Cleanup session tracker

- call current_schema::mark_as_changed() directly
- call state_change::mark_as_changed() directly
- replaced SESSION_TRACKER_CHANGED with dummy tracker
- replaced Session_tracker::mark_as_changed() with
  State_tracker::mark_as_changed()
- hide and devirtualize original State_tracker::mark_as_changed(),
  rename it to set_changed()
- all implementations of mark_as_changed() now check is_enabled() for
  consistency
- no argument casts anymore

sql/session_tracker.cc

@@ -24,7 +24,7 @@
 #include "sql_plugin.h"
 #include "set_var.h"
 
-void State_tracker::mark_as_changed(THD *thd, LEX_CSTRING *tracked_item_name)
+void State_tracker::set_changed(THD *thd)
 {
   m_changed= true;
   thd->lex->safe_to_cache_query= 0;
@@ -506,11 +506,12 @@ bool Session_sysvars_tracker::store(THD *thd, String *buf)
   @param               [IN] pointer on a variable
 */
 
-void Session_sysvars_tracker::mark_as_changed(THD *thd,
-                                              LEX_CSTRING *var)
+void Session_sysvars_tracker::mark_as_changed(THD *thd, const sys_var *var)
 {
   sysvar_node_st *node;
-  sys_var *svar= (sys_var *)var;
+
+  if (!is_enabled())
+    return;
 
   if (!m_parsed)
   {
@@ -529,10 +530,10 @@ void Session_sysvars_tracker::mark_as_changed(THD *thd,
     Check if the specified system variable is being tracked, if so
     mark it as changed and also set the class's m_changed flag.
   */
-  if (orig_list.is_enabled() && (node= orig_list.insert_or_search(svar)))
+  if (orig_list.is_enabled() && (node= orig_list.insert_or_search(var)))
   {
     node->m_changed= true;
-    State_tracker::mark_as_changed(thd, var);
+    set_changed(thd);
   }
 }
 
@@ -679,7 +680,7 @@ bool Transaction_state_tracker::update(THD *thd, set_var *)
     }
     if (thd->variables.session_track_transaction_info == TX_TRACK_CHISTICS)
       tx_changed       |= TX_CHG_CHISTICS;
-    mark_as_changed(thd, NULL);
+    set_changed(thd);
   }
   else
     m_enabled= false;
@@ -1112,7 +1113,7 @@ void Transaction_state_tracker::set_read_flags(THD *thd,
   {
     tx_read_flags = flags;
     tx_changed   |= TX_CHG_CHISTICS;
-    mark_as_changed(thd, NULL);
+    set_changed(thd);
   }
 }
 
@@ -1131,7 +1132,7 @@ void Transaction_state_tracker::set_isol_level(THD *thd,
   {
     tx_isol_level = level;
     tx_changed   |= TX_CHG_CHISTICS;
-    mark_as_changed(thd, NULL);
+    set_changed(thd);
   }
 }
 

sql/session_tracker.h

@@ -66,6 +66,8 @@ class State_tracker
   */
   bool m_enabled;
 
+  void set_changed(THD *thd);
+
 private:
   /** Has the session state type changed ? */
   bool m_changed;
@@ -102,7 +104,7 @@ class State_tracker
   virtual bool store(THD *thd, String *buf)= 0;
 
   /** Mark the entity as changed. */
-  virtual void mark_as_changed(THD *thd, LEX_CSTRING *name);
+  void mark_as_changed(THD *thd) { if (is_enabled()) set_changed(thd); }
 };
 
 
@@ -207,7 +209,7 @@ class Session_sysvars_tracker: public State_tracker
   bool enable(THD *thd);
   bool update(THD *thd, set_var *var);
   bool store(THD *thd, String *buf);
-  void mark_as_changed(THD *thd, LEX_CSTRING *tracked_item_name);
+  void mark_as_changed(THD *thd, const sys_var *var);
   void deinit() { orig_list.deinit(); }
   /* callback */
   static uchar *sysvars_get_key(const char *entry, size_t *length,
@@ -376,15 +378,13 @@ class Transaction_state_tracker : public State_tracker
     tx_changed &= uint(~TX_CHG_STATE);
     tx_changed |= (tx_curr_state != tx_reported_state) ? TX_CHG_STATE : 0;
     if (tx_changed != TX_CHG_NONE)
-      mark_as_changed(thd, NULL);
+      set_changed(thd);
   }
 };
 
