Add unified checksum type in refs package

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

v2/refs/convert.go

@@ -111,3 +111,31 @@ func AddressFromGRPCMessage(m *refs.Address) *Address {
 
 	return a
 }
+
+func ChecksumToGRPCMessage(c *Checksum) *refs.Checksum {
+	if c == nil {
+		return nil
+	}
+
+	m := new(refs.Checksum)
+
+	m.SetChecksumType(refs.ChecksumType(c.GetType()))
+
+	m.SetSum(c.GetSum())
+
+	return m
+}
+
+func ChecksumFromGRPCMessage(m *refs.Checksum) *Checksum {
+	if m == nil {
+		return nil
+	}
+
+	c := new(Checksum)
+
+	c.SetType(ChecksumType(m.GetType()))
+
+	c.SetSum(m.GetSum())
+
+	return c
+}

v2/refs/grpc/types.go

@@ -34,3 +34,17 @@ func (m *Address) SetObjectId(v *ObjectID) {
 		m.ObjectId = v
 	}
 }
+
+// SetChecksumType in generic checksum structure.
+func (m *Checksum) SetChecksumType(v ChecksumType) {
+	if m != nil {
+		m.Type = v
+	}
+}
+
+// SetChecksumSum in generic checksum structure.
+func (m *Checksum) SetSum(v []byte) {
+	if m != nil {
+		m.Sum = v
+	}
+}

v2/refs/marshal.go

@@ -13,6 +13,9 @@ const (
 
 	addressContainerField = 1
 	addressObjectField    = 2
+
+	checksumTypeField  = 1
+	checksumValueField = 2
 )
 
 func (o *OwnerID) StableMarshal(buf []byte) ([]byte, error) {
@@ -130,3 +133,43 @@ func (a *Address) StableSize() (size int) {
 
 	return size
 }
+
+func (c *Checksum) StableMarshal(buf []byte) ([]byte, error) {
+	if c == nil {
+		return []byte{}, nil
+	}
+
+	if buf == nil {
+		buf = make([]byte, c.StableSize())
+	}
+
+	var (
+		offset, n int
+		err       error
+	)
+
+	n, err = proto.EnumMarshal(checksumTypeField, buf[offset:], int32(c.typ))
+	if err != nil {
+		return nil, err
+	}
+
+	offset += n
+
+	_, err = proto.BytesMarshal(checksumValueField, buf[offset:], c.sum)
+	if err != nil {
+		return nil, err
+	}
+
+	return buf, nil
+}
+
+func (c *Checksum) StableSize() (size int) {
+	if c == nil {
+		return 0
+	}
+
+	size += proto.EnumSize(checksumTypeField, int32(c.typ))
+	size += proto.BytesSize(checksumValueField, c.sum)
+
+	return size
+}

v2/refs/marshal_test.go

@@ -87,3 +87,22 @@ func TestAddress_StableMarshal(t *testing.T) {
 		require.Equal(t, addressFrom, addressTo)
 	})
 }
+
+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)
+		checksumFrom.SetSum([]byte("Homomorphic Hash"))
+
+		wire, err := checksumFrom.StableMarshal(nil)
+		require.NoError(t, err)
+
+		err = transport.Unmarshal(wire)
+		require.NoError(t, err)
+
+		checksumTo := refs.ChecksumFromGRPCMessage(transport)
+		require.Equal(t, checksumFrom, checksumTo)
+	})
+}

v2/refs/types.go

@@ -18,6 +18,20 @@ type Address struct {
 	oid *ObjectID
 }
 
+type Checksum struct {
+	typ ChecksumType
+
+	sum []byte
+}
+
+type ChecksumType uint32
+
+const (
+	UnknownChecksum ChecksumType = iota
+	TillichZemor
+	SHA256
+)
+
 func (o *OwnerID) GetValue() []byte {
 	if o != nil {
 		return o.val
@@ -87,3 +101,31 @@ func (a *Address) SetObjectID(v *ObjectID) {
 		a.oid = v
 	}
 }
+
+func (c *Checksum) GetType() ChecksumType {
+	if c != nil {
+		return c.typ
+	}
+
+	return UnknownChecksum
+}
+
+func (c *Checksum) SetType(v ChecksumType) {
+	if c != nil {
+		c.typ = v
+	}
+}
+
+func (c *Checksum) GetSum() []byte {
+	if c != nil {
+		return c.sum
+	}
+
+	return nil
+}
+
+func (c *Checksum) SetSum(v []byte) {
+	if c != nil {
+		c.sum = v
+	}
+}