aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs
blob: 81522cf8fefd1a7913c6e87720ba917dd4a28015 (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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
#region Copyright notice and license

// Copyright 2015 gRPC authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Grpc.Core.Interceptors;
using Grpc.Core.Internal;
using Grpc.Core.Logging;
using Grpc.Core.Utils;

namespace Grpc.Core.Internal
{
    internal interface IServerCallHandler
    {
        Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq);
        IServerCallHandler Intercept(Interceptor interceptor);
    }

    internal class UnaryServerCallHandler<TRequest, TResponse> : IServerCallHandler
        where TRequest : class
        where TResponse : class
    {
        static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<UnaryServerCallHandler<TRequest, TResponse>>();

        readonly Method<TRequest, TResponse> method;
        readonly UnaryServerMethod<TRequest, TResponse> handler;

        public UnaryServerCallHandler(Method<TRequest, TResponse> method, UnaryServerMethod<TRequest, TResponse> handler)
        {
            this.method = method;
            this.handler = handler;
        }

        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
        {
            var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                method.ResponseMarshaller.Serializer,
                method.RequestMarshaller.Deserializer,
                newRpc.Server);

            asyncCall.Initialize(newRpc.Call, cq);
            var finishedTask = asyncCall.ServerSideCallAsync();
            var requestStream = new ServerRequestStream<TRequest, TResponse>(asyncCall);
            var responseStream = new ServerResponseStream<TRequest, TResponse>(asyncCall);

            Status status;
            AsyncCallServer<TRequest,TResponse>.ResponseWithFlags? responseWithFlags = null;
            var context = HandlerUtils.NewContext(newRpc, responseStream, asyncCall.CancellationToken);
            try
            {
                GrpcPreconditions.CheckArgument(await requestStream.MoveNext().ConfigureAwait(false));
                var request = requestStream.Current;
                var response = await handler(request, context).ConfigureAwait(false);
                status = context.Status;
                responseWithFlags = new AsyncCallServer<TRequest, TResponse>.ResponseWithFlags(response, HandlerUtils.GetWriteFlags(context.WriteOptions));
            } 
            catch (Exception e)
            {
                if (!(e is RpcException))
                {
                    Logger.Warning(e, "Exception occurred in the handler or an interceptor.");
                }
                status = HandlerUtils.GetStatusFromExceptionAndMergeTrailers(e, context.ResponseTrailers);
            }
            try
            {
                await asyncCall.SendStatusFromServerAsync(status, context.ResponseTrailers, responseWithFlags).ConfigureAwait(false);
            }
            catch (Exception)
            {
                asyncCall.Cancel();
                throw;
            }
            await finishedTask.ConfigureAwait(false);
        }

        public IServerCallHandler Intercept(Interceptor interceptor)
        {
            return new UnaryServerCallHandler<TRequest, TResponse>(method, (request, context) => interceptor.UnaryServerHandler(request, context, handler));
        }
    }

    internal class ServerStreamingServerCallHandler<TRequest, TResponse> : IServerCallHandler
        where TRequest : class
        where TResponse : class
    {
        static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<ServerStreamingServerCallHandler<TRequest, TResponse>>();

        readonly Method<TRequest, TResponse> method;
        readonly ServerStreamingServerMethod<TRequest, TResponse> handler;

        public ServerStreamingServerCallHandler(Method<TRequest, TResponse> method, ServerStreamingServerMethod<TRequest, TResponse> handler)
        {
            this.method = method;
            this.handler = handler;
        }

        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
        {
            var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                method.ResponseMarshaller.Serializer,
                method.RequestMarshaller.Deserializer,
                newRpc.Server);

            asyncCall.Initialize(newRpc.Call, cq);
            var finishedTask = asyncCall.ServerSideCallAsync();
            var requestStream = new ServerRequestStream<TRequest, TResponse>(asyncCall);
            var responseStream = new ServerResponseStream<TRequest, TResponse>(asyncCall);

