root/kern/include/bitmap.h

INCLUDED FROM

   1 /*
   2  * Copyright (c) 2000, 2001
   3  *      The President and Fellows of Harvard College.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  30 #ifndef _BITMAP_H_
  31 #define _BITMAP_H_
  33 /*
  34  * Fixed-size array of bits. (Intended for storage management.)
  35  *
  36  * Functions:
  37  *     bitmap_create  - allocate a new bitmap object.
  38  *                      Returns NULL on error.
  39  *     bitmap_getdata - return pointer to raw bit data (for I/O).
  40  *     bitmap_alloc   - locate a cleared bit, set it, and return its index.
  41  *     bitmap_mark    - set a clear bit by its index.
  42  *     bitmap_unmark  - clear a set bit by its index.
  43  *     bitmap_isset   - return whether a particular bit is set or not.
  44  *     bitmap_destroy - destroy bitmap.
  45  */
  48 struct bitmap;  /* Opaque. */
  50 struct bitmap *bitmap_create(unsigned nbits);
  51 void          *bitmap_getdata(struct bitmap *);
  52 int            bitmap_alloc(struct bitmap *, unsigned *index);
  53 void           bitmap_mark(struct bitmap *, unsigned index);
  54 void           bitmap_unmark(struct bitmap *, unsigned index);
  55 int            bitmap_isset(struct bitmap *, unsigned index);
  56 void           bitmap_destroy(struct bitmap *);
  59 #endif /* _BITMAP_H_ */