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Scott Baker2d897982019-09-24 11:50:08 -07001/*
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 "context"
26
27 "google.golang.org/grpc/grpclog"
28)
29
30// State indicates the state of connectivity.
31// It can be the state of a ClientConn or SubConn.
32type State int
33
34func (s State) String() string {
35 switch s {
36 case Idle:
37 return "IDLE"
38 case Connecting:
39 return "CONNECTING"
40 case Ready:
41 return "READY"
42 case TransientFailure:
43 return "TRANSIENT_FAILURE"
44 case Shutdown:
45 return "SHUTDOWN"
46 default:
47 grpclog.Errorf("unknown connectivity state: %d", s)
48 return "Invalid-State"
49 }
50}
51
52const (
53 // Idle indicates the ClientConn is idle.
54 Idle State = iota
55 // Connecting indicates the ClientConn is connecting.
56 Connecting
57 // Ready indicates the ClientConn is ready for work.
58 Ready
59 // TransientFailure indicates the ClientConn has seen a failure but expects to recover.
60 TransientFailure
61 // Shutdown indicates the ClientConn has started shutting down.
62 Shutdown
63)
64
65// Reporter reports the connectivity states.
66type Reporter interface {
67 // CurrentState returns the current state of the reporter.
68 CurrentState() State
69 // WaitForStateChange blocks until the reporter's state is different from the given state,
70 // and returns true.
71 // It returns false if <-ctx.Done() can proceed (ctx got timeout or got canceled).
72 WaitForStateChange(context.Context, State) bool
73}