/*******************************************************************************
*Copyright (c) 2009 Eucalyptus Systems, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, only version 3 of the License.
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*
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Please contact Eucalyptus Systems, Inc., 130 Castilian
* Dr., Goleta, CA 93101 USA or visit <http://www.eucalyptus.com/licenses/>
* if you need additional information or have any questions.
*
* This file may incorporate work covered under the following copyright and
* permission notice:
*
* Software License Agreement (BSD License)
*
* Copyright (c) 2008, Regents of the University of California
* All rights reserved.
*
* Redistribution and use of this software in source and binary forms, with
* or without modification, are permitted provided that the following
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*
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* LICENSED MATERIAL, COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS
* SOFTWARE, AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING
* IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, SANTA
* BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, WHICH IN
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*******************************************************************************/
/*
* Author: chris grzegorczyk <grze@eucalyptus.com>
*/
package com.eucalyptus.ws.handlers;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.log4j.Logger;
import org.jboss.netty.channel.ChannelEvent;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipelineCoverage;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
import org.jboss.netty.channel.WriteCompletionEvent;
import com.eucalyptus.http.MappingHttpMessage;
import com.eucalyptus.http.MappingHttpResponse;
import com.eucalyptus.records.EventType;
import com.eucalyptus.util.EucalyptusClusterException;
import com.eucalyptus.util.LogUtil;
import edu.ucsb.eucalyptus.cloud.NotImplementedException;
import edu.ucsb.eucalyptus.msgs.BaseMessage;
import com.eucalyptus.records.EventRecord;
@ChannelPipelineCoverage( "one" )
public class NioResponseHandler extends SimpleChannelHandler implements ResponseHandler {
private static Logger LOG = Logger.getLogger( NioResponseHandler.class );
private Lock canHas = new ReentrantLock();
private Condition ready = canHas.newCondition( );
private AtomicReference<Object> response = new AtomicReference<Object>(null);
protected BlockingQueue<BaseMessage> requestQueue = new LinkedBlockingQueue<BaseMessage>( );
public boolean hasException( ) {
return this.response.get() instanceof Throwable;
}
public boolean hasResponse( ) {
return this.response.get() instanceof BaseMessage;
}
public BaseMessage getResponse( ) throws Exception {
this.waitForResponse( );
if( this.response.get( ) instanceof BaseMessage ) {
return (BaseMessage) this.response.get( );
} else if ( this.response.get() instanceof Throwable ) {
throw new EucalyptusClusterException( "Exception in NIO request.", (Throwable) this.response.get( ) );
}
throw new EucalyptusClusterException( "Failed to retrieve result of asynchronous operation." );
}
public void exceptionCaught( final ChannelHandlerContext ctx, final Throwable e ) {
LOG.debug( e, e );
this.queueResponse( e );
}
@Override
public void exceptionCaught( final ChannelHandlerContext ctx, final ExceptionEvent e ) {
this.exceptionCaught( ctx, e.getCause( ) );
ctx.getChannel( ).close( );
}
@Override
public void messageReceived( final ChannelHandlerContext ctx, final MessageEvent e ) throws Exception {
final MappingHttpMessage httpResponse = ( MappingHttpMessage ) e.getMessage( );
final BaseMessage reply = ( BaseMessage ) httpResponse.getMessage( );
this.queueResponse( reply );
ctx.getChannel( ).close( );
}
public void queueResponse( Object o ) {
if ( o instanceof MappingHttpResponse ) {
MappingHttpResponse httpResponse = (MappingHttpResponse) o;
if( httpResponse.getMessage( ) != null ) {
o = httpResponse.getMessage( );
} else {
o = new EucalyptusClusterException( httpResponse.getMessageString( ) );
}
}
this.canHas.lock( );
try {
if( !this.response.compareAndSet( null, o ) ) {
if( !( o instanceof Throwable ) ) {
LOG.debug( LogUtil.subheader( "Received spurious second response: " + LogUtil.dumpObject( o ) ) );
}
o = this.response.getAndSet( o );
LOG.debug( LogUtil.subheader( "Previous response was: " + LogUtil.dumpObject( this.response.get( ) ) ) );
} else {
if( o instanceof Throwable ) {
LOG.error( "Caught exception in asynchronous response handler.", (Throwable) o );
} else {
LOG.trace( this.getClass( ).getSimpleName( ) + " Got response of: " + LogUtil.dumpObject( o ) );
}
}
this.ready.signalAll( );
} finally {
this.canHas.unlock( );
}
}
public Throwable getException( ) {
this.waitForResponse();
return (Throwable) this.response.get( );
}
public void waitForResponse( ) {
this.canHas.lock( );
try {
while( this.response.get( ) == null ) {
try {
this.ready.await( 10000, TimeUnit.MILLISECONDS );
LOG.debug( "Waiting for response." );
} catch ( InterruptedException e ) {
LOG.debug( e, e );
Thread.currentThread( ).interrupt( );
}
}
EventRecord.here( NioResponseHandler.class, EventType.MSG_SERVICED, this.response.get().getClass( ).toString( ) ).debug( );
} finally {
this.canHas.unlock( );
}
}
@Override
public void channelClosed( ChannelHandlerContext ctx, ChannelStateEvent e ) throws Exception {
if( this.response.get( ) == null ) {
this.queueResponse( new EucalyptusClusterException( LogUtil.dumpObject( e ) ) );
}
super.channelClosed( ctx, e );
}
@Override
public BaseMessage getRequest( ) {
throw new RuntimeException( "Not implemented" );
}
}