service: transfer TTL code to a separate file

service/meta.go

@@ -1,11 +1,5 @@
 package service
 
-import (
-	"github.com/pkg/errors"
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
-)
-
 type (
 	// MetaHeader contains meta information of request.
 	// It provides methods to get or set meta information meta header.
@@ -15,9 +9,8 @@ type (
 		ResetMeta() RequestMetaHeader
 		RestoreMeta(RequestMetaHeader)
 
-		// TTLRequest to verify and update ttl requests.
+		// TTLHeader allows to get and set TTL value of request.
-		GetTTL() uint32
+		TTLHeader
-		SetTTL(uint32)
 
 		// EpochHeader gives possibility to get or set epoch in RPC Requests.
 		EpochHeader
@@ -46,20 +39,6 @@ type (
 		GetRaw() bool
 		SetRaw(bool)
 	}
-
-	// TTLCondition is closure, that allows to validate request with ttl.
-	TTLCondition func(ttl uint32) error
-)
-
-const (
-	// ZeroTTL is empty ttl, should produce ErrZeroTTL.
-	ZeroTTL = iota
-
-	// NonForwardingTTL is a ttl that allows direct connections only.
-	NonForwardingTTL
-
-	// SingleForwardingTTL is a ttl that allows connections through another node.
-	SingleForwardingTTL
 )
 
 // SetVersion sets protocol version to ResponseMetaHeader.
@@ -71,9 +50,6 @@ func (m *ResponseMetaHeader) SetEpoch(v uint64) { m.Epoch = v }
 // SetVersion sets protocol version to RequestMetaHeader.
 func (m *RequestMetaHeader) SetVersion(v uint32) { m.Version = v }
 
-// SetTTL sets TTL to RequestMetaHeader.
-func (m *RequestMetaHeader) SetTTL(v uint32) { m.TTL = v }
-
 // SetEpoch sets Epoch to RequestMetaHeader.
 func (m *RequestMetaHeader) SetEpoch(v uint64) { m.Epoch = v }
 
@@ -91,42 +67,3 @@ func (m *RequestMetaHeader) ResetMeta() RequestMetaHeader {
 
 // RestoreMeta sets current RequestMetaHeader to passed value.
 func (m *RequestMetaHeader) RestoreMeta(v RequestMetaHeader) { *m = v }
-
-// IRNonForwarding condition that allows NonForwardingTTL only for IR
-func IRNonForwarding(role NodeRole) TTLCondition {
-	return func(ttl uint32) error {
-		if ttl == NonForwardingTTL && role != InnerRingNode {
-			return ErrInvalidTTL
-		}
-
-		return nil
-	}
-}
-
-// ProcessRequestTTL validates and update ttl requests.
-func ProcessRequestTTL(req MetaHeader, cond ...TTLCondition) error {
-	ttl := req.GetTTL()
-
-	if ttl == ZeroTTL {
-		return status.New(codes.InvalidArgument, ErrInvalidTTL.Error()).Err()
-	}
-
-	for i := range cond {
-		if cond[i] == nil {
-			continue
-		}
-
-		// check specific condition:
-		if err := cond[i](ttl); err != nil {
-			if st, ok := status.FromError(errors.Cause(err)); ok {
-				return st.Err()
-			}
-
-			return status.New(codes.InvalidArgument, err.Error()).Err()
-		}
-	}
-
-	req.SetTTL(ttl - 1)
-
-	return nil
-}

service/meta_test.go

@@ -3,92 +3,9 @@ package service
 import (
 	"testing"
 
-	"github.com/pkg/errors"
 	"github.com/stretchr/testify/require"
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
 )
 
