MDEV-16470: switch off user variables (and fixes of its support)

Author: sanja-byelkin

client/mysqltest.cc

@@ -7711,6 +7711,28 @@ void append_info(DYNAMIC_STRING *ds, ulonglong affected_rows,
 }
 
 
+#ifndef EMBEDDED_LIBRARY
+static const char *trking_info_desc[SESSION_TRACK_END + 1]=
+{
+  "Tracker : SESSION_TRACK_SYSTEM_VARIABLES\n",
+  "Tracker : SESSION_TRACK_SCHEMA\n",
+  "Tracker : SESSION_TRACK_STATE_CHANGE\n",
+  "Tracker : SESSION_TRACK_GTIDS\n",
+  "Tracker : SESSION_TRACK_TRANSACTION_CHARACTERISTICS\n",
+  "Tracker : SESSION_TRACK_TRANSACTION_TYPE\n"
+#ifdef USER_VAR_TRACKING
+  ,
+  "Tracker : SESSION_TRACK_MYSQL_RESERVED1\n",
+  "Tracker : SESSION_TRACK_MYSQL_RESERVED2\n",
+  "Tracker : SESSION_TRACK_MYSQL_RESERVED3\n",
+  "Tracker : SESSION_TRACK_MYSQL_RESERVED4\n",
+  "Tracker : SESSION_TRACK_MYSQL_RESERVED5\n",
+  "Tracker : SESSION_TRACK_MYSQL_RESERVED6\n",
+  "Tracker : SESSION_TRACK_USER_VARIABLES\n"
+#endif // USER_VAR_TRACKING
+};
+#endif // EMBEDDED_LIBRARY
+
 /**
   @brief Append state change information (received through Ok packet) to the output.
 
@@ -7731,31 +7753,15 @@ static void append_session_track_info(DYNAMIC_STRING *ds, MYSQL *mysql)
                                        &data, &data_length))
     {
       dynstr_append(ds, "-- ");
-      switch (type)
+      if (type <= SESSION_TRACK_END)
       {
-        case SESSION_TRACK_SYSTEM_VARIABLES:
-          dynstr_append(ds, "Tracker : SESSION_TRACK_SYSTEM_VARIABLES\n");
-          break;
-        case SESSION_TRACK_SCHEMA:
-          dynstr_append(ds, "Tracker : SESSION_TRACK_SCHEMA\n");
-          break;
-        case SESSION_TRACK_STATE_CHANGE:
-          dynstr_append(ds, "Tracker : SESSION_TRACK_STATE_CHANGE\n");
-          break;
-        case SESSION_TRACK_GTIDS:
-          dynstr_append(ds, "Tracker : SESSION_TRACK_GTIDS\n");
-          break;
-        case SESSION_TRACK_TRANSACTION_CHARACTERISTICS:
-          dynstr_append(ds, "Tracker : SESSION_TRACK_TRANSACTION_CHARACTERISTICS\n");
-          break;
-        case SESSION_TRACK_TRANSACTION_TYPE:
-          dynstr_append(ds, "Tracker : SESSION_TRACK_TRANSACTION_TYPE\n");
-          break;
-        default:
-          DBUG_ASSERT(0);
-          dynstr_append(ds, "\n");
+        dynstr_append(ds, trking_info_desc[type]);
+      }
+      else
+      {
+        DBUG_ASSERT(0);
+        dynstr_append(ds, "Tracker???\n");
       }
-
 
       dynstr_append(ds, "-- ");
       dynstr_append_mem(ds, data, data_length);
@@ -7767,7 +7773,13 @@ static void append_session_track_info(DYNAMIC_STRING *ds, MYSQL *mysql)
                                         &data, &data_length))
     {
       dynstr_append(ds, "\n-- ");
-      dynstr_append_mem(ds, data, data_length);
+      if (data == NULL)
+      {
+        DBUG_ASSERT(data_length == 0);
+        dynstr_append_mem(ds, "<NULL>", sizeof("<NULL>") - 1);
+      }
+      else
+        dynstr_append_mem(ds, data, data_length);
     }
     dynstr_append(ds, "\n\n");
   }

include/mysql.h.pp

@@ -113,7 +113,6 @@
   SESSION_TRACK_GTIDS,
   SESSION_TRACK_TRANSACTION_CHARACTERISTICS,
   SESSION_TRACK_TRANSACTION_STATE,
-  SESSION_TRACK_USER_VARIABLES,
   SESSION_TRACK_always_at_the_end
 };
 extern "C" {

