Add stable marshal for session package

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

v2/session/marshal.go

@@ -0,0 +1,93 @@
+package session
+
+import (
+	"github.com/nspcc-dev/neofs-api-go/util/proto"
+)
+
+const (
+	createReqBodyOwnerField    = 1
+	createReqBodyLifetimeField = 2
+
+	createRespBodyIDField  = 1
+	createRespBodyKeyField = 2
+)
+
+func (c *CreateRequestBody) 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.NestedStructureMarshal(createReqBodyOwnerField, buf[offset:], c.ownerID)
+	if err != nil {
+		return nil, err
+	}
+
+	offset += n
+
+	_, err = proto.NestedStructureMarshal(createReqBodyLifetimeField, buf[offset:], c.lifetime)
+	if err != nil {
+		return nil, err
+	}
+
+	return buf, nil
+}
+
+func (c *CreateRequestBody) StableSize() (size int) {
+	if c == nil {
+		return 0
+	}
+
+	size += proto.NestedStructureSize(createReqBodyOwnerField, c.ownerID)
+	size += proto.NestedStructureSize(createReqBodyLifetimeField, c.lifetime)
+
+	return size
+}
+
+func (c *CreateResponseBody) 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.BytesMarshal(createRespBodyIDField, buf[offset:], c.id)
+	if err != nil {
+		return nil, err
+	}
+
+	offset += n
+
+	_, err = proto.BytesMarshal(createRespBodyKeyField, buf[offset:], c.sessionKey)
+	if err != nil {
+		return nil, err
+	}
+
+	return buf, nil
+}
+
+func (c *CreateResponseBody) StableSize() (size int) {
+	if c == nil {
+		return 0
+	}
+
+	size += proto.BytesSize(createRespBodyIDField, c.id)
+	size += proto.BytesSize(createRespBodyKeyField, c.sessionKey)
+
+	return size
+}

v2/session/marshal_test.go

@@ -0,0 +1,67 @@
+package session_test
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neofs-api-go/v2/refs"
+	"github.com/nspcc-dev/neofs-api-go/v2/service"
+	"github.com/nspcc-dev/neofs-api-go/v2/session"
+	grpc "github.com/nspcc-dev/neofs-api-go/v2/session/grpc"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCreateRequestBody_StableMarshal(t *testing.T) {
+	requestFrom := generateCreateSessionRequestBody("Owner ID")
+	transport := new(grpc.CreateRequest_Body)
+
+	t.Run("non empty", func(t *testing.T) {
+		wire, err := requestFrom.StableMarshal(nil)
+		require.NoError(t, err)
+
+		err = transport.Unmarshal(wire)
+		require.NoError(t, err)
+
+		requestTo := session.CreateRequestBodyFromGRPCMessage(transport)
+		require.Equal(t, requestFrom, requestTo)
+	})
+}
+
+func TestCreateResponseBody_StableMarshal(t *testing.T) {
+	responseFrom := generateCreateSessionResponseBody("ID", "Session Public Key")
+	transport := new(grpc.CreateResponse_Body)
+
+	t.Run("non empty", func(t *testing.T) {
+		wire, err := responseFrom.StableMarshal(nil)
+		require.NoError(t, err)
+
+		err = transport.Unmarshal(wire)
+		require.NoError(t, err)
+
+		responseTo := session.CreateResponseBodyFromGRPCMessage(transport)
+		require.Equal(t, responseFrom, responseTo)
+	})
+}
+
+func generateCreateSessionRequestBody(id string) *session.CreateRequestBody {
+	lifetime := new(service.TokenLifetime)
+	lifetime.SetIat(1)
+	lifetime.SetNbf(2)
+	lifetime.SetExp(3)
+
+	owner := new(refs.OwnerID)
+	owner.SetValue([]byte(id))
+
+	s := new(session.CreateRequestBody)
+	s.SetOwnerID(owner)
+	s.SetLifetime(lifetime)
+
+	return s
+}
+
+func generateCreateSessionResponseBody(id, key string) *session.CreateResponseBody {
+	s := new(session.CreateResponseBody)
+	s.SetID([]byte(id))
+	s.SetSessionKey([]byte(key))
+
+	return s
+}