MCOL-5943: MCOL-4740 update rows counter for multi-table update (#3555)

* fix(plugin): MCOL-4740: This fixes update rows counter for multi-table update
For UPDATEs involving a single table, the server call to handler::direct_update_rows() is used to correctly set the count for the number of updated rows in the UPDATE statement.
However, for UPDATEs involving multi-tables, the server does not call handler::direct_update_rows(). This patch adds support to correctly report the number of updated rows to the client by setting
multi_update::updated and multi_update::found in handler::rnd_end().

* fix(plugin): MCOL-4740: this is to addres the original patch QA found in the original patch

---------

Co-authored-by: Roman Nozdrin <rnozdrin@mariadb.com>
Co-authored-by: drrtuy <roman.nozdrin@mariadb.com>

dbcon/mysql/ha_mcs_common.h

@@ -0,0 +1,148 @@
+/* Copyright (C) 2016-2023 MariaDB Corporation
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+#pragma once
+
+#include "idb_mysql.h"
+
+namespace ha_mcs_common
+{
+
+inline bool isMCSTable(TABLE* table_ptr)
+{
+#if (defined(_MSC_VER) && defined(_DEBUG)) || defined(SAFE_MUTEX)
+
+  if (!(table_ptr->s && (*table_ptr->s->db_plugin)->name.str))
+#else
+  if (!(table_ptr->s && (table_ptr->s->db_plugin)->name.str))
+#endif
+    return true;
+
+#if (defined(_MSC_VER) && defined(_DEBUG)) || defined(SAFE_MUTEX)
+  std::string engineName = (*table_ptr->s->db_plugin)->name.str;
+#else
+  std::string engineName = table_ptr->s->db_plugin->name.str;
+#endif
+
+  if (engineName == "Columnstore" || engineName == "Columnstore_cache")
+    return true;
+  return false;
+}
+
+inline bool isMultiUpdateStatement(const enum_sql_command& command)
+{
+  return command == SQLCOM_UPDATE_MULTI;
+}
+
+inline bool isUpdateStatement(const enum_sql_command& command)
+{
+  return command == SQLCOM_UPDATE || isMultiUpdateStatement(command);
+}
+
+inline bool isDeleteStatement(const enum_sql_command& command)
+{
+  return (command == SQLCOM_DELETE) || (command == SQLCOM_DELETE_MULTI);
+}
+
+inline bool isUpdateOrDeleteStatement(const enum_sql_command& command)
+{
+  return isUpdateStatement(command) || isDeleteStatement(command);
+}
+
+inline bool isDMLStatement(const enum_sql_command& command)
+{
+  return (command == SQLCOM_INSERT || command == SQLCOM_INSERT_SELECT || command == SQLCOM_TRUNCATE ||
+          command == SQLCOM_LOAD || isUpdateOrDeleteStatement(command));
+}
+
+inline bool isForeignTableUpdate(THD* thd)
+{
+  LEX* lex = thd->lex;
+
+  if (!isUpdateStatement(lex->sql_command))
+    return false;
+
+  Item_field* item;
+  List_iterator_fast<Item> field_it(lex->first_select_lex()->item_list);
+
+  while ((item = (Item_field*)field_it++))
+  {
+    if (item->field && item->field->table && !isMCSTable(item->field->table))
+      return true;
+  }
+
+  return false;
+}
+
+// This function is different from isForeignTableUpdate()
+// above as it only checks if any of the tables involved
+// in the multi-table update statement is a foreign table,
+// irrespective of whether the update is performed on the
+// foreign table or not, as in isForeignTableUpdate().
+inline bool isUpdateHasForeignTable(THD* thd)
+{
+  LEX* lex = thd->lex;
+
+  if (!isUpdateStatement(lex->sql_command))
+    return false;
+
+  TABLE_LIST* table_ptr = lex->first_select_lex()->get_table_list();
+
+  for (; table_ptr; table_ptr = table_ptr->next_local)
+  {
+    if (table_ptr->table && !isMCSTable(table_ptr->table))
+      return true;
+  }
+
+  return false;
+}
+
+inline bool isMCSTableUpdate(THD* thd)
+{
+  LEX* lex = thd->lex;
+
+  if (!isUpdateStatement(lex->sql_command))
+    return false;
+
+  Item_field* item;
+  List_iterator_fast<Item> field_it(lex->first_select_lex()->item_list);
+
+  while ((item = (Item_field*)field_it++))
+  {
+    if (item->field && item->field->table && isMCSTable(item->field->table))
+      return true;
+  }
+
+  return false;
+}
+
+inline bool isMCSTableDelete(THD* thd)
+{
+  LEX* lex = thd->lex;
+
+  if (!isDeleteStatement(lex->sql_command))
+    return false;
+
+  TABLE_LIST* table_ptr = lex->first_select_lex()->get_table_list();
+
+  if (table_ptr && table_ptr->table && isMCSTable(table_ptr->table))
+    return true;
+
+  return false;
+}
+
+}  // namespace ha_mcs_common