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Diffstat (limited to 'sql/item_cmpfunc.h')
| -rw-r--r-- | sql/item_cmpfunc.h | 3593 |
1 files changed, 3593 insertions, 0 deletions
diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h new file mode 100644 index 00000000..aa7269ab --- /dev/null +++ b/sql/item_cmpfunc.h @@ -0,0 +1,3593 @@ +#ifndef ITEM_CMPFUNC_INCLUDED +#define ITEM_CMPFUNC_INCLUDED +/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. + Copyright (c) 2009, 2020, MariaDB + + 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 02110-1335 USA */ + + +/* compare and test functions */ + +#ifdef USE_PRAGMA_INTERFACE +#pragma interface /* gcc class implementation */ +#endif + +#include "item_func.h" /* Item_int_func, Item_bool_func */ +#include "item.h" + +extern Item_result item_cmp_type(Item_result a,Item_result b); +inline Item_result item_cmp_type(const Item *a, const Item *b) +{ + return item_cmp_type(a->cmp_type(), b->cmp_type()); +} +inline Item_result item_cmp_type(Item_result a, const Item *b) +{ + return item_cmp_type(a, b->cmp_type()); +} +class Item_bool_func2; +class Arg_comparator; + +typedef int (Arg_comparator::*arg_cmp_func)(); + +typedef int (*Item_field_cmpfunc)(Item *f1, Item *f2, void *arg); + +class Arg_comparator: public Sql_alloc +{ + Item **a, **b; + const Type_handler *m_compare_handler; + CHARSET_INFO *m_compare_collation; + arg_cmp_func func; + Item_func_or_sum *owner; + bool set_null; // TRUE <=> set owner->null_value + Arg_comparator *comparators; // used only for compare_row() + double precision; + /* Fields used in DATE/DATETIME comparison. */ + Item *a_cache, *b_cache; // Cached values of a and b items + // when one of arguments is NULL. + + int set_cmp_func(Item_func_or_sum *owner_arg, Item **a1, Item **a2); + + int compare_not_null_values(longlong val1, longlong val2) + { + if (set_null) + owner->null_value= false; + if (val1 < val2) return -1; + if (val1 == val2) return 0; + return 1; + } + NativeBuffer<STRING_BUFFER_USUAL_SIZE> m_native1, m_native2; +public: + /* Allow owner function to use string buffers. */ + String value1, value2; + + Arg_comparator(): + m_compare_handler(&type_handler_null), + m_compare_collation(&my_charset_bin), + set_null(TRUE), comparators(0), + a_cache(0), b_cache(0) {}; + Arg_comparator(Item **a1, Item **a2): a(a1), b(a2), + m_compare_handler(&type_handler_null), + m_compare_collation(&my_charset_bin), + set_null(TRUE), comparators(0), + a_cache(0), b_cache(0) {}; + +public: + bool set_cmp_func_for_row_arguments(); + bool set_cmp_func_row(); + bool set_cmp_func_string(); + bool set_cmp_func_time(); + bool set_cmp_func_datetime(); + bool set_cmp_func_native(); + bool set_cmp_func_int(); + bool set_cmp_func_real(); + bool set_cmp_func_decimal(); + + inline int set_cmp_func(Item_func_or_sum *owner_arg, + Item **a1, Item **a2, bool set_null_arg) + { + set_null= set_null_arg; + return set_cmp_func(owner_arg, a1, a2); + } + inline int compare() { return (this->*func)(); } + + int compare_string(); // compare args[0] & args[1] + int compare_real(); // compare args[0] & args[1] + int compare_decimal(); // compare args[0] & args[1] + int compare_int_signed(); // compare args[0] & args[1] + int compare_int_signed_unsigned(); + int compare_int_unsigned_signed(); + int compare_int_unsigned(); + int compare_row(); // compare args[0] & args[1] + int compare_e_string(); // compare args[0] & args[1] + int compare_e_real(); // compare args[0] & args[1] + int compare_e_decimal(); // compare args[0] & args[1] + int compare_e_int(); // compare args[0] & args[1] + int compare_e_int_diff_signedness(); + int compare_e_row(); // compare args[0] & args[1] + int compare_real_fixed(); + int compare_e_real_fixed(); + int compare_datetime(); + int compare_e_datetime(); + int compare_time(); + int compare_e_time(); + int compare_native(); + int compare_e_native(); + int compare_json_str_basic(Item *j, Item *s); + int compare_json_str(); + int compare_str_json(); + int compare_e_json_str_basic(Item *j, Item *s); + int compare_e_json_str(); + int compare_e_str_json(); + + void min_max_update_field_native(THD *thd, Field *field, Item *item, + int cmp_sign); + + Item** cache_converted_constant(THD *thd, Item **value, Item **cache, + const Type_handler *type); + inline bool is_owner_equal_func() + { + return (owner->type() == Item::FUNC_ITEM && + ((Item_func*)owner)->functype() == Item_func::EQUAL_FUNC); + } + const Type_handler *compare_type_handler() const { return m_compare_handler; } + Item_result compare_type() const { return m_compare_handler->cmp_type(); } + CHARSET_INFO *compare_collation() const { return m_compare_collation; } + Arg_comparator *subcomparators() const { return comparators; } + void cleanup() + { + delete [] comparators; + comparators= 0; + } + friend class Item_func; + friend class Item_bool_rowready_func2; +}; + + +class SEL_ARG; +struct KEY_PART; + +class Item_bool_func :public Item_int_func, + public Type_cmp_attributes +{ +protected: + /* + Build a SEL_TREE for a simple predicate + @param param PARAM from SQL_SELECT::test_quick_select + @param field field in the predicate + @param value constant in the predicate + @return Pointer to the tree built tree + */ + virtual SEL_TREE *get_func_mm_tree(RANGE_OPT_PARAM *param, + Field *field, Item *value) + { + DBUG_ENTER("Item_bool_func::get_func_mm_tree"); + DBUG_ASSERT(0); + DBUG_RETURN(0); + } + /* + Return the full select tree for "field_item" and "value": + - a single SEL_TREE if the field is not in a multiple equality, or + - a conjunction of all SEL_TREEs for all fields from + the same multiple equality with "field_item". + */ + SEL_TREE *get_full_func_mm_tree(RANGE_OPT_PARAM *param, + Item_field *field_item, Item *value); + /** + Test if "item" and "value" are suitable for the range optimization + and get their full select tree. + + "Suitable" means: + - "item" is a field or a field reference + - "value" is NULL (e.g. WHERE field IS NULL), or + "value" is an unexpensive item (e.g. WHERE field OP value) + + @param item - the argument that is checked to be a field + @param value - the other argument + @returns - NULL if the arguments are not suitable for the range optimizer. + @returns - the full select tree if the arguments are suitable. + */ + SEL_TREE *get_full_func_mm_tree_for_args(RANGE_OPT_PARAM *param, + Item *item, Item *value) + { + DBUG_ENTER("Item_bool_func::get_full_func_mm_tree_for_args"); + Item *field= item->real_item(); + if (field->type() == Item::FIELD_ITEM && !field->const_item() && + (!value || !value->is_expensive())) + DBUG_RETURN(get_full_func_mm_tree(param, (Item_field *) field, value)); + DBUG_RETURN(NULL); + } + SEL_TREE *get_mm_parts(RANGE_OPT_PARAM *param, Field *field, + Item_func::Functype type, Item *value); + SEL_TREE *get_ne_mm_tree(RANGE_OPT_PARAM *param, + Field *field, Item *lt_value, Item *gt_value); + virtual SEL_ARG *get_mm_leaf(RANGE_OPT_PARAM *param, Field *field, + KEY_PART *key_part, + Item_func::Functype type, Item *value); +public: + Item_bool_func(THD *thd): Item_int_func(thd) {} + Item_bool_func(THD *thd, Item *a): Item_int_func(thd, a) {} + Item_bool_func(THD *thd, Item *a, Item *b): Item_int_func(thd, a, b) {} + Item_bool_func(THD *thd, Item *a, Item *b, Item *c): Item_int_func(thd, a, b, c) {} + Item_bool_func(THD *thd, List<Item> &list): Item_int_func(thd, list) { } + Item_bool_func(THD *thd, Item_bool_func *item) :Item_int_func(thd, item) {} + const Type_handler *type_handler() const { return &type_handler_bool; } + const Type_handler *fixed_type_handler() const { return &type_handler_bool; } + CHARSET_INFO *compare_collation() const { return NULL; } + bool fix_length_and_dec() { decimals=0; max_length=1; return FALSE; } + uint decimal_precision() const { return 1; } + bool need_parentheses_in_default() { return true; } +}; + + +/** + Abstract Item class, to represent <code>X IS [NOT] (TRUE | FALSE)</code> + boolean predicates. +*/ + +class Item_func_truth : public Item_bool_func +{ +public: + virtual bool val_bool(); + virtual longlong val_int(); + virtual bool fix_length_and_dec(); + virtual void print(String *str, enum_query_type query_type); + enum precedence precedence() const { return CMP_PRECEDENCE; } + +protected: + Item_func_truth(THD *thd, Item *a, bool a_value, bool a_affirmative): + Item_bool_func(thd, a), value(a_value), affirmative(a_affirmative) + {} + + ~Item_func_truth() + {} +private: + /** + True for <code>X IS [NOT] TRUE</code>, + false for <code>X IS [NOT] FALSE</code> predicates. + */ + const bool value; + /** + True for <code>X IS Y</code>, false for <code>X IS NOT Y</code> predicates. + */ + const bool affirmative; +}; + + +/** + This Item represents a <code>X IS TRUE</code> boolean predicate. +*/ + +class Item_func_istrue : public Item_func_truth +{ +public: + Item_func_istrue(THD *thd, Item *a): Item_func_truth(thd, a, true, true) {} + ~Item_func_istrue() {} + virtual const char* func_name() const { return "istrue"; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_istrue>(thd, this); } +}; + + +/** + This Item represents a <code>X IS NOT TRUE</code> boolean predicate. +*/ + +class Item_func_isnottrue : public Item_func_truth +{ +public: + Item_func_isnottrue(THD *thd, Item *a): + Item_func_truth(thd, a, true, false) {} + ~Item_func_isnottrue() {} + virtual const char* func_name() const { return "isnottrue"; } + bool find_not_null_fields(table_map allowed) { return false; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_isnottrue>(thd, this); } + bool eval_not_null_tables(void *) { not_null_tables_cache= 0; return false; } +}; + + +/** + This Item represents a <code>X IS FALSE</code> boolean predicate. +*/ + +class Item_func_isfalse : public Item_func_truth +{ +public: + Item_func_isfalse(THD *thd, Item *a): Item_func_truth(thd, a, false, true) {} + ~Item_func_isfalse() {} + virtual const char* func_name() const { return "isfalse"; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_isfalse>(thd, this); } +}; + + +/** + This Item represents a <code>X IS NOT FALSE</code> boolean predicate. +*/ + +class Item_func_isnotfalse : public Item_func_truth +{ +public: + Item_func_isnotfalse(THD *thd, Item *a): + Item_func_truth(thd, a, false, false) {} + ~Item_func_isnotfalse() {} + virtual const char* func_name() const { return "isnotfalse"; } + bool find_not_null_fields(table_map allowed) { return false; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_isnotfalse>(thd, this); } + bool eval_not_null_tables(void *) { not_null_tables_cache= 0; return false; } +}; + + +class Item_cache; +#define UNKNOWN (-1) + + +/* + Item_in_optimizer(left_expr, Item_in_subselect(...)) + + Item_in_optimizer is used to wrap an instance of Item_in_subselect. This + class does the following: + - Evaluate the left expression and store it in Item_cache_* object (to + avoid re-evaluating it many times during subquery execution) + - Shortcut the evaluation of "NULL IN (...)" to NULL in the cases where we + don't care if the result is NULL or FALSE. + + NOTE + It is not quite clear why the above listed functionality should be + placed into a separate class called 'Item_in_optimizer'. +*/ + +class Item_in_optimizer: public Item_bool_func +{ +protected: + Item_cache *cache; + Item *expr_cache; + bool save_cache; + /* + Stores the value of "NULL IN (SELECT ...)" for uncorrelated subqueries: + UNKNOWN - "NULL in (SELECT ...)" has not yet been evaluated + FALSE - result is FALSE + TRUE - result is NULL + */ + int result_for_null_param; +public: + Item_in_optimizer(THD *thd, Item *a, Item *b): + Item_bool_func(thd, a, b), cache(0), expr_cache(0), + save_cache(0), result_for_null_param(UNKNOWN) + { m_with_subquery= true; } + bool fix_fields(THD *, Item **) override; + bool fix_left(THD *thd); + table_map not_null_tables() const override { return 0; } + bool is_null() override; + longlong val_int() override; + void cleanup() override; + enum Functype functype() const override { return IN_OPTIMIZER_FUNC; } + const char *func_name() const override { return "<in_optimizer>"; } + Item_cache **get_cache() { return &cache; } + void keep_top_level_cache(); + Item *transform(THD *thd, Item_transformer transformer, uchar *arg) override; + Item *expr_cache_insert_transformer(THD *thd, uchar *unused) override; + bool is_expensive_processor(void *arg) override; + bool is_expensive() override; + void set_join_tab_idx(uint join_tab_idx_arg) override + { args[1]->set_join_tab_idx(join_tab_idx_arg); } + void get_cache_parameters(List<Item> ¶meters) override; + bool is_top_level_item() const override; + bool eval_not_null_tables(void *opt_arg) override; + bool find_not_null_fields(table_map allowed) override; + void fix_after_pullout(st_select_lex *new_parent, Item **ref, + bool merge) override; + bool invisible_mode(); + void reset_cache() { cache= NULL; } + void print(String *str, enum_query_type query_type) override; + void restore_first_argument(); + Item* get_wrapped_in_subselect_item() + { return args[1]; } + Item *get_copy(THD *thd) override + { return get_item_copy<Item_in_optimizer>(thd, this); } + enum precedence precedence() const override { return args[1]->precedence(); } +}; + + +/* + Functions and operators with two arguments that can use range optimizer. +*/ +class Item_bool_func2 :public Item_bool_func +{ /* Bool with 2 string args */ +protected: + void add_key_fields_optimize_op(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, table_map usable_tables, + SARGABLE_PARAM **sargables, bool equal_func); +public: + Item_bool_func2(THD *thd, Item *a, Item *b): + Item_bool_func(thd, a, b) { } + + bool is_null() { return MY_TEST(args[0]->is_null() || args[1]->is_null()); } + COND *remove_eq_conds(THD *thd, Item::cond_result *cond_value, + bool top_level); + bool count_sargable_conds(void *arg); + /* + Specifies which result type the function uses to compare its arguments. + This method is used in equal field propagation. + */ + virtual const Type_handler *compare_type_handler() const + { + /* + Have STRING_RESULT by default, which means the function compares + val_str() results of the arguments. This is suitable for Item_func_like + and for Item_func_spatial_rel. + Note, Item_bool_rowready_func2 overrides this default behaviour. + */ + return &type_handler_varchar; + } + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr) + { + DBUG_ENTER("Item_bool_func2::get_mm_tree"); + DBUG_ASSERT(arg_count == 2); + SEL_TREE *ftree= get_full_func_mm_tree_for_args(param, args[0], args[1]); + if (!ftree) + ftree= Item_func::get_mm_tree(param, cond_ptr); + DBUG_RETURN(ftree); + } +}; + + +/** + A class for functions and operators that can use the range optimizer and + have a reverse function/operator that can also use the range optimizer, + so this condition: + WHERE value OP field + can be optimized as equivalent to: + WHERE field REV_OP value + + This class covers: + - scalar comparison predicates: <, <=, =, <=>, >=, > + - MBR and precise spatial relation predicates (e.g. SP_TOUCHES(x,y)) + + For example: + WHERE 10 > field + can be optimized as: + WHERE field < 10 +*/ +class Item_bool_func2_with_rev :public Item_bool_func2 +{ +protected: + SEL_TREE *get_func_mm_tree(RANGE_OPT_PARAM *param, + Field *field, Item *value) + { + DBUG_ENTER("Item_bool_func2_with_rev::get_func_mm_tree"); + Item_func::Functype func_type= + (value != arguments()[0]) ? functype() : rev_functype(); + DBUG_RETURN(get_mm_parts(param, field, func_type, value)); + } +public: + Item_bool_func2_with_rev(THD *thd, Item *a, Item *b): + Item_bool_func2(thd, a, b) { } + virtual enum Functype rev_functype() const= 0; + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr) + { + DBUG_ENTER("Item_bool_func2_with_rev::get_mm_tree"); + DBUG_ASSERT(arg_count == 2); + SEL_TREE *ftree; + /* + Even if get_full_func_mm_tree_for_args(param, args[0], args[1]) will not + return a range predicate it may still be possible to create one + by reversing the order of the operands. Note that this only + applies to predicates where both operands are fields. Example: A + query of the form + + WHERE t1.a OP t2.b + + In this case, args[0] == t1.a and args[1] == t2.b. + When creating range predicates for t2, + get_full_func_mm_tree_for_args(param, args[0], args[1]) + will return NULL because 'field' belongs to t1 and only + predicates that applies to t2 are of interest. In this case a + call to get_full_func_mm_tree_for_args() with reversed operands + may succeed. + */ + if (!