Source: status.go in package google.golang.org/grpc/status

* * Copyright 2017 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 (
	"context"
	"fmt"

	spb "google.golang.org/genproto/googleapis/rpc/status"

	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/internal/status"
)

Status references google.golang.org/grpc/internal/status. It represents an 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

type Status = status.Status

New returns a Status representing c and msg.

func New(c codes.Code, msg string) *Status {
	return status.New(c, 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...))
}

Error returns an error representing c and msg. If c is OK, returns nil.

func Error(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 Error(c, fmt.Sprintf(format, a...))
}

ErrorProto returns an error representing s. If s.Code is OK, returns nil.

func ErrorProto(s *spb.Status) error {
	return FromProto(s).Err()
}

FromProto returns a Status representing s.

func FromProto(s *spb.Status) *Status {
	return status.FromProto(s)
}

FromError returns a Status representing err if it was produced from this package or has a method `GRPCStatus() *Status`. Otherwise, ok is false and a Status is returned with codes.Unknown and the original error message.

func FromError(err error) (s *Status, ok bool) {
	if err == nil {
		return nil, true
	}
	if se, ok := err.(interface {
		GRPCStatus() *Status
	}); ok {
		return se.GRPCStatus(), true
	}
	return New(codes.Unknown, err.Error()), false
}

Convert is a convenience function which removes the need to handle the boolean return value from FromError.

func Convert(err error) *Status {
	s, _ := FromError(err)
	return s
}

Code returns the Code of the error if it is a Status error, codes.OK if err is nil, or codes.Unknown otherwise.

Don't use FromError to avoid allocation of OK status.

	if err == nil {
		return codes.OK
	}
	if se, ok := err.(interface {
		GRPCStatus() *Status
	}); ok {
		return se.GRPCStatus().Code()
	}
	return codes.Unknown
}

FromContextError converts a context error into a Status. It returns a Status with codes.OK if err is nil, or a Status with codes.Unknown if err is non-nil and not a context error.

func FromContextError(err error) *Status {
	switch err {
	case nil:
		return nil
	case context.DeadlineExceeded:
		return New(codes.DeadlineExceeded, err.Error())
	case context.Canceled:
		return New(codes.Canceled, err.Error())
	default:
		return New(codes.Unknown, err.Error())
	}