Current File : //backups/router/usr/include/sys/bitstring.h
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Paul Vixie.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
*
* Copyright (c) 2014 Spectra Logic Corporation
* 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,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
*/
#ifndef _SYS_BITSTRING_H_
#define _SYS_BITSTRING_H_
#ifdef _KERNEL
#include <sys/libkern.h>
#include <sys/malloc.h>
#endif
#include <sys/types.h>
typedef unsigned long bitstr_t;
/*---------------------- Private Implementation Details ----------------------*/
#define _BITSTR_MASK (~0UL)
#define _BITSTR_BITS (sizeof(bitstr_t) * 8)
/* round up x to the next multiple of y if y is a power of two */
#define _bit_roundup2(x, y) \
(((size_t)(x) + (y) - 1) & ~((size_t)(y) - 1))
/* bitstr_t in bit string containing the bit. */
static inline size_t
_bit_idx(size_t _bit)
{
return (_bit / _BITSTR_BITS);
}
/* bit number within bitstr_t at _bit_idx(_bit). */
static inline size_t
_bit_offset(size_t _bit)
{
return (_bit % _BITSTR_BITS);
}
/* Mask for the bit within its long. */
static inline bitstr_t
_bit_mask(size_t _bit)
{
return (1UL << _bit_offset(_bit));
}
static inline bitstr_t
_bit_make_mask(size_t _start, size_t _stop)
{
return ((_BITSTR_MASK << _bit_offset(_start)) &
(_BITSTR_MASK >> (_BITSTR_BITS - _bit_offset(_stop) - 1)));
}
/*----------------------------- Public Interface -----------------------------*/
/* Number of bytes allocated for a bit string of nbits bits */
#define bitstr_size(_nbits) (_bit_roundup2((_nbits), _BITSTR_BITS) / 8)
/* Allocate a bit string initialized with no bits set. */
#ifdef _KERNEL
static inline bitstr_t *
bit_alloc(size_t _nbits, struct malloc_type *type, int flags)
{
return ((bitstr_t *)malloc(bitstr_size(_nbits), type, flags | M_ZERO));
}
#else
static inline bitstr_t *
bit_alloc(size_t _nbits)
{
return ((bitstr_t *)calloc(bitstr_size(_nbits), 1));
}
#endif
/* Allocate a bit string on the stack */
#define bit_decl(name, nbits) \
((name)[bitstr_size(nbits) / sizeof(bitstr_t)])
/* Is bit N of bit string set? */
static inline int
bit_test(const bitstr_t *_bitstr, size_t _bit)
{
return ((_bitstr[_bit_idx(_bit)] & _bit_mask(_bit)) != 0);
}
/* Set bit N of bit string. */
static inline void
bit_set(bitstr_t *_bitstr, size_t _bit)
{
_bitstr[_bit_idx(_bit)] |= _bit_mask(_bit);
}
/* clear bit N of bit string name */
static inline void
bit_clear(bitstr_t *_bitstr, size_t _bit)
{
_bitstr[_bit_idx(_bit)] &= ~_bit_mask(_bit);
}
/* Are bits in [start ... stop] in bit string all 0 or all 1? */
static inline int
bit_ntest(const bitstr_t *_bitstr, size_t _start, size_t _stop, int _match)
{
const bitstr_t *_stopbitstr;
bitstr_t _mask;
_mask = (_match == 0) ? 0 : _BITSTR_MASK;
_stopbitstr = _bitstr + _bit_idx(_stop);
_bitstr += _bit_idx(_start);
if (_bitstr == _stopbitstr)
return (0 == ((*_bitstr ^ _mask) &
_bit_make_mask(_start, _stop)));
if (_bit_offset(_start) != 0 &&
0 != ((*_bitstr++ ^ _mask) &
_bit_make_mask(_start, _BITSTR_BITS - 1)))
return (0);
if (_bit_offset(_stop) == _BITSTR_BITS - 1)
++_stopbitstr;
while (_bitstr < _stopbitstr) {
if (*_bitstr++ != _mask)
return (0);
}
return (_bit_offset(_stop) == _BITSTR_BITS - 1 ||
0 == ((*_stopbitstr ^ _mask) & _bit_make_mask(0, _stop)));
}
/* Set bits start ... stop inclusive in bit string. */
static inline void
bit_nset(bitstr_t *_bitstr, size_t _start, size_t _stop)
