Move monitor script processing and launching into the core

This removes parts of the nearly identical code from all monitors.

The removal of monitor type specific event checking is done based on the
assumption that only the monitor that is monitoring the server can be the
cause for a state change. This removes the need to actually check that the
state change is relevant for each monitor and allows the event handling to
be moved into the core.

server/core/monitor.c

@@ -42,20 +42,6 @@
 #include <maxscale/alloc.h>
 #include <maxscale/gwdirs.h>
 
-/*
- *  Create declarations of the enum for monitor events and also the array of
- *  structs containing the matching names. The data is taken from def_monitor_event.h
- *
- */
-
-#undef ADDITEM
-#define ADDITEM( _event_type, _event_name ) { #_event_name }
-const monitor_def_t monitor_event_definitions[MAX_MONITOR_EVENT] =
-{
-#include <maxscale/def_monitor_event.h>
-};
-#undef ADDITEM
-
 static MONITOR  *allMonitors = NULL;
 static SPINLOCK monLock = SPINLOCK_INIT;
 
@@ -837,7 +823,7 @@ mon_get_event_type(MONITOR_SERVERS* node)
     if (prev == present)
     {
         /* No change in the bits we're interested in */
-        return UNDEFINED_MONITOR_EVENT;
+        return UNDEFINED_EVENT;
     }
 
     if ((prev & SERVER_RUNNING) == 0)
@@ -904,7 +890,7 @@ mon_get_event_type(MONITOR_SERVERS* node)
                    (present & SERVER_JOINED) ? NEW_SYNCED_EVENT :
                    NEW_NDB_EVENT;
         default:
-            return UNDEFINED_MONITOR_EVENT;
+            return UNDEFINED_EVENT;
     }
 }
 
@@ -916,28 +902,17 @@ mon_get_event_type(MONITOR_SERVERS* node)
 const char*
 mon_get_event_name(MONITOR_SERVERS* node)
 {
-    return monitor_event_definitions[mon_get_event_type(node)].name;
-}
+    monitor_event_t event = mon_get_event_type(node);
 
-/*
- * Given the text version of a monitor event, determine the event (enum)
- *
- * @param   event_name          String containing the event name
- * @result  monitor_event_t     Monitor event corresponding to name
- */
-monitor_event_t
-mon_name_to_event(const char *event_name)
-{
-    monitor_event_t event;
-
-    for (event = 0; event < MAX_MONITOR_EVENT; event++)
+    for (int i = 0; monitor_event_enum_values[i].name; i++)
     {
-        if (0 == strcasecmp(monitor_event_definitions[event].name, event_name))
+        if (monitor_event_enum_values[i].enum_value & event)
         {
-            return event;
+            return monitor_event_enum_values[i].name;
         }
     }
-    return UNDEFINED_MONITOR_EVENT;
+
+    return "undefined_event";
 }
 
 /**
@@ -1001,9 +976,12 @@ mon_print_fail_status(MONITOR_SERVERS* mon_srv)
  * @param script Script to execute
  */
 void
-monitor_launch_script(MONITOR* mon, MONITOR_SERVERS* ptr, char* script)
+monitor_launch_script(MONITOR* mon, MONITOR_SERVERS* ptr, const char* script)
 {
-    EXTERNCMD* cmd = externcmd_allocate(script);
+    char arg[strlen(script) + 1];
+    strcpy(arg, script);
+
+    EXTERNCMD* cmd = externcmd_allocate(arg);
 
     if (cmd == NULL)
     {
@@ -1110,49 +1088,6 @@ monitor_launch_script(MONITOR* mon, MONITOR_SERVERS* ptr, char* script)
     externcmd_free(cmd);
 }
 
-/**
- * Parse a string of event names to an array with enabled events.
- * @param events Pointer to an array of boolean values
- * @param count Size of the array
- * @param string String to parse
- * @return 0 on success. 1 when an error has occurred or an unexpected event was
- * found.
- */
-int
-mon_parse_event_string(bool* events, size_t count, char* given_string)
-{
-    char *tok, *saved, *string = MXS_STRDUP(given_string);
-    MXS_ABORT_IF_NULL(string);
-    monitor_event_t event;
-
-    tok = strtok_r(string, ",| ", &saved);
-
-    if (tok == NULL)
-    {
-        MXS_FREE(string);
-        return -1;
-    }
-
-    while (tok)
-    {
-        event = mon_name_to_event(tok);
-        if (event == UNDEFINED_MONITOR_EVENT)
-        {
-            MXS_ERROR("Invalid event name %s", tok);
-            MXS_FREE(string);
-            return -1;
-        }
-        if (event < count)
-        {
-            events[event] = true;
-            tok = strtok_r(NULL, ",| ", &saved);
-        }
-    }
-
-    MXS_FREE(string);
-    return 0;
-}
-
 /**
  * Connect to a database. This will always leave a valid database handle in the
  * database->con pointer. This allows the user to call MySQL C API functions to
@@ -1498,3 +1433,19 @@ void servers_status_current_to_pending(MONITOR *monitor)
         ptr = ptr->next;
     }
 }
+
+void mon_process_state_changes(MONITOR *monitor, const char *script, uint64_t events)
+{
+    for (MONITOR_SERVERS *ptr = monitor->databases; ptr; ptr = ptr->next)
+    {
+        if (mon_status_changed(ptr))
+        {
+            mon_log_state_change(ptr);
+
+            if (script && (events & mon_get_event_type(ptr)))
+            {
+                monitor_launch_script(monitor, ptr, script);
+            }
+        }
+    }
+}