status: move statusError to internal/status package (#3432)

internal/internal.go

@@ -37,11 +37,6 @@ var (
 	// KeepaliveMinPingTime is the minimum ping interval.  This must be 10s by
 	// default, but tests may wish to set it lower for convenience.
 	KeepaliveMinPingTime = 10 * time.Second
-	// StatusRawProto is exported by status/status.go. This func returns a
-	// pointer to the wrapped Status proto for a given status.Status without a
-	// call to proto.Clone(). The returned Status proto should not be mutated by
-	// the caller.
-	StatusRawProto interface{} // func (*status.Status) *spb.Status
 	// NewRequestInfoContext creates a new context based on the argument context attaching
 	// the passed in RequestInfo to the new context.
 	NewRequestInfoContext interface{} // func(context.Context, credentials.RequestInfo) context.Context

internal/status/status.go

@@ -0,0 +1,166 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package status implements errors returned by gRPC.  These errors are
+// serialized and transmitted on the wire between server and client, and allow
+// for additional data to be transmitted via the Details field in the status
+// proto.  gRPC service handlers should return an error created by this
+// package, and gRPC clients should expect a corresponding error to be
+// returned from the RPC call.
+//
+// This package upholds the invariants that a non-nil error may not
+// contain an OK code, and an OK code must result in a nil error.
+package status
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes"
+	spb "google.golang.org/genproto/googleapis/rpc/status"
+	"google.golang.org/grpc/codes"
+)
+
+// Status represents an RPC status code, message, and details.  It is immutable
+// and should be created with New, Newf, or FromProto.
+type Status struct {
+	s *spb.Status
+}
+
+// New returns a Status representing c and msg.
+func New(c codes.Code, msg string) *Status {
+	return &Status{s: &spb.Status{Code: int32(c), Message: msg}}
+}
+
+// Newf returns New(c, fmt.Sprintf(format, a...)).
+func Newf(c codes.Code, format string, a ...interface{}) *Status {
+	return New(c, fmt.Sprintf(format, a...))
+}
+
+// FromProto returns a Status representing s.
+func FromProto(s *spb.Status) *Status {
+	return &Status{s: proto.Clone(s).(*spb.Status)}
+}
+
+// Err returns an error representing c and msg.  If c is OK, returns nil.
+func Err(c codes.Code, msg string) error {
+	return New(c, msg).Err()
+}
+
+// Errorf returns Error(c, fmt.Sprintf(format, a...)).
+func Errorf(c codes.Code, format string, a ...interface{}) error {
+	return Err(c, fmt.Sprintf(format, a...))
+}
+
+// Code returns the status code contained in s.
+func (s *Status) Code() codes.Code {
+	if s == nil || s.s == nil {
+		return codes.OK
+	}
+	return codes.Code(s.s.Code)
+}
+
+// Message returns the message contained in s.
+func (s *Status) Message() string {
+	if s == nil || s.s == nil {
+		return ""
+	}
+	return s.s.Message
+}
+
+// Proto returns s's status as an spb.Status proto message.
+func (s *Status) Proto() *spb.Status {
+	if s == nil {
+		return nil
+	}
+	return proto.Clone(s.s).(*spb.Status)
+}
+
+// Err returns an immutable error representing s; returns nil if s.Code() is OK.
+func (s *Status) Err() error {
+	if s.Code() == codes.OK {
+		return nil
+	}
+	return (*Error)(s.Proto())
+}
+
+func (s *Status) Error() string {
+	p := s.Proto()
+	return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage())
+}
+
+// WithDetails returns a new status with the provided details messages appended to the status.
+// If any errors are encountered, it returns nil and the first error encountered.
+func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
+	if s.Code() == codes.OK {
+		return nil, errors.New("no error details for status with code OK")
+	}
+	// s.Code() != OK implies that s.Proto() != nil.
+	p := s.Proto()
+	for _, detail := range details {
+		any, err := ptypes.MarshalAny(detail)
+		if err != nil {
+			return nil, err
+		}
+		p.Details = append(p.Details, any)
+	}
+	return &Status{s: p}, nil
+}
+
+// Details returns a slice of details messages attached to the status.
+// If a detail cannot be decoded, the error is returned in place of the detail.
+func (s *Status) Details() []interface{} {
+	if s == nil || s.s == nil {
+		return nil
+	}
+	details := make([]interface{}, 0, len(s.s.Details))
+	for _, any := range s.s.Details {
+		detail := &ptypes.DynamicAny{}
+		if err := ptypes.UnmarshalAny(any, detail); err != nil {
+			details = append(details, err)
+			continue
+		}
+		details = append(details, detail.Message)
+	}
+	return details
+}
+
+// Error is an alias of a status proto. It implements error and Status,
+// and a nil Error should never be returned by this package.
+type Error spb.Status
+
+func (se *Error) Error() string {
+	p := (*spb.Status)(se)
+	return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage())
+}
+
+// GRPCStatus returns the Status represented by se.
+func (se *Error) GRPCStatus() *Status {
+	return FromProto((*spb.Status)(se))
+}
+
+// Is implements future error.Is functionality.
+// A Error is equivalent if the code and message are identical.
+func (se *Error) Is(target error) bool {
+	tse, ok := target.(*Error)
+	if !ok {
+		return false
+	}
+	return proto.Equal((*spb.Status)(se), (*spb.Status)(tse))
+}