(ftree= get_full_func_mm_tree_for_args(param, args[0], args[1])) && + !(ftree= get_full_func_mm_tree_for_args(param, args[1], args[0]))) + ftree= Item_func::get_mm_tree(param, cond_ptr); + DBUG_RETURN(ftree); + } +}; + + +class Item_bool_rowready_func2 :public Item_bool_func2_with_rev +{ +protected: + Arg_comparator cmp; + bool check_arguments() const + { + return check_argument_types_like_args0(); + } +public: + Item_bool_rowready_func2(THD *thd, Item *a, Item *b): + Item_bool_func2_with_rev(thd, a, b), cmp(tmp_arg, tmp_arg + 1) + { } + Sql_mode_dependency value_depends_on_sql_mode() const; + void print(String *str, enum_query_type query_type) + { + Item_func::print_op(str, query_type); + } + enum precedence precedence() const { return CMP_PRECEDENCE; } + Item *neg_transformer(THD *thd); + virtual Item *negated_item(THD *thd); + Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond) + { + Item_args::propagate_equal_fields(thd, + Context(ANY_SUBST, + cmp.compare_type_handler(), + compare_collation()), + cond); + return this; + } + bool fix_length_and_dec(); + int set_cmp_func() + { + return cmp.set_cmp_func(this, tmp_arg, tmp_arg + 1, true); + } + CHARSET_INFO *compare_collation() const { return cmp.compare_collation(); } + const Type_handler *compare_type_handler() const + { + return cmp.compare_type_handler(); + } + Arg_comparator *get_comparator() { return &cmp; } + void cleanup() + { + Item_bool_func2::cleanup(); + cmp.cleanup(); + } + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, table_map usable_tables, + SARGABLE_PARAM **sargables) + { + return add_key_fields_optimize_op(join, key_fields, and_level, + usable_tables, sargables, false); + } + Item *build_clone(THD *thd) + { + Item_bool_rowready_func2 *clone= + (Item_bool_rowready_func2 *) Item_func::build_clone(thd); + if (clone) + { + clone->cmp.comparators= 0; + } + return clone; + } +}; + +/** + XOR inherits from Item_bool_func because it is not optimized yet. + Later, when XOR is optimized, it needs to inherit from + Item_cond instead. See WL#5800. +*/ +class Item_func_xor :public Item_bool_func +{ +public: + Item_func_xor(THD *thd, Item *i1, Item *i2): Item_bool_func(thd, i1, i2) {} + enum Functype functype() const { return XOR_FUNC; } + const char *func_name() const { return "xor"; } + enum precedence precedence() const { return XOR_PRECEDENCE; } + void print(String *str, enum_query_type query_type) + { Item_func::print_op(str, query_type); } + longlong val_int(); + bool find_not_null_fields(table_map allowed) { return false; } + Item *neg_transformer(THD *thd); + Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond) + { + Item_args::propagate_equal_fields(thd, Context_boolean(), cond); + return this; + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_xor>(thd, this); } +}; + +class Item_func_not :public Item_bool_func +{ + bool abort_on_null; +public: + Item_func_not(THD *thd, Item *a): + Item_bool_func(thd, a), abort_on_null(FALSE) {} + void top_level_item() override { abort_on_null= 1; } + bool is_top_level_item() const override { return abort_on_null; } + longlong val_int() override; + enum Functype functype() const override { return NOT_FUNC; } + const char *func_name() const override { return "not"; } + bool find_not_null_fields(table_map allowed) override { return false; } + enum precedence precedence() const override { return NEG_PRECEDENCE; } + Item *neg_transformer(THD *thd) override; + bool fix_fields(THD *, Item **) override; + void print(String *str, enum_query_type query_type) override; + Item *get_copy(THD *thd) override + { return get_item_copy<Item_func_not>(thd, this); } +}; + +class Item_maxmin_subselect; + +/* + trigcond<param>(arg) ::= param? arg : TRUE + + The class Item_func_trig_cond is used for guarded predicates + which are employed only for internal purposes. + A guarded predicate is an object consisting of an a regular or + a guarded predicate P and a pointer to a boolean guard variable g. + A guarded predicate P/g is evaluated to true if the value of the + guard g is false, otherwise it is evaluated to the same value that + the predicate P: val(P/g)= g ? val(P):true. + Guarded predicates allow us to include predicates into a conjunction + conditionally. Currently they are utilized for pushed down predicates + in queries with outer join operations. + + In the future, probably, it makes sense to extend this class to + the objects consisting of three elements: a predicate P, a pointer + to a variable g and a firing value s with following evaluation + rule: val(P/g,s)= g==s? val(P) : true. It will allow us to build only + one item for the objects of the form P/g1/g2... + + Objects of this class are built only for query execution after + the execution plan has been already selected. That's why this + class needs only val_int out of generic methods. + + Current uses of Item_func_trig_cond objects: + - To wrap selection conditions when executing outer joins + - To wrap condition that is pushed down into subquery +*/ + +class Item_func_trig_cond: public Item_bool_func +{ + bool *trig_var; +public: + Item_func_trig_cond(THD *thd, Item *a, bool *f): Item_bool_func(thd, a) + { trig_var= f; } + longlong val_int() { return *trig_var ? args[0]->val_int() : 1; } + enum Functype functype() const { return TRIG_COND_FUNC; }; + const char *func_name() const { return "trigcond"; }; + bool const_item() const { return FALSE; } + bool *get_trig_var() { return trig_var; } + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, table_map usable_tables, + SARGABLE_PARAM **sargables); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_trig_cond>(thd, this); } +}; + +class Item_func_not_all :public Item_func_not +{ + /* allow to check presence of values in max/min optimization */ + Item_sum_min_max *test_sum_item; + Item_maxmin_subselect *test_sub_item; + +public: + bool show; + + Item_func_not_all(THD *thd, Item *a): + Item_func_not(thd, a), test_sum_item(0), test_sub_item(0), show(0) + {} + table_map not_null_tables() const { return 0; } + longlong val_int(); + enum Functype functype() const { return NOT_ALL_FUNC; } + const char *func_name() const { return "<not>"; } + bool fix_fields(THD *thd, Item **ref) + {return Item_func::fix_fields(thd, ref);} + virtual void print(String *str, enum_query_type query_type); + void set_sum_test(Item_sum_min_max *item) { test_sum_item= item; test_sub_item= 0; }; + void set_sub_test(Item_maxmin_subselect *item) { test_sub_item= item; test_sum_item= 0;}; + bool empty_underlying_subquery(); + Item *neg_transformer(THD *thd); +}; + + +class Item_func_nop_all :public Item_func_not_all +{ +public: + + Item_func_nop_all(THD *thd, Item *a): Item_func_not_all(thd, a) {} + longlong val_int(); + const char *func_name() const { return "<nop>"; } + Item *neg_transformer(THD *thd); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_nop_all>(thd, this); } +}; + + +class Item_func_eq :public Item_bool_rowready_func2 +{ + bool abort_on_null; +public: + Item_func_eq(THD *thd, Item *a, Item *b): + Item_bool_rowready_func2(thd, a, b), + abort_on_null(false), in_equality_no(UINT_MAX) + {} + longlong val_int(); + enum Functype functype() const { return EQ_FUNC; } + enum Functype rev_functype() const { return EQ_FUNC; } + cond_result eq_cmp_result() const { return COND_TRUE; } + const char *func_name() const { return "="; } + void top_level_item() { abort_on_null= true; } + Item *negated_item(THD *thd); + COND *build_equal_items(THD *thd, COND_EQUAL *inherited, + bool link_item_fields, + COND_EQUAL **cond_equal_ref); + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, table_map usable_tables, + SARGABLE_PARAM **sargables) + { + return add_key_fields_optimize_op(join, key_fields, and_level, + usable_tables, sargables, true); + } + bool check_equality(THD *thd, COND_EQUAL *cond, List<Item> *eq_list); + /* + - If this equality is created from the subquery's IN-equality: + number of the item it was created from, e.g. for + (a,b) IN (SELECT c,d ...) a=c will have in_equality_no=0, + and b=d will have in_equality_no=1. + - Otherwise, UINT_MAX + */ + uint in_equality_no; + virtual uint exists2in_reserved_items() { return 1; }; + friend class Arg_comparator; + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_eq>(thd, this); } +}; + +class Item_func_equal final :public Item_bool_rowready_func2 +{ +public: + Item_func_equal(THD *thd, Item *a, Item *b): + Item_bool_rowready_func2(thd, a, b) {} + longlong val_int(); + bool fix_length_and_dec(); + table_map not_null_tables() const { return 0; } + bool find_not_null_fields(table_map allowed) { return false; } + enum Functype functype() const { return EQUAL_FUNC; } + enum Functype rev_functype() const { return EQUAL_FUNC; } + cond_result eq_cmp_result() const { return COND_TRUE; } + const char *func_name() const { return "<=>"; } + Item *neg_transformer(THD *thd) { return 0; } + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, table_map usable_tables, + SARGABLE_PARAM **sargables) + { + return add_key_fields_optimize_op(join, key_fields, and_level, + usable_tables, sargables, true); + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_equal>(thd, this); } +}; + + +class Item_func_ge :public Item_bool_rowready_func2 +{ +public: + Item_func_ge(THD *thd, Item *a, Item *b): + Item_bool_rowready_func2(thd, a, b) {}; + longlong val_int(); + enum Functype functype() const { return GE_FUNC; } + enum Functype rev_functype() const { return LE_FUNC; } + cond_result eq_cmp_result() const { return COND_TRUE; } + const char *func_name() const { return ">="; } + Item *negated_item(THD *thd); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_ge>(thd, this); } +}; + + +class Item_func_gt :public Item_bool_rowready_func2 +{ +public: + Item_func_gt(THD *thd, Item *a, Item *b): + Item_bool_rowready_func2(thd, a, b) {}; + longlong val_int(); + enum Functype functype() const { return GT_FUNC; } + enum Functype rev_functype() const { return LT_FUNC; } + cond_result eq_cmp_result() const { return COND_FALSE; } + const char *func_name() const { return ">"; } + Item *negated_item(THD *thd); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_gt>(thd, this); } +}; + + +class Item_func_le :public Item_bool_rowready_func2 +{ +public: + Item_func_le(THD *thd, Item *a, Item *b): + Item_bool_rowready_func2(thd, a, b) {}; + longlong val_int(); + enum Functype functype() const { return LE_FUNC; } + enum Functype rev_functype() const { return GE_FUNC; } + cond_result eq_cmp_result() const { return COND_TRUE; } + const char *func_name() const { return "<="; } + Item *negated_item(THD *thd); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_le>(thd, this); } +}; + + +class Item_func_lt :public Item_bool_rowready_func2 +{ +public: + Item_func_lt(THD *thd, Item *a, Item *b): + Item_bool_rowready_func2(thd, a, b) {} + longlong val_int(); + enum Functype functype() const { return LT_FUNC; } + enum Functype rev_functype() const { return GT_FUNC; } + cond_result eq_cmp_result() const { return COND_FALSE; } + const char *func_name() const { return "<"; } + Item *negated_item(THD *thd); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_lt>(thd, this); } +}; + + +class Item_func_ne :public Item_bool_rowready_func2 +{ +protected: + SEL_TREE *get_func_mm_tree(RANGE_OPT_PARAM *param, + Field *field, Item *value); +public: + Item_func_ne(THD *thd, Item *a, Item *b): + Item_bool_rowready_func2(thd, a, b) {} + longlong val_int(); + enum Functype functype() const { return NE_FUNC; } + enum Functype rev_functype() const { return NE_FUNC; } + cond_result eq_cmp_result() const { return COND_FALSE; } + const char *func_name() const { return "<>"; } + Item *negated_item(THD *thd); + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level, + table_map usable_tables, SARGABLE_PARAM **sargables); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_ne>(thd, this); } +}; + + +/* + The class Item_func_opt_neg is defined to factor out the functionality + common for the classes Item_func_between and Item_func_in. The objects + of these classes can express predicates or there negations. + The alternative approach would be to create pairs Item_func_between, + Item_func_notbetween and Item_func_in, Item_func_notin. + +*/ + +class Item_func_opt_neg :public