my_byteorder.h

#ifndef MY_BYTEORDER_INCLUDED
#define MY_BYTEORDER_INCLUDED

/* Copyright (c) 2001, 2021, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   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
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/**
  @file include/my_byteorder.h
  Functions for reading and storing in machine-independent format.
  The little-endian variants are 'korr' (assume 'corrector') variants
  for integer types, but 'get' (assume 'getter') for floating point types.
*/

#include "my_config.h"

#include "my_compiler.h"

#include <string.h>
#include <sys/types.h>

#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#if defined(_MSC_VER)
#include <stdlib.h>
#endif

#if defined(_WIN32) && defined(WIN32_LEAN_AND_MEAN)
#include <winsock2.h>
#endif

#ifdef WORDS_BIGENDIAN
#include "big_endian.h"  // IWYU pragma: export
#else
#include "little_endian.h"  // IWYU pragma: export
#endif

#include "my_inttypes.h"

#ifdef __cplusplus
#include "template_utils.h"
#endif

static inline int32 sint3korr(const uchar *A) {
  return ((int32)(((A[2]) & 128)
                      ? (((uint32)255L << 24) | (((uint32)A[2]) << 16) |
                         (((uint32)A[1]) << 8) | ((uint32)A[0]))
                      : (((uint32)A[2]) << 16) | (((uint32)A[1]) << 8) |
                            ((uint32)A[0])));
}

static inline uint32 uint3korr(const uchar *A) {
  return (uint32)(((uint32)(A[0])) + (((uint32)(A[1])) << 8) +
                  (((uint32)(A[2])) << 16));
}

static inline ulonglong uint5korr(const uchar *A) {
  return ((ulonglong)(((uint32)(A[0])) + (((uint32)(A[1])) << 8) +
                      (((uint32)(A[2])) << 16) + (((uint32)(A[3])) << 24)) +
          (((ulonglong)(A[4])) << 32));
}

static inline ulonglong uint6korr(const uchar *A) {
  return ((ulonglong)(((uint32)(A[0])) + (((uint32)(A[1])) << 8) +
                      (((uint32)(A[2])) << 16) + (((uint32)(A[3])) << 24)) +
          (((ulonglong)(A[4])) << 32) + (((ulonglong)(A[5])) << 40));
}

/**
  int3store

  Stores an unsinged integer in a platform independent way

  @param T  The destination buffer. Must be at least 3 bytes long
  @param A  The integer to store.

  _Example:_
  A @ref a_protocol_type_int3 "int \<3\>" with the value 1 is stored as:
  ~~~~~~~~~~~~~~~~~~~~~
  01 00 00
  ~~~~~~~~~~~~~~~~~~~~~
*/
static inline void int3store(uchar *T, uint A) {
  *(T) = (uchar)(A);
  *(T + 1) = (uchar)(A >> 8);
  *(T + 2) = (uchar)(A >> 16);
}

static inline void int5store(uchar *T, ulonglong A) {
  *(T) = (uchar)(A);
  *(T + 1) = (uchar)(A >> 8);
  *(T + 2) = (uchar)(A >> 16);
  *(T + 3) = (uchar)(A >> 24);
  *(T + 4) = (uchar)(A >> 32);
}

static inline void int6store(uchar *T, ulonglong A) {
  *(T) = (uchar)(A);
  *(T + 1) = (uchar)(A >> 8);
  *(T + 2) = (uchar)(A >> 16);
  *(T + 3) = (uchar)(A >> 24);
  *(T + 4) = (uchar)(A >> 32);
  *(T + 5) = (uchar)(A >> 40);
}

#ifdef __cplusplus

inline int16 sint2korr(const char *pT) {
  return sint2korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline uint16 uint2korr(const char *pT) {
  return uint2korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline uint32 uint3korr(const char *pT) {
  return uint3korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline int32 sint3korr(const char *pT) {
  return sint3korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline uint32 uint4korr(const char *pT) {
  return uint4korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline int32 sint4korr(const char *pT) {
  return sint4korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline ulonglong uint6korr(const char *pT) {
  return uint6korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline ulonglong uint8korr(const char *pT) {
  return uint8korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline longlong sint8korr(const char *pT) {
  return sint8korr(static_cast<const uchar *>(static_cast<const void *>(pT)));
}

inline void int2store(char *pT, uint16 A) {
  int2store(static_cast<uchar *>(static_cast<void *>(pT)), A);
}

inline void int3store(char *pT, uint A) {
  int3store(static_cast<uchar *>(static_cast<void *>(pT)), A);
}

inline void int4store(char *pT, uint32 A) {
  int4store(static_cast<uchar *>(static_cast<void *>(pT)), A);
}

inline void int5store(char *pT, ulonglong A) {
  int5store(static_cast<uchar *>(static_cast<void *>(pT)), A);
}

inline void int6store(char *pT, ulonglong A) {
  int6store(static_cast<uchar *>(static_cast<void *>(pT)), A);
}

inline void int8store(char *pT, ulonglong A) {
  int8store(static_cast<uchar *>(static_cast<void *>(pT)), A);
}

