Repository: rouzwawi/grpc-kotlin Branch: master Commit: a8cac5b44414 Files: 43 Total size: 151.9 KB Directory structure: gitextract_swzgl8ap/ ├── .circleci/ │ └── config.yml ├── .gitignore ├── .mvn/ │ └── wrapper/ │ ├── MavenWrapperDownloader.java │ ├── maven-wrapper.jar │ └── maven-wrapper.properties ├── LICENSE ├── NOTICE ├── README.md ├── grpc-kotlin-example-chatserver/ │ ├── README.md │ ├── pom.xml │ └── src/ │ └── main/ │ ├── kotlin/ │ │ └── io/ │ │ └── rouz/ │ │ └── grpc/ │ │ └── examples/ │ │ └── chat/ │ │ ├── ChatClient.kt │ │ ├── ChatService.kt │ │ ├── Entrypoint.kt │ │ ├── GrpcServer.kt │ │ └── ServerStreaminChatClient.kt │ └── proto/ │ └── chat.proto ├── grpc-kotlin-gen/ │ ├── pom.xml │ └── src/ │ ├── main/ │ │ ├── java/ │ │ │ └── io/ │ │ │ └── rouz/ │ │ │ └── grpc/ │ │ │ └── kotlin/ │ │ │ └── GrpcKotlinGenerator.java │ │ └── resources/ │ │ ├── Adapters.mustache │ │ ├── ImplBase.mustache │ │ └── StubExtensions.mustache │ └── test/ │ └── java/ │ └── io/ │ └── rouz/ │ └── grpc/ │ └── kotlin/ │ └── GrpcKotlinGeneratorTest.java ├── grpc-kotlin-test/ │ ├── pom.xml │ └── src/ │ ├── main/ │ │ ├── kotlin/ │ │ │ └── io/ │ │ │ └── rouz/ │ │ │ └── greeter/ │ │ │ ├── GreeterImpl.kt │ │ │ ├── GreeterMain.kt │ │ │ └── InfiniteStreamGreeterImpl.kt │ │ └── proto/ │ │ └── io/ │ │ └── rouz/ │ │ ├── greeter.proto │ │ └── kvs.proto │ └── test/ │ └── kotlin/ │ └── io/ │ └── rouz/ │ └── greeter/ │ ├── ClientAbandonTest.kt │ ├── ClosingStatusExceptionTest.kt │ ├── ContextBasedGreeterTest.kt │ ├── DelayedClosingStatusExceptionTest.kt │ ├── DelayedThrowingStatusExceptionTest.kt │ ├── ExceptionPropagationTest.kt │ ├── GrpcTestBase.kt │ ├── NoStatusExceptionPropagationTest.kt │ ├── ServiceCallsTest.kt │ ├── StatusExceptionTestBase.kt │ ├── ThrowingStatusExceptionTest.kt │ └── UnimplementedStatusTest.kt ├── mvnw ├── mvnw.cmd └── pom.xml ================================================ FILE CONTENTS ================================================ ================================================ FILE: .circleci/config.yml ================================================ # Java Maven CircleCI 2.0 configuration file # # Check https://circleci.com/docs/2.0/language-java/ for more details # version: 2 jobs: build: docker: # specify the version you desire here - image: circleci/openjdk:8-jdk # Specify service dependencies here if necessary # CircleCI maintains a library of pre-built images # documented at https://circleci.com/docs/2.0/circleci-images/ # - image: circleci/postgres:9.4 working_directory: ~/repo environment: # Customize the JVM maximum heap limit MAVEN_OPTS: -Xmx3200m steps: - checkout # Download and cache dependencies - restore_cache: keys: - v1-dependencies-{{ checksum "pom.xml" }}-{{ checksum "grpc-kotlin-gen/pom.xml" }}-{{ checksum "grpc-kotlin-test/pom.xml" }} # fallback to using the latest cache if no exact match is found - v1-dependencies- # run tests! - run: mvn verify - save_cache: paths: - ~/.m2 key: v1-dependencies-{{ checksum "pom.xml" }}-{{ checksum "grpc-kotlin-gen/pom.xml" }}-{{ checksum "grpc-kotlin-test/pom.xml" }} ================================================ FILE: .gitignore ================================================ # Build products and artifacts target/ pom.xml.tag pom.xml.releaseBackup pom.xml.versionsBackup pom.xml.next release.properties # Stuff from various IDE's and editors *.iml *~ .idea/* # Mac OS X Finder .DS_Store .classpath .project ================================================ FILE: .mvn/wrapper/MavenWrapperDownloader.java ================================================ /* Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. 