gcc/libgo/go/hash/example_test.go

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// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package hash_test
import (
"bytes"
"crypto/sha256"
"encoding"
"fmt"
"log"
)
func Example_binaryMarshaler() {
const (
input1 = "The tunneling gopher digs downwards, "
input2 = "unaware of what he will find."
)
first := sha256.New()
first.Write([]byte(input1))
marshaler, ok := first.(encoding.BinaryMarshaler)
if !ok {
log.Fatal("first does not implement encoding.BinaryMarshaler")
}
state, err := marshaler.MarshalBinary()
if err != nil {
log.Fatal("unable to marshal hash:", err)
}
second := sha256.New()
unmarshaler, ok := second.(encoding.BinaryUnmarshaler)
if !ok {
log.Fatal("second does not implement encoding.BinaryUnmarshaler")
}
if err := unmarshaler.UnmarshalBinary(state); err != nil {
log.Fatal("unable to unmarshal hash:", err)
}
first.Write([]byte(input2))
second.Write([]byte(input2))
fmt.Printf("%x\n", first.Sum(nil))
fmt.Println(bytes.Equal(first.Sum(nil), second.Sum(nil)))
// Output:
// 57d51a066f3a39942649cd9a76c77e97ceab246756ff3888659e6aa5a07f4a52
// true
}