include/mysql_com.h

@@ -617,7 +617,15 @@ enum enum_session_state_type
   SESSION_TRACK_GTIDS,
   SESSION_TRACK_TRANSACTION_CHARACTERISTICS,  /* Transaction chistics */
   SESSION_TRACK_TRANSACTION_STATE,            /* Transaction state */
+#ifdef USER_VAR_TRACKING
+  SESSION_TRACK_MYSQL_RESERVED1,
+  SESSION_TRACK_MYSQL_RESERVED2,
+  SESSION_TRACK_MYSQL_RESERVED3,
+  SESSION_TRACK_MYSQL_RESERVED4,
+  SESSION_TRACK_MYSQL_RESERVED5,
+  SESSION_TRACK_MYSQL_RESERVED6,
   SESSION_TRACK_USER_VARIABLES,
+#endif // USER_VAR_TRACKING
   SESSION_TRACK_always_at_the_end             /* must be last */
 };
 

mysql-test/main/mysqld--help.result

@@ -1151,8 +1151,6 @@ The following specify which files/extra groups are read (specified before remain
  characteristics (isolation level, read only/read
  write,snapshot - but not any work done / data modified
  within the transaction).
- --session-track-user-variables 
- Track changes to user variables.
  --show-slave-auth-info 
  Show user and password in SHOW SLAVE HOSTS on this
  master.
@@ -1758,7 +1756,6 @@ session-track-schema TRUE
 session-track-state-change FALSE
 session-track-system-variables autocommit,character_set_client,character_set_connection,character_set_results,time_zone
 session-track-transaction-info OFF
-session-track-user-variables FALSE
 show-slave-auth-info FALSE
 silent-startup FALSE
 skip-grant-tables TRUE

mysql-test/main/mysqltest_tracking_info.result

@@ -48,20 +48,4 @@ SET @@session.session_track_system_variables= @save_session_track_system_variabl
 #
 # MDEV-16470 - Session user variables tracker
 #
-SET @@session.session_track_user_variables=1;
-SET @a=1;
-SET @b=NULL;
-SELECT @c:=10;
-@c:=10
-10
-SET @@session.session_track_user_variables=0;
-#
-# mdev-22337 Assertion `Alloced_length >= (str_length + length +
-net_length_size(length))' failed in Binary_string::q_net_store_data
-on long MULTIPOLYGON query with session_track_user_variables=1
-(optimized builds)
-#
-set @@session.session_track_user_variables=1;
-set @a=repeat('X', 1029);
-set @@session.session_track_user_variables=0;
 # End of 10.5 tests

mysql-test/main/mysqltest_tracking_info.test

@@ -49,24 +49,24 @@ SET @@session.session_track_system_variables= @save_session_track_system_variabl
 --echo #
 --echo # MDEV-16470 - Session user variables tracker
 --echo #
-SET @@session.session_track_user_variables=1;
---enable_session_track_info
-SET @a=1;
-SET @b=NULL;
-SELECT @c:=10;
---disable_session_track_info
-SET @@session.session_track_user_variables=0;
-
---echo #
---echo # mdev-22337 Assertion `Alloced_length >= (str_length + length +
---echo        net_length_size(length))' failed in Binary_string::q_net_store_data
---echo        on long MULTIPOLYGON query with session_track_user_variables=1
---echo        (optimized builds)
---echo #
-set @@session.session_track_user_variables=1;
---enable_session_track_info
-set @a=repeat('X', 1029);
---disable_session_track_info
-set @@session.session_track_user_variables=0;
+#SET @@session.session_track_user_variables=1;
+#--enable_session_track_info
+#SET @a=1;
+#SET @b=NULL;
+#SELECT @c:=10;
+#--disable_session_track_info
+#SET @@session.session_track_user_variables=0;
+
+#--echo #
+#--echo # mdev-22337 Assertion `Alloced_length >= (str_length + length +
+#--echo        net_length_size(length))' failed in Binary_string::q_net_store_data
+#--echo        on long MULTIPOLYGON query with session_track_user_variables=1
+#--echo        (optimized builds)
+#--echo #
+#set @@session.session_track_user_variables=1;
+#--enable_session_track_info
+#set @a=repeat('X', 1029);
+#--disable_session_track_info
+#set @@session.session_track_user_variables=0;
 