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See the License for the specific language governing permissions and limitations under the License. ================================================ FILE: NOTICE ================================================ File grpc-kotlin-gen/src/main/java/io/rouz/grpc/kotlin/GrpcKotlinGenerator.java Modified redistribution of ReactiveGrpcGenerator.java from https://github.com/salesforce/reactive-grpc Licensed under the BSD 3-Clause license ================================================ FILE: README.md ================================================ # gRPC Kotlin - Coroutine based gRPC for Kotlin [![CircleCI](https://img.shields.io/circleci/project/github/rouzwawi/grpc-kotlin.svg)](https://circleci.com/gh/rouzwawi/grpc-kotlin) [![Maven Central](https://img.shields.io/maven-central/v/io.rouz/grpc-kotlin-gen.svg)](https://search.maven.org/#search%7Cga%7C1%7Cg%3A%22io.rouz%22%20grpc-kotlin-gen) gRPC Kotlin is a [protoc] plugin for generating native Kotlin bindings using [coroutine primitives] for [gRPC] services. * [Why?](#why) * [Quick start](#quick-start) * [Server](#server) * [Client](#client) * [gRPC Context propagation](#grpc-context-propagation) * [Exception handling](#exception-handling) * [Maven configuration](#maven-configuration) * [Gradle configuration](#gradle-configuration) * [Examples](#examples) * [RPC method type reference](#rpc-method-type-reference) * [Unary call](#unary-call) * [Service](#service) * [Client](#client-1) * [Client streaming call](#client-streaming-call) * [Service](#service-1) * [Client](#client-2) * [Server streaming call](#server-streaming-call) * [Service](#service-2) * [Client](#client-3) * [Full bidirectional streaming call](#full-bidirectional-streaming-call) * [Service](#service-3) * [Client](#client-4) --- ## Why? The asynchronous nature of bidirectional streaming rpc calls in gRPC makes them a bit hard to implement and read. Getting your head around the `StreamObserver`'s can be a bit tricky at times. Specially with the method argument being the response observer and the return value being the request observer, it all feels a bit backwards to what a plain old synchronous version of the handler would look like. In situations where you'd want to coordinate several request and response messages in one call, you'll and up having to manage some tricky state and synchronization between the observers. There are [reactive bindings] for gRPC which make this easier. But I think we can do better! Enter Kotlin Coroutines! By generating native Kotlin stubs that allows us to use [`suspend`] functions and [`Channel`], we can write our handler and client code in an idiomatic and easy to read Kotlin style. ## Quick start Note: This has been tested with `gRPC 1.25.0`, `protobuf 3.10.0`, `kotlin 1.3.61` and `coroutines 1.3.3`. Add a gRPC service definition to your project `greeter.proto` ```proto syntax = "proto3"; package org.example.greeter; option java_package = "org.example.greeter"; option java_multiple_files = true; message GreetRequest { string greeting = 1; } message GreetReply { string reply = 1; } service Greeter { rpc Greet (GreetRequest) returns (GreetReply); rpc GreetServerStream (GreetRequest) returns (stream GreetReply); rpc GreetClientStream (stream GreetRequest) returns (GreetReply); rpc GreetBidirectional (stream GreetRequest) returns (stream GreetReply); } ``` Run the protoc plugin to get the generated code, see [build tool configuration](#maven-configuration) ### Server After compilation, you'll find the generated Kotlin code in the same package as the generated Java code. A service base class named `GreeterImplBase` and a file with extension functions for the client stub named `GreeterStubExt.kt`. Both the service base class and client stub extensions will use `suspend` and `Channel` instead of the typical `StreamObserver` interfaces. All functions have the [`suspend`] modifier so they can call into any suspending code, including the [core coroutine primitives] like `delay` and `async`. All the server streaming calls return a `ReceiveChannel` and can easily be implemented using `produce`. All client streaming calls receive an argument of `ReceiveChannel` where they can `receive()` messages from the caller. Here's an example server that demonstrates how each type of endpoint is implemented. ```kotlin import kotlinx.coroutines.