Java example source code file (BufferManagerWriteCollect.java)

This example Java source code file (BufferManagerWriteCollect.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

buffermanagerwritecollect, buffermanagerwritecollectiterator, bufferqueue, bytebufferpool, bytebufferwithinfo, connection, fragmentmessage, iterator, nio, object, stringbuffer, unsupportedoperationexception, util

The BufferManagerWriteCollect.java Java example source code

/*
 * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.sun.corba.se.impl.encoding;

import java.nio.ByteBuffer;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.LinkedList;

import com.sun.corba.se.impl.encoding.BufferQueue;
import com.sun.corba.se.impl.encoding.BufferManagerWrite;
import com.sun.corba.se.impl.orbutil.ORBConstants;
import com.sun.corba.se.impl.protocol.giopmsgheaders.Message;
import com.sun.corba.se.impl.encoding.ByteBufferWithInfo;
import com.sun.corba.se.impl.protocol.giopmsgheaders.MessageBase;
import com.sun.corba.se.impl.protocol.giopmsgheaders.FragmentMessage;
import com.sun.corba.se.spi.orb.ORB;
import com.sun.corba.se.impl.encoding.CDROutputObject;
import com.sun.corba.se.impl.orbutil.ORBUtility;
import com.sun.corba.se.pept.transport.Connection;
import com.sun.corba.se.pept.transport.ByteBufferPool;
import com.sun.corba.se.pept.encoding.OutputObject;

/**
 * Collect buffer manager.
 */
public class BufferManagerWriteCollect extends BufferManagerWrite
{
    private BufferQueue queue = new BufferQueue();

    private boolean sentFragment = false;
    private boolean debug = false;


    BufferManagerWriteCollect(ORB orb)
    {
        super(orb);
         if (orb != null)
            debug = orb.transportDebugFlag;
    }

    public boolean sentFragment() {
        return sentFragment;
    }

    /**
     * Returns the correct buffer size for this type of
     * buffer manager as set in the ORB.
     */
    public int getBufferSize() {
        return orb.getORBData().getGIOPFragmentSize();
    }

    // Set the fragment's "more fragments" bit to true, put it in the
    // queue, and allocate a new bbwi.
    public void overflow (ByteBufferWithInfo bbwi)
    {
        // Set the fragment's moreFragments field to true
        MessageBase.setFlag(bbwi.byteBuffer, Message.MORE_FRAGMENTS_BIT);

        // Enqueue the previous fragment
        queue.enqueue(bbwi);

        // Create a new bbwi
        ByteBufferWithInfo newBbwi = new ByteBufferWithInfo(orb, this);
        newBbwi.fragmented = true;

        // XREVISIT - Downcast
        ((CDROutputObject)outputObject).setByteBufferWithInfo(newBbwi);

        // Now we must marshal in the fragment header/GIOP header

        // REVISIT - we can optimize this by not creating the fragment message
        // each time.

        // XREVISIT - Downcast
        FragmentMessage header =
              ((CDROutputObject)outputObject).getMessageHeader()
                                             .createFragmentMessage();

        header.write((CDROutputObject)outputObject);
    }

    // Send all fragments
    public void sendMessage ()
    {
        // Enqueue the last fragment
        queue.enqueue(((CDROutputObject)outputObject).getByteBufferWithInfo());

        Iterator bufs = iterator();

        Connection conn =
                          ((OutputObject)outputObject).getMessageMediator().
                                                       getConnection();

        // With the collect strategy, we must lock the connection
        // while fragments are being sent.  This is so that there are
        // no interleved fragments in GIOP 1.1.
        //
        // Note that this thread must not call writeLock again in any
        // of its send methods!
        conn.writeLock();

        try {

            // Get a reference to ByteBufferPool so that the ByteBufferWithInfo
            // ByteBuffer can be released to the ByteBufferPool
            ByteBufferPool byteBufferPool = orb.getByteBufferPool();

            while (bufs.hasNext()) {

                ByteBufferWithInfo bbwi = (ByteBufferWithInfo)bufs.next();
                ((CDROutputObject)outputObject).setByteBufferWithInfo(bbwi);

                conn.sendWithoutLock(((CDROutputObject)outputObject));

                sentFragment = true;

                // Release ByteBufferWithInfo's ByteBuffer back to the pool
                // of ByteBuffers.
                if (debug)
                {
                    // print address of ByteBuffer being released
                    int bbAddress = System.identityHashCode(bbwi.byteBuffer);
                    StringBuffer sb = new StringBuffer(80);
                    sb.append("sendMessage() - releasing ByteBuffer id (");
                    sb.append(bbAddress).append(") to ByteBufferPool.");
                    String msg = sb.toString();
                    dprint(msg);
                }
                byteBufferPool.releaseByteBuffer(bbwi.byteBuffer);
                bbwi.byteBuffer = null;
                bbwi = null;
            }

            sentFullMessage = true;

        } finally {

            conn.writeUnlock();
        }
    }

    /**
     * Close the BufferManagerWrite - do any outstanding cleanup.
     *
     * For a BufferManagerWriteGrow any queued ByteBufferWithInfo must
     * have its ByteBuffer released to the ByteBufferPool.
     */
    public void close()
    {
        // iterate thru queue and release any ByteBufferWithInfo's
        // ByteBuffer that may be remaining on the queue to the
        // ByteBufferPool.

        Iterator bufs = iterator();

        ByteBufferPool byteBufferPool = orb.getByteBufferPool();

        while (bufs.hasNext())
        {
            ByteBufferWithInfo bbwi = (ByteBufferWithInfo)bufs.next();
            if (bbwi != null && bbwi.byteBuffer != null)
            {
                if (debug)
                {
                    // print address of ByteBuffer being released
                    int bbAddress = System.identityHashCode(bbwi.byteBuffer);
                    StringBuffer sb = new StringBuffer(80);
                    sb.append("close() - releasing ByteBuffer id (");
                    sb.append(bbAddress).append(") to ByteBufferPool.");
                    String msg = sb.toString();
                    dprint(msg);
                }
                 byteBufferPool.releaseByteBuffer(bbwi.byteBuffer);
                 bbwi.byteBuffer = null;
                 bbwi = null;
            }
        }
    }

    private void dprint(String msg)
    {
        ORBUtility.dprint("BufferManagerWriteCollect", msg);
    }

    private Iterator iterator ()
    {
        return new BufferManagerWriteCollectIterator();
    }

    private class BufferManagerWriteCollectIterator implements Iterator
    {
        public boolean hasNext ()
        {
            return queue.size() != 0;
        }

        public Object next ()
        {
            return queue.dequeue();
        }

        public void remove ()
        {
            throw new UnsupportedOperationException();
        }
    }
}