MDEV-10441 Document the server_audit_loc_info variable

fix PLUGIN_VAR_NOSYSVAR | PLUGIN_VAR_NOCMDOPT plugin thdvars to work.
use that for server_audit_loc_info

mysql-test/suite/plugins/r/server_audit.result

@@ -8,7 +8,6 @@ server_audit_file_rotate_now	OFF
 server_audit_file_rotate_size	1000000
 server_audit_file_rotations	9
 server_audit_incl_users	
-server_audit_loc_info	
 server_audit_logging	OFF
 server_audit_mode	0
 server_audit_output_type	file
@@ -72,7 +71,6 @@ server_audit_file_rotate_now	OFF
 server_audit_file_rotate_size	1000000
 server_audit_file_rotations	9
 server_audit_incl_users	odin, root, dva, tri
-server_audit_loc_info	
 server_audit_logging	ON
 server_audit_mode	0
 server_audit_output_type	file
@@ -218,7 +216,6 @@ server_audit_file_rotate_now	OFF
 server_audit_file_rotate_size	1000000
 server_audit_file_rotations	9
 server_audit_incl_users	odin, root, dva, tri
-server_audit_loc_info	
 server_audit_logging	ON
 server_audit_mode	1
 server_audit_output_type	file

mysql-test/suite/plugins/r/thread_pool_server_audit.result

@@ -8,7 +8,6 @@ server_audit_file_rotate_now	OFF
 server_audit_file_rotate_size	1000000
 server_audit_file_rotations	9
 server_audit_incl_users	
-server_audit_loc_info	
 server_audit_logging	OFF
 server_audit_mode	0
 server_audit_output_type	file
@@ -72,7 +71,6 @@ server_audit_file_rotate_now	OFF
 server_audit_file_rotate_size	1000000
 server_audit_file_rotations	9
 server_audit_incl_users	odin, root, dva, tri
-server_audit_loc_info	
 server_audit_logging	ON
 server_audit_mode	0
 server_audit_output_type	file
@@ -218,7 +216,6 @@ server_audit_file_rotate_now	OFF
 server_audit_file_rotate_size	1000000
 server_audit_file_rotations	9
 server_audit_incl_users	odin, root, dva, tri
-server_audit_loc_info	
 server_audit_logging	ON
 server_audit_mode	1
 server_audit_output_type	file

plugin/server_audit/server_audit.c

@@ -429,9 +429,8 @@ static MYSQL_SYSVAR_UINT(query_log_limit, query_log_limit,
 char locinfo_ini_value[sizeof(struct connection_info)+4];
 
 static MYSQL_THDVAR_STR(loc_info,
-                        PLUGIN_VAR_READONLY | PLUGIN_VAR_MEMALLOC,
-                        "Auxiliary info.", NULL, NULL,
-                        locinfo_ini_value);
+                        PLUGIN_VAR_NOSYSVAR | PLUGIN_VAR_NOCMDOPT | PLUGIN_VAR_MEMALLOC,
+                        "Internal info", NULL, NULL, locinfo_ini_value);
 
 static const char *syslog_facility_names[]=
 {

sql/sql_plugin.cc

@@ -2756,6 +2756,22 @@ static st_bookmark *find_bookmark(const char *plugin, const char *name,
 }
 
 
+static size_t var_storage_size(int flags)
+{
+  switch (flags & PLUGIN_VAR_TYPEMASK) {
+  case PLUGIN_VAR_BOOL:         return sizeof(my_bool);
+  case PLUGIN_VAR_INT:          return sizeof(int);
+  case PLUGIN_VAR_LONG:         return sizeof(long);
+  case PLUGIN_VAR_ENUM:         return sizeof(long);
+  case PLUGIN_VAR_LONGLONG:     return sizeof(ulonglong);
+  case PLUGIN_VAR_SET:          return sizeof(ulonglong);
+  case PLUGIN_VAR_STR:          return sizeof(char*);
+  case PLUGIN_VAR_DOUBLE:       return sizeof(double);
+  default: DBUG_ASSERT(0);      return 0;
+  }
+}
+
+
 /*
   returns a bookmark for thd-local variables, creating if neccessary.
   returns null for non thd-local variables.
@@ -2764,39 +2780,13 @@ static st_bookmark *find_bookmark(const char *plugin, const char *name,
 static st_bookmark *register_var(const char *plugin, const char *name,
                                  int flags)
 {
-  uint length= strlen(plugin) + strlen(name) + 3, size= 0, offset, new_size;
+  uint length= strlen(plugin) + strlen(name) + 3, size, offset, new_size;
   st_bookmark *result;
   char *varname, *p;
 
