1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems, Inc.
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#pragma once
#include <drizzled/item/basic_constant.h>
#include <drizzled/item/field.h>
#include <drizzled/item/ident.h>
#include <drizzled/type/decimal.h>
#include <drizzled/util/test.h>
namespace drizzled {
class Item_cache : public Item_basic_constant
{
protected:
Item *example;
table_map used_table_map;
/*
Field that this object will get value from. This is set/used by
index-based subquery engines to detect and remove the equality injected
by IN->EXISTS transformation.
For all other uses of Item_cache, cached_field doesn't matter.
*/
Field *cached_field;
enum enum_field_types cached_field_type;
public:
Item_cache():
example(0), used_table_map(0), cached_field(0), cached_field_type(DRIZZLE_TYPE_VARCHAR)
{
fixed= 1;
null_value= 1;
}
Item_cache(enum_field_types field_type_arg):
example(0), used_table_map(0), cached_field(0), cached_field_type(field_type_arg)
{
fixed= 1;
null_value= 1;
}
void set_used_tables(table_map map) { used_table_map= map; }
virtual void allocate(uint32_t) {};
virtual bool setup(Item *item)
{
example= item;
max_length= item->max_length;
decimals= item->decimals;
collation.set(item->collation);
unsigned_flag= item->unsigned_flag;
if (item->type() == FIELD_ITEM)
cached_field= ((Item_field *)item)->field;
return 0;
};
virtual void store(Item *)= 0;
enum Type type() const { return CACHE_ITEM; }
enum_field_types field_type() const { return cached_field_type; }
static Item_cache* get_cache(const Item *item);
table_map used_tables() const { return used_table_map; }
virtual void keep_array() {}
virtual void print(String *str);
bool eq_def(Field *field);
bool eq(const Item *item, bool) const
{
return this == item;
}
bool basic_const_item() const
{
return test(example && example->basic_const_item());
}
};
} /* namespace drizzled */
|