GRPC C++  1.62.0
client_unary_call.h
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18 
19 #ifndef GRPCPP_IMPL_CLIENT_UNARY_CALL_H
20 #define GRPCPP_IMPL_CLIENT_UNARY_CALL_H
21 
22 #include <grpcpp/impl/call.h>
25 #include <grpcpp/support/config.h>
26 #include <grpcpp/support/status.h>
27 
28 namespace grpc {
29 
30 class ClientContext;
31 namespace internal {
32 class RpcMethod;
33 
39 template <class InputMessage, class OutputMessage,
40  class BaseInputMessage = InputMessage,
41  class BaseOutputMessage = OutputMessage>
43  grpc::ClientContext* context,
44  const InputMessage& request, OutputMessage* result) {
45  static_assert(std::is_base_of<BaseInputMessage, InputMessage>::value,
46  "Invalid input message specification");
47  static_assert(std::is_base_of<BaseOutputMessage, OutputMessage>::value,
48  "Invalid output message specification");
50  channel, method, context, request, result)
51  .status();
52 }
53 
54 template <class InputMessage, class OutputMessage>
55 class BlockingUnaryCallImpl {
56  public:
58  grpc::ClientContext* context,
59  const InputMessage& request, OutputMessage* result) {
62  nullptr}); // Pluckable completion queue
63  grpc::internal::Call call(channel->CreateCall(method, context, &cq));
67  ops;
68  status_ = ops.SendMessagePtr(&request);
69  if (!status_.ok()) {
70  return;
71  }
72  ops.SendInitialMetadata(&context->send_initial_metadata_,
73  context->initial_metadata_flags());
74  ops.RecvInitialMetadata(context);
75  ops.RecvMessage(result);
76  ops.AllowNoMessage();
77  ops.ClientSendClose();
78  ops.ClientRecvStatus(context, &status_);
79  call.PerformOps(&ops);
80  cq.Pluck(&ops);
81  // Some of the ops might fail. If the ops fail in the core layer, status
82  // would reflect the error. But, if the ops fail in the C++ layer, the
83  // status would still be the same as the one returned by gRPC Core. This can
84  // happen if deserialization of the message fails.
85  // TODO(yashykt): If deserialization fails, but the status received is OK,
86  // then it might be a good idea to change the status to something better
87  // than StatusCode::UNIMPLEMENTED to reflect this.
88  if (!ops.got_message && status_.ok()) {
90  "No message returned for unary request");
91  }
92  }
93  Status status() { return status_; }
94 
95  private:
96  Status status_;
97 };
98 
99 } // namespace internal
100 } // namespace grpc
101 
102 #endif // GRPCPP_IMPL_CLIENT_UNARY_CALL_H
grpc::internal::CallOpRecvInitialMetadata
Definition: call_op_set.h:721
grpc::internal::CallOpClientSendClose
Definition: call_op_set.h:619
grpc
An Alarm posts the user-provided tag to its associated completion queue or invokes the user-provided ...
Definition: alarm.h:33
grpc::internal::CallOpSet
Primary implementation of CallOpSetInterface.
Definition: completion_queue.h:96
grpc::internal::CallOpSendMessage
Definition: call_op_set.h:286
grpc::internal::BlockingUnaryCallImpl
Definition: client_context.h:101
grpc::internal::Call
Straightforward wrapping of the C call object.
Definition: call.h:36
status.h
grpc::internal::CallOpSendInitialMetadata
Definition: call_op_set.h:216
grpc::Status::ok
bool ok() const
Is the status OK?
Definition: status.h:126
grpc::Status
Did it work? If it didn't, why?
Definition: status.h:35
GRPC_CQ_DEFAULT_POLLING
@ GRPC_CQ_DEFAULT_POLLING
The completion queue will have an associated pollset and there is no restriction on the type of file ...
Definition: grpc_types.h:415
grpc::ClientContext
A ClientContext allows the person implementing a service client to:
Definition: client_context.h:193
channel_interface.h
grpc::ChannelInterface
Codegen interface for grpc::Channel.
Definition: channel_interface.h:71
GRPC_CQ_PLUCK
@ GRPC_CQ_PLUCK
Events are popped out by calling grpc_completion_queue_pluck() API ONLY.
Definition: grpc_types.h:435
grpc_completion_queue_attributes
Definition: grpc_types.h:463
grpc::internal::BlockingUnaryCallImpl::BlockingUnaryCallImpl
BlockingUnaryCallImpl(ChannelInterface *channel, const RpcMethod &method, grpc::ClientContext *context, const InputMessage &request, OutputMessage *result)
Definition: client_unary_call.h:57
grpc::UNIMPLEMENTED
@ UNIMPLEMENTED
Operation is not implemented or not supported/enabled in this service.
Definition: status_code_enum.h:117
config.h
GRPC_CQ_CURRENT_VERSION
#define GRPC_CQ_CURRENT_VERSION
Definition: grpc_types.h:461
call_op_set.h
call.h
grpc::internal::CallOpClientRecvStatus
Definition: call_op_set.h:769
grpc::CompletionQueue
A thin wrapper around grpc_completion_queue (see src/core/lib/surface/completion_queue....
Definition: completion_queue.h:103
grpc::internal::CallOpRecvMessage
Definition: call_op_set.h:424
grpc::internal::RpcMethod
Descriptor of an RPC method.
Definition: rpc_method.h:29
grpc::internal::BlockingUnaryCall
Status BlockingUnaryCall(ChannelInterface *channel, const RpcMethod &method, grpc::ClientContext *context, const InputMessage &request, OutputMessage *result)
Wrapper that performs a blocking unary call.
Definition: client_unary_call.h:42
grpc::protobuf::util::Status
::absl::Status Status
Definition: config_protobuf.h:97
grpc::internal::BlockingUnaryCallImpl::status
Status status()
Definition: client_unary_call.h:93