// ========================================================================
// Copyright (c) 2009-2009 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
package org.eclipse.jetty.continuation;
import java.util.ArrayList;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.ServletResponseWrapper;
import org.eclipse.jetty.continuation.ContinuationFilter.FilteredContinuation;
/* ------------------------------------------------------------ */
/**
* A blocking implementation of Continuation.
* This implementation of Continuation is used by the {@link ContinuationFilter}
* when there are is no native or asynchronous continuation type available.
*/
class FauxContinuation implements FilteredContinuation
{
// common exception used for all continuations.
// Turn on debug in ContinuationFilter to see real stack trace.
private final static ContinuationThrowable __exception = new ContinuationThrowable();
private static final int __HANDLING=1; // Request dispatched to filter/servlet
private static final int __SUSPENDING=2; // Suspend called, but not yet returned to container
private static final int __RESUMING=3; // resumed while suspending
private static final int __COMPLETING=4; // resumed while suspending or suspended
private static final int __SUSPENDED=5; // Suspended and parked
private static final int __UNSUSPENDING=6;
private static final int __COMPLETE=7;
private final ServletRequest _request;
private ServletResponse _response;
private int _state=__HANDLING;
private boolean _initial=true;
private boolean _resumed=false;
private boolean _timeout=false;
private boolean _responseWrapped=false;
private long _timeoutMs=30000; // TODO configure
private ArrayList<ContinuationListener> _listeners;
FauxContinuation(final ServletRequest request)
{
_request=request;
}
/* ------------------------------------------------------------ */
public void onComplete()
{
if (_listeners!=null)
for (ContinuationListener l:_listeners)
l.onComplete(this);
}
/* ------------------------------------------------------------ */
public void onTimeout()
{
if (_listeners!=null)
for (ContinuationListener l:_listeners)
l.onTimeout(this);
}
/* ------------------------------------------------------------ */
/**
* @see org.eclipse.jetty.continuation.Continuation#isResponseWrapped()
*/
public boolean isResponseWrapped()
{
return _responseWrapped;
}
/* ------------------------------------------------------------ */
public boolean isInitial()
{
synchronized(this)
{
return _initial;
}
}
/* ------------------------------------------------------------ */
public boolean isResumed()
{
synchronized(this)
{
return _resumed;
}
}
/* ------------------------------------------------------------ */
public boolean isSuspended()
{
synchronized(this)
{
switch(_state)
{
case __HANDLING:
return false;
case __SUSPENDING:
case __RESUMING:
case __COMPLETING:
case __SUSPENDED:
return true;
case __UNSUSPENDING:
default:
return false;
}
}
}
/* ------------------------------------------------------------ */
public boolean isExpired()
{
synchronized(this)
{
return _timeout;
}
}
/* ------------------------------------------------------------ */
public void setTimeout(long timeoutMs)
{
_timeoutMs = timeoutMs;
}
/* ------------------------------------------------------------ */
public void suspend(ServletResponse response)
{
_response=response;
_responseWrapped=response instanceof ServletResponseWrapper;
suspend();
}
/* ------------------------------------------------------------ */
public void suspend()
{
synchronized (this)
{
switch(_state)
{
case __HANDLING:
_timeout=false;
_resumed=false;
_state=__SUSPENDING;
return;
case __SUSPENDING:
case __RESUMING:
return;
case __COMPLETING:
case __SUSPENDED:
case __UNSUSPENDING:
throw new IllegalStateException(this.getStatusString());
default:
throw new IllegalStateException(""+_state);
}
}
}
/* ------------------------------------------------------------ */
/* (non-Javadoc)
* @see org.mortbay.jetty.Suspendor#resume()
*/
public void resume()
{
synchronized (this)
{
switch(_state)
{
case __HANDLING:
_resumed=true;
return;
case __SUSPENDING:
_resumed=true;
_state=__RESUMING;
return;
case __RESUMING:
case __COMPLETING:
return;
case __SUSPENDED:
fauxResume();
_resumed=true;
_state=__UNSUSPENDING;
break;
case __UNSUSPENDING:
_resumed=true;
return;
default:
throw new IllegalStateException(this.getStatusString());
}
}
}
/* ------------------------------------------------------------ */
public void complete()
{
// just like resume, except don't set _resumed=true;
synchronized (this)
{
switch(_state)
{
case __HANDLING:
throw new IllegalStateException(this.getStatusString());
case __SUSPENDING:
_state=__COMPLETING;
break;
case __RESUMING:
break;
case __COMPLETING:
return;
case __SUSPENDED:
_state=__COMPLETING;
fauxResume();
break;
case __UNSUSPENDING:
return;
default:
throw new IllegalStateException(this.getStatusString());
}
}
}
/* ------------------------------------------------------------ */
/**
* @see org.eclipse.jetty.continuation.Continuation#getServletResponse()
*/
public boolean enter(ServletResponse response)
{
_response=response;
return true;
}
/* ------------------------------------------------------------ */
/**
* @see org.eclipse.jetty.continuation.Continuation#getServletResponse()
*/
public ServletResponse getServletResponse()
{
return _response;
}
/* ------------------------------------------------------------ */
void handling()
{
synchronized (this)
{
_responseWrapped=false;
switch(_state)
{
case __HANDLING:
throw new IllegalStateException(this.getStatusString());
case __SUSPENDING:
case __RESUMING:
throw new IllegalStateException(this.getStatusString());
case __COMPLETING:
return;
case __SUSPENDED:
fauxResume();
case __UNSUSPENDING:
_state=__HANDLING;
return;
default:
throw new IllegalStateException(""+_state);
}
}
}
/* ------------------------------------------------------------ */
/**
* @return true if handling is complete
*/
public boolean exit()
{
synchronized (this)
{
switch(_state)
{
case __HANDLING:
_state=__COMPLETE;
onComplete();
return true;
case __SUSPENDING:
_initial=false;
_state=__SUSPENDED;
fauxSuspend(); // could block and change state.