            Status status;
            var context = HandlerUtils.NewContext(newRpc, responseStream, asyncCall.CancellationToken);
            try
            {
                GrpcPreconditions.CheckArgument(await requestStream.MoveNext().ConfigureAwait(false));
                var request = requestStream.Current;
                await handler(request, responseStream, context).ConfigureAwait(false);
                status = context.Status;
            }
            catch (Exception e)
            {
                if (!(e is RpcException))
                {
                    Logger.Warning(e, "Exception occurred in the handler or an interceptor.");
                }
                status = HandlerUtils.GetStatusFromExceptionAndMergeTrailers(e, context.ResponseTrailers);
            }

            try
            {
                await asyncCall.SendStatusFromServerAsync(status, context.ResponseTrailers, null).ConfigureAwait(false);
            }
            catch (Exception)
            {
                asyncCall.Cancel();
                throw;
            }
            await finishedTask.ConfigureAwait(false);
        }

        public IServerCallHandler Intercept(Interceptor interceptor)
        {
            return new ServerStreamingServerCallHandler<TRequest, TResponse>(method, (request, responseStream, context) => interceptor.ServerStreamingServerHandler(request, responseStream, context, handler));
        }
    }

    internal class ClientStreamingServerCallHandler<TRequest, TResponse> : IServerCallHandler
        where TRequest : class
        where TResponse : class
    {
        static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<ClientStreamingServerCallHandler<TRequest, TResponse>>();

        readonly Method<TRequest, TResponse> method;
        readonly ClientStreamingServerMethod<TRequest, TResponse> handler;

        public ClientStreamingServerCallHandler(Method<TRequest, TResponse> method, ClientStreamingServerMethod<TRequest, TResponse> handler)
        {
            this.method = method;
            this.handler = handler;
        }

        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
        {
            var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                method.ResponseMarshaller.Serializer,
                method.RequestMarshaller.Deserializer,
                newRpc.Server);

            asyncCall.Initialize(newRpc.Call, cq);
            var finishedTask = asyncCall.ServerSideCallAsync();
            var requestStream = new ServerRequestStream<TRequest, TResponse>(asyncCall);
            var responseStream = new ServerResponseStream<TRequest, TResponse>(asyncCall);

            Status status;
            AsyncCallServer<TRequest, TResponse>.ResponseWithFlags? responseWithFlags = null;
            var context = HandlerUtils.NewContext(newRpc, responseStream, asyncCall.CancellationToken);
            try
            {
                var response = await handler(requestStream, context).ConfigureAwait(false);
                status = context.Status;
                responseWithFlags = new AsyncCallServer<TRequest, TResponse>.ResponseWithFlags(response, HandlerUtils.GetWriteFlags(context.WriteOptions));
            }
            catch (Exception e)
            {
                if (!(e is RpcException))
                {
                    Logger.Warning(e, "Exception occurred in the handler or an interceptor.");
                }
                status = HandlerUtils.GetStatusFromExceptionAndMergeTrailers(e, context.ResponseTrailers);
            }

            try
            {
                await asyncCall.SendStatusFromServerAsync(status, context.ResponseTrailers, responseWithFlags).ConfigureAwait(false);
            }
            catch (Exception)
            {
                asyncCall.Cancel();
                throw;
            }
            await finishedTask.ConfigureAwait(false);
        }

        public IServerCallHandler Intercept(Interceptor interceptor)
        {
            return new ClientStreamingServerCallHandler<TRequest, TResponse>(method, (requestStream, context) => interceptor.ClientStreamingServerHandler(requestStream, context, handler));
        }
    }

    internal class DuplexStreamingServerCallHandler<TRequest, TResponse> : IServerCallHandler
        where TRequest : class
        where TResponse : class
    {
        static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<DuplexStreamingServerCallHandler<TRequest, TResponse>>();

        readonly Method<TRequest, TResponse> method;
        readonly DuplexStreamingServerMethod<TRequest, TResponse> handler;

        public DuplexStreamingServerCallHandler(Method<TRequest, TResponse> method, DuplexStreamingServerMethod<TRequest, TResponse> handler)
        {
            this.method = method;
            this.handler = handler;
        }

        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
        {
            var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                method.ResponseMarshaller.Serializer,
                method.RequestMarshaller.Deserializer,
                newRpc.Server);

            asyncCall.Initialize(newRpc.Call, cq);
            var finishedTask = asyncCall.ServerSideCallAsync();
            var requestStream = new ServerRequestStream<TRequest, TResponse>(asyncCall);
            var responseStream = new ServerResponseStream<TRequest, TResponse>(asyncCall);

