1 files changed, 77 insertions, 5 deletions
diff --git a/sql/sql_delete.h b/sql/sql_delete.h
index 520524c7..1842c5c0 100644
--- a/sql/sql_delete.h
+++ b/sql/sql_delete.h
@@ -17,6 +17,9 @@
 #define SQL_DELETE_INCLUDED
 
 #include "my_base.h"                            /* ha_rows */
+#include "sql_class.h"                          /* enum_duplicates */
+#include "sql_cmd.h"                            // Sql_cmd_dml
+#include "sql_base.h"
 
 class THD;
 struct TABLE_LIST;
@@ -26,10 +29,79 @@ class select_result;
 typedef class Item COND;
 template <typename T> class SQL_I_List;
 
-int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds,
-                         bool *delete_while_scanning);
-bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
-                  SQL_I_List<ORDER> *order, ha_rows rows, 
-                  ulonglong options, select_result *result);
+/**
+   @class Sql_cmd_delete - class used for any DELETE statements
 
+   This class is derived from Sql_cmd_dml and contains implementations
+   for abstract virtual function of the latter such as precheck() and
+   prepare_inner(). It also overrides the implementation of execute_inner()
+   providing a special handling for single-table delete statements that
+   are not converted to multi-table delete.
+   The class provides an object of the DML_prelocking_strategy class
+   for the virtual function get_dml_prelocking_strategy().
+*/
+class Sql_cmd_delete final : public Sql_cmd_dml
+{
+public:
+  Sql_cmd_delete(bool multitable_arg)
+    : orig_multitable(multitable_arg), multitable(multitable_arg),
+      save_protocol(NULL)
+  {}
+
+  enum_sql_command sql_command_code() const override
+  {
+    return orig_multitable ? SQLCOM_DELETE_MULTI : SQLCOM_DELETE;
+  }
+
+  DML_prelocking_strategy *get_dml_prelocking_strategy() override
+  {
+    return &dml_prelocking_strategy;
+  }
+
+  bool processing_as_multitable_delete_prohibited(THD *thd);
+
+  bool is_multitable() const { return multitable; }
+
+  void set_as_multitable() { multitable= true; }
+
+  void remove_order_by_without_limit(THD *thd);
+
+protected:
+  /**
+    @brief Perform precheck of table privileges for delete statements
+  */
+  bool precheck(THD *thd) override;
+
+  /**
+    @brief Perform context analysis for delete statements
+  */
+  bool prepare_inner(THD *thd) override;
+
+  /**
+    @brief Perform optimization and execution actions needed for deletes
+  */
+  bool execute_inner(THD *thd) override;
+
+ private:
+  /**
+    @biefSpecial handling of single-table deletes after prepare phase
+  */
+  bool delete_from_single_table(THD *thd);
+
+  /* Original value of the 'multitable' flag set by constructor */
+  const bool orig_multitable;
+
+  /*
+    True if the statement is a multitable delete or converted to such.
+    For a single-table delete this flag is set to true if the statement
+    is supposed to be converted to multi-table delete.
+  */
+  bool multitable;
+
+  /* The prelocking strategy used when opening the used tables */
+  DML_prelocking_strategy dml_prelocking_strategy;
+
+  List<Item> empty_list;   /**< auxiliary empty list used by prepare_inner() */
+  Protocol *save_protocol; /**< needed for ANALYZE .. DELETE .. RETURNING */
+};
 #endif /* SQL_DELETE_INCLUDED */