aboutsummaryrefslogtreecommitdiffhomepage
path: root/include/grpc++/impl/codegen/client_context.h
blob: 52018086007ec51b0201c5db7d99f4c2ec999f8f (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
/*
 *
 * 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.
 *
 */

/// A ClientContext allows the person implementing a service client to:
///
/// - Add custom metadata key-value pairs that will propagated to the server
/// side.
/// - Control call settings such as compression and authentication.
/// - Initial and trailing metadata coming from the server.
/// - Get performance metrics (ie, census).
///
/// Context settings are only relevant to the call they are invoked with, that
/// is to say, they aren't sticky. Some of these settings, such as the
/// compression options, can be made persistant at channel construction time
/// (see \a grpc::CreateCustomChannel).
///
/// \warning ClientContext instances should \em not be reused across rpcs.

#ifndef GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H
#define GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H

#include <map>
#include <memory>
#include <string>

#include <grpc++/impl/codegen/config.h>
#include <grpc++/impl/codegen/core_codegen_interface.h>
#include <grpc++/impl/codegen/security/auth_context.h>
#include <grpc++/impl/codegen/status.h>
#include <grpc++/impl/codegen/string_ref.h>
#include <grpc++/impl/codegen/sync.h>
#include <grpc++/impl/codegen/time.h>
#include <grpc/impl/codegen/compression_types.h>
#include <grpc/impl/codegen/log.h>
#include <grpc/impl/codegen/propagation_bits.h>
#include <grpc/impl/codegen/time.h>

struct census_context;
struct grpc_call;

namespace grpc {

class Channel;
class ChannelInterface;
class CompletionQueue;
class CallCredentials;
class RpcMethod;
template <class R>
class ClientReader;
template <class W>
class ClientWriter;
template <class W, class R>
class ClientReaderWriter;
template <class R>
class ClientAsyncReader;
template <class W>
class ClientAsyncWriter;
template <class W, class R>
class ClientAsyncReaderWriter;
template <class R>
class ClientAsyncResponseReader;
class ServerContext;

/// Options for \a ClientContext::FromServerContext specifying which traits from
/// the \a ServerContext to propagate (copy) from it into a new \a
/// ClientContext.
///
/// \see ClientContext::FromServerContext
class PropagationOptions {
 public:
  PropagationOptions() : propagate_(GRPC_PROPAGATE_DEFAULTS) {}

  PropagationOptions& enable_deadline_propagation() {
    propagate_ |= GRPC_PROPAGATE_DEADLINE;
    return *this;
  }

  PropagationOptions& disable_deadline_propagation() {
    propagate_ &= ~GRPC_PROPAGATE_DEADLINE;
    return *this;
  }

  PropagationOptions& enable_census_stats_propagation() {
    propagate_ |= GRPC_PROPAGATE_CENSUS_STATS_CONTEXT;
    return *this;
  }

  PropagationOptions& disable_census_stats_propagation() {
    propagate_ &= ~GRPC_PROPAGATE_CENSUS_STATS_CONTEXT;
    return *this;
  }

  PropagationOptions& enable_census_tracing_propagation() {
    propagate_ |= GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT;
    return *this;
  }

  PropagationOptions& disable_census_tracing_propagation() {
    propagate_ &= ~GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT;
    return *this;
  }

  PropagationOptions& enable_cancellation_propagation() {
    propagate_ |= GRPC_PROPAGATE_CANCELLATION;
    return *this;
  }

  PropagationOptions& disable_cancellation_propagation() {
    propagate_ &= ~GRPC_PROPAGATE_CANCELLATION;
    return *this;
  }

  uint32_t c_bitmask() const { return propagate_; }

 private:
  uint32_t propagate_;
};

namespace testing {
class InteropClientContextInspector;
}  // namespace testing

class ClientContext {
 public:
  ClientContext();
  ~ClientContext();

  /// Create a new \a ClientContext as a child of an incoming server call,
  /// according to \a options (\see PropagationOptions).
  ///
  /// \param server_context The source server context to use as the basis for
  /// constructing the client context.
  /// \param options The options controlling what to copy from the \a
  /// server_context.
  ///
  /// \return A newly constructed \a ClientContext instance based on \a
  /// server_context, with traits propagated (copied) according to \a options.
  static std::unique_ptr<ClientContext> FromServerContext(
      const ServerContext& server_context,
      PropagationOptions options = PropagationOptions());

  /// Add the (\a meta_key, \a meta_value) pair to the metadata associated with
  /// a client call. These are made available at the server side by the \a
  /// grpc::ServerContext::client_metadata() method.
  ///
  /// \warning This method should only be called before invoking the rpc.
  ///
  /// \param meta_key The metadata key. If \a meta_value is binary data, it must
  /// end in "-bin".
  /// \param meta_value The metadata value. If its value is binary, it must be
  /// base64-encoding (see https://tools.ietf.org/html/rfc4648#section-4) and \a
  /// meta_key must end in "-bin".
  void AddMetadata(const grpc::string& meta_key,
                   const grpc::string& meta_value);

  /// Return a collection of initial metadata key-value pairs. Note that keys
  /// may happen more than once (ie, a \a std::multimap is returned).
  ///
  /// \warning This method should only be called after initial metadata has been
  /// received. For streaming calls, see \a
  /// ClientReaderInterface::WaitForInitialMetadata().
  ///
  /// \return A multimap of initial metadata key-value pairs from the server.
  const std::multimap<grpc::string_ref, grpc::string_ref>&
  GetServerInitialMetadata() {
    GPR_CODEGEN_ASSERT(initial_metadata_received_);
    return recv_initial_metadata_;
  }

