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/**
 * Copyright (C) 2010-2011, FuseSource Corp.  All rights reserved.
 *
 *     http://fusesource.com
 *
 * The software in this package is published under the terms of the
 * CDDL license a copy of which has been included with this distribution
 * in the license.txt file.
 */
package org.fusesource.stomp.client;

import org.fusesource.hawtbuf.AsciiBuffer;
import org.fusesource.hawtdispatch.DispatchQueue;
import org.fusesource.hawtdispatch.Task;
import org.fusesource.hawtdispatch.transport.DefaultTransportListener;
import org.fusesource.stomp.codec.StompFrame;
import org.fusesource.hawtdispatch.transport.Transport;
import org.fusesource.hawtdispatch.transport.TransportListener;

import java.io.IOException;
import java.nio.channels.ClosedChannelException;
import java.util.*;
import java.util.concurrent.atomic.AtomicLong;

import static org.fusesource.stomp.client.Constants.*;

/**
 * 

*

* * @author Hiram Chirino */ public class CallbackConnection { private static class OverflowEntry { final StompFrame frame; final Callback cb; OverflowEntry(StompFrame frame, Callback cb) { this.cb = cb; this.frame = frame; } } private final Transport transport; private final StompFrame connectedFrame; private Callback receiver; private Runnable refiller; private final AtomicLong requestCounter = new AtomicLong(); private HashMap> requests = new HashMap>(); private LinkedList overflow = new LinkedList(); private Throwable failure; CallbackConnection(Transport transport, StompFrame connectedFrame) { this.transport = transport; this.connectedFrame = connectedFrame; this.transport.setTransportListener(new DefaultTransportListener() { public void onTransportCommand(Object command) { processStompFrame((StompFrame)command); } public void onRefill() { drainOverflow(); } public void onTransportFailure(IOException error) { processFailure(error); } }); } public StompFrame connectedFrame() { return connectedFrame; } public Transport transport() { return transport; } public CallbackConnection refiller(Runnable refiller) { getDispatchQueue().assertExecuting(); this.refiller = refiller; return this; } public CallbackConnection receive(Callback receiver) { getDispatchQueue().assertExecuting(); this.receiver = receiver; return this; } private void processStompFrame(StompFrame frame) { getDispatchQueue().assertExecuting(); AsciiBuffer action = frame.action(); if (action.equals(RECEIPT)) { AsciiBuffer id = frame.getHeader(RECEIPT_ID); if (id != null) { Callback cb = this.requests.remove(id); if (cb != null) { cb.onSuccess(frame); } else { if( !toReceiver(frame) ) { processFailure(new ProtocolException("Stomp Response without a valid receipt id: " + id + " for frame " + frame)); } } } else { processFailure(new ProtocolException("Stomp Response with no receipt id: " + frame)); } } else if (action.startsWith(ERROR)) { processFailure(new ProtocolException("Received an error: " + frame.errorMessage())); } else { toReceiver(frame); } } private boolean toReceiver(StompFrame frame) { if( receiver!=null ) { try { receiver.onSuccess(frame); } catch (Exception e) { processFailure(e); } return true; } return false; } private void processFailure(Throwable error) { if( failure == null ) { failure = error; failRequests(failure); if( receiver!=null ) { try { receiver.onFailure(failure); } catch (Exception e) { e.printStackTrace(); } } } } private void failRequests(Throwable failure) { ArrayList> values = new ArrayList(requests.values()); requests.clear(); for (Callback value : values) { value.onFailure(failure); } ArrayList overflowEntries = new ArrayList(overflow); overflow.clear(); for (OverflowEntry entry : overflowEntries) { if( entry.cb !=null ) { entry.cb.onFailure(failure); } } } public DispatchQueue getDispatchQueue() { return this.transport.getDispatchQueue(); } public void resume() { this.transport.resumeRead(); } public void suspend() { this.transport.suspendRead(); } public void close(final Runnable onComplete) { this.transport.stop(new Task() { public void run() { if( onComplete!=null ) { failRequests(new ClosedChannelException()); onComplete.run(); } } }); } public boolean offer(StompFrame frame) { return this.offer(frame, true); } public boolean offer(StompFrame frame, boolean addContentLength) { getDispatchQueue().assertExecuting(); if( this.transport.full() ) { return false; } else { if( addContentLength && SEND.equals(frame.action()) ) { frame.addContentLengthHeader(); } return this.transport.offer(frame); } } public boolean full() { getDispatchQueue().assertExecuting(); return this.transport.full(); } public Throwable getFailure() { getDispatchQueue().assertExecuting(); return failure; } public AsciiBuffer nextId() { return new AsciiBuffer(Long.toString(requestCounter.incrementAndGet())); } public AsciiBuffer nextId(String prefix) { return new AsciiBuffer(prefix+(requestCounter.incrementAndGet())); } public void request(StompFrame frame, Callback cb) { getDispatchQueue().assertExecuting(); assert cb!=null : "Callback must not be null"; if( failure !=null ) { cb.onFailure(failure); } else { AsciiBuffer id = nextId(); this.requests.put(id, cb); frame.addHeader(RECEIPT_REQUESTED, id); send(frame, null); } } private void drainOverflow() { getDispatchQueue().assertExecuting(); if( overflow.isEmpty() ){ return; } OverflowEntry entry; while((entry=overflow.peek())!=null) { if( offer(entry.frame) ) { overflow.removeFirst(); if( entry.cb!=null ) { entry.cb.onSuccess(null); } } else { break; } } if( overflow.isEmpty() ) { if( refiller!=null ) { try { refiller.run(); } catch (Throwable e) { e.printStackTrace(); } } } } public void send(StompFrame frame, Callback cb) { getDispatchQueue().assertExecuting(); if( failure !=null ) { if( cb!=null ) { cb.onFailure(failure); } } else { if( overflow.isEmpty() && offer(frame) ) { if( cb!=null ) { cb.onSuccess(null); } } else { overflow.addLast(new OverflowEntry(frame, cb)); } } } }




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