* import kotlinx.coroutines.channels.ReceiveChannel import kotlinx.coroutines.channels.produce import java.util.concurrent.Executors.newFixedThreadPool class GreeterImpl : GreeterImplBase( coroutineContext = newFixedThreadPool(4).asCoroutineDispatcher() ) { // unary rpc override suspend fun greet(request: GreetRequest): GreetReply { return GreetReply.newBuilder() .setReply("Hello " + request.greeting) .build() } // server streaming rpc override fun greetServerStream(request: GreetRequest) = produce { send(GreetReply.newBuilder() .setReply("Hello ${request.greeting}!") .build()) send(GreetReply.newBuilder() .setReply("Greetings ${request.greeting}!") .build()) } // client streaming rpc override suspend fun greetClientStream(requestChannel: ReceiveChannel): GreetReply { val greetings = mutableListOf() for (request in requestChannel) { greetings.add(request.greeting) } return GreetReply.newBuilder() .setReply("Hi to all of $greetings!") .build() } // bidirectional rpc override fun greetBidirectional(requestChannel: ReceiveChannel) = produce { var count = 0 for (request in requestChannel) { val n = count++ launch { delay(1000) send(GreetReply.newBuilder() .setReply("Yo #$n ${request.greeting}") .build()) } } } } ``` ### Client Extensions functions for the original Java stubs are generated that use `suspend` functions, `Deferred` and `SendChannel`. ```kotlin import io.grpc.ManagedChannelBuilder import kotlinx.coroutines.delay import kotlinx.coroutines.launch import kotlinx.coroutines.runBlocking fun main(args: Array) { val localhost = ManagedChannelBuilder.forAddress("localhost", 8080) .usePlaintext() .build() val greeter = GreeterGrpc.newStub(localhost) runBlocking { // === Unary call ============================================================================= val unaryResponse = greeter.greet(req("Alice")) println("unary reply = ${unaryResponse.reply}") // === Server streaming call ================================================================== val serverResponses = greeter.greetServerStream(req("Bob")) for (serverResponse in serverResponses) { println("server response = ${serverResponse.reply}") } // === Client streaming call ================================================================== val manyToOneCall = greeter.greetClientStream() manyToOneCall.send(req("Caroline")) manyToOneCall.send(req("David")) manyToOneCall.close() val oneReply = manyToOneCall.await() println("single reply = ${oneReply.reply}") // === Bidirectional call ===================================================================== val bidiCall = greeter.greetBidirectional() launch { var n = 0 for (greetReply in bidiCall) { println("r$n = ${greetReply.reply}") n++ } println("no more replies") } delay(200) bidiCall.send(req("Eve")) delay(200) bidiCall.send(req("Fred")) delay(200) bidiCall.send(req("Gina")) bidiCall.close() } } ``` ## gRPC Context propagation gRPC has a thread-local [`Context`] which is used to carry scoped values across API boundaries. With Kotlin coroutines possibly being dispatched on multiple threads, the thread-local nature of `Context` needs some special care. This is solved by two details in the generated Kotlin code. First, all the generated service `*ImplBase` classes implement `CoroutineScope`. This allows you to use any of the top level coroutine primitives such as `launch`, `async` and `produce` in your service implementation while still keeping them within the context of your service code. The actual `CoroutineContext` that is used can be set through the base class constructor, but defaults to `Dispatchers.default`. ```kotlin abstract class MyServiceImplBase( coroutineContext: CoroutineContext = Dispatchers.Default ) ``` Second, in the getter for `CoroutineScope.coroutineContext`, an additional context key is added to the `CoroutineContext` that manages the gRPC Context `attach()` and `detach()` calls when dispatching coroutine continuations. This will ensure that the the gRPC context is always propagated across different coroutine boundaries, and eliminates the need to manually carry it across in user code. Here's a simple example that makes calls to other services concurrently and expects an authenticated user to be present in the gRPC Context. The two accesses to the context key may execute on different threads in the `CoroutineContext` but the accesses work as expected. ```kotlin val authenticatedUser = Context.key("authenticatedUser") override