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
|
/*
Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file
This file is part of 0MQ.
0MQ is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
0MQ is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include "xsub.hpp"
#include "err.hpp"
zmq::xsub_t::xsub_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
socket_base_t (parent_, tid_, sid_),
has_message (false),
more (false)
{
options.type = ZMQ_XSUB;
// When socket is being closed down we don't want to wait till pending
// subscription commands are sent to the wire.
options.linger = 0;
int rc = message.init ();
errno_assert (rc == 0);
}
zmq::xsub_t::~xsub_t ()
{
int rc = message.close ();
errno_assert (rc == 0);
}
void zmq::xsub_t::xattach_pipe (pipe_t *pipe_, bool subscribe_to_all_)
{
// subscribe_to_all_ is unused
(void) subscribe_to_all_;
zmq_assert (pipe_);
fq.attach (pipe_);
dist.attach (pipe_);
// Send all the cached subscriptions to the new upstream peer.
subscriptions.apply (send_subscription, pipe_);
pipe_->flush ();
}
void zmq::xsub_t::xread_activated (pipe_t *pipe_)
{
fq.activated (pipe_);
}
void zmq::xsub_t::xwrite_activated (pipe_t *pipe_)
{
dist.activated (pipe_);
}
void zmq::xsub_t::xpipe_terminated (pipe_t *pipe_)
{
fq.pipe_terminated (pipe_);
dist.pipe_terminated (pipe_);
}
void zmq::xsub_t::xhiccuped (pipe_t *pipe_)
{
// Send all the cached subscriptions to the hiccuped pipe.
subscriptions.apply (send_subscription, pipe_);
pipe_->flush ();
}
int zmq::xsub_t::xsend (msg_t *msg_)
{
size_t size = msg_->size ();
unsigned char *data = (unsigned char *) msg_->data ();
if (size > 0 && *data == 1) {
// Process subscribe message
// This used to filter out duplicate subscriptions,
// however this is alread done on the XPUB side and
// doing it here as well breaks ZMQ_XPUB_VERBOSE
// when there are forwarding devices involved.
subscriptions.add (data + 1, size - 1);
return dist.send_to_all (msg_);
}
else
if (size > 0 && *data == 0) {
// Process unsubscribe message
if (subscriptions.rm (data + 1, size - 1))
return dist.send_to_all (msg_);
}
else
// User message sent upstream to XPUB socket
return dist.send_to_all (msg_);
int rc = msg_->close ();
errno_assert (rc == 0);
rc = msg_->init ();
errno_assert (rc == 0);
return 0;
}
bool zmq::xsub_t::xhas_out ()
{
// Subscription can be added/removed anytime.
return true;
}
int zmq::xsub_t::xrecv (msg_t *msg_)
{
// If there's already a message prepared by a previous call to zmq_poll,
// return it straight ahead.
if (has_message) {
int rc = msg_->move (message);
errno_assert (rc == 0);
has_message = false;
more = msg_->flags () & msg_t::more ? true : false;
return 0;
}
// TODO: This can result in infinite loop in the case of continuous
// stream of non-matching messages which breaks the non-blocking recv
// semantics.
while (true) {
// Get a message using fair queueing algorithm.
int rc = fq.recv (msg_);
// If there's no message available, return immediately.
// The same when error occurs.
if (rc != 0)
return -1;
// Check whether the message matches at least one subscription.
// Non-initial parts of the message are passed
if (more || !options.filter || match (msg_)) {
more = msg_->flags () & msg_t::more ? true : false;
return 0;
}
// Message doesn't match. Pop any remaining parts of the message
// from the pipe.
while (msg_->flags () & msg_t::more) {
rc = fq.recv (msg_);
errno_assert (rc == 0);
}
}
}
bool zmq::xsub_t::xhas_in ()
{
// There are subsequent parts of the partly-read message available.
if (more)
return true;
// If there's already a message prepared by a previous call to zmq_poll,
// return straight ahead.
if (has_message)
return true;
// TODO: This can result in infinite loop in the case of continuous
// stream of non-matching messages.
while (true) {
// Get a message using fair queueing algorithm.
int rc = fq.recv (&message);
// If there's no message available, return immediately.
// The same when error occurs.
if (rc != 0) {
errno_assert (errno == EAGAIN);
return false;
}
// Check whether the message matches at least one subscription.
if (!options.filter || match (&message)) {
has_message = true;
return true;
}
// Message doesn't match. Pop any remaining parts of the message
// from the pipe.
while (message.flags () & msg_t::more) {
rc = fq.recv (&message);
errno_assert (rc == 0);
}
}
}
bool zmq::xsub_t::match (msg_t *msg_)
{
return subscriptions.check ((unsigned char*) msg_->data (), msg_->size ());
}
void zmq::xsub_t::send_subscription (unsigned char *data_, size_t size_,
void *arg_)
{
pipe_t *pipe = (pipe_t*) arg_;
// Create the subsctription message.
msg_t msg;
int rc = msg.init_size (size_ + 1);
errno_assert (rc == 0);
unsigned char *data = (unsigned char*) msg.data ();
data [0] = 1;
memcpy (data + 1, data_, size_);
// Send it to the pipe.
bool sent = pipe->write (&msg);
// If we reached the SNDHWM, and thus cannot send the subscription, drop
// the subscription message instead. This matches the behaviour of
// zmq_setsockopt(ZMQ_SUBSCRIBE, ...), which also drops subscriptions
// when the SNDHWM is reached.
if (!sent)
msg.close ();
}
|
