endian.go 1022 B

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  1. // Copyright 2017 The etcd Authors
  2. //
  3. // Licensed under the Apache License, Version 2.0 (the "License");
  4. // you may not use this file except in compliance with the License.
  5. // You may obtain a copy of the License at
  6. //
  7. // http://www.apache.org/licenses/LICENSE-2.0
  8. //
  9. // Unless required by applicable law or agreed to in writing, software
  10. // distributed under the License is distributed on an "AS IS" BASIS,
  11. // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12. // See the License for the specific language governing permissions and
  13. // limitations under the License.
  14. package cpuutil
  15. import (
  16. "encoding/binary"
  17. "unsafe"
  18. )
  19. const intWidth int = int(unsafe.Sizeof(0))
  20. var byteOrder binary.ByteOrder
  21. // ByteOrder returns the byte order for the CPU's native endianness.
  22. func ByteOrder() binary.ByteOrder { return byteOrder }
  23. func init() {
  24. i := int(0x1)
  25. if v := (*[intWidth]byte)(unsafe.Pointer(&i)); v[0] == 0 {
  26. byteOrder = binary.BigEndian
  27. } else {
  28. byteOrder = binary.LittleEndian
  29. }
  30. }