 #define TRANSACT_TRACKER(X) \
  do { if (thd->variables.session_track_transaction_info > TX_TRACK_NONE) \
         thd->session_tracker.transaction_info.X; } while(0)
-#define SESSION_TRACKER_CHANGED(A,B,C) \
-  thd->session_tracker.mark_as_changed(A,B,C)
 
 
 /**
@@ -430,14 +430,6 @@ class Session_tracker
       m_trackers[i]->enable(thd);
   }
 
-  inline void mark_as_changed(THD *thd, enum enum_session_tracker tracker,
-                              LEX_CSTRING *data)
-  {
-    if (m_trackers[tracker]->is_enabled())
-      m_trackers[tracker]->mark_as_changed(thd, data);
-  }
-
-
   void store(THD *thd, String *main_buf);
 };
 
@@ -446,7 +438,20 @@ int session_tracker_init();
 #else
 
 #define TRANSACT_TRACKER(X) do{}while(0)
-#define SESSION_TRACKER_CHANGED(A,B,C) do{}while(0)
+
+class Session_tracker
+{
+  class Dummy_tracker
+  {
+  public:
+    void mark_as_changed(THD *thd) {}
+    void mark_as_changed(THD *thd, const sys_var *var) {}
+  };
+public:
+  Dummy_tracker current_schema;
+  Dummy_tracker state_change;
+  Dummy_tracker sysvars;
+};
 
 #endif //EMBEDDED_LIBRARY
 

sql/set_var.cc

@@ -220,13 +220,12 @@ bool sys_var::update(THD *thd, set_var *var)
     */
     if ((var->type == OPT_SESSION) && (!ret))
     {
-      SESSION_TRACKER_CHANGED(thd, SESSION_SYSVARS_TRACKER,
-                              (LEX_CSTRING*)var->var);
+      thd->session_tracker.sysvars.mark_as_changed(thd, var->var);
       /*
         Here MySQL sends variable name to avoid reporting change of
         the tracker itself, but we decided that it is not needed
       */
-      SESSION_TRACKER_CHANGED(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
+      thd->session_tracker.state_change.mark_as_changed(thd);
     }
 
     return ret;
@@ -907,7 +906,7 @@ int set_var_user::update(THD *thd)
     return -1;
   }
 
-  SESSION_TRACKER_CHANGED(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
+  thd->session_tracker.state_change.mark_as_changed(thd);
   return 0;
 }
 
@@ -957,8 +956,7 @@ int set_var_role::update(THD *thd)
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   int res= acl_setrole(thd, role.str, access);
   if (!res)
-    thd->session_tracker.mark_as_changed(thd, SESSION_STATE_CHANGE_TRACKER,
-                                         NULL);
+    thd->session_tracker.state_change.mark_as_changed(thd);
   return res;
 #else
   return 0;
@@ -1015,18 +1013,13 @@ int set_var_collation_client::update(THD *thd)
                       character_set_results);
 
   /* Mark client collation variables as changed */
-#ifndef EMBEDDED_LIBRARY
-  if (thd->session_tracker.sysvars.is_enabled())
-  {
-    thd->session_tracker.sysvars.
-      mark_as_changed(thd, (LEX_CSTRING*)Sys_character_set_client_ptr);
-    thd->session_tracker.sysvars.
-      mark_as_changed(thd, (LEX_CSTRING*)Sys_character_set_results_ptr);
-    thd->session_tracker.sysvars.
-      mark_as_changed(thd, (LEX_CSTRING*)Sys_character_set_connection_ptr);
-  }
-  thd->session_tracker.mark_as_changed(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
-#endif //EMBEDDED_LIBRARY
+  thd->session_tracker.sysvars.mark_as_changed(thd,
+                                               Sys_character_set_client_ptr);
+  thd->session_tracker.sysvars.mark_as_changed(thd,
+                                               Sys_character_set_results_ptr);
+  thd->session_tracker.sysvars.mark_as_changed(thd,
+                                               Sys_character_set_connection_ptr);
+  thd->session_tracker.state_change.mark_as_changed(thd);
 
