120253Sjoerg/*- 220302Sjoerg * Copyright (C) 1996 320302Sjoerg * David L. Nugent. All rights reserved. 420253Sjoerg * 520253Sjoerg * Redistribution and use in source and binary forms, with or without 620253Sjoerg * modification, are permitted provided that the following conditions 720253Sjoerg * are met: 820253Sjoerg * 1. Redistributions of source code must retain the above copyright 920302Sjoerg * notice, this list of conditions and the following disclaimer. 1020253Sjoerg * 2. Redistributions in binary form must reproduce the above copyright 1120253Sjoerg * notice, this list of conditions and the following disclaimer in the 1220253Sjoerg * documentation and/or other materials provided with the distribution. 1320253Sjoerg * 1420302Sjoerg * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND 1520253Sjoerg * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1620253Sjoerg * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1720302Sjoerg * ARE DISCLAIMED. IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE 1820253Sjoerg * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1920253Sjoerg * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2020253Sjoerg * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2120253Sjoerg * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2220253Sjoerg * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2320253Sjoerg * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2420253Sjoerg * SUCH DAMAGE. 2520253Sjoerg */ 2620253Sjoerg 2730259Scharnier#ifndef lint 2830259Scharnierstatic const char rcsid[] = 2950479Speter "$FreeBSD$"; 3030259Scharnier#endif /* not lint */ 3130259Scharnier 3220253Sjoerg#include <stdlib.h> 3320253Sjoerg#include <string.h> 3420253Sjoerg 3520253Sjoerg#include "bitmap.h" 3620253Sjoerg 3720253Sjoergstruct bitmap 3820253Sjoergbm_alloc(int size) 3920253Sjoerg{ 4020253Sjoerg struct bitmap bm; 4120253Sjoerg int szmap = (size / 8) + !!(size % 8); 4220253Sjoerg 4320253Sjoerg bm.size = size; 4420253Sjoerg bm.map = malloc(szmap); 4520253Sjoerg if (bm.map) 4620253Sjoerg memset(bm.map, 0, szmap); 4720253Sjoerg return bm; 4820253Sjoerg} 4920253Sjoerg 5020253Sjoergvoid 5120253Sjoergbm_dealloc(struct bitmap * bm) 5220253Sjoerg{ 53243894Seadler free(bm->map); 5420253Sjoerg} 5520253Sjoerg 5620253Sjoergstatic void 5720253Sjoergbm_getmask(int *pos, unsigned char *bmask) 5820253Sjoerg{ 5920253Sjoerg *bmask = (unsigned char) (1 << (*pos % 8)); 6020253Sjoerg *pos /= 8; 6120253Sjoerg} 6220253Sjoerg 6320253Sjoergvoid 6420253Sjoergbm_setbit(struct bitmap * bm, int pos) 6520253Sjoerg{ 6620253Sjoerg unsigned char bmask; 6720253Sjoerg 6820253Sjoerg bm_getmask(&pos, &bmask); 6920253Sjoerg bm->map[pos] |= bmask; 7020253Sjoerg} 7120253Sjoerg 7220253Sjoergvoid 7320253Sjoergbm_clrbit(struct bitmap * bm, int pos) 7420253Sjoerg{ 7520253Sjoerg unsigned char bmask; 7620253Sjoerg 7720253Sjoerg bm_getmask(&pos, &bmask); 7820253Sjoerg bm->map[pos] &= ~bmask; 7920253Sjoerg} 8020253Sjoerg 8120253Sjoergint 8220253Sjoergbm_isset(struct bitmap * bm, int pos) 8320253Sjoerg{ 8420253Sjoerg unsigned char bmask; 8520253Sjoerg 8620253Sjoerg bm_getmask(&pos, &bmask); 8720253Sjoerg return !!(bm->map[pos] & bmask); 8820253Sjoerg} 8920253Sjoerg 9020253Sjoergint 9120253Sjoergbm_firstunset(struct bitmap * bm) 9220253Sjoerg{ 9320253Sjoerg int szmap = (bm->size / 8) + !!(bm->size % 8); 9420253Sjoerg int at = 0; 9520253Sjoerg int pos = 0; 9620253Sjoerg 9720253Sjoerg while (pos < szmap) { 9820253Sjoerg unsigned char bmv = bm->map[pos++]; 9920253Sjoerg unsigned char bmask = 1; 10020253Sjoerg 10120253Sjoerg while (bmask & 0xff) { 10220253Sjoerg if ((bmv & bmask) == 0) 10320253Sjoerg return at; 10420253Sjoerg bmask <<= 1; 10520253Sjoerg ++at; 10620253Sjoerg } 10720253Sjoerg } 10820253Sjoerg return at; 10920253Sjoerg} 11020253Sjoerg 11120253Sjoergint 11220253Sjoergbm_lastset(struct bitmap * bm) 11320253Sjoerg{ 11420253Sjoerg int szmap = (bm->size / 8) + !!(bm->size % 8); 11520253Sjoerg int at = 0; 11620253Sjoerg int pos = 0; 11720253Sjoerg int ofs = 0; 11820253Sjoerg 11920253Sjoerg while (pos < szmap) { 12020253Sjoerg unsigned char bmv = bm->map[pos++]; 12120253Sjoerg unsigned char bmask = 1; 12220253Sjoerg 12320253Sjoerg while (bmask & 0xff) { 12420253Sjoerg if ((bmv & bmask) != 0) 12520253Sjoerg ofs = at; 12620253Sjoerg bmask <<= 1; 12720253Sjoerg ++at; 12820253Sjoerg } 12920253Sjoerg } 13020253Sjoerg return ofs; 13120253Sjoerg} 132