Remove ntdb from scripts
[Samba.git] / lib / util / bitmap.c
blob77de55aec7c626b6a665cbab007cf8a8923a5665
1 /*
2 Unix SMB/CIFS implementation.
3 simple bitmap functions
4 Copyright (C) Andrew Tridgell 1992-1998
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #include "includes.h"
21 #include "lib/util/bitmap.h"
23 struct bitmap {
24 unsigned int n;
25 uint32_t b[1]; /* We allocate more */
28 /* these functions provide a simple way to allocate integers from a
29 pool without repetition */
31 /****************************************************************************
32 talloc a bitmap
33 ****************************************************************************/
34 struct bitmap *bitmap_talloc(TALLOC_CTX *mem_ctx, int n)
36 struct bitmap *bm;
38 bm = (struct bitmap *)talloc_zero_size(
39 mem_ctx,
40 offsetof(struct bitmap, b) + sizeof(uint32_t)*((n+31)/32));
42 if (!bm) return NULL;
44 talloc_set_name_const(bm, "struct bitmap");
46 bm->n = n;
47 return bm;
50 /****************************************************************************
51 copy as much of the source bitmap as will fit in the destination bitmap.
52 ****************************************************************************/
54 int bitmap_copy(struct bitmap * const dst, const struct bitmap * const src)
56 int count = MIN(dst->n, src->n);
58 SMB_ASSERT(dst->b != src->b);
59 memcpy(dst->b, src->b, sizeof(uint32_t)*((count+31)/32));
61 return count;
64 /****************************************************************************
65 set a bit in a bitmap
66 ****************************************************************************/
67 bool bitmap_set(struct bitmap *bm, unsigned i)
69 if (i >= bm->n) {
70 DEBUG(0,("Setting invalid bitmap entry %d (of %d)\n",
71 i, bm->n));
72 return false;
74 bm->b[i/32] |= (1<<(i%32));
75 return true;
78 /****************************************************************************
79 clear a bit in a bitmap
80 ****************************************************************************/
81 bool bitmap_clear(struct bitmap *bm, unsigned i)
83 if (i >= bm->n) {
84 DEBUG(0,("clearing invalid bitmap entry %d (of %d)\n",
85 i, bm->n));
86 return false;
88 bm->b[i/32] &= ~(1<<(i%32));
89 return true;
92 /****************************************************************************
93 query a bit in a bitmap
94 ****************************************************************************/
95 bool bitmap_query(struct bitmap *bm, unsigned i)
97 if (i >= bm->n) return false;
98 if (bm->b[i/32] & (1<<(i%32))) {
99 return true;
101 return false;
104 /****************************************************************************
105 find a zero bit in a bitmap starting at the specified offset, with
106 wraparound
107 ****************************************************************************/
108 int bitmap_find(struct bitmap *bm, unsigned ofs)
110 unsigned int i, j;
112 if (ofs > bm->n) ofs = 0;
114 i = ofs;
115 while (i < bm->n) {
116 if (~(bm->b[i/32])) {
117 j = i;
118 do {
119 if (!bitmap_query(bm, j)) return j;
120 j++;
121 } while (j & 31 && j < bm->n);
123 i += 32;
124 i &= ~31;
127 i = 0;
128 while (i < ofs) {
129 if (~(bm->b[i/32])) {
130 j = i;
131 do {
132 if (!bitmap_query(bm, j)) return j;
133 j++;
134 } while (j & 31 && j < bm->n);
136 i += 32;
137 i &= ~31;
140 return -1;