File: bitstring.h

package info (click to toggle)
hfsprogs 332.25-8
  • links: PTS
  • area: main
  • in suites: squeeze
  • size: 6,424 kB
  • ctags: 7,768
  • sloc: ansic: 58,114; makefile: 59
file content (164 lines) | stat: -rw-r--r-- 5,969 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 *
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 *
 *	@(#)bitstring.h	8.1 (Berkeley) 7/19/93
 */

#ifndef _BITSTRING_H_
#define	_BITSTRING_H_

typedef	unsigned char bitstr_t;

/* internal macros */
				/* byte of the bitstring bit is in */
#define	_bit_byte(bit) \
	((bit) >> 3)

				/* mask for the bit within its byte */
#define	_bit_mask(bit) \
	(1 << ((bit)&0x7))

/* external macros */
				/* bytes in a bitstring of nbits bits */
#define	bitstr_size(nbits) \
	((((nbits) - 1) >> 3) + 1)

				/* allocate a bitstring */
#define	bit_alloc(nbits) \
	(bitstr_t *)calloc(1, \
	    (unsigned int)bitstr_size(nbits) * sizeof(bitstr_t))

				/* allocate a bitstring on the stack */
#define	bit_decl(name, nbits) \
	(name)[bitstr_size(nbits)]

				/* is bit N of bitstring name set? */
#define	bit_test(name, bit) \
	((name)[_bit_byte(bit)] & _bit_mask(bit))

				/* set bit N of bitstring name */
#define	bit_set(name, bit) \
	(name)[_bit_byte(bit)] |= _bit_mask(bit)

				/* clear bit N of bitstring name */
#define	bit_clear(name, bit) \
	(name)[_bit_byte(bit)] &= ~_bit_mask(bit)

				/* clear bits start ... stop in bitstring */
#define	bit_nclear(name, start, stop) { \
	register bitstr_t *_name = name; \
	register int _start = start, _stop = stop; \
	register int _startbyte = _bit_byte(_start); \
	register int _stopbyte = _bit_byte(_stop); \
	if (_startbyte == _stopbyte) { \
		_name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
				      (0xff << ((_stop&0x7) + 1))); \
	} else { \
		_name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
		while (++_startbyte < _stopbyte) \
			_name[_startbyte] = 0; \
		_name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
	} \
}

				/* set bits start ... stop in bitstring */
#define	bit_nset(name, start, stop) { \
	register bitstr_t *_name = name; \
	register int _start = start, _stop = stop; \
	register int _startbyte = _bit_byte(_start); \
	register int _stopbyte = _bit_byte(_stop); \
	if (_startbyte == _stopbyte) { \
		_name[_startbyte] |= ((0xff << (_start&0x7)) & \
				    (0xff >> (7 - (_stop&0x7)))); \
	} else { \
		_name[_startbyte] |= 0xff << ((_start)&0x7); \
		while (++_startbyte < _stopbyte) \
	    		_name[_startbyte] = 0xff; \
		_name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
	} \
}

				/* find first bit clear in name */
#define	bit_ffc(name, nbits, value) { \
	register bitstr_t *_name = name; \
	register int _byte, _nbits = nbits; \
	register int _stopbyte = _bit_byte(_nbits), _value = -1; \
	for (_byte = 0; _byte <= _stopbyte; ++_byte) \
		if (_name[_byte] != 0xff) { \
			_value = _byte << 3; \
			for (_stopbyte = _name[_byte]; (_stopbyte&0x1); \
			    ++_value, _stopbyte >>= 1); \
			break; \
		} \
	*(value) = _value; \
}

				/* find first bit set in name */
#define	bit_ffs(name, nbits, value) { \
	register bitstr_t *_name = name; \
	register int _byte, _nbits = nbits; \
	register int _stopbyte = _bit_byte(_nbits), _value = -1; \
	for (_byte = 0; _byte <= _stopbyte; ++_byte) \
		if (_name[_byte]) { \
			_value = _byte << 3; \
			for (_stopbyte = _name[_byte]; !(_stopbyte&0x1); \
			    ++_value, _stopbyte >>= 1); \
			break; \
		} \
	*(value) = _value; \
}

#endif /* !_BITSTRING_H_ */