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// Copyright (c) 2016 Couchbase, Inc.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the
// License. You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an "AS
// IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
// express or implied. See the License for the specific language
// governing permissions and limitations under the License.
// +build !safe
package moss
import (
"reflect"
"unsafe"
)
// Uint64SliceToByteSlice gives access to []uint64 as []byte. By
// default, an efficient O(1) implementation of this function is used,
// but which requires the unsafe package. See the "safe" build tag to
// use an O(N) implementation that does not need the unsafe package.
func Uint64SliceToByteSlice(in []uint64) ([]byte, error) {
inHeader := (*reflect.SliceHeader)(unsafe.Pointer(&in))
var out []byte
outHeader := (*reflect.SliceHeader)(unsafe.Pointer(&out))
outHeader.Data = inHeader.Data
outHeader.Len = inHeader.Len * 8
outHeader.Cap = inHeader.Cap * 8
return out, nil
}
// ByteSliceToUint64Slice gives access to []byte as []uint64. By
// default, an efficient O(1) implementation of this function is used,
// but which requires the unsafe package. See the "safe" build tag to
// use an O(N) implementation that does not need the unsafe package.
func ByteSliceToUint64Slice(in []byte) ([]uint64, error) {
inHeader := (*reflect.SliceHeader)(unsafe.Pointer(&in))
var out []uint64
outHeader := (*reflect.SliceHeader)(unsafe.Pointer(&out))
outHeader.Data = inHeader.Data
outHeader.Len = inHeader.Len / 8
outHeader.Cap = outHeader.Len
return out, nil
}
// --------------------------------------------------------------
func endian() string { // See golang-nuts / how-to-tell-endian-ness-of-machine,
var x uint32 = 0x01020304
if *(*byte)(unsafe.Pointer(&x)) == 0x01 {
return "big"
}
return "little"
}
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