Drizzled Public API Documentation

func.h
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4  * Copyright (C) 2008 Sun Microsystems, Inc.
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19 
20 
21 
22 #pragma once
23 
25 
26 #include <drizzled/charset.h>
27 #include <drizzled/item.h>
28 #include <drizzled/item/bin_string.h>
29 #include <drizzled/lex_string.h>
30 #include <drizzled/sql_list.h>
31 #include <drizzled/type/decimal.h>
32 
33 #include <drizzled/visibility.h>
34 
35 namespace drizzled {
36 
38 {
39 protected:
40  Item **args, *tmp_arg[2];
41  /*
42  Allowed numbers of columns in result (usually 1, which means scalar value)
43  0 means get this number from first argument
44  */
45  uint32_t allowed_arg_cols;
46 
47 public:
48 
49  using Item::split_sum_func;
50 
51  uint32_t arg_count;
52  table_map used_tables_cache, not_null_tables_cache;
53  bool const_item_cache;
54  enum Functype { UNKNOWN_FUNC,EQ_FUNC,EQUAL_FUNC,NE_FUNC,LT_FUNC,LE_FUNC,
55  GE_FUNC,GT_FUNC,
56  LIKE_FUNC,ISNULL_FUNC,ISNOTNULL_FUNC,
57  COND_AND_FUNC, COND_OR_FUNC, COND_XOR_FUNC,
58  BETWEEN, IN_FUNC, MULT_EQUAL_FUNC,
59  INTERVAL_FUNC, ISNOTNULLTEST_FUNC,
60  NOT_FUNC, NOT_ALL_FUNC,
61  NOW_FUNC, TRIG_COND_FUNC,
62  SUSERVAR_FUNC, GUSERVAR_FUNC, COLLATE_FUNC,
63  EXTRACT_FUNC, CHAR_TYPECAST_FUNC, FUNC_SP,
64  NEG_FUNC };
65  enum optimize_type { OPTIMIZE_NONE,OPTIMIZE_KEY,OPTIMIZE_OP, OPTIMIZE_NULL,
66  OPTIMIZE_EQUAL };
67  enum Type type() const { return FUNC_ITEM; }
68  virtual enum Functype functype() const { return UNKNOWN_FUNC; }
69  virtual ~Item_func() {}
70 
71  Item_func(void);
72 
73  Item_func(Item *a);
74 
75  Item_func(Item *a,Item *b);
76 
77  Item_func(Item *a,Item *b,Item *c);
78 
79  Item_func(Item *a,Item *b,Item *c,Item *d);
80 
81  Item_func(Item *a,Item *b,Item *c,Item *d,Item* e);
82 
83  Item_func(List<Item> &list);
84 
85  // Constructor used for Item_cond_and/or (see Item comment)
86  Item_func(Session *session, Item_func *item);
87 
88  bool fix_fields(Session *, Item **ref);
89  void fix_after_pullout(Select_Lex *new_parent, Item **ref);
90  table_map used_tables() const;
91  table_map not_null_tables() const;
92  void update_used_tables();
93  bool eq(const Item *item, bool binary_cmp) const;
94  virtual optimize_type select_optimize() const { return OPTIMIZE_NONE; }
95  virtual bool have_rev_func() const { return 0; }
96  virtual Item *key_item() const { return args[0]; }
97  /*
98  This method is used for debug purposes to print the name of an
99  item to the debug log. The second use of this method is as
100  a helper function of print(), where it is applicable.
101  To suit both goals it should return a meaningful,
102  distinguishable and sintactically correct string. This method
103  should not be used for runtime type identification, use enum
104  {Sum}Functype and Item_func::functype()/Item_sum::sum_func()
105  instead.
106  */
107  virtual const char *func_name() const { return NULL; }
108  virtual bool const_item() const { return const_item_cache; }
109  Item **arguments() const { return args; }
110  void set_arguments(List<Item> &list);
111  uint32_t argument_count() const { return arg_count; }
112  void remove_arguments() { arg_count=0; }
113 
118  virtual bool check_argument_count(int) { return true ; }
119  virtual void split_sum_func(Session *session, Item **ref_pointer_array,
120  List<Item> &fields);
121 
122  virtual void print(String *str);
123  void print_op(String *str);
124  void print_args(String *str, uint32_t from);
125  virtual void fix_num_length_and_dec();
126  void count_only_length();
127  void count_real_length();
128  void count_decimal_length();
129 
130  bool get_arg0_date(type::Time &ltime, uint32_t fuzzy_date);
131  bool get_arg0_time(type::Time &ltime);
132 
133  bool is_null();
134 
135  virtual bool deterministic() const
136  {
137  return false;
138  }
139 
140  void signal_divide_by_null();
141 
142  virtual Field *tmp_table_field() { return result_field; }
143  virtual Field *tmp_table_field(Table *t_arg);
144 
145  Item *get_tmp_table_item(Session *session);
146 
147  type::Decimal *val_decimal(type::Decimal *);
148 
149  bool agg_arg_collations(DTCollation &c, Item **items, uint32_t nitems,
150  uint32_t flags);
151  bool agg_arg_collations_for_comparison(DTCollation &c,
152  Item **items, uint32_t nitems,
153  uint32_t flags);
154  bool agg_arg_charsets(DTCollation &c, Item **items, uint32_t nitems,
155  uint32_t flags, int item_sep);
156  bool walk(Item_processor processor, bool walk_subquery, unsigned char *arg);
157  Item *transform(Item_transformer transformer, unsigned char *arg);
158  Item* compile(Item_analyzer analyzer, unsigned char **arg_p,
159  Item_transformer transformer, unsigned char *arg_t);
160  void traverse_cond(Cond_traverser traverser,
161  void * arg, traverse_order order);
162  double fix_result(double value);
163 };
164 
165 } /* namespace drizzled */
166 
167 
#define DRIZZLED_API
Definition: visibility.h:62
virtual bool const_item() const
Definition: func.h:108
Visibility Control Macros.
virtual bool check_argument_count(int)
Definition: func.h:118