Difference between revisions of "How to create a C++ gRPC application"
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− | <font size="+ | + | <font size="+1"> |
: '''Setup some environmental variables (assuming bash)''' | : '''Setup some environmental variables (assuming bash)''' | ||
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=== As an example, implement ERSAP backend reassembler communication of fifo fill percentage to load-balancer control plane === | === As an example, implement ERSAP backend reassembler communication of fifo fill percentage to load-balancer control plane === | ||
− | : '''Start by modifying loadBalancerControl.proto to define the message and the communication API. | + | : '''Start by modifying loadBalancerControl.proto to define the message and the communication API. Make it look like the following and don't worry about option and package statements.''' |
<blockquote> | <blockquote> | ||
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</blockquote> | </blockquote> | ||
+ | |||
+ | : '''Next modify 6 lines in the loadBalancerControl/CMakefile.txt in order to reflection file/directory name changes''' | ||
+ | |||
+ | <blockquote> | ||
+ | <pre> | ||
+ | # Proto file | ||
+ | get_filename_component(hw_proto "../../protos/loadBalancerControl.proto" ABSOLUTE) | ||
+ | get_filename_component(hw_proto_path "${hw_proto}" PATH) | ||
+ | |||
+ | # Generated sources | ||
+ | set(hw_proto_srcs "${CMAKE_CURRENT_BINARY_DIR}/loadBalancerControl.pb.cc") | ||
+ | set(hw_proto_hdrs "${CMAKE_CURRENT_BINARY_DIR}/loadBalancerControl.pb.h") | ||
+ | set(hw_grpc_srcs "${CMAKE_CURRENT_BINARY_DIR}/loadBalancerControl.grpc.pb.cc") | ||
+ | set(hw_grpc_hdrs "${CMAKE_CURRENT_BINARY_DIR}/loadBalancerControl.grpc.pb.h") | ||
+ | </pre> | ||
+ | </blockquote> | ||
: '''Now recompile''' | : '''Now recompile''' |
Revision as of 22:41, 16 December 2022
- Setup some environmental variables (assuming bash)
export GRPC_INSTALL_DIR=/daqfs/gRPC/installation export PATH="$GRPC_INSTALL_DIR/bin:$PATH" export LD_LIBRARY_PATH="$GRPC_INSTALL_DIR/lib:$LD_LIBRARY_PATH"
- Start by copying the hello world example and compiling it (official instructions here). The compilation steps differ slightly between examples.
cd <my_gRPC_dir> mkdir ejfat cd ejfat mkdir cpp protos cp /daqfs/gRPC/grpc/examples/protos/helloworld.proto protos/. cp -r /daqfs/gRPC/grpc/examples/cpp/cmake cpp/. cp -r /daqfs/gRPC/grpc/examples/cpp/helloworld cpp/. cd cpp/helloworld mkdir -p cmake/build cd cmake/build cmake -DCMAKE_PREFIX_PATH=$GRPC_INSTALL_DIR -DBUILD_SHARED_LIBS=ON ../.. make -j 4
- Rename a few files and directories, from helloworld to loadBalancerControl (or whatever you want)
cd <my_gRPC_dir>/ejfat mv protos/helloworld.proto protos/loadBalancerControl.proto mv cpp/helloworld cpp/loadBalancerControl
As an example, implement ERSAP backend reassembler communication of fifo fill percentage to load-balancer control plane
- Start by modifying loadBalancerControl.proto to define the message and the communication API. Make it look like the following and don't worry about option and package statements.
// The ERSAP backend state reporting service definition. service BackendState { // Sends a request to get the backend's state rpc GetState (StateRequest) returns (StateReply) {} } // The get-state request message containing the LB control plane's name. message StateRequest { string name = 1; } // The response message containing the backend's current state message StateReply { int32 bufferCount = 1; // number of backend's buffers or fifo entries int32 bufferSize = 2; // size in bytes of each buffer or fifo entry int32 fillPercent = 3; // % of fifo entries that are filled with unprocessed data int32 pidError = 4; // PID loop error term in percentage of fifo entries }
- Next modify 6 lines in the loadBalancerControl/CMakefile.txt in order to reflection file/directory name changes
# Proto file get_filename_component(hw_proto "../../protos/loadBalancerControl.proto" ABSOLUTE) get_filename_component(hw_proto_path "${hw_proto}" PATH) # Generated sources set(hw_proto_srcs "${CMAKE_CURRENT_BINARY_DIR}/loadBalancerControl.pb.cc") set(hw_proto_hdrs "${CMAKE_CURRENT_BINARY_DIR}/loadBalancerControl.pb.h") set(hw_grpc_srcs "${CMAKE_CURRENT_BINARY_DIR}/loadBalancerControl.grpc.pb.cc") set(hw_grpc_hdrs "${CMAKE_CURRENT_BINARY_DIR}/loadBalancerControl.grpc.pb.h")
- Now recompile
cd cpp/loadBalancerControl rm -fr cmake mkdir -p cmake/build cd cmake/build cmake -DCMAKE_PREFIX_PATH=$GRPC_INSTALL_DIR -DBUILD_SHARED_LIBS=ON ../.. make -j 4
The application in this case is the reporting to the control plane of the fill level of an ERSAP backend reassembler's fifo.