/*
  Functions for reading and storing in machine format from/to
  short/long to/from some place in memory V should be a variable
  and M a pointer to byte.
*/

inline void float4store(char *V, float M) {
  float4store(static_cast<uchar *>(static_cast<void *>(V)), M);
}

inline double float8get(const char *M) {
  return float8get(static_cast<const uchar *>(static_cast<const void *>(M)));
}

inline void float8store(char *V, double M) {
  float8store(static_cast<uchar *>(static_cast<void *>(V)), M);
}

/*
 Functions that have the same behavior on little- and big-endian.
*/

inline float floatget(const uchar *ptr) {
  float val;
  memcpy(&val, ptr, sizeof(val));
  return val;
}

inline void floatstore(uchar *ptr, float val) {
  memcpy(ptr, &val, sizeof(val));
}

inline double doubleget(const uchar *ptr) {
  double val;
  memcpy(&val, ptr, sizeof(val));
  return val;
}

inline void doublestore(uchar *ptr, double val) {
  memcpy(ptr, &val, sizeof(val));
}

inline uint16 ushortget(const uchar *ptr) {
  uint16 val;
  memcpy(&val, ptr, sizeof(val));
  return val;
}

inline int16 shortget(const uchar *ptr) {
  int16 val;
  memcpy(&val, ptr, sizeof(val));
  return val;
}

inline void shortstore(uchar *ptr, int16 val) {
  memcpy(ptr, &val, sizeof(val));
}

inline int32 longget(const uchar *ptr) {
  int32 val;
  memcpy(&val, ptr, sizeof(val));
  return val;
}

inline void longstore(uchar *ptr, int32 val) { memcpy(ptr, &val, sizeof(val)); }

inline uint32 ulongget(const uchar *ptr) {
  uint32 val;
  memcpy(&val, ptr, sizeof(val));
  return val;
}

inline longlong longlongget(const uchar *ptr) {
  longlong val;
  memcpy(&val, ptr, sizeof(val));
  return val;
}

inline void longlongstore(uchar *ptr, longlong val) {
  memcpy(ptr, &val, sizeof(val));
}

/*
 Functions for big-endian loads and stores. These are safe to use
 no matter what the compiler, CPU or alignment, and also with -fstrict-aliasing.

 The stores return a pointer just past the value that was written.
*/

inline uint16 load16be(const char *ptr) {
  uint16 val;
  memcpy(&val, ptr, sizeof(val));
  return ntohs(val);
}

inline uint32 load32be(const char *ptr) {
  uint32 val;
  memcpy(&val, ptr, sizeof(val));
  return ntohl(val);
}

ALWAYS_INLINE char *store16be(char *ptr, uint16 val) {
#if defined(_MSC_VER)
  // _byteswap_ushort is an intrinsic on MSVC, but htons is not.
  val = _byteswap_ushort(val);
#else
  val = htons(val);
#endif
  memcpy(ptr, &val, sizeof(val));
  return ptr + sizeof(val);
}

inline char *store32be(char *ptr, uint32 val) {
  val = htonl(val);
  memcpy(ptr, &val, sizeof(val));
  return ptr + sizeof(val);
}

// Adapters for using uchar * instead of char *.

inline uint16 load16be(const uchar *ptr) {
  return load16be(pointer_cast<const char *>(ptr));
}

inline uint32 load32be(const uchar *ptr) {
  return load32be(pointer_cast<const char *>(ptr));
}

ALWAYS_INLINE uchar *store16be(uchar *ptr, uint16 val) {
  return pointer_cast<uchar *>(store16be(pointer_cast<char *>(ptr), val));
}

inline uchar *store32be(uchar *ptr, uint32 val) {
  return pointer_cast<uchar *>(store32be(pointer_cast<char *>(ptr), val));
}

#endif /* __cplusplus */

#endif /* MY_BYTEORDER_INCLUDED */