#pragma once

/**

  @file

  @brief deal with big and little endian

  @author MITSUNARI Shigeo(@herumi)

*/

#include <cybozu/inttype.hpp>

#include <string.h>

namespace cybozu {

#ifdef _MSC_VER

inline uint16_t byteSwap(uint16_t x) { return _byteswap_ushort(x); }

inline uint32_t byteSwap(uint32_t x) { return _byteswap_ulong(x); }

inline uint64_t byteSwap(uint64_t x) { return _byteswap_uint64(x); }

#else

#if (((__GNUC__) << 16) + (__GNUC_MINOR__)) >= ((4 << 16) + 8)

inline uint16_t byteSwap(uint16_t x) { return __builtin_bswap16(x); }

#else

inline uint16_t byteSwap(uint16_t x) { return (x >> 8) | (x << 8); }

#endif

inline uint32_t byteSwap(uint32_t x) { return __builtin_bswap32(x); }

inline uint64_t byteSwap(uint64_t x) { return __builtin_bswap64(x); }

#endif

/**

  get 16bit integer as little endian

  @param src [in] pointer

*/

inline uint16_t Get16bitAsLE(const void *src)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  uint16_t x;

  memcpy(&x, src, sizeof(x));

  return x;

#else

  const uint8_t *p = static_cast<const uint8_t *>(src);

  return p[0] | (p[1] << 8);

#endif

}

/**

  get 32bit integer as little endian

  @param src [in] pointer

*/

inline uint32_t Get32bitAsLE(const void *src)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  uint32_t x;

  memcpy(&x, src, sizeof(x));

  return x;

#else

  const uint8_t *p = static_cast<const uint8_t *>(src);

  return Get16bitAsLE(p) | (static_cast<uint32_t>(Get16bitAsLE(p + 2)) << 16);

#endif

}

/**

  get 64bit integer as little endian

  @param src [in] pointer

*/

inline uint64_t Get64bitAsLE(const void *src)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  uint64_t x;

  memcpy(&x, src, sizeof(x));

  return x;

#else

  const uint8_t *p = static_cast<const uint8_t *>(src);

  return Get32bitAsLE(p) | (static_cast<uint64_t>(Get32bitAsLE(p + 4)) << 32);

#endif

}

/**

  get 16bit integer as bit endian

  @param src [in] pointer

*/

inline uint16_t Get16bitAsBE(const void *src)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  uint16_t x;

  memcpy(&x, src, sizeof(x));

  return byteSwap(x);

#else

  const uint8_t *p = static_cast<const uint8_t *>(src);

  return p[1] | (p[0] << 8);

#endif

}

/**

  get 32bit integer as bit endian

  @param src [in] pointer

*/

inline uint32_t Get32bitAsBE(const void *src)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  uint32_t x;

  memcpy(&x, src, sizeof(x));

  return byteSwap(x);

#else

  const uint8_t *p = static_cast<const uint8_t *>(src);

  return Get16bitAsBE(p + 2) | (static_cast<uint32_t>(Get16bitAsBE(p)) << 16);

#endif

}

/**

  get 64bit integer as big endian

  @param src [in] pointer

*/

inline uint64_t Get64bitAsBE(const void *src)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  uint64_t x;

  memcpy(&x, src, sizeof(x));

  return byteSwap(x);

#else

  const uint8_t *p = static_cast<const uint8_t *>(src);

  return Get32bitAsBE(p + 4) | (static_cast<uint64_t>(Get32bitAsBE(p)) << 32);

#endif

}

/**

  set 16bit integer as little endian

  @param src [out] pointer

  @param x [in] integer

*/

inline void Set16bitAsLE(void *src, uint16_t x)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  memcpy(src, &x, sizeof(x));

#else

  uint8_t *p = static_cast<uint8_t *>(src);

  p[0] = static_cast<uint8_t>(x);

  p[1] = static_cast<uint8_t>(x >> 8);

#endif

}

/**

  set 32bit integer as little endian

  @param src [out] pointer

  @param x [in] integer

*/

inline void Set32bitAsLE(void *src, uint32_t x)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  memcpy(src, &x, sizeof(x));

#else

  uint8_t *p = static_cast<uint8_t *>(src);

  p[0] = static_cast<uint8_t>(x);

  p[1] = static_cast<uint8_t>(x >> 8);

  p[2] = static_cast<uint8_t>(x >> 16);

  p[3] = static_cast<uint8_t>(x >> 24);

#endif

}

/**

  set 64bit integer as little endian

  @param src [out] pointer

  @param x [in] integer

*/

inline void Set64bitAsLE(void *src, uint64_t x)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  memcpy(src, &x, sizeof(x));

#else

  uint8_t *p = static_cast<uint8_t *>(src);

  Set32bitAsLE(p, static_cast<uint32_t>(x));

  Set32bitAsLE(p + 4, static_cast<uint32_t>(x >> 32));

#endif

}

/**

  set 16bit integer as big endian

  @param src [out] pointer

  @param x [in] integer

*/

inline void Set16bitAsBE(void *src, uint16_t x)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  x = byteSwap(x);

  memcpy(src, &x, sizeof(x));

#else

  uint8_t *p = static_cast<uint8_t *>(src);

  p[0] = static_cast<uint8_t>(x >> 8);

  p[1] = static_cast<uint8_t>(x);

#endif

}

/**

  set 32bit integer as big endian

  @param src [out] pointer

  @param x [in] integer

*/

inline void Set32bitAsBE(void *src, uint32_t x)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  x = byteSwap(x);

  memcpy(src, &x, sizeof(x));

#else

  uint8_t *p = static_cast<uint8_t *>(src);

  p[0] = static_cast<uint8_t>(x >> 24);

  p[1] = static_cast<uint8_t>(x >> 16);

  p[2] = static_cast<uint8_t>(x >> 8);

  p[3] = static_cast<uint8_t>(x);

#endif

}

/**

  set 64bit integer as big endian

  @param src [out] pointer

  @param x [in] integer

*/

inline void Set64bitAsBE(void *src, uint64_t x)

{

#if CYBOZU_ENDIAN == CYBOZU_ENDIAN_LITTLE

  x = byteSwap(x);

  memcpy(src, &x, sizeof(x));

#else

  uint8_t *p = static_cast<uint8_t *>(src);

  Set32bitAsBE(p, static_cast<uint32_t>(x >> 32));

  Set32bitAsBE(p + 4, static_cast<uint32_t>(x));

#endif

}

} // cybozu