            Status status;
            var context = HandlerUtils.NewContext(newRpc, responseStream, asyncCall.CancellationToken);
            try
            {
                await handler(requestStream, responseStream, context).ConfigureAwait(false);
                status = context.Status;
            }
            catch (Exception e)
            {
                if (!(e is RpcException))
                {
                    Logger.Warning(e, "Exception occurred in the handler or an interceptor.");
                }
                status = HandlerUtils.GetStatusFromExceptionAndMergeTrailers(e, context.ResponseTrailers);
            }
            try
            {
                await asyncCall.SendStatusFromServerAsync(status, context.ResponseTrailers, null).ConfigureAwait(false);
            }
            catch (Exception)
            {
                asyncCall.Cancel();
                throw;
            }
            await finishedTask.ConfigureAwait(false);
        }

        public IServerCallHandler Intercept(Interceptor interceptor)
        {
            return new DuplexStreamingServerCallHandler<TRequest, TResponse>(method, (requestStream, responseStream, context) => interceptor.DuplexStreamingServerHandler(requestStream, responseStream, context, handler));
        }
    }

    internal class UnimplementedMethodCallHandler : IServerCallHandler
    {
        public static readonly UnimplementedMethodCallHandler Instance = new UnimplementedMethodCallHandler();

        DuplexStreamingServerCallHandler<byte[], byte[]> callHandlerImpl;

        public UnimplementedMethodCallHandler()
        {
            var marshaller = new Marshaller<byte[]>((payload) => payload, (payload) => payload);
            var method = new Method<byte[], byte[]>(MethodType.DuplexStreaming, "", "", marshaller, marshaller);
            this.callHandlerImpl = new DuplexStreamingServerCallHandler<byte[], byte[]>(method, new DuplexStreamingServerMethod<byte[], byte[]>(UnimplementedMethod));
        }

        /// <summary>
        /// Handler used for unimplemented method.
        /// </summary>
        private Task UnimplementedMethod(IAsyncStreamReader<byte[]> requestStream, IServerStreamWriter<byte[]> responseStream, ServerCallContext ctx)
        {
            ctx.Status = new Status(StatusCode.Unimplemented, "");
            return TaskUtils.CompletedTask;
        }

        public Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
        {
            return callHandlerImpl.HandleCall(newRpc, cq);
        }

        public IServerCallHandler Intercept(Interceptor interceptor)
        {
            return this;  // Do not intercept unimplemented methods.
        }
    }

    internal static class HandlerUtils
    {
        public static Status GetStatusFromExceptionAndMergeTrailers(Exception e, Metadata callContextResponseTrailers)
        {
            var rpcException = e as RpcException;
            if (rpcException != null)
            {
                // There are two sources of metadata entries on the server-side:
                // 1. serverCallContext.ResponseTrailers
                // 2. trailers in RpcException thrown by user code in server side handler.
                // As metadata allows duplicate keys, the logical thing to do is
                // to just merge trailers from RpcException into serverCallContext.ResponseTrailers.
                foreach (var entry in rpcException.Trailers)
                {
                    callContextResponseTrailers.Add(entry);
                }
                // use the status thrown by handler.
                return rpcException.Status;
            }

            return new Status(StatusCode.Unknown, "Exception was thrown by handler.");
        }

        public static WriteFlags GetWriteFlags(WriteOptions writeOptions)
        {
            return writeOptions != null ? writeOptions.Flags : default(WriteFlags);
        }

        public static ServerCallContext NewContext<TRequest, TResponse>(ServerRpcNew newRpc, ServerResponseStream<TRequest, TResponse> serverResponseStream, CancellationToken cancellationToken)
            where TRequest : class
            where TResponse : class
        {
            DateTime realtimeDeadline = newRpc.Deadline.ToClockType(ClockType.Realtime).ToDateTime();

            return new ServerCallContext(newRpc.Call, newRpc.Method, newRpc.Host, realtimeDeadline,
                newRpc.RequestMetadata, cancellationToken, serverResponseStream.WriteResponseHeadersAsync, serverResponseStream);
        }
    }
}