db_swap.h
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- /*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1996-2002
- * 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. 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,v 11.8 2002/01/11 15:52:26 bostic Exp $
- */
- #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);
- }
- /*
- * 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.
- */
- #define DB_HTONL(p) do {
- if (!__db_isbigendian())
- P_32_SWAP(p);
- } while (0)
- #define DB_NTOHL(p) do {
- if (!__db_isbigendian())
- P_32_SWAP(p);
- } while (0)
- #endif /* !_DB_SWAP_H_ */