Item_bool_func +{ +protected: + /* + The data type handler that will be used for comparison. + Data type handlers of all arguments are mixed to here. + */ + Type_handler_hybrid_field_type m_comparator; + /* + The collation that will be used for comparison in case + when m_compare_type is STRING_RESULT. + */ + DTCollation cmp_collation; +public: + bool negated; /* <=> the item represents NOT <func> */ + bool pred_level; /* <=> [NOT] <func> is used on a predicate level */ +public: + Item_func_opt_neg(THD *thd, Item *a, Item *b, Item *c): + Item_bool_func(thd, a, b, c), negated(0), pred_level(0) {} + Item_func_opt_neg(THD *thd, List<Item> &list): + Item_bool_func(thd, list), negated(0), pred_level(0) {} +public: + void top_level_item() override { pred_level= 1; } + bool is_top_level_item() const override { return pred_level; } + Item *neg_transformer(THD *thd) override + { + negated= !negated; + return this; + } + bool eq(const Item *item, bool binary_cmp) const override; + CHARSET_INFO *compare_collation() const override + { + return cmp_collation.collation; + } + Item *propagate_equal_fields(THD *, const Context &, + COND_EQUAL *) override= 0; +}; + +class Item_func_between :public Item_func_opt_neg +{ +protected: + SEL_TREE *get_func_mm_tree(RANGE_OPT_PARAM *param, + Field *field, Item *value); + bool val_int_cmp_int_finalize(longlong value, longlong a, longlong b); +public: + String value0,value1,value2; + Item_func_between(THD *thd, Item *a, Item *b, Item *c): + Item_func_opt_neg(thd, a, b, c) { } + longlong val_int() + { + DBUG_ASSERT(fixed); + return m_comparator.type_handler()->Item_func_between_val_int(this); + } + enum Functype functype() const { return BETWEEN; } + const char *func_name() const { return "between"; } + enum precedence precedence() const { return BETWEEN_PRECEDENCE; } + bool fix_length_and_dec(); + bool fix_length_and_dec_string(THD *) + { + return agg_arg_charsets_for_comparison(cmp_collation, args, 3); + } + bool fix_length_and_dec_temporal(THD *); + bool fix_length_and_dec_numeric(THD *); + virtual void print(String *str, enum_query_type query_type); + bool eval_not_null_tables(void *opt_arg); + bool find_not_null_fields(table_map allowed); + void fix_after_pullout(st_select_lex *new_parent, Item **ref, bool merge); + bool count_sargable_conds(void *arg); + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, table_map usable_tables, + SARGABLE_PARAM **sargables); + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr); + Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond) + { + Item_args::propagate_equal_fields(thd, + Context(ANY_SUBST, + m_comparator.type_handler(), + compare_collation()), + cond); + return this; + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_between>(thd, this); } + + longlong val_int_cmp_string(); + longlong val_int_cmp_datetime(); + longlong val_int_cmp_time(); + longlong val_int_cmp_native(); + longlong val_int_cmp_int(); + longlong val_int_cmp_real(); + longlong val_int_cmp_decimal(); +}; + + +class Item_func_strcmp :public Item_long_func +{ + bool check_arguments() const + { return check_argument_types_can_return_str(0, 2); } + String value1, value2; + DTCollation cmp_collation; +public: + Item_func_strcmp(THD *thd, Item *a, Item *b): + Item_long_func(thd, a, b) {} + longlong val_int(); + uint decimal_precision() const { return 1; } + const char *func_name() const { return "strcmp"; } + bool fix_length_and_dec() + { + if (agg_arg_charsets_for_comparison(cmp_collation, args, 2)) + return TRUE; + fix_char_length(2); // returns "1" or "0" or "-1" + return FALSE; + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_strcmp>(thd, this); } +}; + + +struct interval_range +{ + Item_result type; + double dbl; + my_decimal dec; +}; + +class Item_func_interval :public Item_long_func +{ + Item_row *row; + bool use_decimal_comparison; + interval_range *intervals; + bool check_arguments() const + { + return check_argument_types_like_args0(); + } +public: + Item_func_interval(THD *thd, Item_row *a): + Item_long_func(thd, a), row(a), intervals(0) + { } + bool fix_fields(THD *, Item **); + longlong val_int(); + bool fix_length_and_dec(); + const char *func_name() const { return "interval"; } + uint decimal_precision() const { return 2; } + void print(String *str, enum_query_type query_type) + { + str->append(func_name()); + print_args(str, 0, query_type); + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_interval>(thd, this); } +}; + + +class Item_func_coalesce :public Item_func_case_expression +{ +public: + Item_func_coalesce(THD *thd, Item *a, Item *b): + Item_func_case_expression(thd, a, b) {} + Item_func_coalesce(THD *thd, List<Item> &list): + Item_func_case_expression(thd, list) {} + double real_op(); + longlong int_op(); + String *str_op(String *); + my_decimal *decimal_op(my_decimal *); + bool date_op(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate); + bool time_op(THD *thd, MYSQL_TIME *ltime); + bool native_op(THD *thd, Native *to); + bool fix_length_and_dec() + { + if (aggregate_for_result(func_name(), args, arg_count, true)) + return TRUE; + fix_attributes(args, arg_count); + return FALSE; + } + const char *func_name() const { return "coalesce"; } + table_map not_null_tables() const { return 0; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_coalesce>(thd, this); } +}; + + +/* + Case abbreviations that aggregate its result field type by two arguments: + IFNULL(arg1, arg2) + IF(switch, arg1, arg2) + NVL2(switch, arg1, arg2) +*/ +class Item_func_case_abbreviation2 :public Item_func_case_expression +{ +protected: + bool fix_length_and_dec2(Item **items) + { + if (aggregate_for_result(func_name(), items, 2, true)) + return TRUE; + fix_attributes(items, 2); + return FALSE; + } + + void cache_type_info(const Item *source, bool maybe_null_arg) + { + Type_std_attributes::set(source); + set_handler(source->type_handler()); + maybe_null= maybe_null_arg; + } + + bool fix_length_and_dec2_eliminate_null(Item **items) + { + // Let IF(cond, expr, NULL) and IF(cond, NULL, expr) inherit type from expr. + if (items[0]->type() == NULL_ITEM) + { + cache_type_info(items[1], true); + // If both arguments are NULL, make resulting type BINARY(0). + if (items[1]->type() == NULL_ITEM) + set_handler(&type_handler_string); + } + else if (items[1]->type() == NULL_ITEM) + { + cache_type_info(items[0], true); + } + else + { + if (fix_length_and_dec2(items)) + return TRUE; + } + return FALSE; + } + +public: + Item_func_case_abbreviation2(THD *thd, Item *a, Item *b): + Item_func_case_expression(thd, a, b) { } + Item_func_case_abbreviation2(THD *thd, Item *a, Item *b, Item *c): + Item_func_case_expression(thd, a, b, c) { } +}; + + +class Item_func_ifnull :public Item_func_case_abbreviation2 +{ +public: + Item_func_ifnull(THD *thd, Item *a, Item *b): + Item_func_case_abbreviation2(thd, a, b) {} + double real_op(); + longlong int_op(); + String *str_op(String *str); + my_decimal *decimal_op(my_decimal *); + bool date_op(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate); + bool time_op(THD *thd, MYSQL_TIME *ltime); + bool native_op(THD *thd, Native *to); + bool fix_length_and_dec() + { + /* + Set nullability from args[1] by default. + Note, some type handlers may reset maybe_null + in Item_hybrid_func_fix_attributes() if args[1] + is NOT NULL but cannot always be converted to + the data type of "this" safely. + E.g. Type_handler_inet6 does: + IFNULL(inet6_not_null_expr, 'foo') -> INET6 NULL + IFNULL(inet6_not_null_expr, '::1') -> INET6 NOT NULL + */ + maybe_null= args[1]->maybe_null; + if (Item_func_case_abbreviation2::fix_length_and_dec2(args)) + return TRUE; + return FALSE; + } + const char *func_name() const { return "ifnull"; } + + table_map not_null_tables() const { return 0; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_ifnull>(thd, this); } +}; + + +/** + Case abbreviations that have a switch argument and + two return arguments to choose from. Returns the value + of either of the two return arguments depending on the switch argument value. + + IF(switch, arg1, arg2) + NVL(switch, arg1, arg2) +*/ +class Item_func_case_abbreviation2_switch: public Item_func_case_abbreviation2 +{ +protected: + virtual Item *find_item() const= 0; + +public: + Item_func_case_abbreviation2_switch(THD *thd, Item *a, Item *b, Item *c) + :Item_func_case_abbreviation2(thd, a, b, c) + { } + + bool date_op(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate) + { + Datetime_truncation_not_needed dt(thd, find_item(), fuzzydate); + return (null_value= dt.copy_to_mysql_time(ltime, mysql_timestamp_type())); + } + bool time_op(THD *thd, MYSQL_TIME *ltime) + { + return (null_value= Time(find_item()).copy_to_mysql_time(ltime)); + } + longlong int_op() + { + return val_int_from_item(find_item()); + } + double real_op() + { + return val_real_from_item(find_item()); + } + my_decimal *decimal_op(my_decimal *decimal_value) + { + return val_decimal_from_item(find_item(), decimal_value); + } + String *str_op(String *str) + { + return val_str_from_item(find_item(), str); + } + bool native_op(THD *thd, Native *to) + { + return val_native_with_conversion_from_item(thd, find_item(), to, + type_handler()); + } +}; + + +class Item_func_if :public Item_func_case_abbreviation2_switch +{ +protected: + Item *find_item() const { return args[0]->val_bool() ? args[1] : args[2]; } + +public: + Item_func_if(THD *thd, Item *a, Item *b, Item *c): + Item_func_case_abbreviation2_switch(thd, a, b, c) + {} + bool fix_fields(THD *, Item **); + bool fix_length_and_dec() + { + return fix_length_and_dec2_eliminate_null(args + 1); + } + const char *func_name() const { return "if"; } + bool eval_not_null_tables(void *opt_arg); + void fix_after_pullout(st_select_lex *new_parent, Item **ref, bool merge); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_if>(thd, this); } +private: + void cache_type_info(Item *source); +}; + + +class Item_func_nvl2 :public Item_func_case_abbreviation2_switch +{ +protected: + Item *find_item() const { return args[0]->is_null() ? args[2] : args[1]; } + +public: + Item_func_nvl2(THD *thd, Item *a, Item *b, Item *c): + Item_func_case_abbreviation2_switch(thd, a, b, c) + {} + const char *func_name() const { return "nvl2"; } + bool fix_length_and_dec() + { + return fix_length_and_dec2_eliminate_null(args + 1); + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_nvl2>(thd, this); } +}; + + +class Item_func_nullif :public Item_func_case_expression +{ + Arg_comparator cmp; + /* + NULLIF(a,b) is a short for: + CASE WHEN a=b THEN NULL ELSE a END + + The left "a" is for comparison purposes. + The right "a" is for return value purposes. + These are two different "a" and they can be replaced to different items. + + The left "a" is in a comparison and can be replaced by: + - Item_func::convert_const_compared_to_int_field() + - agg_item_set_converter() in set_cmp_func() + - cache_converted_constant() in set_cmp_func() + + Both "a"s are subject to equal fields propagation and can be replaced by: + - Item_field::propagate_equal_fields(ANY_SUBST) for the left "a" + - Item_field::propagate_equal_fields(IDENTITY_SUBST) for the right "a" + */ + Item_cache *m_cache; + int compare(); + void reset_first_arg_if_needed() + { + if (arg_count == 3 && args[0] != args[2]) + args[0]= args[2]; + } + Item *m_arg0; +public: + /* + Here we pass three arguments to the parent constructor, as NULLIF + is a three-argument function, it needs two copies of the first argument + (see above). But fix_fields() will be confused if we try to prepare the + same Item twice (if args[0]==args[2]), so we hide the third argument + (decrementing arg_count) and copy args[2]=args[0] again after fix_fields(). + See also Item_func_nullif::fix_length_and_dec(). + */ + Item_func_nullif(THD *thd, Item *a, Item *b): + Item_func_case_expression(thd, a, b, a), + m_cache(NULL), + m_arg0(NULL) + { arg_count--; } + void cleanup() + { + Item_func_hybrid_field_type::cleanup(); + arg_count= 2; // See the comment to the constructor + } + bool date_op(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate); + bool time_op(THD *thd, MYSQL_TIME *ltime); + double real_op(); + longlong int_op(); + String *str_op(String *str); + my_decimal *decimal_op(my_decimal *); + bool native_op(THD *thd, Native *to); + bool fix_length_and_dec(); + bool walk(Item_processor processor, bool walk_subquery, void *arg); + const char *func_name() const { return "nullif"; } + void print(String *str, enum_query_type query_type); + void split_sum_func(THD *thd, Ref_ptr_array ref_pointer_array, + List<Item> &fields, uint flags); + void update_used_tables(); + table_map not_null_tables() const { return 0; } + bool is_null(); + Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond) + { + Context cmpctx(ANY_SUBST, cmp.compare_type_handler(), + cmp.compare_collation()); + const Item *old0= args[0]; + args[0]->propagate_equal_fields_and_change_item_tree(thd, cmpctx, + cond, &args[0]); + args[1]->propagate_equal_fields_and_change_item_tree(thd, cmpctx, + cond, &args[1]); + /* + MDEV-9712 Performance degradation of nested NULLIF + ANY_SUBST is more relaxed than IDENTITY_SUBST. + If ANY_SUBST did not change args[0], + then we can skip propagation for args[2]. + */ + if (old0 != args[0]) + args[2]->propagate_equal_fields_and_change_item_tree(thd, + Context_identity(), + cond, &args[2]); + return this; + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_nullif>(thd, this); } + Item *derived_field_transformer_for_having(THD *thd, uchar *arg) + { reset_first_arg_if_needed(); return this; } + Item *derived_field_transformer_for_where(THD *thd, uchar *arg) + { reset_first_arg_if_needed(); return this; } + Item *grouping_field_transformer_for_where(THD *thd, uchar *arg) + { reset_first_arg_if_needed(); return this; } + Item *in_subq_field_transformer_for_where(THD *thd, uchar *arg) + { reset_first_arg_if_needed(); return this; } + Item *in_subq_field_transformer_for_having(THD *thd, uchar *arg) + { reset_first_arg_if_needed(); return this; } +}; + + +/* Functions to handle the optimized IN */ + + +/* A vector of values of some type */ + +class in_vector :public Sql_alloc +{ +public: + char *base; + uint size; + qsort2_cmp compare; + CHARSET_INFO *collation; + uint count; + uint used_count; + in_vector() {} + in_vector(THD *thd, uint elements, uint element_length, qsort2_cmp