{
bitstr_t *_stopbitstr;
_stopbitstr = _bitstr + _bit_idx(_stop);
_bitstr += _bit_idx(_start);
if (_bitstr == _stopbitstr) {
*_bitstr |= _bit_make_mask(_start, _stop);
} else {
if (_bit_offset(_start) != 0)
*_bitstr++ |= _bit_make_mask(_start, _BITSTR_BITS - 1);
if (_bit_offset(_stop) == _BITSTR_BITS - 1)
++_stopbitstr;
while (_bitstr < _stopbitstr)
*_bitstr++ = _BITSTR_MASK;
if (_bit_offset(_stop) != _BITSTR_BITS - 1)
*_stopbitstr |= _bit_make_mask(0, _stop);
}
}
/* Clear bits start ... stop inclusive in bit string. */
static inline void
bit_nclear(bitstr_t *_bitstr, size_t _start, size_t _stop)
{
bitstr_t *_stopbitstr;
_stopbitstr = _bitstr + _bit_idx(_stop);
_bitstr += _bit_idx(_start);
if (_bitstr == _stopbitstr) {
*_bitstr &= ~_bit_make_mask(_start, _stop);
} else {
if (_bit_offset(_start) != 0)
*_bitstr++ &= ~_bit_make_mask(_start, _BITSTR_BITS - 1);
if (_bit_offset(_stop) == _BITSTR_BITS - 1)
++_stopbitstr;
while (_bitstr < _stopbitstr)
*_bitstr++ = 0;
if (_bit_offset(_stop) != _BITSTR_BITS - 1)
*_stopbitstr &= ~_bit_make_mask(0, _stop);
}
}
/* Find the first '_match'-bit in bit string at or after bit start. */
static inline ssize_t
bit_ff_at_(bitstr_t *_bitstr, size_t _start, size_t _nbits, int _match)
{
bitstr_t *_curbitstr;
bitstr_t *_stopbitstr;
bitstr_t _mask;
bitstr_t _test;
ssize_t _value;
if (_start >= _nbits || _nbits <= 0)
return (-1);
_curbitstr = _bitstr + _bit_idx(_start);
_stopbitstr = _bitstr + _bit_idx(_nbits - 1);
_mask = _match ? 0 : _BITSTR_MASK;
_test = _mask ^ *_curbitstr;
if (_bit_offset(_start) != 0)
_test &= _bit_make_mask(_start, _BITSTR_BITS - 1);
while (_test == 0 && _curbitstr < _stopbitstr)
_test = _mask ^ *(++_curbitstr);
_value = ((_curbitstr - _bitstr) * _BITSTR_BITS) + ffsl(_test) - 1;
if (_test == 0 ||
(_bit_offset(_nbits) != 0 && (size_t)_value >= _nbits))
_value = -1;
return (_value);
}
#define bit_ff_at(_bitstr, _start, _nbits, _match, _resultp) \
*(_resultp) = bit_ff_at_((_bitstr), (_start), (_nbits), (_match))
/* Find the first bit set in bit string at or after bit start. */
#define bit_ffs_at(_bitstr, _start, _nbits, _resultp) \
*(_resultp) = bit_ff_at_((_bitstr), (_start), (_nbits), 1)
/* Find the first bit clear in bit string at or after bit start. */
#define bit_ffc_at(_bitstr, _start, _nbits, _resultp) \
*(_resultp) = bit_ff_at_((_bitstr), (_start), (_nbits), 0)
/* Find the first bit set in bit string. */
#define bit_ffs(_bitstr, _nbits, _resultp) \
*(_resultp) = bit_ff_at_((_bitstr), 0, (_nbits), 1)
/* Find the first bit clear in bit string. */
#define bit_ffc(_bitstr, _nbits, _resultp) \
*(_resultp) = bit_ff_at_((_bitstr), 0, (_nbits), 0)
/* Find contiguous sequence of at least size '_match'-bits at or after start */
static inline ssize_t
bit_ff_area_at_(bitstr_t *_bitstr, size_t _start, size_t _nbits, size_t _size,
int _match)
{
bitstr_t *_curbitstr, _mask, _test;
size_t _last, _shft, _maxshft;
ssize_t _value;
if (_start + _size > _nbits || _nbits <= 0)
return (-1);
_mask = _match ? _BITSTR_MASK : 0;
_maxshft = _bit_idx(_size - 1) == 0 ? _size : (int)_BITSTR_BITS;
_value = _start;
_curbitstr = _bitstr + _bit_idx(_start);
_test = ~(_BITSTR_MASK << _bit_offset(_start));
for (_last = _size - 1, _test |= _mask ^ *_curbitstr;
!(_bit_idx(_last) == 0 &&
(_test & _bit_make_mask(0, _last)) == 0);
_last -= _BITSTR_BITS, _test = _mask ^ *++_curbitstr) {
if (_test == 0)
continue;
