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"
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 /****************************************************************************
33 ****************************************************************************/
34 struct bitmap
*bitmap_talloc(TALLOC_CTX
*mem_ctx
, int n
)
38 bm
= (struct bitmap
*)talloc_zero_size(
40 offsetof(struct bitmap
, b
) + sizeof(uint32_t)*((n
+31)/32));
44 talloc_set_name_const(bm
, "struct bitmap");
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));
64 /****************************************************************************
66 ****************************************************************************/
67 bool bitmap_set(struct bitmap
*bm
, unsigned i
)
70 DEBUG(0,("Setting invalid bitmap entry %d (of %d)\n",
74 bm
->b
[i
/32] |= (1<<(i
%32));
78 /****************************************************************************
79 clear a bit in a bitmap
80 ****************************************************************************/
81 bool bitmap_clear(struct bitmap
*bm
, unsigned i
)
84 DEBUG(0,("clearing invalid bitmap entry %d (of %d)\n",
88 bm
->b
[i
/32] &= ~(1<<(i
%32));
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))) {
104 /****************************************************************************
105 find a zero bit in a bitmap starting at the specified offset, with
107 ****************************************************************************/
108 int bitmap_find(struct bitmap
*bm
, unsigned ofs
)
112 if (ofs
> bm
->n
) ofs
= 0;
116 if (~(bm
->b
[i
/32])) {
119 if (!bitmap_query(bm
, j
)) return j
;
121 } while (j
& 31 && j
< bm
->n
);
129 if (~(bm
->b
[i
/32])) {
132 if (!bitmap_query(bm
, j
)) return j
;
134 } while (j
& 31 && j
< bm
->n
);