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/*
*
* 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"
"errors"
"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 representation of err.
//
// - If err was produced by this package or implements the method `GRPCStatus()
// *Status` and `GRPCStatus()` does not return nil, or if err wraps a type
// satisfying this, the Status from `GRPCStatus()` is returned. For wrapped
// errors, the message returned contains the entire err.Error() text and not
// just the wrapped status. In that case, ok is true.
//
// - If err is nil, a Status is returned with codes.OK and no message, and ok
// is true.
//
// - If err implements the method `GRPCStatus() *Status` and `GRPCStatus()`
// returns nil (which maps to Codes.OK), or if err wraps a type
// satisfying this, a Status is returned with codes.Unknown and err's
// Error() message, and ok is false.
//
// - Otherwise, err is an error not compatible with this package. In this
// case, a Status is returned with codes.Unknown and err's Error() message,
// and ok is false.
func FromError(err error) (s *Status, ok bool) {
if err == nil {
return nil, true
}
type grpcstatus interface{ GRPCStatus() *Status }
if gs, ok := err.(grpcstatus); ok {
if gs.GRPCStatus() == nil {
// Error has status nil, which maps to codes.OK. There
// is no sensible behavior for this, so we turn it into
// an error with codes.Unknown and discard the existing
// status.
return New(codes.Unknown, err.Error()), false
}
return gs.GRPCStatus(), true
}
var gs grpcstatus
if errors.As(err, &gs) {
if gs.GRPCStatus() == nil {
// Error wraps an error that has status nil, which maps
// to codes.OK. There is no sensible behavior for this,
// so we turn it into an error with codes.Unknown and
// discard the existing status.
return New(codes.Unknown, err.Error()), false
}
p := gs.GRPCStatus().Proto()
p.Message = err.Error()
return status.FromProto(p), 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 or if it wraps a
// Status error. If that is not the case, it returns codes.OK if err is nil, or
// codes.Unknown otherwise.
func Code(err error) codes.Code {
// Don't use FromError to avoid allocation of OK status.
if err == nil {
return codes.OK
}
return Convert(err).Code()
}
// FromContextError converts a context error or wrapped 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 {
if err == nil {
return nil
}
if errors.Is(err, context.DeadlineExceeded) {
return New(codes.DeadlineExceeded, err.Error())
}
if errors.Is(err, context.Canceled) {
return New(codes.Canceled, err.Error())
}
return New(codes.Unknown, err.Error())
}
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