suspend fun greet(request: GreetRequest): GreetReply { val motd = async { messageOfTheDay.getMessage() } val weatherReport = async { weather.getWeatherReport(authenticatedUser.get().location) } val reply = buildString { append("Hello ${authenticatedUser.get().fullName}") append("---") append("Today's weather report: ${weatherReport.await()}") append("---") append(motd.await()) } return GreetReply.newBuilder() .setReply(reply) .build() } ``` For another example of gRPC Context usage, see the code in [ContextBasedGreeterTest](grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/ContextBasedGreeterTest.kt) Thanks to [`wfhartford`](https://github.com/wfhartford) for contributing! ## Exception handling The generated server code follows the standard exception propagation for Kotlin coroutines as described in the [Exception handling] documentation. This means that it's safe to throw exceptions from within the server implementation code. These will propagate up the coroutine scope and be translated to `responseObserver.onError(Throwable)` calls. The preferred way to respond with a status code is to throw a `StatusException`. Note that you should not call `close(Throwable)` or `close()` from within the `ProducerScope` blocks you get from `produce` as the producer will automatically be closed when all sub-contexts are closed (or if an exception is thrown). ## Maven configuration Add the `grpc-kotlin-gen` plugin to your `protobuf-maven-plugin` configuration (see [compile-custom goal](https://www.xolstice.org/protobuf-maven-plugin/compile-custom-mojo.html)) ```xml 1.3.61 1.3.3 1.25.0 3.10.0 0.1.4 org.jetbrains.kotlin kotlin-stdlib ${kotlin.version} org.jetbrains.kotlinx kotlinx-coroutines-core ${kotlinx-coroutines.version} io.grpc grpc-netty ${grpc.version} io.grpc grpc-protobuf ${grpc.version} io.grpc grpc-stub ${grpc.version} kr.motd.maven os-maven-plugin 1.5.0.Final org.xolstice.maven.plugins protobuf-maven-plugin 0.6.1 com.google.protobuf:protoc:${protobuf.version}:exe:${os.detected.classifier} compile grpc-java compile-custom grpc-java io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier} grpc-kotlin compile-custom grpc-kotlin io.rouz:grpc-kotlin-gen:${grpc-kotlin.version}:exe:${os.detected.classifier} kotlin-maven-plugin org.jetbrains.kotlin ${kotlin.version} compile compile ${project.basedir}/src/main/kotlin ${project.basedir}/target/generated-sources/protobuf/grpc-kotlin ${project.basedir}/target/generated-sources/protobuf/grpc-java ${project.basedir}/target/generated-sources/protobuf/java ``` ## Gradle configuration Add the `grpc-kotlin-gen` plugin to the plugins section of `protobuf-gradle-plugin` ```gradle def protobufVersion = '3.10.0' def grpcVersion = '1.25.0' def grpcKotlinVersion = '0.1.4' protobuf { protoc { // The artifact spec for the Protobuf Compiler artifact = "com.google.protobuf:protoc:${protobufVersion}" } plugins { grpc { artifact = "io.grpc:protoc-gen-grpc-java:${grpcVersion}" } grpckotlin { artifact = "io.rouz:grpc-kotlin-gen:${grpcKotlinVersion}" } } generateProtoTasks { all()*.plugins { grpc {} grpckotlin {} } } } ``` Add the kotlin dependencies ```gradle def kotlinVersion = '1.3.61' def kotlinCoroutinesVersion = '1.3.3' dependencies { compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion" compile "org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlinCoroutinesVersion" } ``` ## Examples This is a list of example gRPC services and clients written using this project - [`grpc-kotlin-example-chatserver`](grpc-kotlin-example-chatserver) - [`kotlin-grpc-sample`](https://github.com/FlavioF/kotlin-grpc-sample) - [`grpc-death-star`](https://github.com/leveretka/grpc-death-star) ## RPC method type reference ### Unary call > `rpc Greet (GreetRequest) returns (GreetReply);` #### Service A suspendable function which returns a single message. ```kotlin override suspend fun greet(request: GreetRequest): GreetReply { // return GreetReply message } ``` #### Client Suspendable call returning a single message. ```kotlin val response: GreetReply = stub.greet( /* GreetRequest */ ) ``` ### Client streaming call > `rpc GreetClientStream (stream