06 +0200 (Thu, 01 Jun 2006) $
*
$Id: CachedExpressionPool.java 2717 2006-06-01 15:26:06Z jmettraux $
*
* @author [email protected]
*/
public class CachedExpressionPool
extends SimpleExpressionPool
{
private final static org.apache.log4j.Logger log = org.apache.log4j.Logger
.getLogger(CachedExpressionPool.class.getName());
//
// INNER CLASSES
//
// CONSTANTS
/**
* Use this parameter name to tell the expression pool how may
* expressions should be kept cached (ie not requiring a IO operation
* or whatever costly to fetch back from the ExpressionStore).
*/
public static String P_CACHE_SIZE = "cacheSize";
//
// FIELDS
private int cacheSize = -1;
private Cache cache = null;
//
// CONSTRUCTORS
/*
public CachedExpressionPool ()
{
super();
}
*/
public void init
(final String serviceName,
final ApplicationContext context,
final java.util.Map serviceParams)
throws
ServiceException
{
super.init(serviceName, context, serviceParams);
//
// prepare cache
this.cacheSize = MapUtils.getAsInt(serviceParams, P_CACHE_SIZE, 500);
this.cache = new Cache(this.cacheSize);
log.info("init() "+P_CACHE_SIZE+" : "+this.cacheSize);
}
//
// METHODS
/**
* Returns the cache used by the pool.
*/
public Cache getCache ()
{
return this.cache;
}
/**
* Usually called by WorkflowInstanceBuilders to add a freshly created
* expression to the pool.
*/
public void add (final FlowExpression fe)
throws PoolException
{
this.cache.put(fe.getId(), fe);
super.add(fe);
}
/**
* Stores the flow expression (as it may have changed).
*/
public void update (final FlowExpression fe)
throws PoolException
{
//log.debug("update() "+fe.getId());
this.cache.put(fe.getId(), fe);
//log.debug("update() put in cache");
super.update(fe);
//log.debug("update() super.update()...");
}
/**
* Retrieves an expression from the pool.
* If the expression cannot be retrieved from the pool, null will be
* returned.
*/
public /*synchronized*/ FlowExpression fetch (final FlowExpressionId fei)
{
if (log.isDebugEnabled())
log.debug("fetch() for "+fei);
if (fei == null) return null;
FlowExpression result = (FlowExpression)this.cache.get(fei);
if (result != null) return result;
if (log.isDebugEnabled())
log.debug("fetch() not cached : "+fei);
//log.debug
// ("fetch()\n"+
// openwfe.org.xml.XmlUtils.toString(this.cache.getStatus()));
//log.debug
// ("fetch() cache size : "+this.cache.size());
result = super.fetch(fei);
if (result != null) this.cache.put(result.getId(), result);
return result;
}
/**
* Removes a flow expression :
* - removes it from cache;
* - removes it from store (disk or db)
*
* This method is called by the replyToFather method, as the
* expression tree gets diminished.
*/
public /*synchronized*/ void removeExpression (final FlowExpression fe)
{
//log.debug("removeExpression() is fe null ? "+(fe == null));
this.cache.remove(fe.getId());
super.removeExpression(fe);
}
//
// STATUS
public org.jdom.Element getStatus ()
{
org.jdom.Element result = super.getStatus();
result.addContent(this.cache.getStatus());
return result;
}
}