-  if (!(flags & PLUGIN_VAR_THDLOCAL))
-    return NULL;
-
-  switch (flags & PLUGIN_VAR_TYPEMASK) {
-  case PLUGIN_VAR_BOOL:
-    size= sizeof(my_bool);
-    break;
-  case PLUGIN_VAR_INT:
-    size= sizeof(int);
-    break;
-  case PLUGIN_VAR_LONG:
-  case PLUGIN_VAR_ENUM:
-    size= sizeof(long);
-    break;
-  case PLUGIN_VAR_LONGLONG:
-  case PLUGIN_VAR_SET:
-    size= sizeof(ulonglong);
-    break;
-  case PLUGIN_VAR_STR:
-    size= sizeof(char*);
-    break;
-  case PLUGIN_VAR_DOUBLE:
-    size= sizeof(double);
-    break;
-  default:
-    DBUG_ASSERT(0);
-    return NULL;
-  };
+  DBUG_ASSERT(flags & PLUGIN_VAR_THDLOCAL);
 
+  size= var_storage_size(flags);
   varname= ((char*) my_alloca(length));
   strxmov(varname + 1, plugin, "_", name, NullS);
   for (p= varname + 1; *p; p++)
@@ -3005,25 +2995,17 @@ void sync_dynamic_session_variables(THD* thd, bool global_lock)
   */
   for (idx= 0; idx < bookmark_hash.records; idx++)
   {
-    sys_var_pluginvar *pi;
-    sys_var *var;
     st_bookmark *v= (st_bookmark*) my_hash_element(&bookmark_hash,idx);
 
     if (v->version <= thd->variables.dynamic_variables_version)
       continue; /* already in thd->variables */
 
-    if (!(var= intern_find_sys_var(v->key + 1, v->name_len)) ||
-        !(pi= var->cast_pluginvar()) ||
-        v->key[0] != plugin_var_bookmark_key(pi->plugin_var->flags))
-      continue;
-
     /* Here we do anything special that may be required of the data types */
 
-    if ((pi->plugin_var->flags & PLUGIN_VAR_TYPEMASK) == PLUGIN_VAR_STR &&
-        pi->plugin_var->flags & PLUGIN_VAR_MEMALLOC)
+    if ((v->key[0] & PLUGIN_VAR_TYPEMASK) == PLUGIN_VAR_STR &&
+         v->key[0] & BOOKMARK_MEMALLOC)
     {
-      int offset= ((thdvar_str_t *)(pi->plugin_var))->offset;
-      char **pp= (char**) (thd->variables.dynamic_variables_ptr + offset);
+      char **pp= (char**) (thd->variables.dynamic_variables_ptr + v->offset);
       if (*pp)
         *pp= my_strdup(*pp, MYF(MY_WME|MY_FAE));
     }
@@ -3284,69 +3266,58 @@ bool sys_var_pluginvar::session_update(THD *thd, set_var *var)
   return false;
 }
 
