/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.proxy.ejb;
import java.io.IOException;
import java.io.ObjectOutput;
import java.io.ObjectInput;
import java.lang.reflect.Method;
import java.util.List;
import java.util.HashMap;
import java.util.Map;
import org.jboss.ejb.ListCacheKey;
import org.jboss.invocation.Invocation;
/**
* An EJB CMP entity bean proxy class holds info about the List that the entity belongs to,
* is used for reading ahead.
*
* @author <a href="mailto:on@ibis.odessa.ua">Oleg Nitz</a>
* @version $Revision: 81030 $
*
* @todo: (marcf) methinks that this behavior should be moved to a REAL interceptor (i.e not as extends)
*/
public class ListEntityInterceptor
extends EntityInterceptor
{
/** Serial Version Identifier. @since 1.1 */
private static final long serialVersionUID = -5165912623246270565L;
protected static final Method GET_READ_AHEAD_VALUES;
// Attributes ----------------------------------------------------
/**
* A List that this entity belongs to (used for reading ahead).
*/
private List list;
/**
* A hash map of read ahead values, maps Methods to values.
*/
private transient HashMap readAheadValues;
// Static --------------------------------------------------------
static
{
try
{
final Class[] empty = {};
GET_READ_AHEAD_VALUES = ReadAheadBuffer.class.getMethod("getReadAheadValues", empty);
}
catch (Exception e)
{
e.printStackTrace();
throw new ExceptionInInitializerError(e);
}
}
// Constructors --------------------------------------------------
/**
* No-argument constructor for externalization.
*/
public ListEntityInterceptor()
{
}
/**
* Construct a <tt>ListEntityProxy</tt>.
*
* @param name The JNDI name of the container that we proxy for.
* @param container The remote interface of the invoker for which
* this is a proxy for.
* @param id The primary key of the entity.
* @param optimize True if the proxy will attempt to optimize
* VM-local calls.
* @param list A List that this entity belongs to (used for reading ahead).
* @param listId The list id.
* @param index The index of this entity in the list.
*
* @throws NullPointerException Id may not be null.
*/
public ListEntityInterceptor(List list)
{
this.list = list;
}
// Public --------------------------------------------------------
public Map getReadAheadValues()
{
if (readAheadValues == null)
{
readAheadValues = new HashMap();
}
return readAheadValues;
}
/**
* InvocationHandler implementation.
*
* @param proxy The proxy object.
* @param m The method being invoked.
* @param args The arguments for the method.
*
* @throws Throwable Any exception or error thrown while processing.
*/
public Object invoke(Invocation invocation)
throws Throwable
{
Object result;
ReadAheadResult raResult;
Object[] aheadResult;
int from;
int to;
ReadAheadBuffer buf;
Method m = invocation.getMethod();
if (m.equals(GET_READ_AHEAD_VALUES))
{
return getReadAheadValues();
}
// have we read ahead the result?
if (readAheadValues != null)
{
result = readAheadValues.get(m);
if (readAheadValues.containsKey(m))
{
return readAheadValues.remove(m);
}
}
result = super.invoke(invocation);
// marcf : I think all these will map nicely to the in/out of real interceptor, i.e. do not "extend"
if (result instanceof ReadAheadResult)
{
raResult = (ReadAheadResult) result;
aheadResult = raResult.getAheadResult();
ListCacheKey key = (ListCacheKey) invocation.getInvocationContext().getCacheId();
from = key.getIndex() + 1;
to = Math.min(from + aheadResult.length, list.size());
for (int i = from; i < to; i++)
{
buf = (ReadAheadBuffer) list.get(i);
buf.getReadAheadValues().put(m, aheadResult[i - from]);
}
return raResult.getMainResult();
}
else
{
return result;
}
}
// Package protected ---------------------------------------------
// Protected -----------------------------------------------------
/**
* Externalization support.
*
* @param out
*
* @throws IOException
*/
public void writeExternal(final ObjectOutput out)
throws IOException
{
super.writeExternal(out);
out.writeObject(list);
}
/**
* Externalization support.
*
* @param in
*
* @throws IOException
* @throws ClassNotFoundException
*/
public void readExternal(final ObjectInput in)
throws IOException, ClassNotFoundException
{
super.readExternal(in);
list = (List) in.readObject();
}
// Private -------------------------------------------------------
// Inner classes -------------------------------------------------
}