cmp_func, + CHARSET_INFO *cmp_coll) + :base((char*) thd_calloc(thd, elements * element_length)), + size(element_length), compare(cmp_func), collation(cmp_coll), + count(elements), used_count(elements) {} + virtual ~in_vector() {} + virtual void set(uint pos,Item *item)=0; + virtual uchar *get_value(Item *item)=0; + void sort() + { + my_qsort2(base,used_count,size,compare,(void*)collation); + } + bool find(Item *item); + + /* + Create an instance of Item_{type} (e.g. Item_decimal) constant object + which type allows it to hold an element of this vector without any + conversions. + The purpose of this function is to be able to get elements of this + vector in form of Item_xxx constants without creating Item_xxx object + for every array element you get (i.e. this implements "FlyWeight" pattern) + */ + virtual Item* create_item(THD *thd) { return NULL; } + + /* + Store the value at position #pos into provided item object + SYNOPSIS + value_to_item() + pos Index of value to store + item Constant item to store value into. The item must be of the same + type that create_item() returns. + */ + virtual void value_to_item(uint pos, Item *item) { } + + /* Compare values number pos1 and pos2 for equality */ + bool compare_elems(uint pos1, uint pos2) + { + return MY_TEST(compare(collation, base + pos1 * size, base + pos2 * size)); + } + virtual const Type_handler *type_handler() const= 0; +}; + +class in_string :public in_vector +{ + char buff[STRING_BUFFER_USUAL_SIZE]; + String tmp; + class Item_string_for_in_vector: public Item_string + { + public: + Item_string_for_in_vector(THD *thd, CHARSET_INFO *cs): + Item_string(thd, cs) + { } + void set_value(const String *str) + { + str_value= *str; + collation.set(str->charset()); + } + }; +public: + in_string(THD *thd, uint elements, qsort2_cmp cmp_func, CHARSET_INFO *cs); + ~in_string(); + void set(uint pos,Item *item); + uchar *get_value(Item *item); + Item* create_item(THD *thd); + void value_to_item(uint pos, Item *item) + { + String *str=((String*) base)+pos; + Item_string_for_in_vector *to= (Item_string_for_in_vector*) item; + to->set_value(str); + } + const Type_handler *type_handler() const { return &type_handler_varchar; } +}; + +class in_longlong :public in_vector +{ +protected: + /* + Here we declare a temporary variable (tmp) of the same type as the + elements of this vector. tmp is used in finding if a given value is in + the list. + */ + struct packed_longlong + { + longlong val; + longlong unsigned_flag; // Use longlong, not bool, to preserve alignment + } tmp; +public: + in_longlong(THD *thd, uint elements); + void set(uint pos,Item *item); + uchar *get_value(Item *item); + Item* create_item(THD *thd); + void value_to_item(uint pos, Item *item) + { + ((Item_int*) item)->value= ((packed_longlong*) base)[pos].val; + ((Item_int*) item)->unsigned_flag= (bool) + ((packed_longlong*) base)[pos].unsigned_flag; + } + const Type_handler *type_handler() const { return &type_handler_slonglong; } + + friend int cmp_longlong(void *cmp_arg, packed_longlong *a,packed_longlong *b); +}; + + +class in_timestamp :public in_vector +{ + Timestamp_or_zero_datetime tmp; +public: + in_timestamp(THD *thd, uint elements); + void set(uint pos,Item *item); + uchar *get_value(Item *item); + Item* create_item(THD *thd); + void value_to_item(uint pos, Item *item); + const Type_handler *type_handler() const { return &type_handler_timestamp2; } +}; + + +/* + Class to represent a vector of constant DATE/DATETIME values. +*/ +class in_temporal :public in_longlong +{ +public: + /* Cache for the left item. */ + + in_temporal(THD *thd, uint elements) + :in_longlong(thd, elements) {}; + Item *create_item(THD *thd); + void value_to_item(uint pos, Item *item) + { + packed_longlong *val= reinterpret_cast<packed_longlong*>(base)+pos; + Item_datetime *dt= static_cast<Item_datetime*>(item); + dt->set(val->val, type_handler()->mysql_timestamp_type()); + } + friend int cmp_longlong(void *cmp_arg, packed_longlong *a,packed_longlong *b); +}; + + +class in_datetime :public in_temporal +{ +public: + in_datetime(THD *thd, uint elements) + :in_temporal(thd, elements) + {} + void set(uint pos,Item *item); + uchar *get_value(Item *item); + const Type_handler *type_handler() const { return &type_handler_datetime2; } +}; + + +class in_time :public in_temporal +{ +public: + in_time(THD *thd, uint elements) + :in_temporal(thd, elements) + {} + void set(uint pos,Item *item); + uchar *get_value(Item *item); + const Type_handler *type_handler() const { return &type_handler_time2; } +}; + + +class in_double :public in_vector +{ + double tmp; +public: + in_double(THD *thd, uint elements); + void set(uint pos,Item *item); + uchar *get_value(Item *item); + Item *create_item(THD *thd); + void value_to_item(uint pos, Item *item) + { + ((Item_float*)item)->value= ((double*) base)[pos]; + } + const Type_handler *type_handler() const { return &type_handler_double; } +}; + + +class in_decimal :public in_vector +{ + my_decimal val; +public: + in_decimal(THD *thd, uint elements); + void set(uint pos, Item *item); + uchar *get_value(Item *item); + Item *create_item(THD *thd); + void value_to_item(uint pos, Item *item) + { + my_decimal *dec= ((my_decimal *)base) + pos; + Item_decimal *item_dec= (Item_decimal*)item; + item_dec->set_decimal_value(dec); + } + const Type_handler *type_handler() const { return &type_handler_newdecimal; } +}; + + +/* +** Classes for easy comparing of non const items +*/ + +class cmp_item :public Sql_alloc +{ +public: + CHARSET_INFO *cmp_charset; + cmp_item() { cmp_charset= &my_charset_bin; } + virtual ~cmp_item() {} + virtual void store_value(Item *item)= 0; + /** + @returns result (TRUE, FALSE or UNKNOWN) of + "stored argument's value <> item's value" + */ + virtual int cmp(Item *item)= 0; + virtual int cmp_not_null(const Value *value)= 0; + // for optimized IN with row + virtual int compare(cmp_item *item)= 0; + virtual cmp_item *make_same()= 0; + virtual void store_value_by_template(THD *thd, cmp_item *tmpl, Item *item) + { + store_value(item); + } +}; + +/// cmp_item which stores a scalar (i.e. non-ROW). +class cmp_item_scalar : public cmp_item +{ +protected: + bool m_null_value; ///< If stored value is NULL +}; + +class cmp_item_string : public cmp_item_scalar +{ +protected: + String *value_res; +public: + cmp_item_string () {} + cmp_item_string (CHARSET_INFO *cs) { cmp_charset= cs; } + void set_charset(CHARSET_INFO *cs) { cmp_charset= cs; } + friend class cmp_item_sort_string; + friend class cmp_item_sort_string_in_static; +}; + +class cmp_item_sort_string :public cmp_item_string +{ +protected: + char value_buff[STRING_BUFFER_USUAL_SIZE]; + String value; +public: + cmp_item_sort_string(): + cmp_item_string() {} + cmp_item_sort_string(CHARSET_INFO *cs): + cmp_item_string(cs), + value(value_buff, sizeof(value_buff), cs) {} + void store_value(Item *item) + { + value_res= item->val_str(&value); + m_null_value= item->null_value; + // Make sure to cache the result String inside "value" + if (value_res && value_res != &value) + { + if (value.copy(*value_res)) + value.set("", 0, item->collation.collation); + value_res= &value; + } + } + int cmp_not_null(const Value *val) + { + DBUG_ASSERT(!val->is_null()); + DBUG_ASSERT(val->is_string()); + return sortcmp(value_res, &val->m_string, cmp_charset) != 0; + } + int cmp(Item *arg) + { + char buff[STRING_BUFFER_USUAL_SIZE]; + String tmp(buff, sizeof(buff), cmp_charset), *res= arg->val_str(&tmp); + if (m_null_value || arg->null_value) + return UNKNOWN; + if (value_res && res) + return sortcmp(value_res, res, cmp_charset) != 0; + else if (!value_res && !res) + return FALSE; + else + return TRUE; + } + int compare(cmp_item *ci) + { + cmp_item_string *l_cmp= (cmp_item_string *) ci; + return sortcmp(value_res, l_cmp->value_res, cmp_charset); + } + cmp_item *make_same(); + void set_charset(CHARSET_INFO *cs) + { + cmp_charset= cs; + value.set_quick(value_buff, sizeof(value_buff), cs); + } +}; + +class cmp_item_int : public cmp_item_scalar +{ + longlong value; +public: + cmp_item_int() {} /* Remove gcc warning */ + void store_value(Item *item) + { + value= item->val_int(); + m_null_value= item->null_value; + } + int cmp_not_null(const Value *val) + { + DBUG_ASSERT(!val->is_null()); + DBUG_ASSERT(val->is_longlong()); + return value != val->value.m_longlong; + } + int cmp(Item *arg) + { + const bool rc= value != arg->val_int(); + return (m_null_value || arg->null_value) ? UNKNOWN : rc; + } + int compare(cmp_item *ci) + { + cmp_item_int *l_cmp= (cmp_item_int *)ci; + return (value < l_cmp->value) ? -1 : ((value == l_cmp->value) ? 0 : 1); + } + cmp_item *make_same(); +}; + +/* + Compare items in the DATETIME context. +*/ +class cmp_item_temporal: public cmp_item_scalar +{ +protected: + longlong value; +public: + cmp_item_temporal() {} + int compare(cmp_item *ci); +}; + + +class cmp_item_datetime: public cmp_item_temporal +{ +public: + cmp_item_datetime() + :cmp_item_temporal() + { } + void store_value(Item *item) + { + value= item->val_datetime_packed(current_thd); + m_null_value= item->null_value; + } + int cmp_not_null(const Value *val); + int cmp(Item *arg); + cmp_item *make_same(); +}; + + +class cmp_item_time: public cmp_item_temporal +{ +public: + cmp_item_time() + :cmp_item_temporal() + { } + void store_value(Item *item) + { + value= item->val_time_packed(current_thd); + m_null_value= item->null_value; + } + int cmp_not_null(const Value *val); + int cmp(Item *arg); + cmp_item *make_same(); +}; + + +class cmp_item_timestamp: public cmp_item_scalar +{ + Timestamp_or_zero_datetime_native m_native; +public: + cmp_item_timestamp() :cmp_item_scalar() { } + void store_value(Item *item); + int cmp_not_null(const Value *val); + int cmp(Item *arg); + int compare(cmp_item *ci); + cmp_item *make_same(); +}; + + +class cmp_item_real : public cmp_item_scalar +{ + double value; +public: + cmp_item_real() {} /* Remove gcc warning */ + void store_value(Item *item) + { + value= item->val_real(); + m_null_value= item->null_value; + } + int cmp_not_null(const Value *val) + { + DBUG_ASSERT(!val->is_null()); + DBUG_ASSERT(val->is_double()); + return value != val->value.m_double; + } + int cmp(Item *arg) + { + const bool rc= value != arg->val_real(); + return (m_null_value || arg->null_value) ? UNKNOWN : rc; + } + int compare(cmp_item *ci) + { + cmp_item_real *l_cmp= (cmp_item_real *) ci; + return (value < l_cmp->value)? -1 : ((value == l_cmp->value) ? 0 : 1); + } + cmp_item *make_same(); +}; + + +class cmp_item_decimal : public cmp_item_scalar +{ + my_decimal value; +public: + cmp_item_decimal() {} /* Remove gcc warning */ + void store_value(Item *item); + int cmp(Item *arg); + int cmp_not_null(const Value *val); + int compare(cmp_item *c); + cmp_item *make_same(); +}; + + +/* + cmp_item for optimized IN with row (right part string, which never + be changed) +*/ + +class cmp_item_sort_string_in_static :public cmp_item_string +{ + protected: + String value; +public: + cmp_item_sort_string_in_static(CHARSET_INFO *cs): + cmp_item_string(cs) {} + void store_value(Item *item) + { + value_res= item->val_str(&value); + m_null_value= item->null_value; + } + int cmp_not_null(const Value *val) + { + DBUG_ASSERT(false); + return TRUE; + } + int cmp(Item *item) + { + // Should never be called + DBUG_ASSERT(false); + return TRUE; + } + int compare(cmp_item *ci) + { + cmp_item_string *l_cmp= (cmp_item_string *) ci; + return sortcmp(value_res, l_cmp->value_res, cmp_charset); + } + cmp_item *make_same() + { + return new cmp_item_sort_string_in_static(cmp_charset); + } +}; + + +/** + A helper class to handle situations when some item "pred" (the predicant) + is consequently compared to a list of other items value0..valueN (the values). + Currently used to handle: + - <in predicate> + pred IN (value0, value1, value2) + - <simple case> + CASE pred WHEN value0 .. WHEN value1 .. WHEN value2 .. END + + Every pair {pred,valueN} can be compared by its own Type_handler. + Some pairs can use the same Type_handler. + In cases when all pairs use exactly the same Type_handler, + we say "all types are compatible". + + For example, for an expression + 1 IN (1, 1e0, 1.0, 2) + - pred is 1 + - value0 is 1 + - value1 is 1e0 + - value2 is 1.1 + - value3 is 2 + + Pairs (pred,valueN) are compared as follows: + N expr1 Type + - ----- ---- + 0 1 INT + 1 1e0 DOUBLE + 2 1.0 DECIMAL + 3 2 INT + + Types are not compatible in this example. + + During add_value() calls, each pair {pred,valueN} is analysed: + - If valueN is an explicit NULL, it can be ignored in the caller asks to do so + - If valueN is not an explicit NULL (or if the caller didn't ask to skip + NULLs), then the value add an element in the array m_comparators[]. + + Every element m_comparators[] stores the following information: + 1. m_arg_index - the position of the value expression in the original + argument array, e.g. in Item_func_in::args[] or Item_func_case::args[]. + + 2. m_handler - the pointer to the data type handler that the owner + will use to compare the pair {args[m_predicate_index],args[m_arg_index]}. + + 3. m_handler_index - the index of an m_comparators[] element corresponding + to the leftmost pair that uses exactly the same Type_handler for + comparison. m_handler_index helps to maintain unique data type handlers. + - m_comparators[i].m_handler_index==i means that this is the + leftmost pair that uses the Type_handler m_handler for comparision. + - If m_comparators[i].m_handlex_index!=i, it means that some earlier + element m_comparators[j<i] is already using this Type_handler + pointed by m_handler. + + 4. m_cmp_item - the pointer to a cmp_item instance to handle comparison + for this pair. Only unique type handlers have m_cmp_item!=NULL. + Non-unique type handlers share the same cmp_item instance. + For all m_comparators[] elements the following assersion it true: + (m_handler_index==i) == (m_cmp_item!