cubefs

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