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/>.
21 #include "lib/util/bitmap.h"
23 /* these functions provide a simple way to allocate integers from a
24 pool without repetition */
26 /****************************************************************************
28 ****************************************************************************/
29 struct bitmap *bitmap_talloc(TALLOC_CTX *mem_ctx, int n)
33 bm = talloc(mem_ctx, struct bitmap);
38 bm->b = talloc_zero_array(bm, uint32_t, (n+31)/32);
46 /****************************************************************************
47 copy as much of the source bitmap as will fit in the destination bitmap.
48 ****************************************************************************/
50 int bitmap_copy(struct bitmap * const dst, const struct bitmap * const src)
52 int count = MIN(dst->n, src->n);
54 SMB_ASSERT(dst->b != src->b);
55 memcpy(dst->b, src->b, sizeof(uint32_t)*((count+31)/32));
60 /****************************************************************************
62 ****************************************************************************/
63 bool bitmap_set(struct bitmap *bm, unsigned i)
66 DEBUG(0,("Setting invalid bitmap entry %d (of %d)\n",
70 bm->b[i/32] |= (1<<(i%32));
74 /****************************************************************************
75 clear a bit in a bitmap
76 ****************************************************************************/
77 bool bitmap_clear(struct bitmap *bm, unsigned i)
80 DEBUG(0,("clearing invalid bitmap entry %d (of %d)\n",
84 bm->b[i/32] &= ~(1<<(i%32));
88 /****************************************************************************
89 query a bit in a bitmap
90 ****************************************************************************/
91 bool bitmap_query(struct bitmap *bm, unsigned i)
93 if (i >= bm->n) return false;
94 if (bm->b[i/32] & (1<<(i%32))) {
100 /****************************************************************************
101 find a zero bit in a bitmap starting at the specified offset, with
103 ****************************************************************************/
104 int bitmap_find(struct bitmap *bm, unsigned ofs)
108 if (ofs > bm->n) ofs = 0;
112 if (~(bm->b[i/32])) {
115 if (!bitmap_query(bm, j)) return j;
117 } while (j & 31 && j < bm->n);
125 if (~(bm->b[i/32])) {
128 if (!bitmap_query(bm, j)) return j;
130 } while (j & 31 && j < bm->n);