1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
// -*- C++ -*-
//=============================================================================
/**
* @file Pluggable_Messaging.h
*
* $Id$
*
* Interface for the TAO pluggable messaging framework.
*
*
* @author Balachandran Natarajan <bala@cs.wustl.edu>
*/
//=============================================================================
//
#ifndef TAO_PLUGGABLE_MESSAGING_H
#define TAO_PLUGGABLE_MESSAGING_H
#include "ace/pre.h"
#include "tao/Pluggable_Messaging_Utils.h"
#include "tao/Exception.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
class TAO_Target_Specification;
class TAO_Pluggable_Reply_Params;
class TAO_Transport;
class TAO_Operation_Details;
class TAO_Target_Specification;
class TAO_OutputCDR;
class TAO_Queued_Data;
// @@ The more I think I about this class, I feel that this class need
// not be a ABC as it is now. Instead we have these options
// (1) Parametrize this class with the "Messaging Object". Then the
// implementations can just redirect the request to the class
// that it has been specialised with
// (2) Use a bridge pattern here ie. the interface exposed by this
// class will redirect the request to the implementation which
// would be "right messaging" object.
// Both of them feasible. If we are not going like templates much, (2)
// is seems to be a better option.
// I am going to take a closer look on this after my MS defense -
// Bala
/**
* @class TAO_Pluggable_Messaging
*
* @brief Generic definitions Messaging class.
*
* This interface tries to define generic methods that could be
* different messaging protocols
*/
class TAO_Export TAO_Pluggable_Messaging
{
public:
/// Dtor
virtual ~TAO_Pluggable_Messaging (void);
/// Write the RequestHeader in to the <cdr> stream. The underlying
/// implementation of the mesaging should do the right thing.
virtual int generate_request_header (
TAO_Operation_Details &op,
TAO_Target_Specification &spec,
TAO_OutputCDR &cdr) = 0;
/// Write the RequestHeader in to the <cdr> stream.
virtual int generate_locate_request_header (
TAO_Operation_Details &op,
TAO_Target_Specification &spec,
TAO_OutputCDR &cdr) = 0;
/**
* Write the reply header
* The reply header is a part of any messaging protocol. The
* messaging protocol implementation would implement the way the
* reply header is written.
*/
virtual int generate_reply_header (
TAO_OutputCDR &cdr,
TAO_Pluggable_Reply_Params_Base ¶ms) = 0;
/**
* Write the locate reply header
* The locate reply header is a part of any messaging protocol. The
* messaging protocol implementation would implement the way the
* locate reply header is written.
*/
virtual int generate_locate_reply_header (
TAO_OutputCDR &cdr,
TAO_Pluggable_Reply_Params_Base ¶ms) = 0;
/**
* This method reads the message on the connection. Returns 0 when
* there is short read on the connection. Returns 1 when the full
* message is read and handled. Returns -1 on errors. If <block> is
* 1, then reply is read in a blocking manner. <bytes> indicates the
* number of bytes that needs to be read from the connection.
*/
virtual int read_message (TAO_Transport *transport,
int block = 0,
ACE_Time_Value *max_wait_time = 0) = 0;
/// Format the message in the <cdr>. May not be needed in
/// general.
virtual int format_message (TAO_OutputCDR &cdr) = 0;
/// Do any initialisations that may be needed.
virtual void init (CORBA::Octet major,
CORBA::Octet minor) = 0;
/// Parse the incoming messages..
virtual int parse_incoming_messages (ACE_Message_Block &message_block) = 0;
/// Calculate the amount of data that is missing in the <incoming>
/// message block.
virtual ssize_t missing_data (ACE_Message_Block &incoming) = 0;
/// Get the details of the message parsed through the <qd>.
virtual void get_message_data (TAO_Queued_Data *qd) = 0;
/* Extract the details of the next message from the <incoming>
* through <qd>. Returns 1 if there are more messages and returns a
* 0 if there are no more messages in <incoming>.
*/
virtual int extract_next_message (ACE_Message_Block &incoming,
TAO_Queued_Data *&qd) = 0;
/// Check whether the node <qd> needs consolidation from <incoming>
virtual int consolidate_node (TAO_Queued_Data *qd,
ACE_Message_Block &incoming) = 0;
/// @@Bala:Docu??
virtual int consolidate_fragments (TAO_Queued_Data *dqd,
const TAO_Queued_Data *sqd) = 0;
/// Parse the request message, make an upcall and send the reply back
/// to the "request initiator"
virtual int process_request_message (TAO_Transport *transport,
TAO_Queued_Data *qd) = 0;
/// Parse the reply message that we received and return the reply
/// information though <reply_info>
virtual int process_reply_message (
TAO_Pluggable_Reply_Params &reply_info,
TAO_Queued_Data *qd) = 0;
/// Generate a reply message with the exception <ex>.
virtual int generate_exception_reply (
TAO_OutputCDR &cdr,
TAO_Pluggable_Reply_Params_Base ¶ms,
CORBA::Exception &x) = 0;
/// Is the messaging object ready for processing BiDirectional
/// request/response?
virtual int is_ready_for_bidirectional (void) = 0;
/// Reset the messaging the object
virtual void reset (void) = 0;
};
#if defined (__ACE_INLINE__)
# include "tao/Pluggable_Messaging.i"
#endif /* __ACE_INLINE__ */
#include "ace/post.h"
#endif /*TAO_PLUGGABLE_MESSAGING_H*/
|
