1  // Copyright (c) 2016-2018 The Bitcoin Core developers
 2  // Distributed under the MIT software license, see the accompanying
 3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 4  
 5  #ifndef BITCOIN_SUPPORT_EVENTS_H
 6  #define BITCOIN_SUPPORT_EVENTS_H
 7  
 8  #include <ios>
 9  #include <memory>
10  
11  #include <event2/event.h>
12  #include <event2/http.h>
13  
14  #define MAKE_RAII(type) \
15  /* deleter */\
16  struct type##_deleter {\
17      void operator()(struct type* ob) {\
18          type##_free(ob);\
19      }\
20  };\
21  /* unique ptr typedef */\
22  typedef std::unique_ptr<struct type, type##_deleter> raii_##type
23  
24  MAKE_RAII(event_base);
25  MAKE_RAII(event);
26  MAKE_RAII(evhttp);
27  MAKE_RAII(evhttp_request);
28  MAKE_RAII(evhttp_connection);
29  
30  inline raii_event_base obtain_event_base() {
31      auto result = raii_event_base(event_base_new());
32      if (!result.get())
33          throw std::runtime_error("cannot create event_base");
34      return result;
35  }
36  
37  inline raii_event obtain_event(struct event_base* base, evutil_socket_t s, short events, event_callback_fn cb, void* arg) {
38      return raii_event(event_new(base, s, events, cb, arg));
39  }
40  
41  inline raii_evhttp obtain_evhttp(struct event_base* base) {
42      return raii_evhttp(evhttp_new(base));
43  }
44  
45  inline raii_evhttp_request obtain_evhttp_request(void(*cb)(struct evhttp_request *, void *), void *arg) {
46      return raii_evhttp_request(evhttp_request_new(cb, arg));
47  }
48  
49  inline raii_evhttp_connection obtain_evhttp_connection_base(struct event_base* base, std::string host, uint16_t port) {
50      auto result = raii_evhttp_connection(evhttp_connection_base_new(base, nullptr, host.c_str(), port));
51      if (!result.get())
52          throw std::runtime_error("create connection failed");
53      return result;
54  }
55  
56  #endif // BITCOIN_SUPPORT_EVENTS_H