com.vaushell.superpipes.nodes.test.N_ReceiveBlocking.java Source code

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Here is the source code for com.vaushell.superpipes.nodes.test.N_ReceiveBlocking.java

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/*
 * Copyright (C) 2013 Fabien Vauchelles (fabien_AT_vauchelles_DOT_com).
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3, 29 June 2007, of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301  USA
 */

package com.vaushell.superpipes.nodes.test;

import com.vaushell.superpipes.dispatch.Message;
import com.vaushell.superpipes.nodes.A_Node;
import java.util.LinkedList;
import org.joda.time.DateTime;
import org.joda.time.Duration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Wait message to be receive and send it to a function.
 *
 * @author Fabien Vauchelles (fabien_AT_vauchelles_DOT_com)
 */
public class N_ReceiveBlocking extends A_Node {
    // PUBLIC
    public N_ReceiveBlocking() {
        super(null, null);

        this.messages = new LinkedList<>();
    }

    /**
     * Get the actual processing message, or wait it.
     *
     * @return the Message
     * @throws InterruptedException
     */
    public Message getProcessingMessageOrWait() throws InterruptedException {
        if (LOGGER.isTraceEnabled()) {
            LOGGER.trace("[" + getNodeID() + "] getProcessingMessageOrWait()");
        }

        synchronized (messages) {
            while (messages.isEmpty()) {
                messages.wait();
            }

            return messages.pollFirst();
        }
    }

    /**
     * Get the actual processing message, or wait it.
     *
     * @param timeout a timeout
     * @return the Message
     * @throws InterruptedException
     */
    public Message getProcessingMessageOrWait(final Duration timeout) throws InterruptedException {
        if (timeout == null) {
            throw new IllegalArgumentException();
        }

        if (LOGGER.isTraceEnabled()) {
            LOGGER.trace("[" + getNodeID() + "] getProcessingMessageOrWait() : timeout=" + timeout);
        }

        synchronized (messages) {
            DateTime start = new DateTime();
            Duration remaining = timeout;
            while (messages.isEmpty() && remaining.getMillis() > 0L) {
                messages.wait(remaining.getMillis());

                final DateTime now = new DateTime();

                final Duration elapsed = new Duration(start, now);

                remaining = remaining.minus(elapsed);

                start = now;
            }

            return messages.pollFirst();
        }
    }

    // PROTECTED
    @Override
    protected void prepareImpl() throws Exception {
        // Nothing
    }

    @SuppressWarnings("unchecked")
    @Override
    protected void loop() throws Exception {
        // Receive
        setMessage(getLastMessageOrWait());

        synchronized (messages) {
            messages.addLast(getMessage());

            messages.notifyAll();
        }

        sendMessage();
    }

    @Override
    protected void terminateImpl() throws Exception {
        // Nothing
    }

    // PRIVATE
    private final LinkedList<Message> messages;
    private static final Logger LOGGER = LoggerFactory.getLogger(N_ReceiveBlocking.class);

}