/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2006-2009 Sun Microsystems, Inc.
 */
package org.opends.server.replication.protocol;

import java.io.IOException;
import java.net.SocketException;
import java.util.zip.DataFormatException;

/**
 * The ProtocolSession interface should be implemented by a class that
 * implement the send/reception part of the Multi-master replication
 * protocol.
 *
 * This interface is designed to make easy the move from one format
 * of the ReplicationMsg on the wire to another format.
 */
public interface ProtocolSession
{

  /**
   * This method is called when the session with the remote must be closed.
   * This object won't be used anymore after this method is called.
   *
   * @throws IOException If an error happen during the close process.
   */
  public abstract void close() throws IOException;

  /**
   * This method is called when a ReplicationMsg must be sent to
   * the remote entity. The PDU is send using serialization of the current
   * protocol version.
   *
   * It can be called by several threads and must implement appropriate
   * replication (typically, this method or a part of it should be
   * synchronized).
   *
   * @param msg The ReplicationMsg that must be sent.
   * @throws IOException If an IO error happen during the publish process.
   */
  public abstract void publish(ReplicationMsg msg)
                  throws IOException;

  /**
   * Same as publish(ReplicationMsg msg), but forcing the usage of a particular
   * protocol version for the PDU serialization.
   *
   * @param msg The ReplicationMsg that must be sent.
   * @param reqProtocolVersion The protocol version to use for serialization.
   * The version should normally be older than the current one.
   * @throws IOException If an IO error happen during the publish process.
   */
  public abstract void publish(ReplicationMsg msg, short reqProtocolVersion)
                  throws IOException;

  /**
   * Attempt to receive a ReplicationMsg.
   * This method should block the calling thread until a
   * ReplicationMsg is available or until an error condition.
   *
   * This method can only be called by a single thread and therefore does not
   * need to implement any replication.
   *
   * @return The ReplicationMsg that was received.
   * @throws IOException When error happened during IO process.
   * @throws ClassNotFoundException When the data received does extend the
   *         ReplicationMsg class.
   * @throws DataFormatException When the data received is not formatted as a
   *         ReplicationMsg.
   * @throws NotSupportedOldVersionPDUException If the received PDU is part of
   * an old protocol version and we do not support it.
   */
  public abstract ReplicationMsg receive()
                  throws IOException, ClassNotFoundException,
                         DataFormatException,
                         NotSupportedOldVersionPDUException;

  /**
   * Stop using the security layer, if there is any.
   */
  public abstract void stopEncryption();

  /**
   * Determine whether the session is using a security layer.
   * @return true if the connection is encrypted, false otherwise.
   */
  public abstract boolean isEncrypted();

  /**
   * Retrieve the IP address of the remote server.
   *
   * @return The IP address of the remote server.
   */
  public abstract String getRemoteAddress();

  /**
   * Retrieve the human readable address of the remote server.
   *
   * @return The human readable address of the remote server.
   */
  public abstract String getReadableRemoteAddress();


  /**
  * Set a timeout value.
  * With this option set to a non-zero value, calls to the receive() method
  * block for only this amount of time after which a
  * java.net.SocketTimeoutException is raised.
  * The Broker is valid and usable even after such an Exception is raised.
  *
  * @param timeout the specified timeout, in milliseconds.
  * @throws SocketException if there is an error in the underlying protocol,
  *         such as a TCP error.
  */
  public abstract void setSoTimeout(int timeout) throws SocketException;



  /**
   * Gets the time the last replication message was published on this
   * session.
   * @return The timestamp in milliseconds of the last message published.
   */
  public abstract long getLastPublishTime();



  /**
   * Gets the time the last replication message was received on this
   * session.
   * @return The timestamp in milliseconds of the last message received.
   */
  public abstract long getLastReceiveTime();

  /**
   * This methods allows to determine if the session close was initiated
   * on this ProtocolSession.
   *
   * @return A boolean allowing to determine if the session close was initiated
   * on this ProtocolSession.
   */
  public abstract boolean closeInitiated();

  /**
   * This method is called at the establishment of the session and can
   * be used to record the version of the protocol that is currently used.
   *
   * @param version The version of the protocol that is currently used.
   */
  public abstract void setProtocolVersion(short version);
}