GreetRequest) returns (GreetReply);` #### Service A suspendable function which returns a single message, and receives messages from a `ReceiveChannel`. ```kotlin override suspend fun greetClientStream(requestChannel: ReceiveChannel): GreetReply { // receive request messages val firstRequest = requestChannel.receive() // or iterate all request messages for (request in requestChannel) { // ... } // return GreetReply message } ``` #### Client Using `send()` and `close()` on `SendChannel`. ```kotlin val call: ManyToOneCall = stub.greetClientStream() call.send( /* GreetRequest */ ) call.send( /* GreetRequest */ ) call.close() // don't forget to close the send channel val responseMessage = call.await() ``` ### Server streaming call > `rpc GreetServerStream (GreetRequest) returns (stream GreetReply);` #### Service Using `produce` and `send()` to send a stream of messages. ```kotlin override fun greetServerStream(request: GreetRequest) = produce { send( /* GreetReply message */ ) send( /* GreetReply message */ ) // ... } ``` Note that `close()` or `close(Throwable)` should not be used, see [Exception handling](#exception-handling). In `kotlinx-coroutines-core:1.0.0` `produce` is marked with `@ExperimentalCoroutinesApi`. In order to use it, mark your server class with `@UseExperimental(ExperimentalCoroutinesApi::class)` and add the `-Xuse-experimental=kotlin.Experimental` compiler flag. #### Client Using `receive()` on `ReceiveChannel` or iterating with a `for` loop. ```kotlin val responses: ReceiveChannel = stub.greetServerStream( /* GreetRequest */ ) // await individual responses val responseMessage = serverResponses.receive() // or iterate all responses for (responseMessage in responses) { // ... } ``` ### Full bidirectional streaming call > `rpc GreetBidirectional (stream GreetRequest) returns (stream GreetReply);` #### Service Using `produce` and `send()` to send a stream of messages. Receiving messages from a `ReceiveChannel`. ```kotlin override fun greetBidirectional(requestChannel: ReceiveChannel) = produce { // receive request messages val firstRequest = requestChannel.receive() send( /* GreetReply message */ ) val more = requestChannel.receive() send( /* GreetReply message */ ) // ... } ``` Note that `close()` or `close(Throwable)` should not be used, see [Exception handling](#exception-handling). In `kotlinx-coroutines-core:1.0.0` `produce` is marked with `@ExperimentalCoroutinesApi`. In order to use it, mark your server class with `@UseExperimental(ExperimentalCoroutinesApi::class)` and add the `-Xuse-experimental=kotlin.Experimental` compiler flag. #### Client Using both a `SendChannel` and a `ReceiveChannel` to interact with the call. ```kotlin val call: ManyToManyCall = stub.greetBidirectional() launch { for (responseMessage in call) { log.info(responseMessage) } log.info("no more replies") } call.send( /* GreetRequest */ ) call.send( /* GreetRequest */ ) call.close() // don't forget to close the send channel ``` [protoc]: https://www.xolstice.org/protobuf-maven-plugin/examples/protoc-plugin.html [`suspend`]: https://kotlinlang.org/docs/reference/coroutines-overview.html [coroutine primitives]: https://github.com/Kotlin/kotlinx.coroutines [core coroutine primitives]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/ [Exception handling]: https://kotlinlang.org/docs/reference/coroutines/exception-handling.html [`Channel`]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.experimental.channels/-channel/index.html [`Deferred`]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.experimental/-deferred/index.html [`async`]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.experimental/async.html [`produce`]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.experimental.channels/produce.html [`Context`]: https://grpc.io/grpc-java/javadoc/io/grpc/Context.html [gRPC]: https://grpc.io/ [reactive bindings]: https://github.com/salesforce/reactive-grpc ================================================ FILE: grpc-kotlin-example-chatserver/README.md ================================================ # grpc-kotlin-example-chatserver A simple command line chat server written using