db_swap.h revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998
* Sleepycat Software. All rights reserved.
*/
/*
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. 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.
* 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.
*
* @(#)db_swap.h 10.5 (Sleepycat) 4/10/98
*/
#ifndef _DB_SWAP_H_
#define _DB_SWAP_H_
/*
* Little endian <==> big endian 32-bit swap macros.
* M_32_SWAP swap a memory location
* P_32_COPY copy potentially unaligned 4 byte quantities
* P_32_SWAP swap a referenced memory location
*/
#define M_32_SWAP(a) { \
u_int32_t _tmp; \
_tmp = a; \
((u_int8_t *)&a)[0] = ((u_int8_t *)&_tmp)[3]; \
((u_int8_t *)&a)[1] = ((u_int8_t *)&_tmp)[2]; \
((u_int8_t *)&a)[2] = ((u_int8_t *)&_tmp)[1]; \
((u_int8_t *)&a)[3] = ((u_int8_t *)&_tmp)[0]; \
}
#define P_32_COPY(a, b) { \
((u_int8_t *)b)[0] = ((u_int8_t *)a)[0]; \
((u_int8_t *)b)[1] = ((u_int8_t *)a)[1]; \
((u_int8_t *)b)[2] = ((u_int8_t *)a)[2]; \
((u_int8_t *)b)[3] = ((u_int8_t *)a)[3]; \
}
#define P_32_SWAP(a) { \
u_int32_t _tmp; \
P_32_COPY(a, &_tmp); \
((u_int8_t *)a)[0] = ((u_int8_t *)&_tmp)[3]; \
((u_int8_t *)a)[1] = ((u_int8_t *)&_tmp)[2]; \
((u_int8_t *)a)[2] = ((u_int8_t *)&_tmp)[1]; \
((u_int8_t *)a)[3] = ((u_int8_t *)&_tmp)[0]; \
}
/*
* Little endian <==> big endian 16-bit swap macros.
* M_16_SWAP swap a memory location
* P_16_COPY copy potentially unaligned 2 byte quantities
* P_16_SWAP swap a referenced memory location
*/
#define M_16_SWAP(a) { \
u_int16_t _tmp; \
_tmp = (u_int16_t)a; \
((u_int8_t *)&a)[0] = ((u_int8_t *)&_tmp)[1]; \
((u_int8_t *)&a)[1] = ((u_int8_t *)&_tmp)[0]; \
}
#define P_16_COPY(a, b) { \
((u_int8_t *)b)[0] = ((u_int8_t *)a)[0]; \
((u_int8_t *)b)[1] = ((u_int8_t *)a)[1]; \
}
#define P_16_SWAP(a) { \
u_int16_t _tmp; \
P_16_COPY(a, &_tmp); \
((u_int8_t *)a)[0] = ((u_int8_t *)&_tmp)[1]; \
((u_int8_t *)a)[1] = ((u_int8_t *)&_tmp)[0]; \
}
#define SWAP32(p) { \
P_32_SWAP(p); \
(p) += sizeof(u_int32_t); \
}
#define SWAP16(p) { \
P_16_SWAP(p); \
(p) += sizeof(u_int16_t); \
}
#endif /* !_DB_SWAP_H_ */