MXS-1944 Store failover parameters in an object

Several of the parameters are passed on from function to function. Having them all
in an object cleans things up and makes adding more data easier.

server/modules/monitor/mariadbmon/mariadbmon_common.hh

@@ -22,6 +22,7 @@
 
 #include <string>
 #include <maxscale/json_api.h>
+#include <maxbase/stopwatch.hh>
 
 /** Utility macros for printing both MXS_ERROR and json error */
 #define PRINT_MXS_JSON_ERROR(err_out, format, ...) \
@@ -66,14 +67,38 @@ private:
     std::string       m_current_separator;
 };
 
-enum class ClusterOperation
-{
-    SWITCHOVER,
-    FAILOVER
-};
-
 enum class Log
 {
     OFF,
     ON
 };
+
+enum class OperationType
+{
+    SWITCHOVER,
+    FAILOVER
+};
+
+class MariaDBServer;
+
+/**
+ *  Class which encapsulates many settings and status descriptors for a failover/switchover.
+ *  Is more convenient to pass around than the separate elements. Most fields are constants or constant
+ *  pointers since they should not change during an operation.
+ */
+class ClusterOperation
+{
+public:
+    const OperationType  type;                        // Failover or switchover
+    MariaDBServer* const promotion_target;            // Which server will be promoted
+    MariaDBServer* const demotion_target;             // Which server will be demoted
+    const bool           demotion_target_is_master;   // Was the demotion target the master?
+    const bool           handle_events;               // Should scheduled server events be disabled/enabled?
+    json_t** const       error_out;                   // Json error output
+    maxbase::Duration    time_remaining;              // How much time remains to complete the operation
+
+    ClusterOperation(OperationType type,
+                     MariaDBServer* promotion_target, MariaDBServer* demotion_target,
+                     bool demo_target_is_master, bool handle_events,
+                     json_t** error, maxbase::Duration time_remaining);
+};