internal/transport/http2_server.go

@@ -35,11 +35,9 @@ import (
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
 
-	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/grpclog"
-	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/keepalive"
@@ -57,9 +55,6 @@ var (
 	// ErrHeaderListSizeLimitViolation indicates that the header list size is larger
 	// than the limit set by peer.
 	ErrHeaderListSizeLimitViolation = errors.New("transport: trying to send header list size larger than the limit set by peer")
-	// statusRawProto is a function to get to the raw status proto wrapped in a
-	// status.Status without a proto.Clone().
-	statusRawProto = internal.StatusRawProto.(func(*status.Status) *spb.Status)
 )
 
 // serverConnectionCounter counts the number of connections a server has seen
@@ -850,7 +845,7 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-status", Value: strconv.Itoa(int(st.Code()))})
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-message", Value: encodeGrpcMessage(st.Message())})
 
-	if p := statusRawProto(st); p != nil && len(p.Details) > 0 {
+	if p := st.Proto(); p != nil && len(p.Details) > 0 {
 		stBytes, err := proto.Marshal(p)
 		if err != nil {
 			// TODO: return error instead, when callers are able to handle it.

status/status.go

@@ -29,88 +29,23 @@ package status
 
 import (
 	"context"
-	"errors"
 	"fmt"
 
-	"github.com/golang/protobuf/proto"
-	"github.com/golang/protobuf/ptypes"
 	spb "google.golang.org/genproto/googleapis/rpc/status"
+
 	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/internal"
+	"google.golang.org/grpc/internal/status"
 )
 
-func init() {
+// Status references google.golang.org/grpc/internal/status. It represents an
-	internal.StatusRawProto = statusRawProto
+// RPC status code, message, and details.  It is immutable and should be
-}
+// created with New, Newf, or FromProto.
-
+// https://godoc.org/google.golang.org/grpc/internal/status
-func statusRawProto(s *Status) *spb.Status { return s.s }
+type Status = status.Status
-
-// statusError is an alias of a status proto.  It implements error and Status,
-// and a nil statusError should never be returned by this package.
-type statusError spb.Status
-
-func (se *statusError) Error() string {
-	p := (*spb.Status)(se)
-	return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage())
-}
-
-func (se *statusError) GRPCStatus() *Status {
-	return &Status{s: (*spb.Status)(se)}
-}
-
-// Is implements future error.Is functionality.
-// A statusError is equivalent if the code and message are identical.
-func (se *statusError) Is(target error) bool {
-	tse, ok := target.(*statusError)
-	if !ok {
-		return false
-	}
-
-	return proto.Equal((*spb.Status)(se), (*spb.Status)(tse))
-}
-
-// Status represents an RPC status code, message, and details.  It is immutable
-// and should be created with New, Newf, or FromProto.
-type Status struct {
-	s *spb.Status
-}
-
-// Code returns the status code contained in s.
-func (s *Status) Code() codes.Code {
-	if s == nil || s.s == nil {
-		return codes.OK
-	}
-	return codes.Code(s.s.Code)
-}
-
-// Message returns the message contained in s.
-func (s *Status) Message() string {
-	if s == nil || s.s == nil {
-		return ""
-	}
-	return s.s.Message
-}
-
-// Proto returns s's status as an spb.Status proto message.
-func (s *Status) Proto() *spb.Status {
-	if s == nil {
-		return nil
-	}
-	return proto.Clone(s.s).(*spb.Status)
-}
-
-// Err returns an immutable error representing s; returns nil if s.Code() is
-// OK.
-func (s *Status) Err() error {
-	if s.Code() == codes.OK {
-		return nil
-	}
-	return (*statusError)(s.s)
-}
 
