1 #region Copyright notice and license
2 // Copyright 2015 gRPC authors.
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 //     http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 #endregion
16 
17 using System;
18 using System.Collections.Generic;
19 using System.Linq;
20 using System.Text;
21 using System.Threading.Tasks;
22 
23 using Grpc.Core;
24 using Grpc.Core.Utils;
25 using Grpc.Health.V1;
26 
27 namespace Grpc.HealthCheck
28 {
29     /// <summary>
30     /// Implementation of a simple Health service. Useful for health checking.
31     ///
32     /// Registering service with a server:
33     /// <code>
34     /// var serviceImpl = new HealthServiceImpl();
35     /// server = new Server();
36     /// server.AddServiceDefinition(Grpc.Health.V1.Health.BindService(serviceImpl));
37     /// </code>
38     /// </summary>
39     public class HealthServiceImpl : Grpc.Health.V1.Health.HealthBase
40     {
41         private readonly object myLock = new object();
42         private readonly Dictionary<string, HealthCheckResponse.Types.ServingStatus> statusMap =
43             new Dictionary<string, HealthCheckResponse.Types.ServingStatus>();
44 
45         /// <summary>
46         /// Sets the health status for given service.
47         /// </summary>
48         /// <param name="service">The service. Cannot be null.</param>
49         /// <param name="status">the health status</param>
SetStatus(string service, HealthCheckResponse.Types.ServingStatus status)50         public void SetStatus(string service, HealthCheckResponse.Types.ServingStatus status)
51         {
52             lock (myLock)
53             {
54                 statusMap[service] = status;
55             }
56         }
57 
58         /// <summary>
59         /// Clears health status for given service.
60         /// </summary>
61         /// <param name="service">The service. Cannot be null.</param>
ClearStatus(string service)62         public void ClearStatus(string service)
63         {
64             lock (myLock)
65             {
66                 statusMap.Remove(service);
67             }
68         }
69 
70         /// <summary>
71         /// Clears statuses for all services.
72         /// </summary>
ClearAll()73         public void ClearAll()
74         {
75             lock (myLock)
76             {
77                 statusMap.Clear();
78             }
79         }
80 
81         /// <summary>
82         /// Performs a health status check.
83         /// </summary>
84         /// <param name="request">The check request.</param>
85         /// <param name="context">The call context.</param>
86         /// <returns>The asynchronous response.</returns>
Check(HealthCheckRequest request, ServerCallContext context)87         public override Task<HealthCheckResponse> Check(HealthCheckRequest request, ServerCallContext context)
88         {
89             lock (myLock)
90             {
91                 var service = request.Service;
92 
93                 HealthCheckResponse.Types.ServingStatus status;
94                 if (!statusMap.TryGetValue(service, out status))
95                 {
96                     // TODO(jtattermusch): returning specific status from server handler is not supported yet.
97                     throw new RpcException(new Status(StatusCode.NotFound, ""));
98                 }
99                 return Task.FromResult(new HealthCheckResponse { Status = status });
100             }
101         }
102     }
103 }
104