-type mockedRequest struct {
-	msg     string
-	name    string
-	code    codes.Code
-	handler TTLCondition
-	RequestMetaHeader
-}
-
-func TestMetaRequest(t *testing.T) {
-	tests := []mockedRequest{
-		{
-			name:              "direct to ir node",
-			handler:           IRNonForwarding(InnerRingNode),
-			RequestMetaHeader: RequestMetaHeader{TTL: NonForwardingTTL},
-		},
-		{
-			code:              codes.InvalidArgument,
-			msg:               ErrInvalidTTL.Error(),
-			name:              "direct to storage node",
-			handler:           IRNonForwarding(StorageNode),
-			RequestMetaHeader: RequestMetaHeader{TTL: NonForwardingTTL},
-		},
-		{
-			msg:               ErrInvalidTTL.Error(),
-			code:              codes.InvalidArgument,
-			name:              "zero ttl",
-			handler:           IRNonForwarding(StorageNode),
-			RequestMetaHeader: RequestMetaHeader{TTL: ZeroTTL},
-		},
-		{
-			name:              "default to ir node",
-			handler:           IRNonForwarding(InnerRingNode),
-			RequestMetaHeader: RequestMetaHeader{TTL: SingleForwardingTTL},
-		},
-		{
-			name:              "default to storage node",
-			handler:           IRNonForwarding(StorageNode),
-			RequestMetaHeader: RequestMetaHeader{TTL: SingleForwardingTTL},
-		},
-		{
-			msg:               "not found",
-			code:              codes.NotFound,
-			name:              "custom status error",
-			RequestMetaHeader: RequestMetaHeader{TTL: SingleForwardingTTL},
-			handler:           func(_ uint32) error { return status.Error(codes.NotFound, "not found") },
-		},
-		{
-			msg:               "not found",
-			code:              codes.NotFound,
-			name:              "custom wrapped status error",
-			RequestMetaHeader: RequestMetaHeader{TTL: SingleForwardingTTL},
-			handler: func(_ uint32) error {
-				err := status.Error(codes.NotFound, "not found")
-				err = errors.Wrap(err, "some error context")
-				err = errors.Wrap(err, "another error context")
-				return err
-			},
-		},
-	}
-
-	for i := range tests {
-		tt := tests[i]
-		t.Run(tt.name, func(t *testing.T) {
-			before := tt.GetTTL()
-			err := ProcessRequestTTL(&tt, tt.handler)
-			if tt.msg != "" {
-				require.Errorf(t, err, tt.msg)
-
-				state, ok := status.FromError(err)
-				require.True(t, ok)
-				require.Equal(t, tt.code, state.Code())
-				require.Equal(t, tt.msg, state.Message())
-			} else {
-				require.NoError(t, err)
-				require.NotEqualf(t, before, tt.GetTTL(), "ttl should be changed: %d vs %d", before, tt.GetTTL())
-			}
-		})
-	}
-}
-
 func TestRequestMetaHeader_SetEpoch(t *testing.T) {
 	m := new(ResponseMetaHeader)
 	epoch := uint64(3)

service/ttl.go

@@ -0,0 +1,73 @@
+package service
+
+import (
+	"github.com/pkg/errors"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+// TTLHeader is an interface of the container of a numerical TTL value.
+type TTLHeader interface {
+	GetTTL() uint32
+	SetTTL(uint32)
+}
+
+// TTLCondition is a function type that used to verify that TTL value match a specific criterion.
+// Nil error indicates compliance with the criterion.
+type TTLCondition func(ttl uint32) error
+
+// TTL constants.
+const (
+	// ZeroTTL is an upper bound of invalid TTL values.
+	ZeroTTL = iota
+
+	// NonForwardingTTL is a TTL value that does not imply a request forwarding.
+	NonForwardingTTL
+
+	// SingleForwardingTTL is a TTL value that imply potential forwarding with NonForwardingTTL.
+	SingleForwardingTTL
+)
+
+// SetTTL is a TTL field setter.
+func (m *RequestMetaHeader) SetTTL(v uint32) {
+	m.TTL = v
+}
+
+// IRNonForwarding condition that allows NonForwardingTTL only for IR.
+func IRNonForwarding(role NodeRole) TTLCondition {
+	return func(ttl uint32) error {
+		if ttl == NonForwardingTTL && role != InnerRingNode {
+			return ErrInvalidTTL
+		}
+
+		return nil
+	}
+}
+
+// ProcessRequestTTL validates and updates requests with TTL.
+func ProcessRequestTTL(req TTLHeader, cond ...TTLCondition) error {
+	ttl := req.GetTTL()
+
+	if ttl == ZeroTTL {
+		return status.New(codes.InvalidArgument, ErrInvalidTTL.Error()).Err()
+	}
+
+	for i := range cond {
+		if cond[i] == nil {
+			continue
+		}
+
+		// check specific condition:
+		if err := cond[i](ttl); err != nil {
+			if st, ok := status.FromError(errors.Cause(err)); ok {
+				return st.Err()
+			}
+
+			return status.New(codes.InvalidArgument, err.Error()).Err()
+		}
+	}
+
+	req.SetTTL(ttl - 1)
+
+	return nil
+}