 // New returns a Status representing c and msg.
 func New(c codes.Code, msg string) *Status {
-	return &Status{s: &spb.Status{Code: int32(c), Message: msg}}
+	return status.New(c, msg)
 }
 
 // Newf returns New(c, fmt.Sprintf(format, a...)).
@@ -135,7 +70,7 @@ func ErrorProto(s *spb.Status) error {
 
 // FromProto returns a Status representing s.
 func FromProto(s *spb.Status) *Status {
-	return &Status{s: proto.Clone(s).(*spb.Status)}
+	return status.FromProto(s)
 }
 
 // FromError returns a Status representing err if it was produced from this
@@ -160,42 +95,6 @@ func Convert(err error) *Status {
 	return s
 }
 
-// WithDetails returns a new status with the provided details messages appended to the status.
-// If any errors are encountered, it returns nil and the first error encountered.
-func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
-	if s.Code() == codes.OK {
-		return nil, errors.New("no error details for status with code OK")
-	}
-	// s.Code() != OK implies that s.Proto() != nil.
-	p := s.Proto()
-	for _, detail := range details {
-		any, err := ptypes.MarshalAny(detail)
-		if err != nil {
-			return nil, err
-		}
-		p.Details = append(p.Details, any)
-	}
-	return &Status{s: p}, nil
-}
-
-// Details returns a slice of details messages attached to the status.
-// If a detail cannot be decoded, the error is returned in place of the detail.
-func (s *Status) Details() []interface{} {
-	if s == nil || s.s == nil {
-		return nil
-	}
-	details := make([]interface{}, 0, len(s.s.Details))
-	for _, any := range s.s.Details {
-		detail := &ptypes.DynamicAny{}
-		if err := ptypes.UnmarshalAny(any, detail); err != nil {
-			details = append(details, err)
-			continue
-		}
-		details = append(details, detail.Message)
-	}
-	return details
-}
-
 // Code returns the Code of the error if it is a Status error, codes.OK if err
 // is nil, or codes.Unknown otherwise.
 func Code(err error) codes.Code {

status/status_test.go

@@ -34,6 +34,7 @@ import (
 	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/internal/grpctest"
+	"google.golang.org/grpc/internal/status"
 )
 
 type s struct {
@@ -63,7 +64,7 @@ func (s) TestErrorsWithSameParameters(t *testing.T) {
 	e1 := Errorf(codes.AlreadyExists, description)
 	e2 := Errorf(codes.AlreadyExists, description)
 	if e1 == e2 || !errEqual(e1, e2) {
-		t.Fatalf("Errors should be equivalent but unique - e1: %v, %v  e2: %p, %v", e1.(*statusError), e1, e2.(*statusError), e2)
+		t.Fatalf("Errors should be equivalent but unique - e1: %v, %v  e2: %p, %v", e1.(*status.Error), e1, e2.(*status.Error), e2)
 	}
 }
 
@@ -115,7 +116,7 @@ func (s) TestError(t *testing.T) {
 func (s) TestErrorOK(t *testing.T) {
 	err := Error(codes.OK, "foo")
 	if err != nil {
-		t.Fatalf("Error(codes.OK, _) = %p; want nil", err.(*statusError))
+		t.Fatalf("Error(codes.OK, _) = %p; want nil", err.(*status.Error))
 	}
 }
 
@@ -154,13 +155,11 @@ func (c customError) Error() string {
 }
 
 func (c customError) GRPCStatus() *Status {
-	return &Status{
+	return status.FromProto(&spb.Status{
-		s: &spb.Status{
+		Code:    int32(c.Code),
-			Code:    int32(c.Code),
+		Message: c.Message,
-			Message: c.Message,
+		Details: c.Details,
-			Details: c.Details,
+	})
-		},
-	}
 }
 
 func (s) TestFromErrorImplementsInterface(t *testing.T) {
@@ -341,10 +340,10 @@ func str(s *Status) string {
 	if s == nil {
 		return "nil"
 	}
-	if s.s == nil {
+	if s.Proto() == nil {
 		return "<Code=OK>"
 	}
-	return fmt.Sprintf("<Code=%v, Message=%q, Details=%+v>", codes.Code(s.s.GetCode()), s.s.GetMessage(), s.s.GetDetails())
+	return fmt.Sprintf("<Code=%v, Message=%q, Details=%+v>", s.Code(), s.Message(), s.Details())
 }
 
 // mustMarshalAny converts a protobuf message to an any.