Initial implementation of the status interface reporter object.

include/wsrep/reporter.hpp

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2021 Codership Oy <info@codership.com>
+ *
+ * This file is part of wsrep-lib.
+ *
+ * Wsrep-lib is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Wsrep-lib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with wsrep-lib.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/** @file info.hpp
+ *
+ * Interface to report application status to external programs
+ * via JSON file.
+ */
+
+#ifndef WSREP_REPORTER_HPP
+#define WSREP_REPORTER_HPP
+
+#include "mutex.hpp"
+#include "server_state.hpp"
+
+#include <string>
+#include <deque>
+
+namespace wsrep
+{
+    class reporter
+    {
+    public:
+        reporter(mutex&             mutex,
+                 const std::string& file_name,
+                 size_t             max_msg);
+
+        virtual ~reporter();
+
+        // indefinite progress value
+        static float constexpr indefinite = -1.0f;
+
+        void report_state(enum server_state::state state,
+                          float progress = indefinite);
+
+        enum log_level
+        {
+            error,
+            warning
+        };
+
+        // undefined timestamp value
+        static double constexpr undefined = 0.0;
+
+        void report_log_msg(log_level, const std::string& msg,
+                            double timestamp = undefined);
+
+    private:
+        enum substates {
+            s_disconnected_disconnected,
+            s_disconnected_initializing,
+            s_disconnected_initialized,
+            s_connected_waiting, // to become joiner
+            s_joining_initialized,
+            s_joining_sst,
+            s_joining_initializing,
+            s_joining_ist,
+            s_joined_syncing,
+            s_synced_running,
+            s_donor_sending,
+            s_disconnecting_disconnecting,
+            substates_max
+        };
+
+        wsrep::mutex&       mutex_;
+        std::string const   file_name_;
+        char*               template_;
+        substates           state_;
+        float               progress_;
+        bool                initialized_;
+
+        typedef struct {
+            double tstamp;
+            std::string msg;
+        } log_msg;
+
+        std::deque<log_msg> err_msg_;
+        std::deque<log_msg> warn_msg_;
+        size_t const        max_msg_;
+
+        static void write_log_msgs(std::ostream& os,
+                                   const std::string& label,
+                                   const std::deque<log_msg>& msgs);
+        static void write_log_msg(std::ostream& os,
+                                   const log_msg& msg);
+
+        substates substate_map(enum server_state::state state);
+        float     progress_map(float progress) const;
+        void      write_file(double timestamp);
+
+        // make uncopyable
+        reporter(const wsrep::reporter&);
+        void operator=(const wsrep::reporter&);
+    }; /* reporter */
+
+} /* wsrep */
+
+#endif /* WSREP_REPORTER_HPP */