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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>DbEnv::repmgr_msg_dispatch()</title>
<link rel="stylesheet" href="apiReference.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
<link rel="start" href="index.html" title="Berkeley DB C++ API Reference" />
<link rel="up" href="rep.html" title="Chapter 11. Replication Methods" />
<link rel="prev" href="repmgrget_ack_policy.html" title="DbEnv::repmgr_get_ack_policy()" />
<link rel="next" href="repmgrset_ack_policy.html" title="DbEnv::repmgr_set_ack_policy()" />
</head>
<body>
<div xmlns="" class="navheader">
<div class="libver">
<p>Library Version 11.2.5.3</p>
</div>
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">DbEnv::repmgr_msg_dispatch()</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="repmgrget_ack_policy.html">Prev</a> </td>
<th width="60%" align="center">Chapter 11.
Replication Methods
</th>
<td width="20%" align="right"> <a accesskey="n" href="repmgrset_ack_policy.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="repmgr_msg_dispatch"></a>DbEnv::repmgr_msg_dispatch()</h2>
</div>
</div>
</div>
<pre class="programlisting">#include <db_cxx.h>
int
DbEnv::repmgr_msg_dispatch(
void (*msg_dispatch_fcn) (DbEnv *env, DbChannel *channel,
Dbt *request, u_int32_t nrequest,
u_int32_t cb_flags),
u_int32_t flags); </pre>
<p>
Sets the message dispatch function. This function is responsible
for receiving messages sent from remote sites using either the
<a class="xref" href="dbchannel_send_msg.html" title="DbChannel::send_msg()">DbChannel::send_msg()</a>
or
<a class="xref" href="dbchannel_send_request.html" title="DbChannel::send_request()">DbChannel::send_request()</a>
methods. If the message received by this function was sent using the
<a class="xref" href="dbchannel_send_msg.html" title="DbChannel::send_msg()">DbChannel::send_msg()</a>
method then no response is required. If the message was sent using the
<a class="xref" href="dbchannel_send_request.html" title="DbChannel::send_request()">DbChannel::send_request()</a>
method, then this function must send a response using the
<a class="xref" href="dbchannel_send_msg.html" title="DbChannel::send_msg()">DbChannel::send_msg()</a>
method.
</p>
<p>
For best results, the
<code class="methodname">DbEnv::repmgr_msg_dispatch()</code> method should
be called before the Replication Manager has been started.
</p>
<p>
The <code class="methodname">DbEnv::repmgr_msg_dispatch()</code> <span>
<span>
method either returns a non-zero error value or throws an
exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp9871312"></a>Parameters</h3>
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp9870664"></a>msg_dispatch_fcn</h4>
</div>
</div>
</div>
<p>
This parameter is the application-specific function used
to handle messages sent over Replication Manager message
channels. It takes four parameters:
</p>
<div class="itemizedlist">
<ul type="disc">
<li>
<p>
<code class="literal">channel</code>
</p>
<p>
Provides the DbChannel to be used to send
a response back to the originator of the message.
If the message was sent by the remote site using
<a class="xref" href="dbchannel_send_request.html" title="DbChannel::send_request()">DbChannel::send_request()</a>
then this function should send a response back to
the originator using the channel provided on this
parameter. The message should be sent by calling
<a class="xref" href="dbchannel_send_msg.html" title="DbChannel::send_msg()">DbChannel::send_msg()</a>
exactly once.
</p>
<p>
This channel is valid only during the current
invocation of the dispatch function; it is
destroyed when the dispatch function returns. The
application may not save a copy of the pointer and
use it later elsewhere. Methods that do not make
sense in the context of a message dispatch
function (such as
<a class="xref" href="dbchannel_send_request.html" title="DbChannel::send_request()">DbChannel::send_request()</a>
and
<a class="xref" href="dbchannel_close.html" title="DbChannel::close()">DbChannel::close()</a>)
will be rejected with <code class="literal">EINVAL</code>.
</p>
</li>
<li>
<p>
<code class="literal">request</code>
</p>
<p>
Array of Dbts containing the message
received from the remote site.
</p>
</li>
<li>
<p>
<code class="literal">nrequest</code>
</p>
<p>
Specifies the number of elements in the
<code class="literal">request</code> array.
</p>
</li>
<li>
<p>
<code class="literal">cb_flags</code>
</p>
<p>
This flag is
<code class="literal">DB_REPMGR_NEED_RESPONSE</code> if the
message requires a response. Otherwise, it is
<code class="literal">0</code>.
</p>
</li>
</ul>
</div>
<p>
This function does not return a value. If the function
encounters an error, you can reflect the error back to
the originator of the message by formatting an error
message of your own design into the response.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp9883704"></a>flags</h4>
</div>
</div>
</div>
<p>
This parameter is currently unused, and must be
set to 0.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp9877984"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">DbEnv::repmgr_msg_dispatch()</code>
<span>
<span>
method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a>
exception, encapsulating one of the following non-zero errors, or return one
of the following non-zero errors:
</span>
</span>
</p>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp9881048"></a>EINVAL</h4>
</div>
</div>
</div>
<p>
If this method is called from a Base API application,
or if an invalid flag value or parameter was specified.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp9889232"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp9886080"></a>See Also</h3>
</div>
</div>
</div>
<p>
<a class="xref" href="rep.html#replist" title="Replication and Related Methods">Replication and Related Methods</a>
</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="repmgrget_ack_policy.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="rep.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="repmgrset_ack_policy.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">DbEnv::repmgr_get_ack_policy() </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> DbEnv::repmgr_set_ack_policy()</td>
</tr>
</table>
</div>
</body>
</html>
|
