wjones127 commented on a change in pull request #153: URL: https://github.com/apache/arrow-cookbook/pull/153#discussion_r814034453
########## File path: cpp/code/protos/CMakeLists.txt ########## @@ -0,0 +1,30 @@ +# Based on https://www.f-ax.de/dev/2020/11/08/grpc-plugin-cmake-support.html Review comment: Well I did copy from the example, so probably. Forgot about licensing concerns. The flight example seemed to be tied to variables in the Arrow CMake system, and felt a little messy. I can move it to just be included directly in the binary, and hopefully keep the `protobuf_generate()` calls. ########## File path: cpp/code/flight.cc ########## @@ -173,7 +177,41 @@ class ParquetStorageService : public arrow::flight::FlightServerBase { std::shared_ptr<arrow::fs::FileSystem> root_; }; // end ParquetStorageService -arrow::Status TestPutGetDelete() { +class HelloWorldServiceImpl : public HelloWorldService::Service { + grpc::Status SayHello([[maybe_unused]] grpc::ServerContext* ctx, + const HelloRequest* request, HelloResponse* reply) override { + const std::string& name = request->name(); + if (name.empty()) { + return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT, "Must provide a name!"); + } + reply->set_reply("Hello, " + name); + return grpc::Status::OK; + } +}; // end HelloWorldServiceImpl + +class HelloWorldClient { + public: + HelloWorldClient(std::shared_ptr<grpc::Channel> channel) + : stub_(HelloWorldService::NewStub(channel)) {} + + arrow::Result<std::string> HelloWorld(std::string name) { + grpc::ClientContext context; + HelloRequest request; + request.set_name(name); + HelloResponse response; + grpc::Status status = stub_->SayHello(&context, request, &response); + if (!status.ok()) { + return arrow::Status::IOError(status.error_message()); + } + return response.reply(); + } + + protected: + std::unique_ptr<HelloWorldService::Stub> stub_; +}; // end HelloWorldClient + +arrow::Status +TestPutGetDelete() { Review comment: Nah I probably messed it up before committing. I'll run clang-format before my next commit. ########## File path: cpp/source/flight.rst ########## @@ -83,3 +83,79 @@ Finally, we'll stop our server: .. recipe:: ../code/flight.cc ParquetStorageService::StopServer :dedent: 2 + + +Setting gRPC client options +=========================== + +Options for gRPC clients can be passed in using the ``generic_options`` field of +:cpp:class:`arrow::flight::FlightClientOptions`. There is a list of available +client options in the `gRPC API documentation <https://grpc.github.io/grpc/cpp/group__grpc__arg__keys.html>`_. + +For example, you can change the maximum message length sent with: + +.. recipe:: ../code/flight.cc TestClientOptions::Connect + :dedent: 2 + + +Flight Service with other gRPC endpoints +======================================== + +If you are using the gRPC backend, you can add other gRPC endpoints to the +flight server. While Flight clients won't recognize these endpoints, general +gRPC clients will be able to. + +.. note:: + If statically linking Arrow Flight, Protobuf and gRPC must also be statically + linked, and the same goes for dynamic linking. Read more at + https://arrow.apache.org/docs/cpp/build_system.html#a-note-on-linking + +Creating the server +------------------- + +To create a gRPC service, first define a service using protobuf. + +.. literalinclude:: ../code/protos/helloworld.proto + :language: protobuf + :linenos: + :start-at: syntax = "proto3"; + :caption: Hello world protobuf specification + +Next, you'll need to compile that. If you are using CMake, consider the setup +suggested by https://www.f-ax.de/dev/2020/11/08/grpc-plugin-cmake-support.html. Review comment: Yeah I'll just link the gRPC tutorial and people can figure it out from there. ########## File path: cpp/code/flight.cc ########## @@ -43,9 +47,9 @@ class ParquetStorageService : public arrow::flight::FlightServerBase { explicit ParquetStorageService(std::shared_ptr<arrow::fs::FileSystem> root) : root_(std::move(root)) {} - arrow::Status ListFlights(const arrow::flight::ServerCallContext&, - const arrow::flight::Criteria*, - std::unique_ptr<arrow::flight::FlightListing>* listings) override { + arrow::Status ListFlights( + const arrow::flight::ServerCallContext&, const arrow::flight::Criteria*, + std::unique_ptr<arrow::flight::FlightListing>* listings) override { Review comment: Created #157 ########## File path: cpp/code/flight.cc ########## @@ -173,7 +177,41 @@ class ParquetStorageService : public arrow::flight::FlightServerBase { std::shared_ptr<arrow::fs::FileSystem> root_; }; // end ParquetStorageService -arrow::Status TestPutGetDelete() { +class HelloWorldServiceImpl : public HelloWorldService::Service { + grpc::Status SayHello([[maybe_unused]] grpc::ServerContext* ctx, + const HelloRequest* request, HelloResponse* reply) override { + const std::string& name = request->name(); + if (name.empty()) { + return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT, "Must provide a name!"); + } + reply->set_reply("Hello, " + name); + return grpc::Status::OK; + } +}; // end HelloWorldServiceImpl + +class HelloWorldClient { Review comment: Yeah that's true. I was just following the gRPC tutorial. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
