diff options
Diffstat (limited to 'usr.sbin/pw/bitmap.c')
-rw-r--r-- | usr.sbin/pw/bitmap.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/usr.sbin/pw/bitmap.c b/usr.sbin/pw/bitmap.c new file mode 100644 index 0000000..8e96bff --- /dev/null +++ b/usr.sbin/pw/bitmap.c @@ -0,0 +1,131 @@ +/*- + * 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. + */ + +#ifndef lint +static const char rcsid[] = + "$FreeBSD$"; +#endif /* not lint */ + +#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) +{ + 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; +} |