/**
*
* Copyright 2004 Hiram Chirino
*
* 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.activeio.adapter;
import java.io.IOException;
import java.io.InterruptedIOException;
import org.activeio.AsynchChannel;
import org.activeio.AsynchChannelListener;
import org.activeio.Packet;
import org.activeio.SynchChannel;
import EDU.oswego.cs.dl.util.concurrent.Channel;
import EDU.oswego.cs.dl.util.concurrent.LinkedQueue;
/**
* Adapts a {@see org.activeio.AsynchChannel} so that it provides an
* {@see org.activeio.SynchChannel} interface.
*
* This object buffers asynchronous messages from the {@see org.activeio.AsynchChannel}
* and buffers them in a {@see EDU.oswego.cs.dl.util.concurrent.Channel} util the client receives them.
*
* @version $Revision$
*/
final public class AsynchToSynchChannelAdapter implements SynchChannel, AsynchChannelListener {
private final AsynchChannel asynchChannel;
private final Channel buffer;
static public SynchChannel adapt(org.activeio.Channel channel) {
return adapt(channel, new LinkedQueue());
}
static public SynchChannel adapt(org.activeio.Channel channel, Channel upPacketChannel) {
// It might not need adapting
if( channel instanceof SynchChannel ) {
return (SynchChannel) channel;
}
// Can we just just undo the adaptor
if( channel.getClass() == SynchToAsynchChannelAdapter.class ) {
return ((SynchToAsynchChannelAdapter)channel).getSynchChannel();
}
return new AsynchToSynchChannelAdapter((AsynchChannel)channel, upPacketChannel);
}
/**
* @deprecated {@see #adapt(AsynchChannel)}
*/
public AsynchToSynchChannelAdapter(AsynchChannel asynchChannel) {
this(asynchChannel, new LinkedQueue());
}
/**
* @deprecated {@see #adapt(AsynchChannel, Channel)}
*/
public AsynchToSynchChannelAdapter(AsynchChannel asynchChannel, Channel upPacketChannel){
this.asynchChannel = asynchChannel;
this.asynchChannel.setAsynchChannelListener(this);
this.buffer=upPacketChannel;
}
/**
* @see org.activeio.Channel#write(org.activeio.channel.Packet)
*/
public void write(org.activeio.Packet packet) throws IOException {
asynchChannel.write(packet);
}
/**
* @see org.activeio.Channel#flush()
*/
public void flush() throws IOException {
asynchChannel.flush();
}
/**
* @see org.activeio.SynchChannel#read(long)
*/
public Packet read(long timeout) throws IOException {
try {
Object o;
if( timeout == NO_WAIT_TIMEOUT ) {
o = buffer.poll(0);
} else if( timeout == WAIT_FOREVER_TIMEOUT ) {
o = buffer.take();
} else {
o = buffer.poll(timeout);
}
if( o == null )
return null;
if( o instanceof Packet )
return (Packet)o;
Throwable e = (Throwable)o;
throw (IOException)new IOException("Asynch error occured: "+e).initCause(e);
} catch (InterruptedException e) {
throw new InterruptedIOException(e.getMessage());
}
}
/**
* @see org.activeio.Disposable#dispose()
*/
public void dispose() {
asynchChannel.dispose();
}
/**
* @see org.activeio.Service#start()
*/
public void start() throws IOException {
asynchChannel.start();
}
/**
* @see org.activeio.Service#stop(long)
*/
public void stop(long timeout) throws IOException {
asynchChannel.stop(timeout);
}
/**
* @see org.activeio.AsynchChannelListener#onPacket(org.activeio.channel.Packet)
*/
public void onPacket(Packet packet) {
try {
buffer.put(packet);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
/**
* @see org.activeio.AsynchChannelListener#onPacketError(org.activeio.channel.ChannelException)
*/
public void onPacketError(IOException error) {
try {
buffer.put(error);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
public Object narrow(Class target) {
if( target.isAssignableFrom(getClass()) ) {
return this;
}
return asynchChannel.narrow(target);
}
public AsynchChannel getAsynchChannel() {
return asynchChannel;
}
public String toString() {
return asynchChannel.toString();
}
}