com.facebook.infrastructure.net.UdpConnection.java Source code

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Here is the source code for com.facebook.infrastructure.net.UdpConnection.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 com.facebook.infrastructure.net;

import java.net.SocketAddress;
import java.nio.*;
import java.nio.channels.*;
import java.util.*;
import java.util.concurrent.*;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import org.apache.log4j.Logger;
import org.apache.commons.lang.ArrayUtils;
import com.facebook.infrastructure.concurrent.*;
import com.facebook.infrastructure.net.io.ProtocolState;
import com.facebook.infrastructure.net.sink.SinkManager;
import com.facebook.infrastructure.utils.*;

/**
 * Author : Avinash Lakshman ( alakshman@facebook.com) & Prashant Malik ( pmalik@facebook.com )
 */

public class UdpConnection extends SelectionKeyHandler {
    private static Logger logger_ = Logger.getLogger(UdpConnection.class);
    private static final int BUFFER_SIZE = 4096;
    private static final int protocol_ = 0xBADBEEF;

    private DatagramChannel socketChannel_;
    private SelectionKey key_;
    private EndPoint localEndPoint_;

    public void init() throws IOException {
        socketChannel_ = DatagramChannel.open();
        socketChannel_.socket().setReuseAddress(true);
        socketChannel_.configureBlocking(false);
    }

    public void init(int port) throws IOException {
        // TODO: get TCP port from config and add one.
        localEndPoint_ = new EndPoint(port);
        socketChannel_ = DatagramChannel.open();
        socketChannel_.socket().bind(localEndPoint_.getInetAddress());
        socketChannel_.socket().setReuseAddress(true);
        socketChannel_.configureBlocking(false);
        key_ = SelectorManager.getUdpSelectorManager().register(socketChannel_, this, SelectionKey.OP_READ);
    }

    public boolean write(Message message, EndPoint to) throws IOException {
        boolean bVal = true;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(bos);
        Message.serializer().serialize(message, dos);
        byte[] data = bos.toByteArray();
        if (data.length > 0) {
            logger_.trace("Size of Gossip packet " + data.length);
            byte[] protocol = BasicUtilities.intToByteArray(protocol_);
            ByteBuffer buffer = ByteBuffer.allocate(data.length + protocol.length);
            buffer.put(protocol);
            buffer.put(data);
            buffer.flip();

            int n = socketChannel_.send(buffer, to.getInetAddress());
            if (n == 0) {
                bVal = false;
            }
        }
        return bVal;
    }

    void close() {
        try {
            if (socketChannel_ != null)
                socketChannel_.close();
        } catch (IOException ex) {
            logger_.error(LogUtil.throwableToString(ex));
        }
    }

    public DatagramChannel getDatagramChannel() {
        return socketChannel_;
    }

    private byte[] gobbleHeaderAndExtractBody(ByteBuffer buffer) {
        byte[] body = ArrayUtils.EMPTY_BYTE_ARRAY;
        byte[] protocol = new byte[4];
        buffer = buffer.get(protocol, 0, protocol.length);
        int value = BasicUtilities.byteArrayToInt(protocol);

        if (protocol_ != value) {
            logger_.info("Invalid protocol header in the incoming message " + value);
            return body;
        }
        body = new byte[buffer.remaining()];
        buffer.get(body, 0, body.length);
        return body;
    }

    public void read(SelectionKey key) {
        key.interestOps(key.interestOps() & (~SelectionKey.OP_READ));
        ByteBuffer buffer = ByteBuffer.allocate(BUFFER_SIZE);
        try {
            SocketAddress sa = socketChannel_.receive(buffer);
            if (sa == null) {
                logger_.debug("*** No datagram packet was available to be read ***");
                return;
            }
            buffer.flip();

            byte[] bytes = gobbleHeaderAndExtractBody(buffer);
            if (bytes.length > 0) {
                DataInputStream dis = new DataInputStream(new ByteArrayInputStream(bytes));
                Message message = Message.serializer().deserialize(dis);
                if (message != null) {
                    MessagingService.receive(message);
                }
            }
        } catch (IOException ioe) {
            logger_.warn(LogUtil.throwableToString(ioe));
        } finally {
            key.interestOps(key_.interestOps() | SelectionKey.OP_READ);
        }
    }
}