zfs/include/sys/bitmap.h

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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#ifndef _SYS_BITMAP_H
#define _SYS_BITMAP_H
#ifdef __cplusplus
extern "C" {
#endif
/*
* Operations on bitmaps of arbitrary size
* A bitmap is a vector of 1 or more ulong_t's.
* The user of the package is responsible for range checks and keeping
* track of sizes.
*/
#ifdef _LP64
#define BT_ULSHIFT 6 /* log base 2 of BT_NBIPUL, to extract word index */
#define BT_ULSHIFT32 5 /* log base 2 of BT_NBIPUL, to extract word index */
#else
#define BT_ULSHIFT 5 /* log base 2 of BT_NBIPUL, to extract word index */
#endif
#define BT_NBIPUL (1 << BT_ULSHIFT) /* n bits per ulong_t */
#define BT_ULMASK (BT_NBIPUL - 1) /* to extract bit index */
/*
* bitmap is a ulong_t *, bitindex an index_t
*
* The macros BT_WIM and BT_BIW internal; there is no need
* for users of this package to use them.
*/
/*
* word in map
*/
#define BT_WIM(bitmap, bitindex) \
((bitmap)[(bitindex) >> BT_ULSHIFT])
/*
* bit in word
*/
#define BT_BIW(bitindex) \
(1UL << ((bitindex) & BT_ULMASK))
/*
* These are public macros
*
* BT_BITOUL == n bits to n ulong_t's
*/
#define BT_BITOUL(nbits) \
(((nbits) + BT_NBIPUL - 1l) / BT_NBIPUL)
#define BT_SIZEOFMAP(nbits) \
(BT_BITOUL(nbits) * sizeof (ulong_t))
#define BT_TEST(bitmap, bitindex) \
((BT_WIM((bitmap), (bitindex)) & BT_BIW(bitindex)) ? 1 : 0)
#define BT_SET(bitmap, bitindex) \
{ BT_WIM((bitmap), (bitindex)) |= BT_BIW(bitindex); }
#define BT_CLEAR(bitmap, bitindex) \
{ BT_WIM((bitmap), (bitindex)) &= ~BT_BIW(bitindex); }
#ifdef __cplusplus
}
#endif
#endif /* _SYS_BITMAP_H */