The ScalaPB gRPC generator to run Reactive gRPC server and client on top Project Reactor's Scala extension.
- Uses Reactive gRPC for Java Runtime which provides Reactive Streams on top of gRPC's back-pressure support.
- Uses Reactor Scala Extensions for easily building stream requests and responses.
Add the following configuration to project/plugins.sbt.
addSbtPlugin("com.thesamet" % "sbt-protoc" % "1.0.4")
libraryDependencies += "kr.ikhoon.scalapb-reactor" %% "scalapb-reactor-codegen" % "<latest-version>"Add the following configuration to build.sbt.
PB.targets in Compile := Seq(
scalapb.gen() -> (sourceManaged in Compile).value,
scalapb.reactor.ReactorCodeGenerator -> (sourceManaged in Compile).value
)ScalaPB-Reactor 0.3.0 currently supports Scala 2.12 and 2.13. Please use 0.1.0 for Scala 2.11.
ScalaPB-Reactor generates your stub file to <package>.<file-name>.Reactor<service-name>.
The following proto file will be generated to com.example.test_service.ReactorTestService.
// file: test_service.proto
syntax = "proto3";
package com.example;
message Request {
string in = 1;
}
message Response {
string out = 1;
}
service TestService {
rpc Unary(Request) returns (Response);
rpc ServerStreaming(Request) returns (stream Response);
rpc ClientStreaming(stream Request) returns (Response);
rpc BidiStreaming(stream Request) returns (stream Response);
}The generated gRPC stub for Reactor contains the following structure.
object ReactorTestServiceGrpc {
// Implement this trait for your service.
trait ReactorTestService {
def unary(request: Request): SMono[Response]
def serverStreaming(request: Request): SFlux[Response]
def clientStreaming(request: SFlux[Request]): SMono[Response]
def bidiStreaming(request: SFlux[Request]): SFlux[Response]
}
object ReactorTestService {
// Use this method to bind your service with gRPC server
def bindService(serviceImpl: ReactorTestService): ServerServiceDefinition = {
...
}
}
// You use this class for creating gRPC client stub.
class ReactorTestServiceStub(channel: Channel, options: CallOptions)
extends AbstractStub[ReactorTestServiceStub](channel, options) with ReactorTestService {
}
}Visit examples to find a fully working example.