  /// Return a collection of trailing metadata key-value pairs. Note that keys
  /// may happen more than once (ie, a \a std::multimap is returned).
  ///
  /// \warning This method is only callable once the stream has finished.
  ///
  /// \return A multimap of metadata trailing key-value pairs from the server.
  const std::multimap<grpc::string_ref, grpc::string_ref>&
  GetServerTrailingMetadata() {
    // TODO(yangg) check finished
    return trailing_metadata_;
  }

  /// Set the deadline for the client call.
  ///
  /// \warning This method should only be called before invoking the rpc.
  ///
  /// \param deadline the deadline for the client call. Units are determined by
  /// the type used.
  template <typename T>
  void set_deadline(const T& deadline) {
    TimePoint<T> deadline_tp(deadline);
    deadline_ = deadline_tp.raw_time();
  }

#ifndef GRPC_CXX0X_NO_CHRONO
  /// Return the deadline for the client call.
  std::chrono::system_clock::time_point deadline() {
    return Timespec2Timepoint(deadline_);
  }
#endif  // !GRPC_CXX0X_NO_CHRONO

  /// Return a \a gpr_timespec representation of the client call's deadline.
  gpr_timespec raw_deadline() { return deadline_; }

  /// Set the per call authority header (see
  /// https://tools.ietf.org/html/rfc7540#section-8.1.2.3).
  void set_authority(const grpc::string& authority) { authority_ = authority; }

  /// Return the authentication context for this client call.
  ///
  /// \see grpc::AuthContext.
  std::shared_ptr<const AuthContext> auth_context() const;

  /// Set credentials for the client call.
  ///
  /// A credentials object encapsulates all the state needed by a client to
  /// authenticate with a server and make various assertions, e.g., about the
  /// client’s identity, role, or whether it is authorized to make a particular
  /// call.
  ///
  /// \see  http://www.grpc.io/docs/guides/auth.html
  void set_credentials(const std::shared_ptr<CallCredentials>& creds) {
    creds_ = creds;
  }

  /// Return the compression algorithm to be used by the client call.
  grpc_compression_algorithm compression_algorithm() const {
    return compression_algorithm_;
  }

  /// Set \a algorithm to be the compression algorithm used for the client call.
  ///
  /// \param algorith The compression algorithm used for the client call.
  void set_compression_algorithm(grpc_compression_algorithm algorithm);

  /// Return the peer uri in a string.
  ///
  /// \warning This value is never authenticated or subject to any security
  /// related code. It must not be used for any authentication related
  /// functionality. Instead, use auth_context.
  ///
  /// \return The call's peer URI.
  grpc::string peer() const;

  /// Get and set census context.
  void set_census_context(struct census_context* ccp) { census_context_ = ccp; }
  struct census_context* census_context() const {
    return census_context_;
  }

  /// Send a best-effort out-of-band cancel. The call could be in any stage.
  /// e.g. if it is already finished, it may still return success.
  ///
  /// There is no guarantee the call will be cancelled.
  void TryCancel();

  /// Global Callbacks
  ///
  /// Can be set exactly once per application to install hooks whenever
  /// a client context is constructed and destructed.
  class GlobalCallbacks {
   public:
    virtual ~GlobalCallbacks() {}
    virtual void DefaultConstructor(ClientContext* context) = 0;
    virtual void Destructor(ClientContext* context) = 0;
  };
  static void SetGlobalCallbacks(GlobalCallbacks* callbacks);

 private:
  // Disallow copy and assign.
  ClientContext(const ClientContext&);
  ClientContext& operator=(const ClientContext&);

  friend class ::grpc::testing::InteropClientContextInspector;
  friend class CallOpClientRecvStatus;
  friend class CallOpRecvInitialMetadata;
  friend class Channel;
  template <class R>
  friend class ::grpc::ClientReader;
  template <class W>
  friend class ::grpc::ClientWriter;
  template <class W, class R>
  friend class ::grpc::ClientReaderWriter;
  template <class R>
  friend class ::grpc::ClientAsyncReader;
  template <class W>
  friend class ::grpc::ClientAsyncWriter;
  template <class W, class R>
  friend class ::grpc::ClientAsyncReaderWriter;
  template <class R>
  friend class ::grpc::ClientAsyncResponseReader;
  template <class InputMessage, class OutputMessage>
  friend Status BlockingUnaryCall(ChannelInterface* channel,
                                  const RpcMethod& method,
                                  ClientContext* context,
                                  const InputMessage& request,
                                  OutputMessage* result);

  grpc_call* call() { return call_; }
  void set_call(grpc_call* call, const std::shared_ptr<Channel>& channel);

  grpc::string authority() { return authority_; }

  bool initial_metadata_received_;
  std::shared_ptr<Channel> channel_;
  grpc::mutex mu_;
  grpc_call* call_;
  bool call_canceled_;
  gpr_timespec deadline_;
  grpc::string authority_;
  std::shared_ptr<CallCredentials> creds_;
  mutable std::shared_ptr<const AuthContext> auth_context_;
  struct census_context* census_context_;
  std::multimap<grpc::string, grpc::string> send_initial_metadata_;
  std::multimap<grpc::string_ref, grpc::string_ref> recv_initial_metadata_;
  std::multimap<grpc::string_ref, grpc::string_ref> trailing_metadata_;

  grpc_call* propagate_from_call_;
  PropagationOptions propagation_options_;

  grpc_compression_algorithm compression_algorithm_;
};

}  // namespace grpc

#endif  // GRPCXX_IMPL_CODEGEN_CLIENT_CONTEXT_H