=NULL) +*/ +class Predicant_to_list_comparator +{ + // Allocate memory on thd memory root for "nvalues" values. + bool alloc_comparators(THD *thd, uint nvalues); + + /** + Look up m_comparators[] for a comparator using the given data type handler. + @param [OUT] idx - the index of the found comparator is returned here + @param [IN] handler - the data type handler to find + @param [IN] count - search in the range [0,count) only + @retval true - this type handler was not found + (*idx is not defined in this case). + @retval false - this type handler was found (the position of the + found handler is returned in idx). + */ + bool find_handler(uint *idx, const Type_handler *handler, uint count) + { + DBUG_ASSERT(count < m_comparator_count); + for (uint i= 0 ; i < count; i++) + { + if (m_comparators[i].m_handler == handler) + { + *idx= i; + return false; + } + } + return true; + } + + /** + Populate m_comparators[i].m_handler_index for all elements in + m_comparators using the information in m_comparators[i].m_handlers, + which was previously populated by a add_predicant() call and a number + of add_value() calls. + @param [OUT] compatible - If all comparator types are compatible, + their data type handler is returned here. + @param [OUT] unuque_cnt - The number of unique data type handlers found. + If the value returned in *unique_cnt is 0, + it means all values were explicit NULLs: + expr0 IN (NULL,NULL,..,NULL) + @param [OUT] found_type - The bit mask for all found cmp_type()'s. + */ + void detect_unique_handlers(Type_handler_hybrid_field_type *compatible, + uint *unique_cnt, uint *found_types); + /** + Creates a cmp_item instances for all unique handlers and stores + them into m_comparators[i].m_cmp_item, using the information previously + populated by add_predicant(), add_value(), detect_unque_handlers(). + */ + + /* + Compare the predicant to the value pointed by m_comparators[i]. + @param args - the same argument array which was previously used + with add_predicant() and add_value(). + @param i - which pair to check. + @retval true - the predicant is not equal to the value. + @retval false - the predicant is equal to the value. + @retval UNKNOWN - the result is uncertain yet because the predicant + and/or the value returned NULL, + more pairs {pred,valueN} should be checked. + */ + int cmp_arg(Item_args *args, uint i) + { + Predicant_to_value_comparator *cmp= + &m_comparators[m_comparators[i].m_handler_index]; + cmp_item *in_item= cmp->m_cmp_item; + DBUG_ASSERT(in_item); + /* + If this is the leftmost pair that uses the data type handler + pointed by m_comparators[i].m_handler, then we need to cache + the predicant value representation used by this handler. + */ + if (m_comparators[i].m_handler_index == i) + in_item->store_value(args->arguments()[m_predicant_index]); + /* + If the predicant item has null_value==true then: + - In case of scalar expression we can returns UNKNOWN immediately. + No needs to check the result of the value item. + - In case of ROW, null_value==true means that *some* row elements + returned NULL, but *some* elements can still be non-NULL! + We need to get the result of the value item and test + if non-NULL elements in the predicant and the value produce + TRUE (not equal), or UNKNOWN. + */ + if (args->arguments()[m_predicant_index]->null_value && + m_comparators[i].m_handler != &type_handler_row) + return UNKNOWN; + return in_item->cmp(args->arguments()[m_comparators[i].m_arg_index]); + } + int cmp_args_nulls_equal(THD *thd, Item_args *args, uint i) + { + Predicant_to_value_comparator *cmp= + &m_comparators[m_comparators[i].m_handler_index]; + cmp_item *in_item= cmp->m_cmp_item; + DBUG_ASSERT(in_item); + Item *predicant= args->arguments()[m_predicant_index]; + Item *arg= args->arguments()[m_comparators[i].m_arg_index]; + ValueBuffer<MAX_FIELD_WIDTH> val; + if (m_comparators[i].m_handler_index == i) + in_item->store_value(predicant); + m_comparators[i].m_handler->Item_save_in_value(thd, arg, &val); + if (predicant->null_value && val.is_null()) + return FALSE; // Two nulls are equal + if (predicant->null_value || val.is_null()) + return UNKNOWN; + return in_item->cmp_not_null(&val); + } + /** + Predicant_to_value_comparator - a comparator for one pair (pred,valueN). + See comments above. + */ + struct Predicant_to_value_comparator + { + const Type_handler *m_handler; + cmp_item *m_cmp_item; + uint m_arg_index; + uint m_handler_index; + void cleanup() + { + if (m_cmp_item) + delete m_cmp_item; + memset(this, 0, sizeof(*this)); + } + }; + + Predicant_to_value_comparator *m_comparators; // The comparator array + uint m_comparator_count;// The number of elements in m_comparators[] + uint m_predicant_index; // The position of the predicant in its argument list, + // e.g. for Item_func_in m_predicant_index is 0, + // as predicant is stored in Item_func_in::args[0]. + // For Item_func_case m_predicant_index is + // set to Item_func_case::first_expr_num. + +public: + Predicant_to_list_comparator(THD *thd, uint nvalues) + :m_comparator_count(0), + m_predicant_index(0) + { + alloc_comparators(thd, nvalues); + } + + uint comparator_count() const { return m_comparator_count; } + const Type_handler *get_comparator_type_handler(uint i) const + { + DBUG_ASSERT(i < m_comparator_count); + return m_comparators[i].m_handler; + } + uint get_comparator_arg_index(uint i) const + { + DBUG_ASSERT(i < m_comparator_count); + return m_comparators[i].m_arg_index; + } + cmp_item *get_comparator_cmp_item(uint i) const + { + DBUG_ASSERT(i < m_comparator_count); + return m_comparators[i].m_cmp_item; + } + +#ifndef DBUG_OFF + void debug_print(THD *thd) + { + for (uint i= 0; i < m_comparator_count; i++) + { + DBUG_EXECUTE_IF("Predicant_to_list_comparator", + push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE, + ER_UNKNOWN_ERROR, "DBUG: [%d] arg=%d handler=%d (%s)", i, + m_comparators[i].m_arg_index, + m_comparators[i].m_handler_index, + m_comparators[m_comparators[i].m_handler_index]. + m_handler->name().ptr());); + } + } +#endif + + void add_predicant(Item_args *args, uint predicant_index) + { + DBUG_ASSERT(m_comparator_count == 0); // Set in constructor + DBUG_ASSERT(m_predicant_index == 0); // Set in constructor + DBUG_ASSERT(predicant_index < args->argument_count()); + m_predicant_index= predicant_index; + } + /** + Add a new element into m_comparators[], using a {pred,valueN} pair. + + @param funcname - the name of the operation, for error reporting + @param args - the owner function's argument list + @param value_index - the value position in args + @retval true - could not add an element because of non-comparable + arguments (e.g. ROWs with size) + @retval false - a new element was successfully added. + */ + bool add_value(const char *funcname, Item_args *args, uint value_index); + + /** + Add a new element into m_comparators[], ignoring explicit NULL values. + If the value appeared to be an explicit NULL, nulls_found[0] is set to true. + */ + bool add_value_skip_null(const char *funcname, + Item_args *args, uint value_index, + bool *nulls_found); + + /** + Signal "this" that there will be no new add_value*() calls, + so it can prepare its internal structures for comparison. + + @param [OUT] compatible - If all comparators are compatible, + their data type handler is returned here. + @param [OUT] unuque_cnt - The number of unique data type handlers found. + If the value returned in *unique_cnt is 0, + it means all values were explicit NULLs: + expr0 IN (NULL,NULL,..,NULL) + @param [OUT] found_type - The bit mask for all found cmp_type()'s. + */ + void all_values_added(Type_handler_hybrid_field_type *compatible, + uint *unique_cnt, uint *found_types) + { + detect_unique_handlers(compatible, unique_cnt, found_types); + } + /** + Creates cmp_item instances for all unique handlers and stores + them into m_comparators[].m_cmp_item, using the information previously + populated by add_predicant(), add_value() and detect_unque_handlers(). + */ + bool make_unique_cmp_items(THD *thd, CHARSET_INFO *cs); + void cleanup() + { + DBUG_ASSERT(m_comparators); + for (uint i= 0; i < m_comparator_count; i++) + m_comparators[i].cleanup(); + memset(m_comparators, 0, sizeof(m_comparators[0]) * m_comparator_count); + m_comparator_count= 0; + m_predicant_index= 0; + } + bool init_clone(THD *thd, uint nvalues) + { + m_comparator_count= 0; + m_predicant_index= 0; + return alloc_comparators(thd, nvalues); + } + /** + @param [IN] args - The argument list that was previously used with + add_predicant() and add_value(). + @param [OUT] idx - In case if a value that is equal to the predicant + was found, the index of the matching value is returned + here. Otherwise, *idx is not changed. + @param [IN/OUT] found_unknown_values - how to handle UNKNOWN results. + If found_unknown_values is NULL (e.g. Item_func_case), + cmp() returns immediately when the first UNKNOWN + result is found. + If found_unknown_values is non-NULL (Item_func_in), + cmp() does not return when an UNKNOWN result is found, + sets *found_unknown_values to true, and continues + to compare the remaining pairs to find FALSE + (i.e. the value that is equal to the predicant). + + @retval false - Found a value that is equal to the predicant + @retval true - Didn't find an equal value + */ + bool cmp(Item_args *args, uint *idx, bool *found_unknown_values) + { + for (uint i= 0 ; i < m_comparator_count ; i++) + { + DBUG_ASSERT(m_comparators[i].m_handler != NULL); + const int rc= cmp_arg(args, i); + if (rc == FALSE) + { + *idx= m_comparators[i].m_arg_index; + return false; // Found a matching value + } + if (rc == UNKNOWN) + { + if (!found_unknown_values) + return true; + *found_unknown_values= true; + } + } + return true; // Not found + } + /* + Same as above, but treats two NULLs as equal, e.g. as in DECODE_ORACLE(). + */ + bool cmp_nulls_equal(THD *thd, Item_args *args, uint *idx) + { + for (uint i= 0 ; i < m_comparator_count ; i++) + { + DBUG_ASSERT(m_comparators[i].m_handler != NULL); + if (cmp_args_nulls_equal(thd, args, i) == FALSE) + { + *idx= m_comparators[i].m_arg_index; + return false; // Found a matching value + } + } + return true; // Not found + } +}; + + +/* + The class Item_func_case is the CASE ... WHEN ... THEN ... END function + implementation. +*/ + +class Item_func_case :public Item_func_case_expression +{ +protected: + String tmp_value; + DTCollation cmp_collation; + bool aggregate_then_and_else_arguments(THD *thd, uint count); + virtual Item **else_expr_addr() const= 0; + virtual Item *find_item()= 0; + inline void print_when_then_arguments(String *str, + enum_query_type query_type, + Item **items, uint count); + inline void print_else_argument(String *str, enum_query_type query_type, + Item *item); + void reorder_args(uint start); +public: + Item_func_case(THD *thd, List<Item> &list) + :Item_func_case_expression(thd, list) + { } + double real_op(); + longlong int_op(); + String *str_op(String *); + my_decimal *decimal_op(my_decimal *); + bool date_op(THD *thd, MYSQL_TIME *ltime, date_mode_t fuzzydate); + bool time_op(THD *thd, MYSQL_TIME *ltime); + bool native_op(THD *thd, Native *to); + bool fix_fields(THD *thd, Item **ref); + table_map not_null_tables() const { return 0; } + const char *func_name() const { return "case"; } + CHARSET_INFO *compare_collation() const { return cmp_collation.collation; } + bool need_parentheses_in_default() { return true; } +}; + + +/* + CASE WHEN cond THEN res [WHEN cond THEN res...] [ELSE res] END + + Searched CASE checks all WHEN expressions one after another. + When some WHEN expression evaluated to TRUE then the + value of the corresponding THEN expression is returned. +*/ +class Item_func_case_searched: public Item_func_case +{ + uint when_count() const { return arg_count / 2; } + bool with_else() const { return arg_count % 2; } + Item **else_expr_addr() const { return with_else() ? &args[arg_count - 1] : 0; } +public: + Item_func_case_searched(THD *thd, List<Item> &list) + :Item_func_case(thd, list) + { + DBUG_ASSERT(arg_count >= 2); + reorder_args(0); + } + enum Functype functype() const { return CASE_SEARCHED_FUNC; } + void print(String *str, enum_query_type query_type); + bool fix_length_and_dec(); + Item *propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond) + { + // None of the arguments are in a comparison context + Item_args::propagate_equal_fields(thd, Context_identity(), cond); + return this; + } + Item *find_item(); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_case_searched>(thd, this); } +}; + + +/* + CASE pred WHEN value THEN res [WHEN value THEN res...] [ELSE res] END + + When the predicant expression is specified then it is compared to each WHEN + expression individually. When an equal WHEN expression is found + the corresponding THEN expression is returned. + In order to do correct comparisons several comparators are used. One for + each result type. Different result types that are used in particular + CASE ... END expression are collected in the fix_length_and_dec() member + function and only comparators for there result types are used. +*/ +class Item_func_case_simple: public Item_func_case, + public Predicant_to_list_comparator +{ +protected: + uint m_found_types; + uint when_count() const { return (arg_count - 1) / 2; } + bool with_else() const { return arg_count % 2 == 0; } + Item **else_expr_addr() const { return with_else() ? &args[arg_count - 1] : 0; } + bool aggregate_switch_and_when_arguments(THD *thd, bool nulls_equal); + bool prepare_predicant_and_values(THD *thd, uint *found_types, + bool nulls_equal); +public: + Item_func_case_simple(THD *thd, List<Item> &list) + :Item_func_case(thd, list), + Predicant_to_list_comparator(thd, arg_count), + m_found_types(0) + { + DBUG_ASSERT(arg_count >= 3); + reorder_args(1); + } + void cleanup() + { + DBUG_ENTER("Item_func_case_simple::cleanup"); + Item_func::cleanup(); + Predicant_to_list_comparator::cleanup(); + DBUG_VOID_RETURN; + } + enum Functype functype() const { return CASE_SIMPLE_FUNC; } + void print(String *str, enum_query_type query_type); + bool fix_length_and_dec(); + Item *propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond); + Item *find_item(); + Item *build_clone(THD *thd) + { + Item_func_case_simple *clone= (Item_func_case_simple *) + Item_func_case::build_clone(thd); + uint ncases= when_count(); + if (clone && clone->Predicant_to_list_comparator::init_clone(thd, ncases)) + return NULL; + return clone; + } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_case_simple>(thd, this); } +}; + + +class Item_func_decode_oracle: public Item_func_case_simple +{ +public: + Item_func_decode_oracle(THD *thd, List<Item> &list) + :Item_func_case_simple(thd, list) + { } + const char *func_name() const { return "decode_oracle"; } + void print(String *str, enum_query_type query_type); + bool