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#ifndef __ZMQ_I_ENGINE_HPP_INCLUDED__
31#define __ZMQ_I_ENGINE_HPP_INCLUDED__
32
33#include "endpoint.hpp"
34#include "macros.hpp"
35
36namespace zmq
37{
38class io_thread_t;
39
40// Abstract interface to be implemented by various engines.
41
42struct i_engine
43{
44 enum error_reason_t
45 {
46 protocol_error,
47 connection_error,
48 timeout_error
49 };
50
51 virtual ~i_engine () ZMQ_DEFAULT;
52
53 // Plug the engine to the session.
54 virtual void plug (zmq::io_thread_t *io_thread_,
55 class session_base_t *session_) = 0;
56
57 // Terminate and deallocate the engine. Note that 'detached'
58 // events are not fired on termination.
59 virtual void terminate () = 0;
60
61 // This method is called by the session to signalise that more
62 // messages can be written to the pipe.
63 // Returns false if the engine was deleted due to an error.
64 // TODO it is probably better to change the design such that the engine
65 // does not delete itself
66 virtual bool restart_input () = 0;
67
68 // This method is called by the session to signalise that there
69 // are messages to send available.
70 virtual void restart_output () = 0;
71
72 virtual void zap_msg_available () = 0;
73
74 virtual const endpoint_uri_pair_t &get_endpoint () const = 0;
75};
76}
77
78#endif
79