/*
* Copyright 2000-2004 The Apache Software Foundation.
*
* 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 org.apache.jetspeed.pipeline;
import org.apache.jetspeed.pipeline.valve.Valve;
import org.apache.jetspeed.pipeline.valve.ValveContext;
import org.apache.jetspeed.request.RequestContext;
import java.util.List;
/**
* Flexible implementation of a {@link Pipeline}. <p/> <br/><br/> Suggested
* order of valves:
* <ul>
* <li>ContainerValve</li>
* <li>CapabilityValve</li>
* <li>UserProfilerValve</li>
* <li>PageProfilerValve</li>
* <li>ActionValve</li>
* <li>LayoutValve</li>
* <li>ContentValve</li>
* <li>AggregateValve</li>
* <li>CleanupValve</li>
* </ul>
*
* @author <a href="mailto:jason@zenplex.com">Jason van Zyl</a>
* @author <a href="mailto:david@bluesunrise.com">David Sean Taylor</a>
* @version $Id: JetspeedPipeline.java 360200 2005-12-30 23:49:08Z taylor $
*/
public class JetspeedPipeline implements Pipeline
{
/**
* Name of this pipeline.
*/
protected String name;
/**
* The set of Valves associated with this Pipeline.
*/
protected Valve[] valves;
/**
* Constructor that provides the descriptor for building the pipeline
*/
public JetspeedPipeline(String name, List valveList) throws Exception
{
valves = (Valve[]) valveList.toArray(new Valve[valveList.size()]);
setName(name);
}
public void initialize() throws PipelineException
{
}
/**
* Set the name of this pipeline.
*
* @param name
* Name of this pipeline.
*/
public void setName(String name)
{
this.name = name;
}
/**
* Get the name of this pipeline.
*
* @return String Name of this pipeline.
*/
public String getName()
{
return name;
}
public synchronized void addValve(Valve valve)
{
// Add this Valve to the set associated with this Pipeline
Valve[] results = new Valve[valves.length + 1];
System.arraycopy(valves, 0, results, 0, valves.length);
results[valves.length] = valve;
valves = results;
}
public synchronized Valve[] getValves()
{
Valve[] results = new Valve[valves.length];
System.arraycopy(valves, 0, results, 0, valves.length);
return results;
}
public synchronized void removeValve(Valve valve)
{
// Locate this Valve in our list
int index = -1;
for (int i = 0; i < valves.length; i++)
{
if (valve == valves[i])
{
index = i;
break;
}
}
if (index < 0) { return; }
// Remove this valve from our list
Valve[] results = new Valve[valves.length - 1];
int n = 0;
for (int i = 0; i < valves.length; i++)
{
if (i == index)
{
continue;
}
results[n++] = valves[i];
}
valves = results;
}
public void invoke(RequestContext request) throws PipelineException
{
Invocation invocation;
// TODO use java 5 locks or compare and swap if possible
synchronized (this)
{
invocation = new Invocation(valves);
}
// Invoke the first Valve in this pipeline for this request
invocation.invokeNext(request);
}
private static final class Invocation implements ValveContext
{
private final Valve[] valves;
private int at = 0;
public Invocation(Valve[] valves)
{
this.valves = valves;
}
public void invokeNext(RequestContext request) throws PipelineException
{
if (at < valves.length)
{
Valve next = valves[at];
at++;
next.invoke(request, this);
}
}
}
}