// This may look like C, but it's really -*- C++ -*-
// $Id$

// ============================================================================
//
// = LIBRARY
//     TAO
//
// = AUTHOR
//     Alexander Babu Arulanthu <alex@cs.wustl.edu>
//
// ============================================================================

#ifndef TAO_TRANSPORT_MUX_STRATEGY_H
#define TAO_TRANSPORT_MUX_STRATEGY_H
#include "ace/pre.h"

#include "tao/IOPC.h"

#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */

class TAO_Reply_Dispatcher;
class TAO_GIOP_Version;
class TAO_GIOP_Message_State;
class TAO_Transport;

class TAO_Export TAO_Transport_Mux_Strategy
{
  // = TITLE
  //
  //     Strategy to determine whether the connection should be
  //     multiplexed for multiple requests or it is exclusive for a
  //     single request at a time.
  //
  // = DESCRIPTION
  //

public:
  TAO_Transport_Mux_Strategy (TAO_Transport *transport);
  // Base class constructor.

  virtual ~TAO_Transport_Mux_Strategy (void);
  // Base class destructor.

  virtual CORBA::ULong request_id (void)  = 0;
  // Generate and return an unique request id for the current
  // invocation.

  // = Bind and Find methods for the <Request ID, ReplyDispatcher>
  //   pairs.

  virtual int bind_dispatcher (CORBA::ULong request_id,
                               TAO_Reply_Dispatcher *rd);
  // Bind the dispatcher with the request id. Commonalities in the
  // derived class implementations is kept here.

  virtual void unbind_dispatcher (CORBA::ULong request_id);
  // Unbind the dispatcher, the client is no longer waiting for the
  // request, for example, because the request timedout.
  // The strategy can (must) cleanup any resources associated with the
  // request.
  // A later reply for that request should be ignored.

  virtual int dispatch_reply (CORBA::ULong request_id,
                              CORBA::ULong reply_status,
                              const TAO_GIOP_Version& version,
                              IOP::ServiceContextList& reply_ctx,
                              TAO_GIOP_Message_State* message_state) = 0;
  // Dispatch the reply for <request_id>, cleanup any resources
  // allocated for that request.

  // = "Factory methods" to obtain the CDR stream, in the Muxed case
  //    the factory simply allocates a new one, in the Exclusive case
  //    the factory returns a pointer to the pre-allocated CDR.

  virtual TAO_GIOP_Message_State *get_message_state (void) = 0;
  // Get a CDR stream.

  virtual void destroy_message_state (TAO_GIOP_Message_State *) = 0;
  // Destroy a CDR stream.

  virtual int idle_after_send (void) = 0;
  // Request has been just sent, but the reply is not received. Idle
  // the transport now.

  virtual int idle_after_reply (void) = 0;
  // Request is sent and the reply is received. Idle the transport
  // now.

  virtual void connection_closed (void) = 0;
  // The transport object has closed the connection, inform all Reply
  // dispatchers and waiting strategies.

protected:
  TAO_Transport *transport_;
  // Cache the transport reference.
};

#include "ace/post.h"
#endif /* TRANSPORT_MUX_STRATEGY_H */