1 /* Copyright (c) 2016, 2021, Oracle and/or its affiliates.
2 
3    This program is free software; you can redistribute it and/or modify
4    it under the terms of the GNU General Public License, version 2.0,
5    as published by the Free Software Foundation.
6 
7    This program is also distributed with certain software (including
8    but not limited to OpenSSL) that is licensed under separate terms,
9    as designated in a particular file or component or in included license
10    documentation.  The authors of MySQL hereby grant you an additional
11    permission to link the program and your derivative works with the
12    separately licensed software that they have included with MySQL.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License, version 2.0, for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
22 
23 #ifndef CONNECTION_CONTROL_COORDINATOR_H
24 #define CONNECTION_CONTROL_COORDINATOR_H
25 
26 #include "connection_control_interfaces.h" /* Connection_event_coordinator_services */
27 #include "connection_control_memory.h"  /* Connection_control_alloc */
28 
29 namespace connection_control
30 {
31   /**
32     Connection event coordinator.
33     This class will keep list of subscribers for different  subevents
34     and notify them based on their preference.
35   */
36 
37   class Connection_event_coordinator : public Connection_event_coordinator_services,
38                                        public Connection_control_alloc
39   {
40   public:
Connection_event_coordinator()41     Connection_event_coordinator()
42     {
43       reset();
44     }
~Connection_event_coordinator()45     ~Connection_event_coordinator()
46     {
47       reset();
48     }
49 
50     /* Functions to receive notification from server */
51     void notify_event(MYSQL_THD thd,
52                       Error_handler * error_handler,
53                       const mysql_event_connection *connection_event);
54     void notify_sys_var(Error_handler * error_handler,
55                         opt_connection_control variable,
56                         void *new_value);
57 
58     /* Services provided to observers */
59     bool register_event_subscriber(Connection_event_observer **subscriber,
60                                    std::vector<opt_connection_control> *sys_vars,
61                                    std::vector<stats_connection_control> *status_vars);
62 
63     bool notify_status_var(Connection_event_observer **observer,
64                            stats_connection_control status_var,
65                            status_var_action action);
66 
67   private:
68     void reset();
69     class Connection_event_subscriber
70     {
71     public:
72       Connection_event_observer * m_subscriber;
73       bool m_sys_vars[OPT_LAST];
74     };
75 
76     std::vector<Connection_event_subscriber> m_subscribers;
77     Connection_event_observer *m_status_vars_subscription[STAT_LAST];
78   };
79 }
80 #endif // !CONNECTION_CONTROL_COORDINATOR_H
81