unsafe.go

// Copyright (c) 2021 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package wire

import (
	"reflect"
	"unsafe"
)

// unsafeStringToBytes converts a string into a byte slice without allocating
// new memory for it with the assumption that the resulting byte slice will not
// be mutated.
func unsafeStringToBytes(s string) []byte {
	sh := (*reflect.StringHeader)(unsafe.Pointer(&s))
	sliceHeader := reflect.SliceHeader{
		Data: sh.Data,
		Len:  sh.Len,
		Cap:  sh.Len,
	}
	return *(*[]byte)(unsafe.Pointer(&sliceHeader))
}

// unsafeBytesToString converts a byte slice into a string without allocating
// new memory with the assumption that the source byte slice will not be mutated
// after this.
func unsafeBytesToString(b []byte) string {
	return *(*string)(unsafe.Pointer(&b))
}