-bool sys_var_pluginvar::global_update(THD *thd, set_var *var)
+static const void *var_def_ptr(st_mysql_sys_var *pv)
 {
-  DBUG_ASSERT(!is_readonly());
-  mysql_mutex_assert_owner(&LOCK_global_system_variables);
-
-  void *tgt= real_value_ptr(thd, var->type);
-  const void *src= &var->save_result;
-
-  if (!var->value)
-  {
-    switch (plugin_var->flags & (PLUGIN_VAR_TYPEMASK | PLUGIN_VAR_THDLOCAL)) {
+    switch (pv->flags & (PLUGIN_VAR_TYPEMASK | PLUGIN_VAR_THDLOCAL)) {
     case PLUGIN_VAR_INT:
-      src= &((sysvar_uint_t*) plugin_var)->def_val;
-      break;
+      return &((sysvar_uint_t*) pv)->def_val;
     case PLUGIN_VAR_LONG:
-      src= &((sysvar_ulong_t*) plugin_var)->def_val;
-      break;
+      return &((sysvar_ulong_t*) pv)->def_val;
     case PLUGIN_VAR_LONGLONG:
-      src= &((sysvar_ulonglong_t*) plugin_var)->def_val;
-      break;
+      return &((sysvar_ulonglong_t*) pv)->def_val;
     case PLUGIN_VAR_ENUM:
-      src= &((sysvar_enum_t*) plugin_var)->def_val;
-      break;
+      return &((sysvar_enum_t*) pv)->def_val;
     case PLUGIN_VAR_SET:
-      src= &((sysvar_set_t*) plugin_var)->def_val;
-      break;
+      return &((sysvar_set_t*) pv)->def_val;
     case PLUGIN_VAR_BOOL:
-      src= &((sysvar_bool_t*) plugin_var)->def_val;
-      break;
+      return &((sysvar_bool_t*) pv)->def_val;
     case PLUGIN_VAR_STR:
-      src= &((sysvar_str_t*) plugin_var)->def_val;
-      break;
+      return &((sysvar_str_t*) pv)->def_val;
     case PLUGIN_VAR_DOUBLE:
-      src= &((sysvar_double_t*) plugin_var)->def_val;
-      break;
+      return &((sysvar_double_t*) pv)->def_val;
     case PLUGIN_VAR_INT | PLUGIN_VAR_THDLOCAL:
-      src= &((thdvar_uint_t*) plugin_var)->def_val;
-      break;
+      return &((thdvar_uint_t*) pv)->def_val;
     case PLUGIN_VAR_LONG | PLUGIN_VAR_THDLOCAL:
-      src= &((thdvar_ulong_t*) plugin_var)->def_val;
-      break;
+      return &((thdvar_ulong_t*) pv)->def_val;
     case PLUGIN_VAR_LONGLONG | PLUGIN_VAR_THDLOCAL:
-      src= &((thdvar_ulonglong_t*) plugin_var)->def_val;
-      break;
+      return &((thdvar_ulonglong_t*) pv)->def_val;
     case PLUGIN_VAR_ENUM | PLUGIN_VAR_THDLOCAL:
-      src= &((thdvar_enum_t*) plugin_var)->def_val;
-      break;
+      return &((thdvar_enum_t*) pv)->def_val;
     case PLUGIN_VAR_SET | PLUGIN_VAR_THDLOCAL:
-      src= &((thdvar_set_t*) plugin_var)->def_val;
-      break;
+      return &((thdvar_set_t*) pv)->def_val;
     case PLUGIN_VAR_BOOL | PLUGIN_VAR_THDLOCAL:
-      src= &((thdvar_bool_t*) plugin_var)->def_val;
-      break;
+      return &((thdvar_bool_t*) pv)->def_val;
     case PLUGIN_VAR_STR | PLUGIN_VAR_THDLOCAL:
-      src= &((thdvar_str_t*) plugin_var)->def_val;
-      break;
+      return &((thdvar_str_t*) pv)->def_val;
     case PLUGIN_VAR_DOUBLE | PLUGIN_VAR_THDLOCAL:
-      src= &((thdvar_double_t*) plugin_var)->def_val;
-      break;
+      return &((thdvar_double_t*) pv)->def_val;
     default:
       DBUG_ASSERT(0);
+      return NULL;
     }
-  }
+}
+
+
+bool sys_var_pluginvar::global_update(THD *thd, set_var *var)
+{
+  DBUG_ASSERT(!is_readonly());
+  mysql_mutex_assert_owner(&LOCK_global_system_variables);
+
+  void *tgt= real_value_ptr(thd, var->type);
+  const void *src= &var->save_result;
+
+  if (!var->value)
+    src= var_def_ptr(plugin_var);
 
   plugin_var->update(thd, plugin_var, tgt, src);
   return false;
@@ -3713,7 +3684,18 @@ static int construct_options(MEM_ROOT *mem_root, struct st_plugin_int *tmp,
       *(int*)(opt + 1)= offset= v->offset;
 
       if (opt->flags & PLUGIN_VAR_NOCMDOPT)
+      {
+        char *val= global_system_variables.dynamic_variables_ptr + offset;
+        if (((opt->flags & PLUGIN_VAR_TYPEMASK) == PLUGIN_VAR_STR) &&
+             (opt->flags & PLUGIN_VAR_MEMALLOC))
+        {
+          char *def_val= *(char**)var_def_ptr(opt);
+          *(char**)val= def_val ? my_strdup(def_val, MYF(0)) : NULL;
+        }
+        else
+          memcpy(val, var_def_ptr(opt), var_storage_size(opt->flags));
         continue;
+      }
 
       optname= (char*) memdup_root(mem_root, v->key + 1, 
                                    (optnamelen= v->name_len) + 1);
@@ -3912,9 +3894,10 @@ static int test_plugin_options(MEM_ROOT *tmp_root, struct st_plugin_int *tmp,
         *str->value= strdup_root(mem_root, *str->value);
     }
 
+    var= find_bookmark(plugin_name.str, o->name, o->flags);
     if (o->flags & PLUGIN_VAR_NOSYSVAR)
       continue;
-    if ((var= find_bookmark(plugin_name.str, o->name, o->flags)))
+    if (var)
       v= new (mem_root) sys_var_pluginvar(&chain, var->key + 1, o, tmp);
     else
     {