[#168] refs: Implement binary/JSON encoders/decoders on Checksum

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/checksum.go

@@ -77,3 +77,35 @@ func (c *Checksum) ToV2() *refs.Checksum {
 func EqualChecksums(cs1, cs2 *Checksum) bool {
 	return cs1.GetType() == cs2.GetType() && bytes.Equal(cs1.GetSum(), cs2.GetSum())
 }
+
+// Marshal marshals Checksum into a protobuf binary form.
+//
+// Buffer is allocated when the argument is empty.
+// Otherwise, the first buffer is used.
+func (c *Checksum) Marshal(b ...[]byte) ([]byte, error) {
+	var buf []byte
+	if len(b) > 0 {
+		buf = b[0]
+	}
+
+	return (*refs.Checksum)(c).
+		StableMarshal(buf)
+}
+
+// Unmarshal unmarshals protobuf binary representation of Checksum.
+func (c *Checksum) Unmarshal(data []byte) error {
+	return (*refs.Checksum)(c).
+		Unmarshal(data)
+}
+
+// MarshalJSON encodes Checksum to protobuf JSON format.
+func (c *Checksum) MarshalJSON() ([]byte, error) {
+	return (*refs.Checksum)(c).
+		MarshalJSON()
+}
+
+// UnmarshalJSON decodes Checksum from protobuf JSON format.
+func (c *Checksum) UnmarshalJSON(data []byte) error {
+	return (*refs.Checksum)(c).
+		UnmarshalJSON(data)
+}

pkg/checksum_test.go

@@ -9,6 +9,14 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func randSHA256(t *testing.T) [sha256.Size]byte {
+	cSHA256 := [sha256.Size]byte{}
+	_, err := rand.Read(cSHA256[:])
+	require.NoError(t, err)
+
+	return cSHA256
+}
+
 func TestChecksum(t *testing.T) {
 	c := NewChecksum()
 
@@ -58,3 +66,28 @@ func TestEqualChecksums(t *testing.T) {
 
 	require.False(t, EqualChecksums(cs1, cs2))
 }
+
+func TestChecksumEncoding(t *testing.T) {
+	cs := NewChecksum()
+	cs.SetSHA256(randSHA256(t))
+
+	t.Run("binary", func(t *testing.T) {
+		data, err := cs.Marshal()
+		require.NoError(t, err)
+
+		c2 := NewChecksum()
+		require.NoError(t, c2.Unmarshal(data))
+
+		require.Equal(t, cs, c2)
+	})
+
+	t.Run("json", func(t *testing.T) {
+		data, err := cs.MarshalJSON()
+		require.NoError(t, err)
+
+		cs2 := NewChecksum()
+		require.NoError(t, cs2.UnmarshalJSON(data))
+
+		require.Equal(t, cs, cs2)
+	})
+}

v2/refs/json.go

@@ -124,3 +124,23 @@ func (s *Signature) UnmarshalJSON(data []byte) error {
 
 	return nil
 }
+
+func (c *Checksum) MarshalJSON() ([]byte, error) {
+	return protojson.MarshalOptions{
+		EmitUnpopulated: true,
+	}.Marshal(
+		ChecksumToGRPCMessage(c),
+	)
+}
+
+func (c *Checksum) UnmarshalJSON(data []byte) error {
+	msg := new(refs.Checksum)
+
+	if err := protojson.Unmarshal(data, msg); err != nil {
+		return err
+	}
+
+	*c = *ChecksumFromGRPCMessage(msg)
+
+	return nil
+}

v2/refs/json_test.go

@@ -81,3 +81,17 @@ func TestSignatureSON(t *testing.T) {
 
 	require.Equal(t, s, s2)
 }
+
+func TestChecksumJSON(t *testing.T) {
+	cs := new(refs.Checksum)
+	cs.SetType(refs.SHA256)
+	cs.SetSum([]byte{1, 2, 3})
+
+	data, err := cs.MarshalJSON()
+	require.NoError(t, err)
+
+	cs2 := new(refs.Checksum)
+	require.NoError(t, cs2.UnmarshalJSON(data))
+
+	require.Equal(t, cs, cs2)
+}

v2/refs/marshal.go

@@ -226,6 +226,17 @@ func (c *Checksum) StableSize() (size int) {
 	return size
 }
 
+func (c *Checksum) Unmarshal(data []byte) error {
+	m := new(refs.Checksum)
+	if err := goproto.Unmarshal(data, m); err != nil {
+		return err
+	}
+
+	*c = *ChecksumFromGRPCMessage(m)
+
+	return nil
+}
+
 func (s *Signature) StableMarshal(buf []byte) ([]byte, error) {
 	if s == nil {
 		return []byte{}, nil

v2/refs/marshal_test.go

@@ -4,9 +4,7 @@ import (
 	"testing"
 
 	"github.com/nspcc-dev/neofs-api-go/v2/refs"
-	grpc "github.com/nspcc-dev/neofs-api-go/v2/refs/grpc"
 	"github.com/stretchr/testify/require"
-	goproto "google.golang.org/protobuf/proto"
 )
 
 func TestOwnerID_StableMarshal(t *testing.T) {
@@ -76,7 +74,6 @@ func TestAddress_StableMarshal(t *testing.T) {
 
 func TestChecksum_StableMarshal(t *testing.T) {
 	checksumFrom := new(refs.Checksum)
-	transport := new(grpc.Checksum)
 
 	t.Run("non empty", func(t *testing.T) {
 		checksumFrom.SetType(refs.TillichZemor)
@@ -85,10 +82,9 @@ func TestChecksum_StableMarshal(t *testing.T) {
 		wire, err := checksumFrom.StableMarshal(nil)
 		require.NoError(t, err)
 
-		err = goproto.Unmarshal(wire, transport)
-		require.NoError(t, err)
+		checksumTo := new(refs.Checksum)
+		require.NoError(t, checksumTo.Unmarshal(wire))
 
-		checksumTo := refs.ChecksumFromGRPCMessage(transport)
 		require.Equal(t, checksumFrom, checksumTo)
 	})
 }