s3:smbd/trans2: make use of BVAL() and remove ugly LARGE_SMB_OFF_T ifdef's
[Samba.git] / source3 / lib / bitmap.c
blobbd56b4aad1a5807cef6ee21be1e59646b7212e29
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"
22 /* these functions provide a simple way to allocate integers from a
23 pool without repetition */
25 /****************************************************************************
26 talloc a bitmap
27 ****************************************************************************/
28 struct bitmap *bitmap_talloc(TALLOC_CTX *mem_ctx, int n)
30 struct bitmap *bm;
32 bm = TALLOC_P(mem_ctx, struct bitmap);
34 if (!bm) return NULL;
36 bm->n = n;
37 bm->b = TALLOC_ZERO_ARRAY(bm, uint32, (n+31)/32);
38 if (!bm->b) {
39 TALLOC_FREE(bm);
40 return NULL;
42 return bm;
45 /****************************************************************************
46 copy as much of the source bitmap as will fit in the destination bitmap.
47 ****************************************************************************/
49 int bitmap_copy(struct bitmap * const dst, const struct bitmap * const src)
51 int count = MIN(dst->n, src->n);
53 SMB_ASSERT(dst->b != src->b);
54 memcpy(dst->b, src->b, sizeof(uint32)*((count+31)/32));
56 return count;
59 /****************************************************************************
60 set a bit in a bitmap
61 ****************************************************************************/
62 bool bitmap_set(struct bitmap *bm, unsigned i)
64 if (i >= bm->n) {
65 DEBUG(0,("Setting invalid bitmap entry %d (of %d)\n",
66 i, bm->n));
67 return False;
69 bm->b[i/32] |= (1<<(i%32));
70 return True;
73 /****************************************************************************
74 clear a bit in a bitmap
75 ****************************************************************************/
76 bool bitmap_clear(struct bitmap *bm, unsigned i)
78 if (i >= bm->n) {
79 DEBUG(0,("clearing invalid bitmap entry %d (of %d)\n",
80 i, bm->n));
81 return False;
83 bm->b[i/32] &= ~(1<<(i%32));
84 return True;
87 /****************************************************************************
88 query a bit in a bitmap
89 ****************************************************************************/
90 bool bitmap_query(struct bitmap *bm, unsigned i)
92 if (i >= bm->n) return False;
93 if (bm->b[i/32] & (1<<(i%32))) {
94 return True;
96 return False;
99 /****************************************************************************
100 find a zero bit in a bitmap starting at the specified offset, with
101 wraparound
102 ****************************************************************************/
103 int bitmap_find(struct bitmap *bm, unsigned ofs)
105 unsigned int i, j;
107 if (ofs > bm->n) ofs = 0;
109 i = ofs;
110 while (i < bm->n) {
111 if (~(bm->b[i/32])) {
112 j = i;
113 do {
114 if (!bitmap_query(bm, j)) return j;
115 j++;
116 } while (j & 31 && j < bm->n);
118 i += 32;
119 i &= ~31;
122 i = 0;
123 while (i < ofs) {
124 if (~(bm->b[i/32])) {
125 j = i;
126 do {
127 if (!bitmap_query(bm, j)) return j;
128 j++;
129 } while (j & 31 && j < bm->n);
131 i += 32;
132 i &= ~31;
135 return -1;