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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
/* Copyright (C) 2003 MySQL AB
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; either version 2 of the License, or
(at your option) any later version.
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef ATTRIBUTE_OFFSET_HPP
#define ATTRIBUTE_OFFSET_HPP
class AttributeOffset {
friend class Dbtup;
private:
static void setOffset(Uint32 & desc, Uint32 offset);
static void setCharsetPos(Uint32 & desc, Uint32 offset);
static void setNullFlagPos(Uint32 & desc, Uint32 offset);
static Uint32 getOffset(const Uint32 &);
static bool getCharsetFlag(const Uint32 &);
static Uint32 getCharsetPos(const Uint32 &);
static Uint32 getNullFlagPos(const Uint32 &);
static Uint32 getNullFlagOffset(const Uint32 &);
static Uint32 getNullFlagBitOffset(const Uint32 &);
static bool isNULL(const Uint32 &, const Uint32 &);
};
/**
* Allow for 4096 attributes, all nullable, and for 128 different
* character sets.
*
* a = Attribute offset - 11 bits 0-10 ( addr word in 8 kb )
* c = Has charset flag 1 bits 11-11
* s = Charset pointer position - 7 bits 12-18 ( in table descriptor )
* f = Null flag offset in word - 5 bits 20-24 ( address 32 bits )
* w = Null word offset - 7 bits 25-32 ( f+w addr 4096 attrs )
*
* 1111111111222222222233
* 01234567890123456789012345678901
* aaaaaaaaaaacsssssss fffffwwwwwww
*/
#define AO_ATTRIBUTE_OFFSET_SHIFT 0
#define AO_ATTRIBUTE_OFFSET_MASK 0x7ff
#define AO_CHARSET_FLAG_SHIFT 11
#define AO_CHARSET_POS_SHIFT 12
#define AO_CHARSET_POS_MASK 127
#define AO_NULL_FLAG_POS_MASK 0xfff // f+w
#define AO_NULL_FLAG_POS_SHIFT 20
#define AO_NULL_FLAG_WORD_MASK 31 // f
#define AO_NULL_FLAG_OFFSET_SHIFT 5
inline
void
AttributeOffset::setOffset(Uint32 & desc, Uint32 offset){
ASSERT_MAX(offset, AO_ATTRIBUTE_OFFSET_MASK, "AttributeOffset::setOffset");
desc |= (offset << AO_ATTRIBUTE_OFFSET_SHIFT);
}
inline
void
AttributeOffset::setCharsetPos(Uint32 & desc, Uint32 offset) {
ASSERT_MAX(offset, AO_CHARSET_POS_MASK, "AttributeOffset::setCharsetPos");
desc |= (1 << AO_CHARSET_FLAG_SHIFT);
desc |= (offset << AO_CHARSET_POS_SHIFT);
}
inline
void
AttributeOffset::setNullFlagPos(Uint32 & desc, Uint32 pos){
ASSERT_MAX(pos, AO_NULL_FLAG_POS_MASK, "AttributeOffset::setNullFlagPos");
desc |= (pos << AO_NULL_FLAG_POS_SHIFT);
}
inline
Uint32
AttributeOffset::getOffset(const Uint32 & desc)
{
return (desc >> AO_ATTRIBUTE_OFFSET_SHIFT) & AO_ATTRIBUTE_OFFSET_MASK;
}
inline
bool
AttributeOffset::getCharsetFlag(const Uint32 & desc)
{
return (desc >> AO_CHARSET_FLAG_SHIFT) & 1;
}
inline
Uint32
AttributeOffset::getCharsetPos(const Uint32 & desc)
{
return (desc >> AO_CHARSET_POS_SHIFT) & AO_CHARSET_POS_MASK;
}
inline
Uint32
AttributeOffset::getNullFlagPos(const Uint32 & desc)
{
return ((desc >> AO_NULL_FLAG_POS_SHIFT) & AO_NULL_FLAG_POS_MASK);
}
inline
Uint32
AttributeOffset::getNullFlagOffset(const Uint32 & desc)
{
return (getNullFlagPos(desc) >> AO_NULL_FLAG_OFFSET_SHIFT);
}
inline
Uint32
AttributeOffset::getNullFlagBitOffset(const Uint32 & desc)
{
return (getNullFlagPos(desc) & AO_NULL_FLAG_WORD_MASK);
}
inline
bool
AttributeOffset::isNULL(const Uint32 & pageWord, const Uint32 & desc)
{
return (((pageWord >> getNullFlagBitOffset(desc)) & 1) == 1);
}
#endif
|