   thd->protocol_text.init(thd);
   thd->protocol_binary.init(thd);

sql/sql_class.cc

@@ -7216,11 +7216,10 @@ void THD::set_last_commit_gtid(rpl_gtid &gtid)
 #endif
   m_last_commit_gtid= gtid;
 #ifndef EMBEDDED_LIBRARY
-  if (changed_gtid && session_tracker.sysvars.is_enabled())
+  if (changed_gtid)
   {
     DBUG_ASSERT(current_thd == this);
-    session_tracker.sysvars.
-      mark_as_changed(this, (LEX_CSTRING*)Sys_last_gtid_ptr);
+    session_tracker.sysvars.mark_as_changed(this, Sys_last_gtid_ptr);
   }
 #endif
 }

sql/sql_class.h

@@ -4685,9 +4685,7 @@ class THD: public THD_count, /* this must be first */
   AUTHID invoker;
 
 public:
-#ifndef EMBEDDED_LIBRARY
   Session_tracker session_tracker;
-#endif //EMBEDDED_LIBRARY
   /*
     Flag, mutex and condition for a thread to wait for a signal from another
     thread.

sql/sql_db.cc

@@ -1089,7 +1089,7 @@ mysql_rm_db_internal(THD *thd, const LEX_CSTRING *db, bool if_exists, bool silen
   if (unlikely(thd->db.str && cmp_db_names(&thd->db, db) && !error))
   {
     mysql_change_db_impl(thd, NULL, 0, thd->variables.collation_server);
-    SESSION_TRACKER_CHANGED(thd, CURRENT_SCHEMA_TRACKER, NULL);
+    thd->session_tracker.current_schema.mark_as_changed(thd);
   }
   my_dirend(dirp);
   DBUG_RETURN(error);
@@ -1650,8 +1650,8 @@ uint mysql_change_db(THD *thd, const LEX_CSTRING *new_db_name,
   mysql_change_db_impl(thd, &new_db_file_name, db_access, db_default_cl);
 
 done:
-  SESSION_TRACKER_CHANGED(thd, CURRENT_SCHEMA_TRACKER, NULL);
-  SESSION_TRACKER_CHANGED(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
+  thd->session_tracker.current_schema.mark_as_changed(thd);
+  thd->session_tracker.state_change.mark_as_changed(thd);
   DBUG_RETURN(0);
 }
 

sql/sql_parse.cc

@@ -4814,7 +4814,7 @@ mysql_execute_command(THD *thd)
     */
     if(!res && (lex->create_info.options & HA_LEX_CREATE_TMP_TABLE))
     {
-      SESSION_TRACKER_CHANGED(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
+      thd->session_tracker.state_change.mark_as_changed(thd);
     }
     break;
   }

sql/sql_prepare.cc

@@ -2874,7 +2874,7 @@ void mysql_sql_stmt_prepare(THD *thd)
   }
   else
   {
-    SESSION_TRACKER_CHANGED(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
+    thd->session_tracker.state_change.mark_as_changed(thd);
     my_ok(thd, 0L, 0L, "Statement prepared");
   }
   change_list_savepoint.rollback(thd);
@@ -3554,7 +3554,7 @@ void mysql_sql_stmt_close(THD *thd)
   else
   {
     stmt->deallocate();
-    SESSION_TRACKER_CHANGED(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
+    thd->session_tracker.state_change.mark_as_changed(thd);
     my_ok(thd);
   }
 }

sql/sql_table.cc

@@ -10180,7 +10180,7 @@ do_continue:;
   if (table->s->tmp_table != NO_TMP_TABLE)
   {
     /* in case of alter temp table send the tracker in OK packet */
-    SESSION_TRACKER_CHANGED(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
+    thd->session_tracker.state_change.mark_as_changed(thd);
   }
 
   /*
@@ -11481,7 +11481,7 @@ bool Sql_cmd_create_table_like::execute(THD *thd)
          ON then send session state notification in OK packet */
       if (create_info.options & HA_LEX_CREATE_TMP_TABLE)
       {
-        SESSION_TRACKER_CHANGED(thd, SESSION_STATE_CHANGE_TRACKER, NULL);
+        thd->session_tracker.state_change.mark_as_changed(thd);
       }
       my_ok(thd);
     }