Added std::unique_ptr<> wrappers with deleters for libevent modules.

Author: kallewoof

src/Makefile.am

@@ -134,6 +134,7 @@ BITCOIN_CORE_H = \
   support/allocators/secure.h \
   support/allocators/zeroafterfree.h \
   support/cleanse.h \
+  support/events.h \
   support/lockedpool.h \
   sync.h \
   threadsafety.h \

src/support/events.h

@@ -0,0 +1,55 @@
+// Copyright (c) 2016 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_SUPPORT_EVENTS_H
+#define BITCOIN_SUPPORT_EVENTS_H
+
+#include <ios>
+
+#include <event2/event.h>
+#include <event2/http.h>
+
+#define MAKE_RAII(type) \
+/* deleter */\
+struct type##_deleter {\
+    void operator()(struct type* ob) {\
+        type##_free(ob);\
+    }\
+};\
+/* unique ptr typedef */\
+typedef std::unique_ptr<struct type, type##_deleter> raii_##type
+
+MAKE_RAII(event_base);
+MAKE_RAII(event);
+MAKE_RAII(evhttp);
+MAKE_RAII(evhttp_request);
+MAKE_RAII(evhttp_connection);
+
+raii_event_base obtain_event_base() {
+    auto result = raii_event_base(event_base_new());
+    if (!result.get())
+        throw std::runtime_error("cannot create event_base");
+    return result;
+}
+
+raii_event obtain_event(struct event_base* base, evutil_socket_t s, short events, event_callback_fn cb, void* arg) {
+    return raii_event(event_new(base, s, events, cb, arg));
+}
+
+raii_evhttp obtain_evhttp(struct event_base* base) {
+    return raii_evhttp(evhttp_new(base));
+}
+
+raii_evhttp_request obtain_evhttp_request(void(*cb)(struct evhttp_request *, void *), void *arg) {
+    return raii_evhttp_request(evhttp_request_new(cb, arg));
+}
+
+raii_evhttp_connection obtain_evhttp_connection_base(struct event_base* base, std::string host, uint16_t port) {
+    auto result = raii_evhttp_connection(evhttp_connection_base_new(base, NULL, host.c_str(), port));
+    if (!result.get())
+        throw std::runtime_error("create connection failed");
+    return result;
+}
+
+#endif // BITCOIN_SUPPORT_EVENTS_H