summaryrefslogtreecommitdiff
path: root/src/xsub.cpp
blob: 7272a8e3dee28f1f2d16af270f9d00baf76edf9e (plain)
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
/*
    Copyright (c) 2010-2012 250bpm s.r.o.
    Copyright (c) 2011 VMware, Inc.
    Copyright (c) 2010-2011 Other contributors as noted in the AUTHORS file

    This file is part of Crossroads I/O project.

    Crossroads I/O 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.

    Crossroads 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"
#include "wire.hpp"

xs::xsub_t::xsub_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
    socket_base_t (parent_, tid_, sid_)
{
    options.type = XS_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;

    //  Also, we want the subscription buffer to be elastic by default.
    options.sndhwm = 0;
}

xs::xsub_t::~xsub_t ()
{
}

void xs::xsub_t::xattach_pipe (pipe_t *pipe_, bool icanhasall_)
{
    xs_assert (pipe_);
    fq.attach (pipe_);

    //  Pipes with 0MQ/2.1-style protocol are not eligible for accepting
    //  subscriptions.
    if (pipe_->get_protocol () == 1)
        return;

    dist.attach (pipe_);

    //  Send all the cached subscriptions to the new upstream peer.
    for (subscriptions_t::iterator its = subscriptions.begin ();
          its != subscriptions.end (); ++its)
        send_subscription (pipe_, true, its->first.first,
            its->first.second.data (), its->first.second.size ());
    pipe_->flush ();
}

void xs::xsub_t::xread_activated (pipe_t *pipe_)
{
    fq.activated (pipe_);
}

void xs::xsub_t::xwrite_activated (pipe_t *pipe_)
{
    dist.activated (pipe_);
}

void xs::xsub_t::xterminated (pipe_t *pipe_)
{
    fq.terminated (pipe_);
    if (pipe_->get_protocol () != 1)
        dist.terminated (pipe_);
}

void xs::xsub_t::xhiccuped (pipe_t *pipe_)
{
    //  In 0MQ/2.1 protocol there is no subscription forwarding.
    if (pipe_->get_protocol () == 1)
        return;

    //  Send all the cached subscriptions to the new upstream peer.
    for (subscriptions_t::iterator its = subscriptions.begin ();
          its != subscriptions.end (); ++its)
        send_subscription (pipe_, true, its->first.first,
            its->first.second.data (), its->first.second.size ());
    pipe_->flush ();
}

int xs::xsub_t::xsend (msg_t *msg_, int flags_)
{
    size_t size = msg_->size ();
    unsigned char *data = (unsigned char*) msg_->data ();

    if (size < 4) {
        errno = EINVAL;
        return -1;
    }
    int cmd = get_uint16 (data);
    int filter_id = get_uint16 (data + 2);
    if (cmd != XS_CMD_SUBSCRIBE && cmd != XS_CMD_UNSUBSCRIBE) {
        errno = EINVAL;
        return -1;
    }

    //  Process the subscription.
    if (cmd == XS_CMD_SUBSCRIBE) {
        subscriptions_t::iterator it = subscriptions.insert (
           std::make_pair (std::make_pair (filter_id,
           blob_t (data + 4, size - 4)), 0)).first;
        ++it->second;
        if (it->second == 1)
            return dist.send_to_all (msg_, flags_);
    }
    else if (cmd == XS_CMD_UNSUBSCRIBE) {
        subscriptions_t::iterator it = subscriptions.find (
            std::make_pair (filter_id, blob_t (data + 4, size - 4)));
        if (it != subscriptions.end ()) {
            xs_assert (it->second);
            --it->second;
            if (!it->second) {
                subscriptions.erase (it);
                return dist.send_to_all (msg_, flags_);
            }
        }
    }

    int rc = msg_->close ();
    errno_assert (rc == 0);
    rc = msg_->init ();
    errno_assert (rc == 0);
    return 0;
}

bool xs::xsub_t::xhas_out ()
{
    //  Subscription can be added/removed anytime.
    return true;
}

int xs::xsub_t::xrecv (msg_t *msg_, int flags_)
{
    return fq.recv (msg_, flags_);
}

bool xs::xsub_t::xhas_in ()
{
    return fq.has_in ();
}

void xs::xsub_t::send_subscription (pipe_t *pipe_, bool subscribe_,
    int filter_id_, const unsigned char *data_, size_t size_)
{
    //  Create the subsctription message.
    msg_t msg;
    int rc = msg.init_size (size_ + 4);
    xs_assert (rc == 0);
    unsigned char *data = (unsigned char*) msg.data ();
    put_uint16 (data, subscribe_ ? XS_CMD_SUBSCRIBE : XS_CMD_UNSUBSCRIBE);
    put_uint16 (data + 2, filter_id_);
    memcpy (data + 4, 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
    //  xs_setsockopt(XS_SUBSCRIBE, ...), which also drops subscriptions
    //  when the SNDHWM is reached.
    if (!sent)
        msg.close ();
}

xs::xsub_session_t::xsub_session_t (io_thread_t *io_thread_, bool connect_,
      socket_base_t *socket_, const options_t &options_,
      const char *protocol_, const char *address_) :
    session_base_t (io_thread_, connect_, socket_, options_, protocol_,
        address_)
{
}

xs::xsub_session_t::~xsub_session_t ()
{
}