// -*- C++ -*-

//=============================================================================
/**
 *  @file     Pluggable_Messaging_Utils.h
 *
 *  $Id$
 *
 *   Utility classes for the TAO pluggable messaging framework.
 *
 *  @author  Balachandran Natarajan <bala@cs.wustl.edu>
 */
//=============================================================================


#ifndef TAO_PLUGGABLE_MESSAGING_UTILS_H
#define TAO_PLUGGABLE_MESSAGING_UTILS_H

#include /**/ "ace/pre.h"

#include "tao/IOP_IORC.h"

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

TAO_BEGIN_VERSIONED_NAMESPACE_DECL

class TAO_Transport;

/**
 * @class TAO_Pluggable_Reply_Params_Base
 *
 * @brief TAO_Pluggable_Acceptor_Params
 *
 * This represents a set of data that would be assembled by the
 * acceptor to pass to the connector. This base class is used by
 * TAO_ServerRequest. The child class TAO_Pluggable_Reply_Params
 * is used on the client side, and contains an additional
 * TAO_InputCDR member, not needed on the server side.
 */
class TAO_Export TAO_Pluggable_Reply_Params_Base
{
public:
  /// Constructor.
  TAO_Pluggable_Reply_Params_Base (void);

  /// The IOP service context list.
  IOP::ServiceContextList svc_ctx_;

  /// The request id for which the reply we (connector) has received.
  CORBA::ULong request_id_;

  // @@ Bala: this is (again) an GIOPism (to coin a word).  Other
  // protocol may choose to send different *messages* instead.
  // @@ Carlos: I agree. Please see above.
  /// The reply status.
  CORBA::ULong reply_status_;

  /**
   * Since this class no longer contains an NVList, this is the
   * way to determine if the request was DSI, so we can use Carlos'
   * service context list no-deep-copy optimization.
   */
  CORBA::Boolean is_dsi_;

  /// Info required for DSI optimization that pads the outgoing
  /// CDR stream according to the alignment of the NVList.
  ptrdiff_t dsi_nvlist_align_;

  /**
   * Get and Set methods for the service context list that we dont
   * own. This is useful for cases  where the application objects own
   * a service context list and would like to pass on their contents
   * without a copy.
   */
  IOP::ServiceContextList &service_context_notowned (void);
  void service_context_notowned (IOP::ServiceContextList *svc);

  /// A flag that indicates if there is any data is going to get
  /// marshalled in the reply
  CORBA::Boolean argument_flag_;

protected:
  /// The service context list that we don't own.
  IOP::ServiceContextList *service_context_;
};

/**
 * @class TAO_Pluggable_Reply_Params
 *
 * @brief TAO_Pluggable_Connector_Params
 *
 */
class TAO_Export TAO_Pluggable_Reply_Params
  : public TAO_Pluggable_Reply_Params_Base
{
public:
  /// Constructor.
  TAO_Pluggable_Reply_Params (TAO_Transport *t);

  /// The stream with the non-demarshaled reply. This stream will be
  /// passed up to the stubs to demarshal the parameter values.
  TAO_InputCDR *input_cdr_;

  TAO_Transport *transport_;
};

// @@ Bala: this is a GIOPism too, there is no such thing as locate
// request in HTTP (the basis for SOAP and XIOP), i don't know about
// HTTP-NG, but i wouldn't be surprised if it had.  Furthermore, some
// very influential people (Michi) is arguing against it in the OMG.
//
// @@Carlos: Yes, I also saw some of Michi's ideas. Even if OMG
// decides to remove this, can I point that we may have to support that
// for the existsing GIOP1.0,1.1 & GIOP 1.2.  Above all, the enum type
// contains things that I know of today. I can go ahead and add HTTP-NG
// stuff. They all seem to be in Working Draft stage. So, I am just
// keeping off. I dont want to add something for the kick of it :-)
enum TAO_Pluggable_Header_Type
{
  TAO_PLUGGABLE_MESSAGE_REQUEST_HEADER = 0,
  TAO_PLUGGABLE_MESSAGE_LOCATE_REQUEST_HEADER
};


/**
 * Provide an external interface for the users of this pluggable
 * messaging framework to denote  existing message types. This has
 * an inspiration from GIOP. So if anybody wants to add more message
 * types you are welcome but please do not change the numbering
 * scheme as this would affect GIOP.
 *
 * @note
 * We may not need everything here. It would be good if we
 * have only the following messages TAO_PLUGGABLE_MESSAGE_REQUEST,
 * TAO_PLUGGABLE_MESSAGE_REPLY,
 * TAO_PLUGGABLE_MESSAGE_CLOSECONNECTION,
 * TAO_PLUGGABLE_MESSAGE_MESSAGE_ERROR.  Changes will be made once
 * the rest of the stuff gets ready to roll
 */
enum TAO_Pluggable_Message_Type
{
  TAO_PLUGGABLE_MESSAGE_REQUEST = 0,                // sent by client.
  TAO_PLUGGABLE_MESSAGE_REPLY = 1,                  // by server.
  TAO_PLUGGABLE_MESSAGE_CANCELREQUEST = 2,          // by client.
  TAO_PLUGGABLE_MESSAGE_LOCATEREQUEST = 3,          // by client.
  TAO_PLUGGABLE_MESSAGE_LOCATEREPLY = 4,
  TAO_PLUGGABLE_MESSAGE_CLOSECONNECTION = 5,
  TAO_PLUGGABLE_MESSAGE_MESSAGERROR = 6,
  TAO_PLUGGABLE_MESSAGE_FRAGMENT = 7
};

// @@ Bala: This is a hopeless GIOPism.
// @@ Carlos: Agreed.

/**
 * Provide an external interface for the users of this pluggable
 * messaging framework to denote  existing Exception types. This has
 * an inspiration from GIOP. So if anybody wants to add more message
 * types you are welcome but please do not change the numbering
 * scheme as this would affect GIOP.
 */
enum TAO_Pluggable_Message_Exception_Type
{
  /// Request completed successfully
  TAO_PLUGGABLE_MESSAGE_NO_EXCEPTION = 0,

  /// Request terminated with user exception
  TAO_PLUGGABLE_MESSAGE_USER_EXCEPTION,

  /// Request terminated with system exception
  TAO_PLUGGABLE_MESSAGE_SYSTEM_EXCEPTION,

  /// Reply is a location forward type
  TAO_PLUGGABLE_MESSAGE_LOCATION_FORWARD,

  /// PLUGGABLE_MESSAGE 1.2, Reply is a location forward perm type..
  TAO_PLUGGABLE_MESSAGE_LOCATION_FORWARD_PERM,

  /// GIOP1.2,
  TAO_PLUGGABLE_MESSAGE_NEEDS_ADDRESSING_MODE
};

TAO_END_VERSIONED_NAMESPACE_DECL

#if defined (__ACE_INLINE__)
#include "tao/Pluggable_Messaging_Utils.i"
#endif /* __ACE_INLINE__ */

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

#endif /* TAO_PLUGGABLE_MESSAGING_UTILS_H */