Input to: MDEV-33281 Implement optimizer hints: Comments and renames

sql/opt_hints.cc

@@ -52,7 +52,8 @@ const LEX_CSTRING sys_qb_prefix=  {"select#", 7};
 
 static const Lex_ident_sys null_ident_sys;
 
-static void print_warn(THD *thd, uint err_code, opt_hints_enum hint_type,
+static
+void print_warn(THD *thd, uint err_code, opt_hints_enum hint_type,
                 bool hint_state,
                 const Lex_ident_sys *qb_name_arg,
                 const Lex_ident_sys *table_name_arg,
@@ -221,7 +222,7 @@ static Opt_hints_table *get_table_hints(Parse_context *pc,
 bool Opt_hints::get_switch(opt_hints_enum type_arg) const
 {
   if (is_specified(type_arg))
-    return hints_map.switch_on(type_arg);
+    return hints_map.is_switched_on(type_arg);
 
   if (opt_hint_info[type_arg].check_upper_lvl)
     return parent->get_switch(type_arg);
@@ -263,7 +264,7 @@ void Opt_hints::print(THD *thd, String *str)
 
 void Opt_hints::append_hint_type(String *str, opt_hints_enum type)
 {
-  if(!hints_map.switch_on(type))
+  if (!hints_map.is_switched_on(type))
     str->append(STRING_WITH_LEN("NO_"));
   str->append(opt_hint_info[type].hint_name);
 }
@@ -330,6 +331,11 @@ Opt_hints_table *Opt_hints_qb::adjust_table_hints(TABLE *table,
 }
 
 
+/*
+  @brief
+    For each index IDX, put its hints into keyinfo_array[IDX]
+
+*/
 void Opt_hints_table::adjust_key_hints(TABLE *table)
 {
   set_resolved();
@@ -339,7 +345,7 @@ void Opt_hints_table::adjust_key_hints(TABLE *table)
     return;
   }
 
-  /* Make sure that adjustement is called only once. */
+  /* Make sure that adjustment is called only once. */
   DBUG_ASSERT(keyinfo_array.size() == 0);
   keyinfo_array.resize(table->s->keys, NULL);
 
@@ -414,6 +420,14 @@ static bool get_hint_state(Opt_hints *hint,
 }
 
 
+/* 
+  @brief
+    Check whether a given optimization is enabled for table.keyno.
+  
+  @detail
+    First check if a hint is present, then check optimizer_switch
+*/
+
 bool hint_key_state(const THD *thd, const TABLE *table,
                     uint keyno, opt_hints_enum type_arg,
                     uint optimizer_switch)
@@ -690,7 +704,7 @@ bool Optimizer_hint_parser::Hint_list::resolve(Parse_context *pc)
   while(Optimizer_hint_parser::Hint *hint= li++)
   {
     if (const Table_level_hint &table_hint=
-        static_cast<const Table_level_hint &>(*hint))
+        /*static_cast<const Table_level_hint &>*/(*hint))
     {
       if (table_hint.resolve(pc))
         return true;

sql/opt_hints.h

@@ -112,7 +112,7 @@ class Opt_hints_map : public Sql_alloc
 
      @return switch value.
   */
-  bool switch_on(opt_hints_enum type_arg) const
+  bool is_switched_on(opt_hints_enum type_arg) const
   {
     return hints.is_set(type_arg);
   }
@@ -128,10 +128,10 @@ class Opt_hints_key;
 
   Opt_hints_global class is hierarchical structure.
   It contains information about global hints and also
-  conains array of QUERY BLOCK level objects (Opt_hints_qb class).
+  contains array of QUERY BLOCK level objects (Opt_hints_qb class).
   Each QUERY BLOCK level object contains array of TABLE level hints
   (class Opt_hints_table). Each TABLE level hint contains array of
-  KEY lelev hints (Opt_hints_key class).
+  KEY level hints (Opt_hints_key class).
   Hint information(specified, on|off state) is stored in hints_map object.
 */
 

sql/simple_parser.h

@@ -196,7 +196,7 @@ class Parser_templates
 
 
   /*
-    A rule consisting of three other rules in a row:
+    A rule consisting of four other rules in a row:
       rule ::= rule1 rule2 rule3 rule4
   */
   template<class PARSER, class A, class B, class C, class D>

sql/sql_lex.cc

@@ -10684,7 +10684,7 @@ bool LEX::parsed_insert_select(SELECT_LEX *first_select)
     return true;
 
   // fix "main" select
-  resolve_optimizer_hints();
+  resolve_optimizer_hints_in_last_select();
   SELECT_LEX *blt __attribute__((unused))= pop_select();
   DBUG_ASSERT(blt == &builtin_select);
   push_select(first_select);
@@ -12453,7 +12453,7 @@ LEX::parse_optimizer_hints(const Lex_comment_st &hints_str)
 }
 
 
-void LEX::resolve_optimizer_hints()
+void LEX::resolve_optimizer_hints_in_last_select()
 {
   SELECT_LEX *select_lex;
   if (likely(select_stack_top))

sql/sql_lex.h

@@ -3725,7 +3725,7 @@ struct LEX: public Query_tables_list
     DBUG_RETURN(select_lex);
   }
 
-  void resolve_optimizer_hints();
+  void resolve_optimizer_hints_in_last_select();
 
   SELECT_LEX *current_select_or_default()
   {

sql/sql_yacc.yy

@@ -8765,7 +8765,7 @@ query_specification:
           opt_having_clause
           opt_window_clause
           {
-            Lex->resolve_optimizer_hints();
+            Lex->resolve_optimizer_hints_in_last_select();
             $$= Lex->pop_select();
           }
         ;
@@ -8779,7 +8779,7 @@ select_into_query_specification:
           opt_having_clause
           opt_window_clause
           {
-            Lex->resolve_optimizer_hints();
+            Lex->resolve_optimizer_hints_in_last_select();
             $$= Lex->pop_select();
           }
         ;
@@ -13339,7 +13339,7 @@ insert:
           insert_field_spec opt_insert_update opt_returning
           insert_stmt_end
           {
-            Lex->resolve_optimizer_hints();
+            Lex->resolve_optimizer_hints_in_last_select();
             Lex->mark_first_table_as_inserting();
             thd->get_stmt_da()->reset_current_row_for_warning(0);
           }
@@ -13361,7 +13361,7 @@ replace:
           insert_field_spec opt_returning
           insert_stmt_end
           {
-            Lex->resolve_optimizer_hints();
+            Lex->resolve_optimizer_hints_in_last_select();
             Lex->mark_first_table_as_inserting();
             thd->get_stmt_da()->reset_current_row_for_warning(0);
           }
@@ -13377,7 +13377,7 @@ insert_start: {
               ;
 
 stmt_end: {
-              Lex->resolve_optimizer_hints();
+              Lex->resolve_optimizer_hints_in_last_select();
               Lex->pop_select(); //main select
               if (Lex->check_main_unit_semantics())
                 MYSQL_YYABORT;
@@ -13744,7 +13744,7 @@ delete:
           {
             if (Lex->check_cte_dependencies_and_resolve_references())
               MYSQL_YYABORT;
-            Lex->resolve_optimizer_hints();
+            Lex->resolve_optimizer_hints_in_last_select();
           }
           ;