aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/csharp/Grpc.HealthCheck/HealthServiceImpl.cs
blob: 3c3b9c35f138fb650a36b248a9960d6c1883e2f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
#region Copyright notice and license
// Copyright 2015, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Grpc.Core;
using Grpc.Core.Utils;
using Grpc.Health.V1Alpha;

namespace Grpc.HealthCheck
{
    /// <summary>
    /// Implementation of a simple Health service. Useful for health checking.
    /// 
    /// Registering service with a server:
    /// <code>
    /// var serviceImpl = new HealthServiceImpl();
    /// server = new Server();
    /// server.AddServiceDefinition(Grpc.Health.V1Alpha.Health.BindService(serviceImpl));
    /// </code>
    /// </summary>
    public class HealthServiceImpl : Grpc.Health.V1Alpha.Health.IHealth
    {
        private readonly object myLock = new object();
        private readonly Dictionary<Key, HealthCheckResponse.Types.ServingStatus> statusMap = 
            new Dictionary<Key, HealthCheckResponse.Types.ServingStatus>();

        /// <summary>
        /// Sets the health status for given host and service.
        /// </summary>
        /// <param name="host">The host. Cannot be null.</param>
        /// <param name="service">The service. Cannot be null.</param>
        /// <param name="status">the health status</param>
        public void SetStatus(string host, string service, HealthCheckResponse.Types.ServingStatus status)
        {
            lock (myLock)
            {
                statusMap[CreateKey(host, service)] = status;
            }
        }

        /// <summary>
        /// Clears health status for given host and service.
        /// </summary>
        /// <param name="host">The host. Cannot be null.</param>
        /// <param name="service">The service. Cannot be null.</param>
        public void ClearStatus(string host, string service)
        {
            lock (myLock)
            {
                statusMap.Remove(CreateKey(host, service));
            }
        }
        
        /// <summary>
        /// Clears statuses for all hosts and services.
        /// </summary>
        public void ClearAll()
        {
            lock (myLock)
            {
                statusMap.Clear();
            }
        }

        public Task<HealthCheckResponse> Check(HealthCheckRequest request, ServerCallContext context)
        {
            lock (myLock)
            {
                var host = request.HasHost ? request.Host : "";
                var service = request.HasService ? request.Service : "";

                HealthCheckResponse.Types.ServingStatus status;
                if (!statusMap.TryGetValue(CreateKey(host, service), out status))
                {
                    // TODO(jtattermusch): returning specific status from server handler is not supported yet.
                    throw new RpcException(new Status(StatusCode.NotFound, ""));
                }
                return Task.FromResult(HealthCheckResponse.CreateBuilder().SetStatus(status).Build());
            }
        }

        private static Key CreateKey(string host, string service)
        {
            return new Key(host, service);
        }

        private struct Key
        {
            public Key(string host, string service)
            {
                this.Host = Preconditions.CheckNotNull(host);
                this.Service = Preconditions.CheckNotNull(service);
            }

            readonly string Host;
            readonly string Service;
        }
    }
}