go.etcd.io/etcd@v3.3.27+incompatible/pkg/cpuutil/endian.go (about)

     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  
    15  package cpuutil
    16  
    17  import (
    18  	"encoding/binary"
    19  	"unsafe"
    20  )
    21  
    22  const intWidth int = int(unsafe.Sizeof(0))
    23  
    24  var byteOrder binary.ByteOrder
    25  
    26  // ByteOrder returns the byte order for the CPU's native endianness.
    27  func ByteOrder() binary.ByteOrder { return byteOrder }
    28  
    29  func init() {
    30  	i := int(0x1)
    31  	if v := (*[intWidth]byte)(unsafe.Pointer(&i)); v[0] == 0 {
    32  		byteOrder = binary.BigEndian
    33  	} else {
    34  		byteOrder = binary.LittleEndian
    35  	}
    36  }