/*

 * Copyright (c) 1996, 2005, 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 sun.rmi.transport;

import java.io.IOException;

import java.rmi.server.UID;

import sun.rmi.server.MarshalOutputStream;

/**

 * Special stream to keep track of refs being marshaled as return

 * results to determine whether a special ack needs to be sent

 * to the distributed collector.

 *

 * @author Ann Wollrath

 */

class ConnectionOutputStream extends MarshalOutputStream {

    /** connection associated with ConnectionOutputStream */

    private final Connection conn;

    /** indicates whether output stream is used to marshal results */

    private final boolean resultStream;

    /** identifier for gc ack*/

    private final UID ackID;

    /** to store refs to returned remote object until DGC ack is received */

    private DGCAckHandler dgcAckHandler = null;

    /**

     * Constructs an marshal output stream using the underlying

     * stream associated with the connection, the parameter c.

     * @param c is the Connection object associated with the

     * ConnectionOutputStream object being constructed

     * @param resultStream indicates whether this stream is used

     * to marshal return results

     */

    ConnectionOutputStream(Connection conn, boolean resultStream)

        throws IOException

    {

        super(conn.getOutputStream());

        this.conn = conn;

        this.resultStream = resultStream;

        ackID = resultStream ? new UID() : null;

    }

    void writeID() throws IOException {

        assert resultStream;

        ackID.write(this);

    }

    /**

     * Returns true if this output stream is used to marshal return

     * results; otherwise returns false.

     */

    boolean isResultStream() {

        return resultStream;

    }

    /**

     * Saves a reference to the specified object in this stream's

     * DGCAckHandler.

     **/

    void saveObject(Object obj) {

        // should always be accessed from same thread

        if (dgcAckHandler == null) {

            dgcAckHandler = new DGCAckHandler(ackID);

        }

        dgcAckHandler.add(obj);

    }

    /**

     * Returns this stream's DGCAckHandler, or null if it doesn't have

     * one (saveObject was not invoked).  This method should only be

     * invoked after all objects have been written to the stream,

     * because future objects written may yet cause a DGCAckHandler to

     * be created (by invoking saveObject).

     **/

    DGCAckHandler getDGCAckHandler() {

        return dgcAckHandler;

    }

    void done() {

        if (dgcAckHandler != null) {

            dgcAckHandler.startTimer();

        }

    }

}