 --echo # End of 10.5 tests

mysql-test/suite/sys_vars/r/sysvars_server_notembedded.result

@@ -3543,16 +3543,6 @@ NUMERIC_BLOCK_SIZE	NULL
 ENUM_VALUE_LIST	OFF,STATE,CHARACTERISTICS
 READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	REQUIRED
-VARIABLE_NAME	SESSION_TRACK_USER_VARIABLES
-VARIABLE_SCOPE	SESSION
-VARIABLE_TYPE	BOOLEAN
-VARIABLE_COMMENT	Track changes to user variables.
-NUMERIC_MIN_VALUE	NULL
-NUMERIC_MAX_VALUE	NULL
-NUMERIC_BLOCK_SIZE	NULL
-ENUM_VALUE_LIST	OFF,ON
-READ_ONLY	NO
-COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	SKIP_EXTERNAL_LOCKING
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	BOOLEAN

sql/item_func.cc

@@ -4787,10 +4787,12 @@ update_hash(user_var_entry *entry, bool set_null, void *ptr, size_t length,
     entry->unsigned_flag= unsigned_arg;
   }
   entry->type=type;
+#ifdef USER_VAR_TRACKING
 #ifndef EMBEDDED_LIBRARY
   THD *thd= current_thd;
   thd->session_tracker.user_variables.mark_as_changed(thd, entry);
 #endif
+#endif // USER_VAR_TRACKING
   return 0;
 }
 

sql/session_tracker.cc

@@ -1183,6 +1183,7 @@ bool Session_state_change_tracker::store(THD *thd, String *buf)
   return false;
 }
 
+#ifdef USER_VAR_TRACKING
 
 bool User_variables_tracker::update(THD *thd, set_var *)
 {
@@ -1204,21 +1205,30 @@ bool User_variables_tracker::store(THD *thd, String *buf)
     length= net_length_size(var->name.length) + var->name.length;
     if (!null_value)
       length+= net_length_size(value_str.length()) + value_str.length();
+    else
+      length+= 1;
 
     if (buf->reserve(sizeof(char) + length + net_length_size(length)))
       return true;
 
+    // TODO: check max packet length MDEV-22709
     buf->q_append(static_cast<char>(SESSION_TRACK_USER_VARIABLES));
     buf->q_net_store_length(length);
     buf->q_net_store_data(reinterpret_cast<const uchar*>(var->name.str),
                           var->name.length);
     if (!null_value)
       buf->q_net_store_data(reinterpret_cast<const uchar*>(value_str.ptr()),
                             value_str.length());
+    else
+    {
+      char nullbuff[1]= { (char)251 };
+      buf->q_append(nullbuff, sizeof(nullbuff));
+    }
   }
   m_changed_user_variables.clear();
   return false;
 }
+#endif // USER_VAR_TRACKING
 
 ///////////////////////////////////////////////////////////////////////////////
 

sql/session_tracker.h

@@ -35,7 +35,9 @@ enum enum_session_tracker
   CURRENT_SCHEMA_TRACKER,                        /* Current schema */
   SESSION_STATE_CHANGE_TRACKER,
   TRANSACTION_INFO_TRACKER,                      /* Transaction state */
+#ifdef USER_VAR_TRACKING
   USER_VARIABLES_TRACKER,
+#endif // USER_VAR_TRACKING
   SESSION_TRACKER_END                            /* must be the last */
 };
 
@@ -395,6 +397,7 @@ class Transaction_state_tracker : public State_tracker
   This is a tracker class that enables & manages the tracking of user variables.
 */
 
+#ifdef USER_VAR_TRACKING
 class User_variables_tracker: public State_tracker
 {
   Hash_set<const user_var_entry> m_changed_user_variables;
@@ -415,6 +418,7 @@ class User_variables_tracker: public State_tracker
   }
   void deinit() { m_changed_user_variables.~Hash_set(); }
 };
+#endif // USER_VAR_TRACKING
 
 
 /**
@@ -445,15 +449,19 @@ class Session_tracker
   Session_state_change_tracker state_change;
   Transaction_state_tracker transaction_info;
   Session_sysvars_tracker sysvars;
+#ifdef USER_VAR_TRACKING
   User_variables_tracker user_variables;
+#endif // USER_VAR_TRACKING
 
   Session_tracker()
   {
     m_trackers[SESSION_SYSVARS_TRACKER]= &sysvars;
     m_trackers[CURRENT_SCHEMA_TRACKER]= &current_schema;
     m_trackers[SESSION_STATE_CHANGE_TRACKER]= &state_change;
     m_trackers[TRANSACTION_INFO_TRACKER]= &transaction_info;
+#ifdef USER_VAR_TRACKING
     m_trackers[USER_VARIABLES_TRACKER]= &user_variables;
+#endif // USER_VAR_TRACKING
   }
 
   void enable(THD *thd)