blob: 568ef5dc68baa87c9d9d23c2e96c5a010d0ca943 [file] [log] [blame]
Matthias Andreas Benkard832a54e2019-01-29 09:27:38 +01001/*
2 *
3 * Copyright 2017 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19// Package connectivity defines connectivity semantics.
20// For details, see https://github.com/grpc/grpc/blob/master/doc/connectivity-semantics-and-api.md.
21// All APIs in this package are experimental.
22package connectivity
23
24import (
25 "golang.org/x/net/context"
26 "google.golang.org/grpc/grpclog"
27)
28
29// State indicates the state of connectivity.
30// It can be the state of a ClientConn or SubConn.
31type State int
32
33func (s State) String() string {
34 switch s {
35 case Idle:
36 return "IDLE"
37 case Connecting:
38 return "CONNECTING"
39 case Ready:
40 return "READY"
41 case TransientFailure:
42 return "TRANSIENT_FAILURE"
43 case Shutdown:
44 return "SHUTDOWN"
45 default:
46 grpclog.Errorf("unknown connectivity state: %d", s)
47 return "Invalid-State"
48 }
49}
50
51const (
52 // Idle indicates the ClientConn is idle.
53 Idle State = iota
54 // Connecting indicates the ClienConn is connecting.
55 Connecting
56 // Ready indicates the ClientConn is ready for work.
57 Ready
58 // TransientFailure indicates the ClientConn has seen a failure but expects to recover.
59 TransientFailure
60 // Shutdown indicates the ClientConn has started shutting down.
61 Shutdown
62)
63
64// Reporter reports the connectivity states.
65type Reporter interface {
66 // CurrentState returns the current state of the reporter.
67 CurrentState() State
68 // WaitForStateChange blocks until the reporter's state is different from the given state,
69 // and returns true.
70 // It returns false if <-ctx.Done() can proceed (ctx got timeout or got canceled).
71 WaitForStateChange(context.Context, State) bool
72}