1 /*
2 Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
3
4 This file is part of libzmq, the ZeroMQ core engine in C++.
5
6 libzmq is free software; you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 As a special exception, the Contributors give you permission to link
12 this library with independent modules to produce an executable,
13 regardless of the license terms of these independent modules, and to
14 copy and distribute the resulting executable under terms of your choice,
15 provided that you also meet, for each linked independent module, the
16 terms and conditions of the license of that module. An independent
17 module is a module which is not derived from or based on this library.
18 If you modify this library, you must extend this exception to your
19 version of the library.
20
21 libzmq is distributed in the hope that it will be useful, but WITHOUT
22 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
23 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
24 License for more details.
25
26 You should have received a copy of the GNU Lesser General Public License
27 along with this program. If not, see <http://www.gnu.org/licenses/>.
28 */
29
30 #include "precompiled.hpp"
31 #include "rep.hpp"
32 #include "err.hpp"
33 #include "msg.hpp"
34
rep_t(class ctx_t * parent_,uint32_t tid_,int sid_)35 zmq::rep_t::rep_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
36 router_t (parent_, tid_, sid_),
37 _sending_reply (false),
38 _request_begins (true)
39 {
40 options.type = ZMQ_REP;
41 }
42
~rep_t()43 zmq::rep_t::~rep_t ()
44 {
45 }
46
xsend(msg_t * msg_)47 int zmq::rep_t::xsend (msg_t *msg_)
48 {
49 // If we are in the middle of receiving a request, we cannot send reply.
50 if (!_sending_reply) {
51 errno = EFSM;
52 return -1;
53 }
54
55 const bool more = (msg_->flags () & msg_t::more) != 0;
56
57 // Push message to the reply pipe.
58 const int rc = router_t::xsend (msg_);
59 if (rc != 0)
60 return rc;
61
62 // If the reply is complete flip the FSM back to request receiving state.
63 if (!more)
64 _sending_reply = false;
65
66 return 0;
67 }
68
xrecv(msg_t * msg_)69 int zmq::rep_t::xrecv (msg_t *msg_)
70 {
71 // If we are in middle of sending a reply, we cannot receive next request.
72 if (_sending_reply) {
73 errno = EFSM;
74 return -1;
75 }
76
77 // First thing to do when receiving a request is to copy all the labels
78 // to the reply pipe.
79 if (_request_begins) {
80 while (true) {
81 int rc = router_t::xrecv (msg_);
82 if (rc != 0)
83 return rc;
84
85 if ((msg_->flags () & msg_t::more)) {
86 // Empty message part delimits the traceback stack.
87 const bool bottom = (msg_->size () == 0);
88
89 // Push it to the reply pipe.
90 rc = router_t::xsend (msg_);
91 errno_assert (rc == 0);
92
93 if (bottom)
94 break;
95 } else {
96 // If the traceback stack is malformed, discard anything
97 // already sent to pipe (we're at end of invalid message).
98 rc = router_t::rollback ();
99 errno_assert (rc == 0);
100 }
101 }
102 _request_begins = false;
103 }
104
105 // Get next message part to return to the user.
106 const int rc = router_t::xrecv (msg_);
107 if (rc != 0)
108 return rc;
109
110 // If whole request is read, flip the FSM to reply-sending state.
111 if (!(msg_->flags () & msg_t::more)) {
112 _sending_reply = true;
113 _request_begins = true;
114 }
115
116 return 0;
117 }
118
xhas_in()119 bool zmq::rep_t::xhas_in ()
120 {
121 if (_sending_reply)
122 return false;
123
124 return router_t::xhas_in ();
125 }
126
xhas_out()127 bool zmq::rep_t::xhas_out ()
128 {
129 if (!_sending_reply)
130 return false;
131
132 return router_t::xhas_out ();
133 }
134