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cpython-source-deps/dbinc/db_swap.h
2017-09-04 13:40:25 -05:00

263 lines
8.4 KiB
C

/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996,2008 Oracle. 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. 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.
*
* $Id: db_swap.h 63573 2008-05-23 21:43:21Z trent.nelson $
*/
#ifndef _DB_SWAP_H_
#define _DB_SWAP_H_
#if defined(__cplusplus)
extern "C" {
#endif
/*
* Little endian <==> big endian 64-bit swap macros.
* M_64_SWAP swap a memory location
* P_64_COPY copy potentially unaligned 4 byte quantities
* P_64_SWAP swap a referenced memory location
*/
#undef M_64_SWAP
#define M_64_SWAP(a) { \
u_int64_t _tmp; \
_tmp = (u_int64_t)a; \
((u_int8_t *)&a)[0] = ((u_int8_t *)&_tmp)[7]; \
((u_int8_t *)&a)[1] = ((u_int8_t *)&_tmp)[6]; \
((u_int8_t *)&a)[2] = ((u_int8_t *)&_tmp)[5]; \
((u_int8_t *)&a)[3] = ((u_int8_t *)&_tmp)[4]; \
((u_int8_t *)&a)[4] = ((u_int8_t *)&_tmp)[3]; \
((u_int8_t *)&a)[5] = ((u_int8_t *)&_tmp)[2]; \
((u_int8_t *)&a)[6] = ((u_int8_t *)&_tmp)[1]; \
((u_int8_t *)&a)[7] = ((u_int8_t *)&_tmp)[0]; \
}
#undef P_64_COPY
#define P_64_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]; \
((u_int8_t *)b)[4] = ((u_int8_t *)a)[4]; \
((u_int8_t *)b)[5] = ((u_int8_t *)a)[5]; \
((u_int8_t *)b)[6] = ((u_int8_t *)a)[6]; \
((u_int8_t *)b)[7] = ((u_int8_t *)a)[7]; \
}
#undef P_64_SWAP
#define P_64_SWAP(a) { \
u_int64_t _tmp; \
P_64_COPY(a, &_tmp); \
((u_int8_t *)a)[0] = ((u_int8_t *)&_tmp)[7]; \
((u_int8_t *)a)[1] = ((u_int8_t *)&_tmp)[6]; \
((u_int8_t *)a)[2] = ((u_int8_t *)&_tmp)[5]; \
((u_int8_t *)a)[3] = ((u_int8_t *)&_tmp)[4]; \
((u_int8_t *)a)[4] = ((u_int8_t *)&_tmp)[3]; \
((u_int8_t *)a)[5] = ((u_int8_t *)&_tmp)[2]; \
((u_int8_t *)a)[6] = ((u_int8_t *)&_tmp)[1]; \
((u_int8_t *)a)[7] = ((u_int8_t *)&_tmp)[0]; \
}
/*
* Little endian <==> big endian 32-bit swap macros.
* P_32_COPY copy potentially unaligned 4 byte quantities
* P_32_COPYSWAP copy and swap potentially unaligned 4 byte quantities
* P_32_SWAP swap a referenced memory location
* M_32_SWAP swap a memory location
*/
#undef P_32_COPY
#define P_32_COPY(a, b) do { \
((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]; \
} while (0)
#undef P_32_COPYSWAP
#define P_32_COPYSWAP(a, b) do { \
((u_int8_t *)b)[0] = ((u_int8_t *)a)[3]; \
((u_int8_t *)b)[1] = ((u_int8_t *)a)[2]; \
((u_int8_t *)b)[2] = ((u_int8_t *)a)[1]; \
((u_int8_t *)b)[3] = ((u_int8_t *)a)[0]; \
} while (0)
#undef P_32_SWAP
#define P_32_SWAP(a) do { \
u_int32_t _tmp; \
P_32_COPY(a, &_tmp); \
P_32_COPYSWAP(&_tmp, a); \
} while (0)
#undef M_32_SWAP
#define M_32_SWAP(a) P_32_SWAP(&a)
/*
* Little endian <==> big endian 16-bit swap macros.
* P_16_COPY copy potentially unaligned 2 byte quantities
* P_16_COPYSWAP copy and swap potentially unaligned 2 byte quantities
* P_16_SWAP swap a referenced memory location
* M_16_SWAP swap a memory location
*/
#undef P_16_COPY
#define P_16_COPY(a, b) do { \
((u_int8_t *)b)[0] = ((u_int8_t *)a)[0]; \
((u_int8_t *)b)[1] = ((u_int8_t *)a)[1]; \
} while (0)
#undef P_16_COPYSWAP
#define P_16_COPYSWAP(a, b) do { \
((u_int8_t *)b)[0] = ((u_int8_t *)a)[1]; \
((u_int8_t *)b)[1] = ((u_int8_t *)a)[0]; \
} while (0)
#undef P_16_SWAP
#define P_16_SWAP(a) do { \
u_int16_t _tmp; \
P_16_COPY(a, &_tmp); \
P_16_COPYSWAP(&_tmp, a); \
} while (0)
#undef M_16_SWAP
#define M_16_SWAP(a) P_16_SWAP(&a)
#undef SWAP32
#define SWAP32(p) { \
P_32_SWAP(p); \
(p) += sizeof(u_int32_t); \
}
#undef SWAP16
#define SWAP16(p) { \
P_16_SWAP(p); \
(p) += sizeof(u_int16_t); \
}
/*
* Berkeley DB has local versions of htonl() and ntohl() that operate on
* pointers to the right size memory locations; the portability magic for
* finding the real system functions isn't worth the effort.