fix_length_and_dec(); + Item *find_item(); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_decode_oracle>(thd, this); } +}; + + +/* + The Item_func_in class implements + in_expr IN (<in value list>) + and + in_expr NOT IN (<in value list>) + + The current implementation distinguishes 2 cases: + 1) all items in <in value list> are constants and have the same + result type. This case is handled by in_vector class, + implementing fast bisection search. + 2) otherwise Item_func_in employs several cmp_item objects to perform + comparisons of in_expr and an item from <in value list>. One cmp_item + object for each result type. Different result types are collected in the + fix_length_and_dec() member function by means of collect_cmp_types() + function. + + Bisection is possible when: + 1. All types are similar + 2. All expressions in <in value list> are const + In the presence of NULLs, the correct result of evaluating this item + must be UNKNOWN or FALSE. To achieve that: + - If type is scalar, we can use bisection and the "have_null" boolean. + - If type is ROW, we will need to scan all of <in value list> when + searching, so bisection is impossible. Unless: + 3. UNKNOWN and FALSE are equivalent results + 4. Neither left expression nor <in value list> contain any NULL value +*/ +class Item_func_in :public Item_func_opt_neg, + public Predicant_to_list_comparator +{ + /** + Usable if <in value list> is made only of constants. Returns true if one + of these constants contains a NULL. Example: + IN ( (-5, (12,NULL)), ... ). + */ + bool list_contains_null(); + bool all_items_are_consts(Item **items, uint nitems) const + { + for (uint i= 0; i < nitems; i++) + { + if (!items[i]->const_item() || items[i]->is_expensive()) + return false; + } + return true; + } + bool prepare_predicant_and_values(THD *thd, uint *found_types); + bool check_arguments() const + { + return check_argument_types_like_args0(); + } +protected: + SEL_TREE *get_func_mm_tree(RANGE_OPT_PARAM *param, + Field *field, Item *value); + bool transform_into_subq; +public: + /// An array of values, created when the bisection lookup method is used + in_vector *array; + /** + If there is some NULL among <in value list>, during a val_int() call; for + example + IN ( (1,(3,'col')), ... ), where 'col' is a column which evaluates to + NULL. + */ + bool have_null; + /** + true when all arguments of the IN list are of compatible types + and can be used safely as comparisons for key conditions + */ + bool arg_types_compatible; + + TABLE_LIST *emb_on_expr_nest; + + Item_func_in(THD *thd, List<Item> &list): + Item_func_opt_neg(thd, list), + Predicant_to_list_comparator(thd, arg_count - 1), + transform_into_subq(false), + array(0), have_null(0), + arg_types_compatible(FALSE), emb_on_expr_nest(0) + { } + longlong val_int(); + bool fix_fields(THD *, Item **); + bool fix_length_and_dec(); + bool compatible_types_scalar_bisection_possible() + { + DBUG_ASSERT(m_comparator.cmp_type() != ROW_RESULT); + return all_items_are_consts(args + 1, arg_count - 1); // Bisection #2 + } + bool compatible_types_row_bisection_possible() + { + DBUG_ASSERT(m_comparator.cmp_type() == ROW_RESULT); + return all_items_are_consts(args + 1, arg_count - 1) && // Bisection #2 + ((is_top_level_item() && !negated) || // Bisection #3 + (!list_contains_null() && !args[0]->maybe_null)); // Bisection #4 + } + bool agg_all_arg_charsets_for_comparison() + { + return agg_arg_charsets_for_comparison(cmp_collation, args, arg_count); + } + void fix_in_vector(); + bool value_list_convert_const_to_int(THD *thd); + bool fix_for_scalar_comparison_using_bisection(THD *thd) + { + array= m_comparator.type_handler()->make_in_vector(thd, this, arg_count - 1); + if (!array) // OOM + return true; + fix_in_vector(); + return false; + } + bool fix_for_scalar_comparison_using_cmp_items(THD *thd, uint found_types); + + bool fix_for_row_comparison_using_cmp_items(THD *thd); + bool fix_for_row_comparison_using_bisection(THD *thd); + + void cleanup() + { + DBUG_ENTER("Item_func_in::cleanup"); + Item_int_func::cleanup(); + delete array; + array= 0; + Predicant_to_list_comparator::cleanup(); + DBUG_VOID_RETURN; + } + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level, + table_map usable_tables, SARGABLE_PARAM **sargables); + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr); + SEL_TREE *get_func_row_mm_tree(RANGE_OPT_PARAM *param, Item_row *key_row); + Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond) + { + /* + Note, we pass ANY_SUBST, this makes sure that non of the args + will be replaced to a zero-filled Item_string. + Such a change would require rebuilding of cmp_items. + */ + if (arg_types_compatible) + { + Context cmpctx(ANY_SUBST, m_comparator.type_handler(), + Item_func_in::compare_collation()); + args[0]->propagate_equal_fields_and_change_item_tree(thd, cmpctx, + cond, &args[0]); + } + for (uint i= 0; i < comparator_count(); i++) + { + Context cmpctx(ANY_SUBST, get_comparator_type_handler(i), + Item_func_in::compare_collation()); + uint idx= get_comparator_arg_index(i); + args[idx]->propagate_equal_fields_and_change_item_tree(thd, cmpctx, + cond, &args[idx]); + } + return this; + } + virtual void print(String *str, enum_query_type query_type); + enum Functype functype() const { return IN_FUNC; } + const char *func_name() const { return "in"; } + enum precedence precedence() const { return IN_PRECEDENCE; } + bool eval_not_null_tables(void *opt_arg); + bool find_not_null_fields(table_map allowed); + void fix_after_pullout(st_select_lex *new_parent, Item **ref, bool merge); + bool count_sargable_conds(void *arg); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_in>(thd, this); } + Item *build_clone(THD *thd) + { + Item_func_in *clone= (Item_func_in *) Item_func::build_clone(thd); + if (clone) + { + clone->array= 0; + if (clone->Predicant_to_list_comparator::init_clone(thd, arg_count - 1)) + return NULL; + } + return clone; + } + void mark_as_condition_AND_part(TABLE_LIST *embedding); + bool to_be_transformed_into_in_subq(THD *thd); + bool create_value_list_for_tvc(THD *thd, List< List<Item> > *values); + Item *in_predicate_to_in_subs_transformer(THD *thd, uchar *arg); + uint32 max_length_of_left_expr(); +}; + +class cmp_item_row :public cmp_item +{ + cmp_item **comparators; + uint n; + bool alloc_comparators(THD *thd, uint n); + bool aggregate_row_elements_for_comparison(THD *thd, + Type_handler_hybrid_field_type *cmp, + Item_args *tmp, + const char *funcname, + uint col, + uint level); +public: + cmp_item_row(): comparators(0), n(0) {} + ~cmp_item_row(); + void store_value(Item *item); + bool prepare_comparators(THD *, const char *funcname, + const Item_args *args, uint level); + int cmp(Item *arg); + int cmp_not_null(const Value *val) + { + DBUG_ASSERT(false); + return TRUE; + } + int compare(cmp_item *arg); + cmp_item *make_same(); + void store_value_by_template(THD *thd, cmp_item *tmpl, Item *); + friend class Item_func_in; + cmp_item *get_comparator(uint i) { return comparators[i]; } +}; + + +class in_row :public in_vector +{ + cmp_item_row tmp; +public: + in_row(THD *thd, uint elements, Item *); + ~in_row(); + void set(uint pos,Item *item); + uchar *get_value(Item *item); + friend class Item_func_in; + const Type_handler *type_handler() const { return &type_handler_row; } + cmp_item *get_cmp_item() { return &tmp; } +}; + +/* Functions used by where clause */ +class Item_func_null_predicate :public Item_bool_func +{ +protected: + SEL_TREE *get_func_mm_tree(RANGE_OPT_PARAM *param, + Field *field, Item *value) + { + DBUG_ENTER("Item_func_null_predicate::get_func_mm_tree"); + DBUG_RETURN(get_mm_parts(param, field, functype(), value)); + } + SEL_ARG *get_mm_leaf(RANGE_OPT_PARAM *param, Field *field, + KEY_PART *key_part, + Item_func::Functype type, Item *value); +public: + Item_func_null_predicate(THD *thd, Item *a): Item_bool_func(thd, a) { } + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level, + table_map usable_tables, SARGABLE_PARAM **sargables); + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr) + { + DBUG_ENTER("Item_func_null_predicate::get_mm_tree"); + SEL_TREE *ftree= get_full_func_mm_tree_for_args(param, args[0], NULL); + if (!ftree) + ftree= Item_func::get_mm_tree(param, cond_ptr); + DBUG_RETURN(ftree); + } + CHARSET_INFO *compare_collation() const + { return args[0]->collation.collation; } + bool fix_length_and_dec() + { + decimals=0; max_length=1; maybe_null=0; + return FALSE; + } + bool count_sargable_conds(void *arg); +}; + + +class Item_func_isnull :public Item_func_null_predicate +{ +public: + Item_func_isnull(THD *thd, Item *a): Item_func_null_predicate(thd, a) {} + longlong val_int(); + enum Functype functype() const { return ISNULL_FUNC; } + const char *func_name() const { return "isnull"; } + void print(String *str, enum_query_type query_type); + enum precedence precedence() const { return CMP_PRECEDENCE; } + + bool arg_is_datetime_notnull_field() + { + Item **args= arguments(); + if (args[0]->real_item()->type() == Item::FIELD_ITEM) + { + Field *field=((Item_field*) args[0]->real_item())->field; + + if ((field->flags & NOT_NULL_FLAG) && + field->type_handler()->cond_notnull_field_isnull_to_field_eq_zero()) + return true; + } + return false; + } + + /* Optimize case of not_null_column IS NULL */ + virtual void update_used_tables() + { + if (!args[0]->maybe_null && !arg_is_datetime_notnull_field()) + { + used_tables_cache= 0; /* is always false */ + const_item_cache= 1; + } + else + { + args[0]->update_used_tables(); + used_tables_cache= args[0]->used_tables(); + const_item_cache= args[0]->const_item(); + } + } + COND *remove_eq_conds(THD *thd, Item::cond_result *cond_value, + bool top_level); + table_map not_null_tables() const { return 0; } + bool find_not_null_fields(table_map allowed); + Item *neg_transformer(THD *thd); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_isnull>(thd, this); } +}; + +/* Functions used by HAVING for rewriting IN subquery */ + +class Item_in_subselect; + +/* + This is like IS NOT NULL but it also remembers if it ever has + encountered a NULL. +*/ +class Item_is_not_null_test :public Item_func_isnull +{ + Item_in_subselect* owner; +public: + Item_is_not_null_test(THD *thd, Item_in_subselect* ow, Item *a): + Item_func_isnull(thd, a), owner(ow) + {} + enum Functype functype() const { return ISNOTNULLTEST_FUNC; } + longlong val_int(); + const char *func_name() const { return "<is_not_null_test>"; } + void update_used_tables(); + /* + we add RAND_TABLE_BIT to prevent moving this item from HAVING to WHERE + */ + table_map used_tables() const + { return used_tables_cache | RAND_TABLE_BIT; } + bool const_item() const { return FALSE; } +}; + + +class Item_func_isnotnull :public Item_func_null_predicate +{ + bool abort_on_null; +public: + Item_func_isnotnull(THD *thd, Item *a): + Item_func_null_predicate(thd, a), abort_on_null(0) + { } + longlong val_int(); + enum Functype functype() const { return ISNOTNULL_FUNC; } + const char *func_name() const { return "isnotnull"; } + enum precedence precedence() const { return CMP_PRECEDENCE; } + table_map not_null_tables() const + { return abort_on_null ? not_null_tables_cache : 0; } + Item *neg_transformer(THD *thd); + void print(String *str, enum_query_type query_type); + void top_level_item() { abort_on_null=1; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_isnotnull>(thd, this); } +}; + + +class Item_func_like :public Item_bool_func2 +{ + // Turbo Boyer-Moore data + bool canDoTurboBM; // pattern is '%abcd%' case + const char* pattern; + int pattern_len; + + // TurboBM buffers, *this is owner + int* bmGs; // good suffix shift table, size is pattern_len + 1 + int* bmBc; // bad character shift table, size is alphabet_size + + void turboBM_compute_suffixes(int* suff); + void turboBM_compute_good_suffix_shifts(int* suff); + void turboBM_compute_bad_character_shifts(); + bool turboBM_matches(const char* text, int text_len) const; + enum { alphabet_size = 256 }; + + Item *escape_item; + + bool escape_used_in_parsing; + bool use_sampling; + + DTCollation cmp_collation; + String cmp_value1, cmp_value2; + bool with_sargable_pattern() const; +protected: + SEL_TREE *get_func_mm_tree(RANGE_OPT_PARAM *param, + Field *field, Item *value) + { + DBUG_ENTER("Item_func_like::get_func_mm_tree"); + DBUG_RETURN(get_mm_parts(param, field, LIKE_FUNC, value)); + } + SEL_ARG *get_mm_leaf(RANGE_OPT_PARAM *param, Field *field, + KEY_PART *key_part, + Item_func::Functype type, Item *value); +public: + int escape; + bool negated; + + Item_func_like(THD *thd, Item *a, Item *b, Item *escape_arg, bool escape_used): + Item_bool_func2(thd, a, b), canDoTurboBM(FALSE), pattern(0), pattern_len(0), + bmGs(0), bmBc(0), escape_item(escape_arg), + escape_used_in_parsing(escape_used), use_sampling(0), negated(0) {} + + bool get_negated() const { return negated; } // Used by ColumnStore + + Sql_mode_dependency value_depends_on_sql_mode() const; + longlong val_int(); + enum Functype functype() const { return LIKE_FUNC; } + void print(String *str, enum_query_type query_type); + CHARSET_INFO *compare_collation() const + { return cmp_collation.collation; } + cond_result eq_cmp_result() const + { + /** + We cannot always rewrite conditions as follows: + from: WHERE expr1=const AND expr1 LIKE expr2 + to: WHERE expr1=const AND const LIKE expr2 + or + from: WHERE expr1=const AND expr2 LIKE expr1 + to: WHERE expr1=const AND expr2 LIKE const + + because LIKE works differently comparing to the regular "=" operator: + + 1. LIKE performs a stricter one-character-to-one-character comparison + and does not recognize contractions and expansions. + Replacing "expr1" to "const in LIKE would make the condition + stricter in case of a complex collation. + + 2. LIKE does not ignore trailing spaces and thus works differently + from the "=" operator in case of "PAD SPACE" collations + (which are the majority in MariaDB). So, for "PAD SPACE" collations: + + - expr1=const - ignores trailing spaces + - const LIKE expr2 - does not ignore trailing spaces + - expr2 LIKE const - does not ignore trailing spaces + + Allow only "binary" for now. + It neither ignores trailing spaces nor has contractions/expansions. + + TODO: + We could still replace "expr1" to "const" in "expr1 LIKE expr2" + in case of a "PAD SPACE" collation, but only if "expr2" has '%' + at the end. + */ + return compare_collation() == &my_charset_bin ? COND_TRUE : COND_OK; + } + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level, + table_map usable_tables, SARGABLE_PARAM **sargables); + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr); + Item* propagate_equal_fields(THD *thd, const Context &ctx, COND_EQUAL *cond) + { + /* + LIKE differs from the regular comparison operator ('=') in the following: + - LIKE never ignores trailing spaces (even for PAD SPACE collations) + Propagation of equal fields with a PAD SPACE collation into LIKE + is not safe. + Example: + WHERE a='a ' AND a LIKE 'a' - returns true for 'a' + cannot be rewritten to: + WHERE a='a ' AND 'a ' LIKE 'a' - returns false for 'a' + Note, binary collations in MySQL/MariaDB, e.g. latin1_bin, + still have the PAD SPACE attribute and ignore trailing spaces! + - LIKE does not take into account contractions, expansions, + and ignorable characters. + Propagation of equal fields with contractions/expansions/ignorables + is also not safe. + + It's safe to propagate my_charset_bin (BINARY/VARBINARY/BLOB) values, + because they do not ignore trailing spaces and have one-to-one mapping + between a string and its weights. + The below condition should be true only for my_charset_bin + (as of version 10.1.7). + */ + uint flags= Item_func_like::compare_collation()->state; + if ((flags & MY_CS_NOPAD) && !