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72 lines
1.3 KiB
C
72 lines
1.3 KiB
C
/*-
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* See the file LICENSE for redistribution information.
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*
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* Copyright (c) 1996-2005
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* Sleepycat Software. All rights reserved.
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*
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* $Id: db_byteorder.c,v 12.1 2005/06/16 20:20:52 bostic Exp $
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*/
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#include "db_config.h"
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#ifndef NO_SYSTEM_INCLUDES
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#include <sys/types.h>
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#endif
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#include "db_int.h"
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/*
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* __db_isbigendian --
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* Return 1 if big-endian (Motorola and Sparc), not little-endian
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* (Intel and Vax). We do this work at run-time, rather than at
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* configuration time so cross-compilation and general embedded
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* system support is simpler.
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*
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* PUBLIC: int __db_isbigendian __P((void));
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*/
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int
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__db_isbigendian()
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{
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union { /* From Harbison & Steele. */
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long l;
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char c[sizeof(long)];
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} u;
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u.l = 1;
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return (u.c[sizeof(long) - 1] == 1);
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}
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/*
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* __db_byteorder --
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* Return if we need to do byte swapping, checking for illegal
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* values.
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*
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* PUBLIC: int __db_byteorder __P((DB_ENV *, int));
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*/
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int
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__db_byteorder(dbenv, lorder)
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DB_ENV *dbenv;
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int lorder;
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{
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int is_bigendian;
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is_bigendian = __db_isbigendian();
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switch (lorder) {
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case 0:
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break;
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case 1234:
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if (is_bigendian)
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return (DB_SWAPBYTES);
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break;
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case 4321:
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if (!is_bigendian)
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return (DB_SWAPBYTES);
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break;
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default:
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__db_err(dbenv,
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"unsupported byte order, only big and little-endian supported");
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return (EINVAL);
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}
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return (0);
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}
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