*/
#undef DB_HTONL_SWAP
#define DB_HTONL_SWAP(env, p) do { \
if (F_ISSET((env), ENV_LITTLEENDIAN)) \
P_32_SWAP(p); \
} while (0)
#undef DB_NTOHL_SWAP
#define DB_NTOHL_SWAP(env, p) do { \
if (F_ISSET((env), ENV_LITTLEENDIAN)) \
P_32_SWAP(p); \
} while (0)
#undef DB_NTOHL_COPYIN
#define DB_NTOHL_COPYIN(env, i, p) do { \
u_int8_t *tmp; \
tmp = (u_int8_t *)&(i); \
if (F_ISSET(env, ENV_LITTLEENDIAN)) { \
tmp[3] = *p++; \
tmp[2] = *p++; \
tmp[1] = *p++; \
tmp[0] = *p++; \
} else { \
memcpy(&i, p, sizeof(u_int32_t)); \
p = (u_int8_t *)p + sizeof(u_int32_t); \
} \
} while (0)
#undef DB_NTOHS_COPYIN
#define DB_NTOHS_COPYIN(env, i, p) do { \
u_int8_t *tmp; \
tmp = (u_int8_t *)&(i); \
if (F_ISSET(env, ENV_LITTLEENDIAN)) { \
tmp[1] = *p++; \
tmp[0] = *p++; \
} else { \
memcpy(&i, p, sizeof(u_int16_t)); \
p = (u_int8_t *)p + sizeof(u_int16_t); \
} \
} while (0)
#undef DB_HTONL_COPYOUT
#define DB_HTONL_COPYOUT(env, p, i) do { \
u_int8_t *tmp; \
tmp = (u_int8_t *)p; \
if (F_ISSET(env, ENV_LITTLEENDIAN)) { \
*tmp++ = ((u_int8_t *)&(i))[3]; \
*tmp++ = ((u_int8_t *)&(i))[2]; \
*tmp++ = ((u_int8_t *)&(i))[1]; \
*tmp++ = ((u_int8_t *)&(i))[0]; \
} else \
memcpy(p, &i, sizeof(u_int32_t)); \
p = (u_int8_t *)p + sizeof(u_int32_t); \
} while (0)
#undef DB_HTONS_COPYOUT
#define DB_HTONS_COPYOUT(env, p, i) do { \
u_int8_t *tmp; \
tmp = (u_int8_t *)p; \
if (F_ISSET(env, ENV_LITTLEENDIAN)) { \
*tmp++ = ((u_int8_t *)&(i))[1]; \
*tmp++ = ((u_int8_t *)&(i))[0]; \
} else \
memcpy(p, &i, sizeof(u_int16_t)); \
p = (u_int8_t *)p + sizeof(u_int16_t); \
} while (0)
/*
* Helper macros for swapped logs. We write logs in little endian format to
* minimize disruption on x86 when upgrading from native byte order to
* platform-independent logs.
*/
#define LOG_SWAPPED(env) !F_ISSET(env, ENV_LITTLEENDIAN)
#define LOGCOPY_32(env, x, p) do { \
if (LOG_SWAPPED(env)) \
P_32_COPYSWAP((p), (x)); \
else \
memcpy((x), (p), sizeof (u_int32_t)); \
} while (0)
#define LOGCOPY_16(env, x, p) do { \
if (LOG_SWAPPED(env)) \
P_16_COPYSWAP((p), (x)); \
else \
memcpy((x), (p), sizeof (u_int16_t)); \
} while (0)
#define LOGCOPY_TOLSN(env, lsnp, p) do { \
LOGCOPY_32((env), &(lsnp)->file, (p)); \
LOGCOPY_32((env), &(lsnp)->offset, \
(u_int8_t *)(p) + sizeof (u_int32_t)); \
} while (0)
#define LOGCOPY_FROMLSN(env, p, lsnp) do { \
LOGCOPY_32((env), (p), &(lsnp)->file); \
LOGCOPY_32((env), \
(u_int8_t *)(p) + sizeof (u_int32_t), &(lsnp)->offset); \
} while (0)
#if defined(__cplusplus)
}
#endif
#endif /* !_DB_SWAP_H_ */