(flags & MY_CS_NON1TO1)) + Item_args::propagate_equal_fields(thd, + Context(ANY_SUBST, + &type_handler_long_blob, + compare_collation()), + cond); + return this; + } + const char *func_name() const { return "like"; } + enum precedence precedence() const { return IN_PRECEDENCE; } + bool fix_fields(THD *thd, Item **ref); + bool fix_length_and_dec() + { + max_length= 1; + return agg_arg_charsets_for_comparison(cmp_collation, args, 2); + } + void cleanup(); + + Item *neg_transformer(THD *thd) + { + negated= !negated; + return this; + } + + bool walk(Item_processor processor, bool walk_subquery, void *arg) + { + return walk_args(processor, walk_subquery, arg) + || escape_item->walk(processor, walk_subquery, arg) + || (this->*processor)(arg); + } + + bool find_selective_predicates_list_processor(void *arg); + + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_like>(thd, this); } +}; + + +typedef struct pcre2_real_code_8 pcre2_code; +typedef struct pcre2_real_match_data_8 pcre2_match_data; +#define PCRE2_SIZE size_t +class Regexp_processor_pcre +{ + pcre2_code *m_pcre; + pcre2_match_data *m_pcre_match_data; + bool m_conversion_is_needed; + bool m_is_const; + int m_library_flags; + CHARSET_INFO *m_library_charset; + String m_prev_pattern; + int m_pcre_exec_rc; + PCRE2_SIZE *m_SubStrVec; + void pcre_exec_warn(int rc) const; + int pcre_exec_with_warn(const pcre2_code *code, + pcre2_match_data *data, + const char *subject, int length, int startoffset, + int options); +public: + String *convert_if_needed(String *src, String *converter); + String subject_converter; + String pattern_converter; + String replace_converter; + Regexp_processor_pcre() : + m_pcre(NULL), m_pcre_match_data(NULL), + m_conversion_is_needed(true), m_is_const(0), + m_library_flags(0), + m_library_charset(&my_charset_utf8mb3_general_ci) + {} + int default_regex_flags(); + void init(CHARSET_INFO *data_charset, int extra_flags); + void fix_owner(Item_func *owner, Item *subject_arg, Item *pattern_arg); + bool compile(String *pattern, bool send_error); + bool compile(Item *item, bool send_error); + bool recompile(Item *item) + { + return !m_is_const && compile(item, false); + } + bool exec(const char *str, size_t length, size_t offset); + bool exec(String *str, int offset, uint n_result_offsets_to_convert); + bool exec(Item *item, int offset, uint n_result_offsets_to_convert); + bool match() const { return m_pcre_exec_rc < 0 ? 0 : 1; } + int nsubpatterns() const { return m_pcre_exec_rc <= 0 ? 0 : m_pcre_exec_rc; } + size_t subpattern_start(int n) const + { + return m_pcre_exec_rc <= 0 ? 0 : m_SubStrVec[n * 2]; + } + size_t subpattern_end(int n) const + { + return m_pcre_exec_rc <= 0 ? 0 : m_SubStrVec[n * 2 + 1]; + } + size_t subpattern_length(int n) const + { + return subpattern_end(n) - subpattern_start(n); + } + void reset() + { + m_pcre= NULL; + m_pcre_match_data= NULL; + m_prev_pattern.length(0); + } + void cleanup(); + bool is_compiled() const { return m_pcre != NULL; } + bool is_const() const { return m_is_const; } + void set_const(bool arg) { m_is_const= arg; } + CHARSET_INFO * library_charset() const { return m_library_charset; } +}; + + +class Item_func_regex :public Item_bool_func +{ + Regexp_processor_pcre re; + DTCollation cmp_collation; +public: + Item_func_regex(THD *thd, Item *a, Item *b): Item_bool_func(thd, a, b) + {} + void cleanup() + { + DBUG_ENTER("Item_func_regex::cleanup"); + Item_bool_func::cleanup(); + re.cleanup(); + DBUG_VOID_RETURN; + } + longlong val_int(); + bool fix_length_and_dec(); + const char *func_name() const { return "regexp"; } + enum precedence precedence() const { return IN_PRECEDENCE; } + Item *get_copy(THD *) { return 0; } + void print(String *str, enum_query_type query_type) + { + print_op(str, query_type); + } + + CHARSET_INFO *compare_collation() const { return cmp_collation.collation; } +}; + + +/* + In the corner case REGEXP_INSTR could return (2^32 + 1), + which would not fit into Item_long_func range. + But string lengths are limited with max_allowed_packet, + which cannot be bigger than 1024*1024*1024. +*/ +class Item_func_regexp_instr :public Item_long_func +{ + bool check_arguments() const + { + return args[0]->check_type_can_return_str(func_name()) || + args[1]->check_type_can_return_text(func_name()); + } + Regexp_processor_pcre re; + DTCollation cmp_collation; +public: + Item_func_regexp_instr(THD *thd, Item *a, Item *b) + :Item_long_func(thd, a, b) + {} + void cleanup() + { + DBUG_ENTER("Item_func_regexp_instr::cleanup"); + Item_int_func::cleanup(); + re.cleanup(); + DBUG_VOID_RETURN; + } + longlong val_int(); + bool fix_length_and_dec(); + const char *func_name() const { return "regexp_instr"; } + Item *get_copy(THD *thd) { return 0; } +}; + + +typedef class Item COND; + +class Item_cond :public Item_bool_func +{ +protected: + List<Item> list; + bool abort_on_null; + table_map and_tables_cache; + +public: + /* Item_cond() is only used to create top level items */ + Item_cond(THD *thd): Item_bool_func(thd), abort_on_null(1) + { const_item_cache=0; } + Item_cond(THD *thd, Item *i1, Item *i2); + Item_cond(THD *thd, Item_cond *item); + Item_cond(THD *thd, List<Item> &nlist): + Item_bool_func(thd), list(nlist), abort_on_null(0) {} + bool add(Item *item, MEM_ROOT *root) + { + DBUG_ASSERT(item); + return list.push_back(item, root); + } + bool add_at_head(Item *item, MEM_ROOT *root) + { + DBUG_ASSERT(item); + return list.push_front(item, root); + } + void add_at_head(List<Item> *nlist) + { + DBUG_ASSERT(nlist->elements); + list.prepend(nlist); + } + void add_at_end(List<Item> *nlist) + { + DBUG_ASSERT(nlist->elements); + list.append(nlist); + } + bool fix_fields(THD *, Item **ref); + void fix_after_pullout(st_select_lex *new_parent, Item **ref, bool merge); + + enum Type type() const { return COND_ITEM; } + List<Item>* argument_list() { return &list; } + table_map used_tables() const; + void update_used_tables() + { + used_tables_and_const_cache_init(); + used_tables_and_const_cache_update_and_join(list); + } + COND *build_equal_items(THD *thd, COND_EQUAL *inherited, + bool link_item_fields, + COND_EQUAL **cond_equal_ref); + COND *remove_eq_conds(THD *thd, Item::cond_result *cond_value, + bool top_level); + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, table_map usable_tables, + SARGABLE_PARAM **sargables); + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr); + virtual void print(String *str, enum_query_type query_type); + void split_sum_func(THD *thd, Ref_ptr_array ref_pointer_array, + List<Item> &fields, uint flags); + friend int setup_conds(THD *thd, TABLE_LIST *tables, TABLE_LIST *leaves, + COND **conds); + void top_level_item() { abort_on_null=1; } + bool top_level() { return abort_on_null; } + void copy_andor_arguments(THD *thd, Item_cond *item); + bool walk(Item_processor processor, bool walk_subquery, void *arg); + Item *transform(THD *thd, Item_transformer transformer, uchar *arg); + void traverse_cond(Cond_traverser, void *arg, traverse_order order); + void neg_arguments(THD *thd); + Item* propagate_equal_fields(THD *, const Context &, COND_EQUAL *); + Item *compile(THD *thd, Item_analyzer analyzer, uchar **arg_p, + Item_transformer transformer, uchar *arg_t); + bool eval_not_null_tables(void *opt_arg); + bool find_not_null_fields(table_map allowed); + Item *build_clone(THD *thd); + bool excl_dep_on_table(table_map tab_map); + bool excl_dep_on_grouping_fields(st_select_lex *sel); +}; + +template <template<class> class LI, class T> class Item_equal_iterator; + +/* + The class Item_equal is used to represent conjunctions of equality + predicates of the form field1 = field2, and field=const in where + conditions and on expressions. + + All equality predicates of the form field1=field2 contained in a + conjunction are substituted for a sequence of items of this class. + An item of this class Item_equal(f1,f2,...fk) represents a + multiple equality f1=f2=...=fk.l + + If a conjunction contains predicates f1=f2 and f2=f3, a new item of + this class is created Item_equal(f1,f2,f3) representing the multiple + equality f1=f2=f3 that substitutes the above equality predicates in + the conjunction. + A conjunction of the predicates f2=f1 and f3=f1 and f3=f2 will be + substituted for the item representing the same multiple equality + f1=f2=f3. + An item Item_equal(f1,f2) can appear instead of a conjunction of + f2=f1 and f1=f2, or instead of just the predicate f1=f2. + + An item of the class Item_equal inherits equalities from outer + conjunctive levels. + + Suppose we have a where condition of the following form: + WHERE f1=f2 AND f3=f4 AND f3=f5 AND ... AND (...OR (f1=f3 AND ...)). + In this case: + f1=f2 will be substituted for Item_equal(f1,f2); + f3=f4 and f3=f5 will be substituted for Item_equal(f3,f4,f5); + f1=f3 will be substituted for Item_equal(f1,f2,f3,f4,f5); + + An object of the class Item_equal can contain an optional constant + item c. Then it represents a multiple equality of the form + c=f1=...=fk. + + Objects of the class Item_equal are used for the following: + + 1. An object Item_equal(t1.f1,...,tk.fk) allows us to consider any + pair of tables ti and tj as joined by an equi-condition. + Thus it provide us with additional access paths from table to table. + + 2. An object Item_equal(t1.f1,...,tk.fk) is applied to deduce new + SARGable predicates: + f1=...=fk AND P(fi) => f1=...=fk AND P(fi) AND P(fj). + It also can give us additional index scans and can allow us to + improve selectivity estimates. + + 3. An object Item_equal(t1.f1,...,tk.fk) is used to optimize the + selected execution plan for the query: if table ti is accessed + before the table tj then in any predicate P in the where condition + the occurrence of tj.fj is substituted for ti.fi. This can allow + an evaluation of the predicate at an earlier step. + + When feature 1 is supported they say that join transitive closure + is employed. + When feature 2 is supported they say that search argument transitive + closure is employed. + Both features are usually supported by preprocessing original query and + adding additional predicates. + We do not just add predicates, we rather dynamically replace some + predicates that can not be used to access tables in the investigated + plan for those, obtained by substitution of some fields for equal fields, + that can be used. + + Prepared Statements/Stored Procedures note: instances of class + Item_equal are created only at the time a PS/SP is executed and + are deleted in the end of execution. All changes made to these + objects need not be registered in the list of changes of the parse + tree and do not harm PS/SP re-execution. + + Item equal objects are employed only at the optimize phase. Usually they are + not supposed to be evaluated. Yet in some cases we call the method val_int() + for them. We have to take care of restricting the predicate such an + object represents f1=f2= ...=fn to the projection of known fields fi1=...