Program Listing for File portable_endian.h

↰ Return to documentation for file (include/libcaer/portable_endian.h)

// "License": Public Domain
// I, Mathias Panzenböck, place this file hereby into the public domain. Use it at your own risk for whatever you like.
// In case there are jurisdictions that don't support putting things in the public domain you can also consider it to
// be "dual licensed" under the BSD, MIT and Apache licenses, if you want to. This code is trivial anyway. Consider it
// an example on how to get the endian conversion functions on different platforms.

#ifndef PORTABLE_ENDIAN_H__
#define PORTABLE_ENDIAN_H__

#if (defined(_WIN16) || defined(_WIN32) || defined(_WIN64)) && !defined(__WINDOWS__)
#   define __WINDOWS__
#endif

#if defined(__linux__) || defined(__CYGWIN__)
#   include <endian.h>
#elif defined(__APPLE__)
#   include <libkern/OSByteOrder.h>

#   define htobe16(x) OSSwapHostToBigInt16(x)
#   define htole16(x) OSSwapHostToLittleInt16(x)
#   define be16toh(x) OSSwapBigToHostInt16(x)
#   define le16toh(x) OSSwapLittleToHostInt16(x)

#   define htobe32(x) OSSwapHostToBigInt32(x)
#   define htole32(x) OSSwapHostToLittleInt32(x)
#   define be32toh(x) OSSwapBigToHostInt32(x)
#   define le32toh(x) OSSwapLittleToHostInt32(x)

#   define htobe64(x) OSSwapHostToBigInt64(x)
#   define htole64(x) OSSwapHostToLittleInt64(x)
#   define be64toh(x) OSSwapBigToHostInt64(x)
#   define le64toh(x) OSSwapLittleToHostInt64(x)

#   define __BYTE_ORDER    BYTE_ORDER
#   define __BIG_ENDIAN    BIG_ENDIAN
#   define __LITTLE_ENDIAN LITTLE_ENDIAN
#   define __PDP_ENDIAN    PDP_ENDIAN
#elif defined(__OpenBSD__)
#   include <sys/endian.h>
#elif defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
#   include <sys/endian.h>

#   define be16toh(x) betoh16(x)
#   define le16toh(x) letoh16(x)

#   define be32toh(x) betoh32(x)
#   define le32toh(x) letoh32(x)

#   define be64toh(x) betoh64(x)
#   define le64toh(x) letoh64(x)
#elif defined(__WINDOWS__)
#   include <winsock2.h>

#   if BYTE_ORDER == LITTLE_ENDIAN
#       define htobe16(x) htons(x)
#       define htole16(x) (x)
#       define be16toh(x) ntohs(x)
#       define le16toh(x) (x)

#       define htobe32(x) htonl(x)
#       define htole32(x) (x)
#       define be32toh(x) ntohl(x)
#       define le32toh(x) (x)

#       define htobe64(x) htonll(x)
#       define htole64(x) (x)
#       define be64toh(x) ntohll(x)
#       define le64toh(x) (x)
#   elif BYTE_ORDER == BIG_ENDIAN
/* That would be Xbox 360. */
#       define htobe16(x) (x)
#       define htole16(x) __builtin_bswap16(x)
#       define be16toh(x) (x)
#       define le16toh(x) __builtin_bswap16(x)

#       define htobe32(x) (x)
#       define htole32(x) __builtin_bswap32(x)
#       define be32toh(x) (x)
#       define le32toh(x) __builtin_bswap32(x)

#       define htobe64(x) (x)
#       define htole64(x) __builtin_bswap64(x)
#       define be64toh(x) (x)
#       define le64toh(x) __builtin_bswap64(x)
#   else
#       error byte order not supported
#   endif

#   define __BYTE_ORDER    BYTE_ORDER
#   define __BIG_ENDIAN    BIG_ENDIAN
#   define __LITTLE_ENDIAN LITTLE_ENDIAN
#   define __PDP_ENDIAN    PDP_ENDIAN
#else
#   error platform not supported
#endif

#ifdef __cplusplus

#   include <cstdint>
#   include <cstring>

#else

#   include <stdint.h>
#   include <string.h>

#endif

// libcaer: define macros for floating-point conversions too.
// Floats must be 4 bytes in size, so like a 32-bit integer, but their endianness
// is undefined, so we use the 32bit conversion functions and memcpy() to do the
// conversions safely (assumed integer and floating-point do have the same
// endianness on the system, which is almost always true). For further details, see:
// https://stackoverflow.com/questions/10620601/portable-serialisation-of-ieee754-floating-point-values
static inline float htobeflt(float val) {
    uint32_t rep;
    memcpy(&rep, &val, sizeof(rep));
    rep = htobe32(rep);
    memcpy(&val, &rep, sizeof(rep));
    return (val);
}

static inline float htoleflt(float val) {
    uint32_t rep;
    memcpy(&rep, &val, sizeof(rep));
    rep = htole32(rep);
    memcpy(&val, &rep, sizeof(rep));
    return (val);
}

static inline float beflttoh(float val) {
    uint32_t rep;
    memcpy(&rep, &val, sizeof(rep));
    rep = be32toh(rep);
    memcpy(&val, &rep, sizeof(rep));
    return (val);
}

static inline float leflttoh(float val) {
    uint32_t rep;
    memcpy(&rep, &val, sizeof(rep));
    rep = le32toh(rep);
    memcpy(&val, &rep, sizeof(rep));
    return (val);
}

#endif /* PORTABLE_ENDIAN_H__ */