byteorder.h

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/* Copyright (c) 2014, 2024, Oracle and/or its affiliates.
 
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   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.
 
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   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   You should have received a copy of the GNU General Public License
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/**
  @file libbinlogevents/include/byteorder.h
 
  @brief The file contains functions to convert the byte encoding of integer
  values to and from little-endian and big-endian byte order.
*/
 
#ifndef BYTEORDER_INCLUDED
#define BYTEORDER_INCLUDED
 
#include <stdint.h>
#include "binlog_config.h"
#include "my_compiler.h"
#include "my_config.h"
#ifndef STANDALONE_BINLOG
#define HAVE_MYSYS 1
#endif
 
/*
  Methods for reading and storing in machine independent
  format (low byte first).
*/
 
/*
  Checking le16toh is required because the machine may have the header
  but the functions might not be defined if the version of glibc < 2.9
*/
#ifdef HAVE_ENDIAN_CONVERSION_MACROS
#include <endian.h>
#endif
 
#if !defined(le16toh)
/**
  Converting a 16 bit integer from little-endian byte order to host byteorder
 
  @param x  16-bit integer in little endian byte order
  @return  16-bit integer in host byte order
*/
uint16_t inline le16toh(uint16_t x) {
#ifndef WORDS_BIGENDIAN
  return x;
#else
  return ((x >> 8) | (x << 8));
#endif
}
#endif
 
#if !defined(le32toh)
/**
  Converting a 32 bit integer from little-endian byte order to host byteorder
 
  @param x  32-bit integer in little endian byte order
  @return  32-bit integer in host byte order
*/
uint32_t inline le32toh(uint32_t x) {
#ifndef WORDS_BIGENDIAN
  return x;
#else
  return (((x >> 24) & 0xff) | ((x << 8) & 0xff0000) | ((x >> 8) & 0xff00) |
          ((x << 24) & 0xff000000));
#endif
}
#endif
 
#if !defined(be32toh)
/**
  Converting a 32 bit integer from big-endian byte order to host byteorder
 
  @param x  32-bit integer in big endian byte order
  @return  32-bit integer in host byte order
*/
uint32_t inline be32toh(uint32_t x) {
#ifndef WORDS_BIGENDIAN
  return (((x >> 24) & 0xff) | ((x << 8) & 0xff0000) | ((x >> 8) & 0xff00) |
          ((x << 24) & 0xff000000));
#else
  return x;
#endif
}
#endif
 
#if !defined(le64toh)
/**
  Converting a 64 bit integer from little-endian byte order to host byteorder
 
  @param x  64-bit integer in little endian byte order
  @return  64-bit integer in host byte order
*/
uint64_t inline le64toh(uint64_t x) {
#ifndef WORDS_BIGENDIAN
  return x;
#else
  x = ((x << 8) & 0xff00ff00ff00ff00ULL) | ((x >> 8) & 0x00ff00ff00ff00ffULL);
  x = ((x << 16) & 0xffff0000ffff0000ULL) | ((x >> 16) & 0x0000ffff0000ffffULL);
  return (x << 32) | (x >> 32);
#endif
}
#endif
 
#endif  // BYTEORDER_INCLUDED