if (_state==__SUSPENDED || _state==__COMPLETING)
{
onComplete();
return true;
}
_initial=false;
_state=__HANDLING;
return false;
case __RESUMING:
_initial=false;
_state=__HANDLING;
return false;
case __COMPLETING:
_initial=false;
_state=__COMPLETE;
onComplete();
return true;
case __SUSPENDED:
case __UNSUSPENDING:
default:
throw new IllegalStateException(this.getStatusString());
}
}
}
/* ------------------------------------------------------------ */
protected void expire()
{
// just like resume, except don't set _resumed=true;
synchronized (this)
{
_timeout=true;
}
onTimeout();
synchronized (this)
{
switch(_state)
{
case __HANDLING:
return;
case __SUSPENDING:
_timeout=true;
_state=__RESUMING;
fauxResume();
return;
case __RESUMING:
return;
case __COMPLETING:
return;
case __SUSPENDED:
_timeout=true;
_state=__UNSUSPENDING;
break;
case __UNSUSPENDING:
_timeout=true;
return;
default:
throw new IllegalStateException(this.getStatusString());
}
}
}
private void fauxSuspend()
{
long expire_at = System.currentTimeMillis()+_timeoutMs;
long wait=_timeoutMs;
while (_timeoutMs>0 && wait>0)
{
try
{
this.wait(wait);
}
catch (InterruptedException e)
{
break;
}
wait=expire_at-System.currentTimeMillis();
}
if (_timeoutMs>0 && wait<=0)
expire();
}
private void fauxResume()
{
_timeoutMs=0;
this.notifyAll();
}
@Override
public String toString()
{
return getStatusString();
}
String getStatusString()
{
synchronized (this)
{
return
((_state==__HANDLING)?"HANDLING":
(_state==__SUSPENDING)?"SUSPENDING":
(_state==__SUSPENDED)?"SUSPENDED":
(_state==__RESUMING)?"RESUMING":
(_state==__UNSUSPENDING)?"UNSUSPENDING":
(_state==__COMPLETING)?"COMPLETING":
("???"+_state))+
(_initial?",initial":"")+
(_resumed?",resumed":"")+
(_timeout?",timeout":"");
}
}
public void addContinuationListener(ContinuationListener listener)
{
if (_listeners==null)
_listeners=new ArrayList<ContinuationListener>();
_listeners.add(listener);
}
/* ------------------------------------------------------------ */
/**
* @see org.eclipse.jetty.continuation.Continuation#getAttribute(java.lang.String)
*/
public Object getAttribute(String name)
{
return _request.getAttribute(name);
}
/* ------------------------------------------------------------ */
/**
* @see org.eclipse.jetty.continuation.Continuation#removeAttribute(java.lang.String)
*/
public void removeAttribute(String name)
{
_request.removeAttribute(name);
}
/* ------------------------------------------------------------ */
/**
* @see org.eclipse.jetty.continuation.Continuation#setAttribute(java.lang.String, java.lang.Object)
*/
public void setAttribute(String name, Object attribute)
{
_request.setAttribute(name,attribute);
}
/* ------------------------------------------------------------ */
/**
* @see org.eclipse.jetty.continuation.Continuation#undispatch()
*/
public void undispatch()
{
if (isSuspended())
{
if (ContinuationFilter.__debug)
throw new ContinuationThrowable();
throw __exception;
}
throw new IllegalStateException("!suspended");
}
}