rtc_base/byte_order.h

/*
 *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef RTC_BASE_BYTE_ORDER_H_
#define RTC_BASE_BYTE_ORDER_H_

#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <span>

#include "rtc_base/checks.h"
#include "rtc_base/system/arch.h"  // IWYU pragma: keep

#if defined(WEBRTC_POSIX)
#include <arpa/inet.h>  // IWYU pragma: keep
#endif


#if defined(WEBRTC_MAC)
#include <libkern/OSByteOrder.h>

#define htobe16(v) OSSwapHostToBigInt16(v)
#define htobe32(v) OSSwapHostToBigInt32(v)
#define htobe64(v) OSSwapHostToBigInt64(v)
#define be16toh(v) OSSwapBigToHostInt16(v)
#define be32toh(v) OSSwapBigToHostInt32(v)
#define be64toh(v) OSSwapBigToHostInt64(v)

#define htole16(v) OSSwapHostToLittleInt16(v)
#define htole32(v) OSSwapHostToLittleInt32(v)
#define htole64(v) OSSwapHostToLittleInt64(v)
#define le16toh(v) OSSwapLittleToHostInt16(v)
#define le32toh(v) OSSwapLittleToHostInt32(v)
#define le64toh(v) OSSwapLittleToHostInt64(v)

#elif defined(WEBRTC_WIN)

#if defined(WEBRTC_WIN)
#include <winsock2.h>
#else
#include <netinet/in.h>  // no-presubmit-check
#endif                   // defined(WEBRTC_WIN)

#if defined(WEBRTC_ARCH_LITTLE_ENDIAN)
#define htobe16(v) htons(v)
#define htobe32(v) htonl(v)
#define be16toh(v) ntohs(v)
#define be32toh(v) ntohl(v)
#define htole16(v) (v)
#define htole32(v) (v)
#define htole64(v) (v)
#define le16toh(v) (v)
#define le32toh(v) (v)
#define le64toh(v) (v)
#if defined(WEBRTC_WIN)
#define htobe64(v) _byteswap_uint64(v)
#define be64toh(v) _byteswap_uint64(v)
#endif  // defined(WEBRTC_WIN)

#elif defined(WEBRTC_ARCH_BIG_ENDIAN)
#define htobe16(v) (v)
#define htobe32(v) (v)
#define be16toh(v) (v)
#define be32toh(v) (v)
#define htole16(v) __builtin_bswap16(v)
#define htole32(v) __builtin_bswap32(v)
#define htole64(v) __builtin_bswap64(v)
#define le16toh(v) __builtin_bswap16(v)
#define le32toh(v) __builtin_bswap32(v)
#define le64toh(v) __builtin_bswap64(v)
#if defined(WEBRTC_WIN)
#define htobe64(v) (v)
#define be64toh(v) (v)
#endif  // defined(WEBRTC_WIN)
#else
#error WEBRTC_ARCH_BIG_ENDIAN or WEBRTC_ARCH_LITTLE_ENDIAN must be defined.
#endif  // defined(WEBRTC_ARCH_LITTLE_ENDIAN)

#elif defined(WEBRTC_POSIX)
#include <endian.h>
#else
#error "Missing byte order functions for this arch."
#endif  // defined(WEBRTC_MAC)

namespace webrtc {

// Reading and writing of little and big-endian numbers from memory

inline void Set8(std::span<uint8_t> data, size_t offset, uint8_t v) {
  data[offset] = v;
}

inline uint8_t Get8(std::span<const uint8_t> data, size_t offset) {
  return data[offset];
}

inline void SetBE16(std::span<uint8_t> data, uint16_t v) {
  RTC_DCHECK_GE(data.size(), sizeof(v));
  uint16_t val = htobe16(v);
  memcpy(data.data(), &val, sizeof(val));
}

inline void SetBE32(std::span<uint8_t> data, uint32_t v) {
  RTC_DCHECK_GE(data.size(), sizeof(v));
  uint32_t val = htobe32(v);
  memcpy(data.data(), &val, sizeof(val));
}

inline void SetBE64(std::span<uint8_t> data, uint64_t v) {
  RTC_DCHECK_GE(data.size(), sizeof(v));
  uint64_t val = htobe64(v);
  memcpy(data.data(), &val, sizeof(val));
}

inline uint16_t GetBE16(std::span<const uint8_t> data) {
  uint16_t val;
  RTC_DCHECK_GE(data.size(), sizeof(val));
  memcpy(&val, data.data(), sizeof(val));
  return be16toh(val);
}

inline uint32_t GetBE32(std::span<const uint8_t> data) {
  uint32_t val;
  RTC_DCHECK_GE(data.size(), sizeof(val));
  memcpy(&val, data.data(), sizeof(val));
  return be32toh(val);
}

inline uint64_t GetBE64(std::span<const uint8_t> data) {
  uint64_t val;
  RTC_DCHECK_GE(data.size(), sizeof(val));
  memcpy(&val, data.data(), sizeof(val));
  return be64toh(val);
}

inline void SetLE16(std::span<uint8_t> data, uint16_t v) {
  RTC_DCHECK_GE(data.size(), sizeof(v));
  uint16_t val = htole16(v);
  memcpy(data.data(), &val, sizeof(val));
}

inline void SetLE32(std::span<uint8_t> data, uint32_t v) {
  RTC_DCHECK_GE(data.size(), sizeof(v));
  uint32_t val = htole32(v);
  memcpy(data.data(), &val, sizeof(val));
}

inline void SetLE64(std::span<uint8_t> data, uint64_t v) {
  RTC_DCHECK_GE(data.size(), sizeof(v));
  uint64_t val = htole64(v);
  memcpy(data.data(), &val, sizeof(val));
}

inline uint16_t GetLE16(std::span<const uint8_t> data) {
  uint16_t val;
  RTC_DCHECK_GE(data.size(), sizeof(val));
  memcpy(&val, data.data(), sizeof(val));
  return le16toh(val);
}

inline uint32_t GetLE32(std::span<const uint8_t> data) {
  uint32_t val;
  RTC_DCHECK_GE(data.size(), sizeof(val));
  memcpy(&val, data.data(), sizeof(val));
  return le32toh(val);
}

inline uint64_t GetLE64(std::span<const uint8_t> data) {
  uint64_t val;
  RTC_DCHECK_GE(data.size(), sizeof(val));
  memcpy(&val, data.data(), sizeof(val));
  return le64toh(val);
}

// Check if the current host is big endian.
inline bool IsHostBigEndian() {
#if defined(WEBRTC_ARCH_BIG_ENDIAN)
  return true;
#else
  return false;
#endif
}

inline uint16_t HostToNetwork16(uint16_t n) {
  return htobe16(n);
}

inline uint32_t HostToNetwork32(uint32_t n) {
  return htobe32(n);
}

inline uint64_t HostToNetwork64(uint64_t n) {
  return htobe64(n);
}

inline uint16_t NetworkToHost16(uint16_t n) {
  return be16toh(n);
}

inline uint32_t NetworkToHost32(uint32_t n) {
  return be32toh(n);
}

inline uint64_t NetworkToHost64(uint64_t n) {
  return be64toh(n);
}

}  //  namespace webrtc


#endif  // RTC_BASE_BYTE_ORDER_H_