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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/*****************************************************************
|
| Neptune - Messaging System
|
| Copyright (c) 2002-2008, Axiomatic Systems, LLC.
| All rights reserved.
|
| Redistribution and use in source and binary forms, with or without
| modification, are permitted provided that the following conditions are met:
| * Redistributions of source code must retain the above copyright
| notice, this list of conditions and the following disclaimer.
| * Redistributions in binary form must reproduce the above copyright
| notice, this list of conditions and the following disclaimer in the
| documentation and/or other materials provided with the distribution.
| * Neither the name of Axiomatic Systems nor the
| names of its contributors may be used to endorse or promote products
| derived from this software without specific prior written permission.
|
| THIS SOFTWARE IS PROVIDED BY AXIOMATIC SYSTEMS ''AS IS'' AND ANY
| EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
| WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
| DISCLAIMED. IN NO EVENT SHALL AXIOMATIC SYSTEMS BE LIABLE FOR ANY
| DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
| (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
| LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
| ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
| SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
****************************************************************/
#ifndef _NPT_MESSAGING_H_
#define _NPT_MESSAGING_H_
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "NptConstants.h"
#include "NptTypes.h"
#include "NptResults.h"
#include "NptList.h"
#include "NptThreads.h"
#include "NptDynamicCast.h"
/*----------------------------------------------------------------------
| forward references
+---------------------------------------------------------------------*/
class NPT_Message;
/*----------------------------------------------------------------------
| NPT_MessageHandler
+---------------------------------------------------------------------*/
class NPT_MessageHandler
{
public:
NPT_IMPLEMENT_DYNAMIC_CAST(NPT_MessageHandler)
// methods
virtual ~NPT_MessageHandler() {}
// default message handler
virtual void OnMessage(NPT_Message*) {}
// this method is a central point of handling for received messages.
// it can be overloaded by subclasses that wish to process all
// incoming messages
virtual NPT_Result HandleMessage(NPT_Message* message);
};
/*----------------------------------------------------------------------
| NPT_MessageHandlerProxy
+---------------------------------------------------------------------*/
class NPT_MessageHandlerProxy : public NPT_MessageHandler
{
public:
NPT_IMPLEMENT_DYNAMIC_CAST_D(NPT_MessageHandlerProxy, NPT_MessageHandler)
/**
* Create a proxy for a message handler.
* All calls to HandleMessage() and OnMessage() on the proxy
* are automatically forwarded to the handler.
* This class is useful in cases where a handler is passed
* asynchronously (for example in a message queue) and one wishes
* to guarantee right away that no more calls to the handler will be
* made (because, for example, the handler needs to be deleted).
*
* The proxy object keeps a pointer to the handler, but does not own it.
*/
NPT_MessageHandlerProxy(NPT_MessageHandler* handler);
// destructor
~NPT_MessageHandlerProxy() override;
// NPT_MessageHandler methods
void OnMessage(NPT_Message*) override;
NPT_Result HandleMessage(NPT_Message* message) override;
/**
* Detach the proxy from the handler implementation.
* After this call returns, calls will no longer be
* forwarded to the handler object. It is then safe, for example,
* to delete the handler.
*/
void DetachHandler();
/**
* Increment the reference count
*/
void AddReference();
/**
* Decrement the reference count and delete if 0
*/
void Release();
private:
// members
NPT_MessageHandler* m_Handler;
NPT_Cardinal m_ReferenceCount;
NPT_Mutex m_Lock;
};
/*----------------------------------------------------------------------
| NPT_Messsage
+---------------------------------------------------------------------*/
class NPT_Message
{
public:
// types
typedef const char* Type;
// static members
static Type const MessageType;
// methods
virtual ~NPT_Message() {}
virtual Type GetType() { return MessageType; }
virtual NPT_Result Dispatch(NPT_MessageHandler* handler) {
return DefaultDeliver(handler);
}
// this method should really be called 'Deliver', but this would
// cause a problem when subclasses overload it
virtual NPT_Result DefaultDeliver(NPT_MessageHandler* handler) {
handler->OnMessage(this);
return NPT_SUCCESS;
}
};
/*----------------------------------------------------------------------
| NPT_TerminateMesssage
+---------------------------------------------------------------------*/
class NPT_TerminateMessage : public NPT_Message
{
public:
// methods
NPT_Result Dispatch(NPT_MessageHandler* /*handler*/) override {
return NPT_ERROR_TERMINATED;
}
};
/*----------------------------------------------------------------------
| NPT_MessageQueue
+---------------------------------------------------------------------*/
class NPT_MessageQueue
{
public:
// methods
virtual ~NPT_MessageQueue() {}
virtual NPT_Result PumpMessage(NPT_Timeout timeout = NPT_TIMEOUT_INFINITE) = 0;
virtual NPT_Result QueueMessage(NPT_Message* message,
NPT_MessageHandler* handler) = 0;
};
/*----------------------------------------------------------------------
| NPT_MessageReceiver
+---------------------------------------------------------------------*/
class NPT_MessageReceiver
{
public:
// methods
NPT_MessageReceiver() : m_Queue(NULL), m_Handler(NULL) {}
NPT_MessageReceiver(NPT_MessageHandler* handler) :
m_Queue(NULL), m_Handler(handler) {}
NPT_MessageReceiver(NPT_MessageQueue* queue) :
m_Queue(queue), m_Handler(NULL) {}
NPT_MessageReceiver(NPT_MessageHandler* handler,
NPT_MessageQueue* queue) :
m_Queue(queue), m_Handler(handler) {}
virtual ~NPT_MessageReceiver() {}
NPT_Result SetQueue(NPT_MessageQueue* queue) {
m_Queue = queue;
return NPT_SUCCESS;
}
NPT_Result SetHandler(NPT_MessageHandler* handler) {
m_Handler = handler;
return NPT_SUCCESS;
}
virtual NPT_Result PostMessage(NPT_Message* message) {
if (m_Queue) {
return m_Queue->QueueMessage(message, m_Handler);
} else {
return NPT_FAILURE;
}
}
protected:
// members
NPT_MessageQueue* m_Queue;
NPT_MessageHandler* m_Handler;
};
/*----------------------------------------------------------------------
| NPT_MessageBroadcaster
+---------------------------------------------------------------------*/
class NPT_MessageBroadcaster
{
public:
// methods
NPT_MessageBroadcaster(NPT_Message* message) : m_Message(message) {}
NPT_Result operator()(NPT_MessageReceiver*& receiver) const {
receiver->PostMessage(m_Message);
return NPT_SUCCESS;
}
private:
// members
NPT_Message* m_Message;
};
#endif // _NPT_MESSAGING_H_
|
