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Diffstat (limited to 'db/dbinc/db_swap.h')
| -rw-r--r-- | db/dbinc/db_swap.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/db/dbinc/db_swap.h b/db/dbinc/db_swap.h new file mode 100644 index 000000000..46499deef --- /dev/null +++ b/db/dbinc/db_swap.h @@ -0,0 +1,116 @@ +/*- + * 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_ */ |