/protocols/ss7/m3ua/impl/src/main/java/org/mobicents/protocols/ss7/m3ua/impl/M3UAChannelImpl.java

  1/*
  2 * JBoss, Home of Professional Open Source
  3 * Copyright 2011, Red Hat, Inc. and individual contributors
  4 * by the @authors tag. See the copyright.txt in the distribution for a
  5 * full listing of individual contributors.
  6 *
  7 * This is free software; you can redistribute it and/or modify it
  8 * under the terms of the GNU Lesser General Public License as
  9 * published by the Free Software Foundation; either version 2.1 of
 10 * the License, or (at your option) any later version.
 11 *
 12 * This software is distributed in the hope that it will be useful,
 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 15 * Lesser General Public License for more details.
 16 *
 17 * You should have received a copy of the GNU Lesser General Public
 18 * License along with this software; if not, write to the Free
 19 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 20 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 21 */
 22
 23package org.mobicents.protocols.ss7.m3ua.impl;
 24
 25import java.io.IOException;
 26import java.nio.channels.spi.AbstractSelectableChannel;
 27import java.util.concurrent.ConcurrentLinkedQueue;
 28import org.mobicents.protocols.ss7.m3ua.M3UAChannel;
 29import org.mobicents.protocols.ss7.m3ua.impl.message.M3UAMessageImpl;
 30import org.mobicents.protocols.ss7.m3ua.message.M3UAMessage;
 31
 32/**
 33 * The base implementation for the M3UAChannel based on NIO.
 34 * 
 35 * @author kulikov
 36 */
 37public abstract class M3UAChannelImpl extends M3UASelectableChannelImpl implements M3UAChannel {
 38    
 39    //Queue for incoming messages
 40    protected ConcurrentLinkedQueue<M3UAMessageImpl> rxQueue = new ConcurrentLinkedQueue();
 41    //Queue for outgoing messages
 42    protected ConcurrentLinkedQueue<M3UAMessageImpl> txQueue = new ConcurrentLinkedQueue();
 43    
 44    protected IOException ioException;
 45    
 46    /**
 47     * Constructs new M3UA channel.
 48     * 
 49     * @param channel the underlying network channel.
 50     * @throws java.io.IOException
 51     */
 52    protected M3UAChannelImpl(AbstractSelectableChannel channel) throws IOException {
 53        this.channel = channel;
 54        this.channel.configureBlocking(false);
 55    }
 56
 57    /**
 58     * (Non Java-doc.)
 59     * 
 60     * @see org.mobicents.protocols.ss7.m3ua.M3UAChannel#receive() 
 61     */
 62    public M3UAMessage receive() throws IOException {
 63        //If underlying channel raised Exception at IO, throw the same here
 64        if(ioException != null){
 65            throw ioException;
 66        }
 67        //extracts next message from queue
 68        return rxQueue.poll();
 69    }
 70    
 71    /**
 72     * (Non Java-doc.)
 73     * 
 74     * @see org.mobicents.protocols.ss7.m3ua.M3UAChannel#send(org.mobicents.protocols.ss7.m3ua.message.M3UAMessage)  
 75     */
 76    public void send(M3UAMessage message) throws IOException {
 77        //If underlying channel raised Exception at IO, throw the same here
 78        if(ioException != null){
 79            throw ioException;
 80        }
 81        
 82        //queue next message for sending
 83        txQueue.offer((M3UAMessageImpl) message);
 84    }
 85    
 86    /**
 87     * Implements undelying network read operation.
 88     * 
 89     * @throws java.io.IOException
 90     */
 91    protected abstract void doRead() throws IOException;
 92    
 93    /**
 94     * Implements undelying network write operation.
 95     * 
 96     * @throws java.io.IOException
 97     */
 98    protected abstract void doWrite() throws IOException;
 99    
100    /**
101     * Tests if this channel contains data available for reading
102     * 
103     * @return true if this channel contains data which can be read by user.
104     */
105    protected boolean isReadable() {
106        return !rxQueue.isEmpty();
107    }
108    
109    /**
110     * Tests if write operation available for this channel
111     * 
112     * @return true if this channel allows to user to use write operation.
113     */
114    protected boolean isWritable() {
115        return txQueue.isEmpty();
116    }
117    
118    
119}