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
|
/*-
* Copyright (C) 1996
* David L. Nugent. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id$
*/
#include <stdlib.h>
#include <string.h>
#include "bitmap.h"
struct bitmap
bm_alloc(int size)
{
struct bitmap bm;
int szmap = (size / 8) + !!(size % 8);
bm.size = size;
bm.map = malloc(szmap);
if (bm.map)
memset(bm.map, 0, szmap);
return bm;
}
void
bm_dealloc(struct bitmap * bm)
{
if (bm->map)
free(bm->map);
}
static void
bm_getmask(int *pos, unsigned char *bmask)
{
*bmask = (unsigned char) (1 << (*pos % 8));
*pos /= 8;
}
void
bm_setbit(struct bitmap * bm, int pos)
{
unsigned char bmask;
bm_getmask(&pos, &bmask);
bm->map[pos] |= bmask;
}
void
bm_clrbit(struct bitmap * bm, int pos)
{
unsigned char bmask;
bm_getmask(&pos, &bmask);
bm->map[pos] &= ~bmask;
}
int
bm_isset(struct bitmap * bm, int pos)
{
unsigned char bmask;
bm_getmask(&pos, &bmask);
return !!(bm->map[pos] & bmask);
}
int
bm_firstunset(struct bitmap * bm)
{
int szmap = (bm->size / 8) + !!(bm->size % 8);
int at = 0;
int pos = 0;
while (pos < szmap) {
unsigned char bmv = bm->map[pos++];
unsigned char bmask = 1;
while (bmask & 0xff) {
if ((bmv & bmask) == 0)
return at;
bmask <<= 1;
++at;
}
}
return at;
}
int
bm_lastset(struct bitmap * bm)
{
int szmap = (bm->size / 8) + !!(bm->size % 8);
int at = 0;
int pos = 0;
int ofs = 0;
while (pos < szmap) {
unsigned char bmv = bm->map[pos++];
unsigned char bmask = 1;
while (bmask & 0xff) {
if ((bmv & bmask) != 0)
ofs = at;
bmask <<= 1;
++at;
}
}
return ofs;
}
|