/* Shrink-left every 0-area in _test by maxshft-1 bits. */
for (_shft = _maxshft; _shft > 1 && (_test & (_test + 1)) != 0;
_shft = (_shft + 1) / 2)
_test |= _test >> _shft / 2;
/* Find the start of the first 0-area in _test. */
_last = ffsl(~(_test >> 1));
_value = (_curbitstr - _bitstr) * _BITSTR_BITS + _last;
/* If there's insufficient space left, give up. */
if (_value + _size > _nbits) {
_value = -1;
break;
}
_last += _size - 1;
/* If a solution is contained in _test, success! */
if (_bit_idx(_last) == 0)
break;
/* A solution here needs bits from the next word. */
}
return (_value);
}
#define bit_ff_area_at(_bitstr, _start, _nbits, _size, _match, _resultp) \
*(_resultp) = bit_ff_area_at_(_bitstr, _start, _nbits, _size, _match);
/* Find contiguous sequence of at least size set bits at or after start */
#define bit_ffs_area_at(_bitstr, _start, _nbits, _size, _resultp) \
*(_resultp) = bit_ff_area_at_((_bitstr), (_start), (_nbits), (_size), 1)
/* Find contiguous sequence of at least size cleared bits at or after start */
#define bit_ffc_area_at(_bitstr, _start, _nbits, _size, _resultp) \
*(_resultp) = bit_ff_area_at_((_bitstr), (_start), (_nbits), (_size), 0)
/* Find contiguous sequence of at least size set bits in bit string */
#define bit_ffs_area(_bitstr, _nbits, _size, _resultp) \
*(_resultp) = bit_ff_area_at_((_bitstr), 0, (_nbits), (_size), 1)
/* Find contiguous sequence of at least size cleared bits in bit string */
#define bit_ffc_area(_bitstr, _nbits, _size, _resultp) \
*(_resultp) = bit_ff_area_at_((_bitstr), 0, (_nbits), (_size), 0)
/* Count the number of bits set in a bitstr of size _nbits at or after _start */
static inline ssize_t
bit_count_(bitstr_t *_bitstr, size_t _start, size_t _nbits)
{
bitstr_t *_curbitstr, mask;
size_t curbitstr_len;
ssize_t _value = 0;
if (_start >= _nbits)
return (0);
_curbitstr = _bitstr + _bit_idx(_start);
_nbits -= _BITSTR_BITS * _bit_idx(_start);
_start -= _BITSTR_BITS * _bit_idx(_start);
if (_start > 0) {
curbitstr_len = (int)_BITSTR_BITS < _nbits ?
(int)_BITSTR_BITS : _nbits;
mask = _bit_make_mask(_start, _bit_offset(curbitstr_len - 1));
_value += __bitcountl(*_curbitstr & mask);
_curbitstr++;
if (_nbits < _BITSTR_BITS)
return (_value);
_nbits -= _BITSTR_BITS;
}
while (_nbits >= (int)_BITSTR_BITS) {
_value += __bitcountl(*_curbitstr);
_curbitstr++;
_nbits -= _BITSTR_BITS;
}
if (_nbits > 0) {
mask = _bit_make_mask(0, _bit_offset(_nbits - 1));
_value += __bitcountl(*_curbitstr & mask);
}
return (_value);
}
#define bit_count(_bitstr, _start, _nbits, _resultp) \
*(_resultp) = bit_count_((_bitstr), (_start), (_nbits))
/* Traverse all set bits, assigning each location in turn to iter */
#define bit_foreach_at(_bitstr, _start, _nbits, _iter) \
for ((_iter) = bit_ff_at_((_bitstr), (_start), (_nbits), 1); \
(_iter) != -1; \
(_iter) = bit_ff_at_((_bitstr), (_iter) + 1, (_nbits), 1))
#define bit_foreach(_bitstr, _nbits, _iter) \
bit_foreach_at(_bitstr, /*start*/0, _nbits, _iter)
/* Traverse all unset bits, assigning each location in turn to iter */
#define bit_foreach_unset_at(_bitstr, _start, _nbits, _iter) \
for ((_iter) = bit_ff_at_((_bitstr), (_start), (_nbits), 0); \
(_iter) != -1; \
(_iter) = bit_ff_at_((_bitstr), (_iter) + 1, (_nbits), 0))
#define bit_foreach_unset(_bitstr, _nbits, _iter) \
bit_foreach_unset_at(_bitstr, /*start*/0, _nbits, _iter)
#endif /* _SYS_BITSTRING_H_ */
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