service/ttl_test.go

@@ -0,0 +1,99 @@
+package service
+
+import (
+	"testing"
+
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+type mockedRequest struct {
+	msg     string
+	name    string
+	code    codes.Code
+	handler TTLCondition
+	RequestMetaHeader
+}
+
+func TestMetaRequest(t *testing.T) {
+	tests := []mockedRequest{
+		{
+			name:              "direct to ir node",
+			handler:           IRNonForwarding(InnerRingNode),
+			RequestMetaHeader: RequestMetaHeader{TTL: NonForwardingTTL},
+		},
+		{
+			code:              codes.InvalidArgument,
+			msg:               ErrInvalidTTL.Error(),
+			name:              "direct to storage node",
+			handler:           IRNonForwarding(StorageNode),
+			RequestMetaHeader: RequestMetaHeader{TTL: NonForwardingTTL},
+		},
+		{
+			msg:               ErrInvalidTTL.Error(),
+			code:              codes.InvalidArgument,
+			name:              "zero ttl",
+			handler:           IRNonForwarding(StorageNode),
+			RequestMetaHeader: RequestMetaHeader{TTL: ZeroTTL},
+		},
+		{
+			name:              "default to ir node",
+			handler:           IRNonForwarding(InnerRingNode),
+			RequestMetaHeader: RequestMetaHeader{TTL: SingleForwardingTTL},
+		},
+		{
+			name:              "default to storage node",
+			handler:           IRNonForwarding(StorageNode),
+			RequestMetaHeader: RequestMetaHeader{TTL: SingleForwardingTTL},
+		},
+		{
+			msg:               "not found",
+			code:              codes.NotFound,
+			name:              "custom status error",
+			RequestMetaHeader: RequestMetaHeader{TTL: SingleForwardingTTL},
+			handler:           func(_ uint32) error { return status.Error(codes.NotFound, "not found") },
+		},
+		{
+			msg:               "not found",
+			code:              codes.NotFound,
+			name:              "custom wrapped status error",
+			RequestMetaHeader: RequestMetaHeader{TTL: SingleForwardingTTL},
+			handler: func(_ uint32) error {
+				err := status.Error(codes.NotFound, "not found")
+				err = errors.Wrap(err, "some error context")
+				err = errors.Wrap(err, "another error context")
+				return err
+			},
+		},
+	}
+
+	for i := range tests {
+		tt := tests[i]
+		t.Run(tt.name, func(t *testing.T) {
+			before := tt.GetTTL()
+			err := ProcessRequestTTL(&tt, tt.handler)
+			if tt.msg != "" {
+				require.Errorf(t, err, tt.msg)
+
+				state, ok := status.FromError(err)
+				require.True(t, ok)
+				require.Equal(t, tt.code, state.Code())
+				require.Equal(t, tt.msg, state.Message())
+			} else {
+				require.NoError(t, err)
+				require.NotEqualf(t, before, tt.GetTTL(), "ttl should be changed: %d vs %d", before, tt.GetTTL())
+			}
+		})
+	}
+}
+
+func TestRequestMetaHeader_SetTTL(t *testing.T) {
+	m := new(RequestMetaHeader)
+	ttl := uint32(3)
+
+	m.SetTTL(ttl)
+
+	require.Equal(t, ttl, m.GetTTL())
+}