=fik. +*/ + +class Item_equal: public Item_bool_func +{ + /* + The list of equal items. Currently the list can contain: + - Item_fields items for references to table columns + - Item_direct_view_ref items for references to view columns + - one const item + + If the list contains a constant item this item is always first in the list. + The list contains at least two elements. + Currently all Item_fields/Item_direct_view_ref items in the list should + refer to table columns with equavalent type definitions. In particular + if these are string columns they should have the same charset/collation. + + Use objects of the companion class Item_equal_fields_iterator to iterate + over all items from the list of the Item_field/Item_direct_view_ref classes. + */ + List<Item> equal_items; + /* + TRUE <-> one of the items is a const item. + Such item is always first in in the equal_items list + */ + bool with_const; + /* + The field eval_item is used when this item is evaluated + with the method val_int() + */ + cmp_item *eval_item; + /* + This initially is set to FALSE. It becomes TRUE when this item is evaluated + as being always false. If the flag is TRUE the contents of the list + the equal_items should be ignored. + */ + bool cond_false; + /* + This initially is set to FALSE. It becomes TRUE when this item is evaluated + as being always true. If the flag is TRUE the contents of the list + the equal_items should be ignored. + */ + bool cond_true; + /* + For Item_equal objects inside an OR clause: one of the fields that were + used in the original equality. + */ + Item_field *context_field; + + bool link_equal_fields; + + const Type_handler *m_compare_handler; + CHARSET_INFO *m_compare_collation; +public: + + COND_EQUAL *upper_levels; /* multiple equalities of upper and levels */ + + Item_equal(THD *thd, const Type_handler *handler, + Item *f1, Item *f2, bool with_const_item); + Item_equal(THD *thd, Item_equal *item_equal); + /* Currently the const item is always the first in the list of equal items */ + inline Item* get_const() { return with_const ? equal_items.head() : NULL; } + void add_const(THD *thd, Item *c); + /** Add a non-constant item to the multiple equality */ + void add(Item *f, MEM_ROOT *root) { equal_items.push_back(f, root); } + bool contains(Field *field); + Item* get_first(struct st_join_table *context, Item *field); + /** Get number of field items / references to field items in this object */ + uint n_field_items() { return equal_items.elements - MY_TEST(with_const); } + void merge(THD *thd, Item_equal *item); + bool merge_with_check(THD *thd, Item_equal *equal_item, bool save_merged); + void merge_into_list(THD *thd, List<Item_equal> *list, bool save_merged, + bool only_intersected); + void update_const(THD *thd); + enum Functype functype() const { return MULT_EQUAL_FUNC; } + longlong val_int(); + const char *func_name() const { return "multiple equal"; } + void sort(Item_field_cmpfunc compare, void *arg); + bool fix_length_and_dec(); + bool fix_fields(THD *thd, Item **ref); + void cleanup() + { + delete eval_item; + eval_item= NULL; + } + void update_used_tables(); + bool find_not_null_fields(table_map allowed); + COND *build_equal_items(THD *thd, COND_EQUAL *inherited, + bool link_item_fields, + COND_EQUAL **cond_equal_ref); + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, + uint *and_level, table_map usable_tables, + SARGABLE_PARAM **sargables); + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr); + bool walk(Item_processor processor, bool walk_subquery, void *arg); + Item *transform(THD *thd, Item_transformer transformer, uchar *arg); + virtual void print(String *str, enum_query_type query_type); + const Type_handler *compare_type_handler() const { return m_compare_handler; } + CHARSET_INFO *compare_collation() const { return m_compare_collation; } + + void set_context_field(Item_field *ctx_field) { context_field= ctx_field; } + void set_link_equal_fields(bool flag) { link_equal_fields= flag; } + Item* get_copy(THD *thd) { return 0; } + /* + This does not comply with the specification of the virtual method, + but Item_equal items are processed distinguishly anyway + */ + bool excl_dep_on_table(table_map tab_map) + { + return used_tables() & tab_map; + } + bool excl_dep_on_in_subq_left_part(Item_in_subselect *subq_pred); + bool excl_dep_on_grouping_fields(st_select_lex *sel); + bool create_pushable_equalities(THD *thd, List<Item> *equalities, + Pushdown_checker checker, uchar *arg, + bool clone_const); + /* Return the number of elements in this multiple equality */ + uint elements_count() { return equal_items.elements; } + friend class Item_equal_fields_iterator; + bool count_sargable_conds(void *arg); + Item *multiple_equality_transformer(THD *thd, uchar *arg); + friend class Item_equal_iterator<List_iterator_fast,Item>; + friend class Item_equal_iterator<List_iterator,Item>; + friend Item *eliminate_item_equal(THD *thd, COND *cond, + COND_EQUAL *upper_levels, + Item_equal *item_equal); + friend bool setup_sj_materialization_part1(struct st_join_table *tab); + friend bool setup_sj_materialization_part2(struct st_join_table *tab); +}; + +class COND_EQUAL: public Sql_alloc +{ +public: + uint max_members; /* max number of members the current level + list and all lower level lists */ + COND_EQUAL *upper_levels; /* multiple equalities of upper and levels */ + List<Item_equal> current_level; /* list of multiple equalities of + the current and level */ + COND_EQUAL() + { + upper_levels= 0; + } + COND_EQUAL(Item_equal *item, MEM_ROOT *mem_root) + :upper_levels(0) + { + current_level.push_back(item, mem_root); + } + void copy(COND_EQUAL &cond_equal) + { + max_members= cond_equal.max_members; + upper_levels= cond_equal.upper_levels; + if (cond_equal.current_level.is_empty()) + current_level.empty(); + else + current_level= cond_equal.current_level; + } + bool is_empty() + { + return (current_level.elements == 0); + } +}; + + +/* + The template Item_equal_iterator is used to define classes + Item_equal_fields_iterator and Item_equal_fields_iterator_slow. + These are helper classes for the class Item equal + Both classes are used to iterate over references to table/view columns + from the list of equal items that included in an Item_equal object. + The second class supports the operation of removal of the current member + from the list when performing an iteration. +*/ + +template <template<class> class LI, typename T> class Item_equal_iterator + : public LI<T> +{ +protected: + Item_equal *item_equal; + Item *curr_item; +public: + Item_equal_iterator<LI,T>(Item_equal &item_eq) + :LI<T> (item_eq.equal_items) + { + curr_item= NULL; + item_equal= &item_eq; + if (item_eq.with_const) + { + LI<T> *list_it= this; + curr_item= (*list_it)++; + } + } + Item* operator++(int) + { + LI<T> *list_it= this; + curr_item= (*list_it)++; + return curr_item; + } + void rewind(void) + { + LI<T> *list_it= this; + list_it->rewind(); + if (item_equal->with_const) + curr_item= (*list_it)++; + } + Field *get_curr_field() + { + Item_field *item= (Item_field *) (curr_item->real_item()); + return item->field; + } +}; + +typedef Item_equal_iterator<List_iterator_fast,Item > Item_equal_iterator_fast; + +class Item_equal_fields_iterator + :public Item_equal_iterator_fast +{ +public: + Item_equal_fields_iterator(Item_equal &item_eq) + :Item_equal_iterator_fast(item_eq) + { } + Item ** ref() + { + return List_iterator_fast<Item>::ref(); + } +}; + +typedef Item_equal_iterator<List_iterator,Item > Item_equal_iterator_iterator_slow; + +class Item_equal_fields_iterator_slow + :public Item_equal_iterator_iterator_slow +{ +public: + Item_equal_fields_iterator_slow(Item_equal &item_eq) + :Item_equal_iterator_iterator_slow(item_eq) + { } + void remove() + { + List_iterator<Item>::remove(); + } +}; + + +class Item_cond_and final :public Item_cond +{ +public: + COND_EQUAL m_cond_equal; /* contains list of Item_equal objects for + the current and level and reference + to multiple equalities of upper and levels */ + Item_cond_and(THD *thd): Item_cond(thd) {} + Item_cond_and(THD *thd, Item *i1,Item *i2): Item_cond(thd, i1, i2) {} + Item_cond_and(THD *thd, Item_cond_and *item): Item_cond(thd, item) {} + Item_cond_and(THD *thd, List<Item> &list_arg): Item_cond(thd, list_arg) {} + enum Functype functype() const { return COND_AND_FUNC; } + longlong val_int(); + const char *func_name() const { return "and"; } + enum precedence precedence() const { return AND_PRECEDENCE; } + table_map not_null_tables() const + { return abort_on_null ? not_null_tables_cache: and_tables_cache; } + Item *copy_andor_structure(THD *thd); + Item *neg_transformer(THD *thd); + void mark_as_condition_AND_part(TABLE_LIST *embedding); + virtual uint exists2in_reserved_items() { return list.elements; }; + COND *build_equal_items(THD *thd, COND_EQUAL *inherited, + bool link_item_fields, + COND_EQUAL **cond_equal_ref); + bool set_format_by_check_constraint(Send_field_extended_metadata *to) const; + void add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level, + table_map usable_tables, SARGABLE_PARAM **sargables); + SEL_TREE *get_mm_tree(RANGE_OPT_PARAM *param, Item **cond_ptr); + Item *get_copy(THD *thd) + { return get_item_copy<Item_cond_and>(thd, this); } +}; + +inline bool is_cond_and(Item *item) +{ + Item_func *func_item= item->get_item_func(); + return func_item && func_item->functype() == Item_func::COND_AND_FUNC; +} + +class Item_cond_or final :public Item_cond +{ +public: + Item_cond_or(THD *thd): Item_cond(thd) {} + Item_cond_or(THD *thd, Item *i1,Item *i2): Item_cond(thd, i1, i2) {} + Item_cond_or(THD *thd, Item_cond_or *item): Item_cond(thd, item) {} + Item_cond_or(THD *thd, List<Item> &list_arg): Item_cond(thd, list_arg) {} + enum Functype functype() const { return COND_OR_FUNC; } + longlong val_int(); + const char *func_name() const { return "or"; } + enum precedence precedence() const { return OR_PRECEDENCE; } + table_map not_null_tables() const { return and_tables_cache; } + Item *copy_andor_structure(THD *thd); + Item *neg_transformer(THD *thd); + Item *get_copy(THD *thd) + { return get_item_copy<Item_cond_or>(thd, this); } +}; + +class Item_func_dyncol_check :public Item_bool_func +{ +public: + Item_func_dyncol_check(THD *thd, Item *str): Item_bool_func(thd, str) {} + longlong val_int(); + const char *func_name() const { return "column_check"; } + bool need_parentheses_in_default() { return false; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_dyncol_check>(thd, this); } +}; + +class Item_func_dyncol_exists :public Item_bool_func +{ +public: + Item_func_dyncol_exists(THD *thd, Item *str, Item *num): + Item_bool_func(thd, str, num) {} + longlong val_int(); + const char *func_name() const { return "column_exists"; } + bool need_parentheses_in_default() { return false; } + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_dyncol_exists>(thd, this); } +}; + + +class Item_func_cursor_bool_attr: public Item_bool_func, public Cursor_ref +{ +public: + Item_func_cursor_bool_attr(THD *thd, const LEX_CSTRING *name, uint offset) + :Item_bool_func(thd), Cursor_ref(name, offset) + { } + bool check_vcol_func_processor(void *arg) + { + return mark_unsupported_function(func_name(), arg, VCOL_SESSION_FUNC); + } + void print(String *str, enum_query_type query_type) + { + Cursor_ref::print_func(str, func_name()); + } +}; + + +class Item_func_cursor_isopen: public Item_func_cursor_bool_attr +{ +public: + Item_func_cursor_isopen(THD *thd, const LEX_CSTRING *name, uint offset) + :Item_func_cursor_bool_attr(thd, name, offset) { } + const char *func_name() const { return "%ISOPEN"; } + longlong val_int(); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_cursor_isopen>(thd, this); } +}; + + +class Item_func_cursor_found: public Item_func_cursor_bool_attr +{ +public: + Item_func_cursor_found(THD *thd, const LEX_CSTRING *name, uint offset) + :Item_func_cursor_bool_attr(thd, name, offset) { maybe_null= true; } + const char *func_name() const { return "%FOUND"; } + longlong val_int(); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_cursor_found>(thd, this); } +}; + + +class Item_func_cursor_notfound: public Item_func_cursor_bool_attr +{ +public: + Item_func_cursor_notfound(THD *thd, const LEX_CSTRING *name, uint offset) + :Item_func_cursor_bool_attr(thd, name, offset) { maybe_null= true; } + const char *func_name() const { return "%NOTFOUND"; } + longlong val_int(); + Item *get_copy(THD *thd) + { return get_item_copy<Item_func_cursor_notfound>(thd, this); } +}; + + + +inline bool is_cond_or(Item *item) +{ + Item_func *func_item= item->get_item_func(); + return func_item && func_item->functype() == Item_func::COND_OR_FUNC; +} + +Item *and_expressions(Item *a, Item *b, Item **org_item); + +class Comp_creator +{ +public: + Comp_creator() {} /* Remove gcc warning */ + virtual ~Comp_creator() {} /* Remove gcc warning */ + /** + Create operation with given arguments. + */ + virtual Item_bool_rowready_func2* create(THD *thd, Item *a, Item *b) + const = 0; + /** + Create operation with given arguments in swap order. + */ + virtual Item_bool_rowready_func2* create_swap(THD *thd, Item *a, Item *b) + const = 0; + virtual const char* symbol(bool invert) const = 0; + virtual bool eqne_op() const = 0; + virtual bool l_op() const = 0; +}; + +class Eq_creator :public Comp_creator +{ +public: + Eq_creator() {} /* Remove gcc warning */ + virtual ~Eq_creator() {} /* Remove gcc warning */ + Item_bool_rowready_func2* create(THD *thd, Item *a, Item *b) const; + Item_bool_rowready_func2* create_swap(THD *thd, Item *a, Item *b) const; + const char* symbol(bool invert) const { return invert? "<>" : "="; } + bool eqne_op() const { return 1; } + bool l_op() const { return 0; } +}; + +class Ne_creator :public Comp_creator +{ +public: + Ne_creator() {} /* Remove gcc warning */ + virtual ~Ne_creator() {} /* Remove gcc warning */ + Item_bool_rowready_func2* create(THD *thd, Item *a, Item *b) const; + Item_bool_rowready_func2* create_swap(THD *thd, Item *a, Item *b) const; + const char* symbol(bool invert) const { return invert? "=" : "<>"; } + bool eqne_op() const { return 1; } + bool l_op() const { return 0; } +}; + +class Gt_creator :public Comp_creator +{ +public: + Gt_creator() {} /* Remove gcc warning */ + virtual ~Gt_creator() {} /* Remove gcc warning */ + Item_bool_rowready_func2* create(THD *thd, Item *a, Item *b) const; + Item_bool_rowready_func2* create_swap(THD *thd, Item *a, Item *b) const; + const char* symbol(bool invert) const { return invert? "<=" : ">"; } + bool eqne_op() const { return 0; } + bool l_op() const { return 0; } +}; + +class Lt_creator :public Comp_creator +{ +public: + Lt_creator() {} /* Remove gcc warning */ + virtual ~Lt_creator() {} /* Remove gcc warning */ + Item_bool_rowready_func2* create(THD *thd, Item *a, Item *b) const; + Item_bool_rowready_func2* create_swap(THD *thd, Item *a, Item *b) const; + const char* symbol(bool invert) const { return invert? ">=" : "<"; } + bool eqne_op() const { return 0; } + bool l_op() const { return 1; } +}; + +class Ge_creator :public Comp_creator +{ +public: + Ge_creator() {} /* Remove gcc warning */ + virtual ~Ge_creator() {} /* Remove gcc warning */ + Item_bool_rowready_func2* create(THD *thd, Item *a, Item *b) const; + Item_bool_rowready_func2* create_swap(THD *thd, Item *a, Item *b) const; + const char* symbol(bool invert) const { return invert? "<" : ">="; } + bool eqne_op() const { return 0; } + bool l_op() const { return 0; } +}; + +class Le_creator :public Comp_creator +{ +public: + Le_creator() {} /* Remove gcc warning */ + virtual ~Le_creator() {} /* Remove gcc warning */ + Item_bool_rowready_func2* create(THD *thd, Item *a, Item *b) const; + Item_bool_rowready_func2* create_swap(THD *thd, Item *a, Item *b) const; + const char* symbol(bool invert) const { return invert? ">" : "<="; } + bool eqne_op() const { return 0; } + bool l_op() const { return 1; } +}; + +/* + These need definitions from this file but the variables are defined + in mysqld.h. The variables really belong in this component, but for + the time being we leave them in mysqld.cc to avoid merge problems. +*/ +extern Eq_creator eq_creator; +extern Ne_creator ne_creator; +extern Gt_creator gt_creator; +extern Lt_creator lt_creator; +extern Ge_creator ge_creator; +extern Le_creator le_creator; + +#endif /* ITEM_CMPFUNC_INCLUDED */ |