BigEndian.h

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// Copyright 2019-2026 CERN and copyright holders of ALICE O2.
// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
// All rights not expressly granted are reserved.
//
// This software is distributed under the terms of the GNU General Public
// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
//
// In applying this license CERN does not waive the privileges and immunities
// granted to it by virtue of its status as an Intergovernmental Organization
// or submit itself to any jurisdiction.
 
#ifndef O2_FRAMEWORK_BIGENDIAN_H_
#define O2_FRAMEWORK_BIGENDIAN_H_
 
#include <bit>
#include <cstddef>
#include <cstdint>
#include <cstring>
 
namespace o2::framework
{
 
inline void bigEndianCopy(void* dest, const void* src, int count, size_t typeSize)
{
  auto const totalBytes = static_cast<size_t>(count) * typeSize;
  if constexpr (std::endian::native == std::endian::big) {
    std::memcpy(dest, src, totalBytes);
    return;
  }
  switch (typeSize) {
    case 2: {
      auto* p = static_cast<uint16_t*>(dest);
      auto* q = static_cast<const uint16_t*>(src);
      for (int i = 0; i < count; ++i) {
        p[i] = __builtin_bswap16(q[i]);
      }
      return;
    }
    case 4: {
      auto* p = static_cast<uint32_t*>(dest);
      auto* q = static_cast<const uint32_t*>(src);
      for (int i = 0; i < count; ++i) {
        p[i] = __builtin_bswap32(q[i]);
      }
      return;
    }
    case 8: {
      auto* p = static_cast<uint64_t*>(dest);
      auto* q = static_cast<const uint64_t*>(src);
      for (int i = 0; i < count; ++i) {
        p[i] = __builtin_bswap64(q[i]);
      }
      return;
    }
  }
  std::memcpy(dest, src, totalBytes);
}
 
} // namespace o2::framework
 
#endif // O2_FRAMEWORK_BIGENDIAN_H_