both bidirectional & server streaming gRPC. Build the parent project. From the repo root, run ```sh ./mvnw clean package ``` Start the server ```sh java -jar grpc-kotlin-example-chatserver/target/grpc-kotlin-example-chatserver.jar server ``` From another shell, start a bidirectional streaming client ```sh java -jar grpc-kotlin-example-chatserver/target/grpc-kotlin-example-chatserver.jar client ``` From the third shell, start a server streaming client ```sh java -jar grpc-kotlin-example-chatserver/target/grpc-kotlin-example-chatserver.jar clientSS ``` --- Big thanks to [Björn Hegerfors](https://github.com/Bj0rnen) and [Emilio Del Tessandoro](https://github.com/emmmile) for putting together this example! ================================================ FILE: grpc-kotlin-example-chatserver/pom.xml ================================================ 4.0.0 io.rouz grpc-kotlin-parent 0.1.5-SNAPSHOT grpc-kotlin-example-chatserver grpc-kotlin-example-chatserver jar 1.3.61 1.3.3 1.25.0 3.10.0 org.jetbrains.kotlin kotlin-stdlib ${kotlin.version} org.jetbrains.kotlinx kotlinx-coroutines-core ${kotlinx-coroutines.version} io.grpc grpc-netty ${grpc.version} io.grpc grpc-protobuf ${grpc.version} io.grpc grpc-stub ${grpc.version} io.grpc grpc-services ${grpc.version} javax.annotation javax.annotation-api 1.3.2 org.slf4j slf4j-simple 1.7.25 org.jetbrains.kotlin kotlin-test-junit ${kotlin.version} test kr.motd.maven os-maven-plugin 1.5.0.Final org.xolstice.maven.plugins protobuf-maven-plugin 0.6.1 com.google.protobuf:protoc:${protobuf.version}:exe:${os.detected.classifier} compile grpc-java compile-custom grpc-java io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier} grpc-kotlin compile-custom grpc-kotlin io.rouz:grpc-kotlin-gen:${project.version}:exe:${os.detected.classifier} kotlin-maven-plugin org.jetbrains.kotlin ${kotlin.version} 1.8 -Xuse-experimental=kotlin.Experimental compile compile compile ${project.basedir}/src/main/kotlin ${project.basedir}/target/generated-sources/protobuf/grpc-kotlin ${project.basedir}/target/generated-sources/protobuf/grpc-java ${project.basedir}/target/generated-sources/protobuf/java test-compile test-compile ${project.basedir}/src/test/kotlin org.apache.maven.plugins maven-compiler-plugin default-compile none default-testCompile none java-compile compile compile java-test-compile test-compile testCompile org.apache.maven.plugins maven-jar-plugin 3.1.0 org.springframework.boot spring-boot-maven-plugin 2.1.0.RELEASE repackage io.rouz.grpc.examples.chat.EntrypointKt JAR ${project.name} org.apache.maven.plugins maven-deploy-plugin 2.8.2 true ================================================ FILE: grpc-kotlin-example-chatserver/src/main/kotlin/io/rouz/grpc/examples/chat/ChatClient.kt ================================================ /*- * -\-\- * simple-kotlin-standalone-example * -- * Copyright (C) 2016 - 2018 rouz.io * -- * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * -/-/- */ package io.rouz.grpc.examples.chat import io.grpc.ManagedChannelBuilder import kotlinx.coroutines.GlobalScope import kotlinx.coroutines.channels.ReceiveChannel import kotlinx.coroutines.launch fun main(args: Array) { chatClient() } fun chatClient() { val channel = ManagedChannelBuilder.forAddress("localhost", 15001) .usePlaintext() .build() val chatService = ChatServiceGrpc.newStub(channel) val chat = chatService.chat() println("type :q to quit") print("Enter your name: ") val from = readLine() chat.send( ChatMessage.newBuilder() .setFrom(from) .build() ) startPrintLoop(chat) try { while (true) { print("Message: ") val message = readLine() if (message == null || message == ":q") { break } chat.send( ChatMessage.newBuilder() .setFrom(from) .setMessage(message) .build() ) } } finally { println("closing") chat.close() } } private fun startPrintLoop(chat: ReceiveChannel) = GlobalScope.launch { try { for (responseMessage in chat) { val message = responseMessage.message println("${message.from}: ${message.message}") } println("Server disconnected") } catch (e: Throwable) { println("Server disconnected badly: $e") } } ================================================ FILE: grpc-kotlin-example-chatserver/src/main/kotlin/io/rouz/grpc/examples/chat/ChatService.kt ================================================ /*- * -\-\- * simple-kotlin-standalone-example * -- * Copyright (C) 2016 - 2019 rouz.io * -- * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * -/-/- */ package io.rouz.grpc.examples.chat import com.google.protobuf.Empty import com.google.protobuf.Timestamp import io.grpc.Status import kotlinx.coroutines.ExperimentalCoroutinesApi import kotlinx.coroutines.GlobalScope import kotlinx.coroutines.channels.Channel import kotlinx.coroutines.channels.ReceiveChannel import kotlinx.coroutines.channels.SendChannel import kotlinx.coroutines.launch import java.time.Instant import java.util.concurrent.ConcurrentSkipListMap @UseExperimental(ExperimentalCoroutinesApi::class) class ChatService : ChatServiceImplBase() { private val clientChannels = ConcurrentSkipListMap>() override suspend fun getNames(request: Empty): ChatRoom { return ChatRoom.newBuilder() .addAllNames(clientChannels.keys) .build() } private fun createChannel() = Channel(100).apply { invokeOnClose { it?.printStackTrace() } } private fun subscribe(name: String, ch: SendChannel) { println("New client connected: $name") clientChannels.put(name, ch) ?.apply { println("Close duplicate channel of user: $name") close() } } private suspend fun broadcast(message: ChatMessage) = createMessage(message) .let { broadcastMessage -> println("Broadcast ${message.from}: ${message.message}") clientChannels.asSequence() .filterNot { (name, _) -> name == message.from } .forEach { (other, ch) -> launch { try { println("Sending to $other") ch.send(broadcastMessage) } catch (e: Throwable) { println("$other hung up: ${e.message}. Removing client channel") clientChannels.remove(other)?.close(e) } } } } override fun chat(requests: ReceiveChannel): ReceiveChannel = createChannel().also { GlobalScope.launch { doChat(requests, it) } } private suspend fun doChat(req: ReceiveChannel, resp: SendChannel) { val hello = req.receive() subscribe(hello.from, resp) broadcast(hello) try { for (chatMessage in req) { println("Got request from $req:") println(chatMessage) broadcast(chatMessage) } } catch (t: Throwable) { println("Threw $t") if (Status.fromThrowable(t).code != Status.Code.CANCELLED) { println("An actual error occurred") t.printStackTrace() } } finally { println("${hello.from} hung up. Removing client channel") clientChannels.remove(hello.from) if (!resp.isClosedForSend) { resp.close() } } } override suspend fun say(request: ChatMessage): Empty = Empty.getDefaultInstance().also { broadcast(request) } override fun listen(request: WhoAmI): ReceiveChannel = createChannel().also { subscribe(request.name, it) } fun shutdown() { println("Shutting down Chat service") clientChannels.forEach { (client, channel) -> println("Closing client channel $client") channel.close() } clientChannels.clear() } private fun createMessage(request: ChatMessage) = ChatMessageFromService.newBuilder() .run { timestamp = Instant.now().run { Timestamp.newBuilder().run { seconds = epochSecond nanos = nano build() } } message = request build() } } ================================================ FILE: grpc-kotlin-example-chatserver/src/main/kotlin/io/rouz/grpc/examples/chat/Entrypoint.kt ================================================ /*- * -\-\- * simple-kotlin-standalone-example * -- * Copyright (C) 2016 - 2018 rouz.io * -- * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * -/-/- */ package io.rouz.grpc.examples.chat fun main(args: Array) { when(args[0]) { "server" -> grpcServer() "client" -> chatClient() "clientSS" -> serverStreamingChatClient() } } ================================================ FILE: grpc-kotlin-example-chatserver/src/main/kotlin/io/rouz/grpc/examples/chat/GrpcServer.kt ================================================ /*- * -\-\- * simple-kotlin-standalone-example * -- * Copyright (C) 2016 - 2018 rouz.io * -- * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * -/-/- */ package io.rouz.grpc.examples.chat import io.grpc.ServerBuilder import io.grpc.protobuf.services.ProtoReflectionService fun main(args: Array) { grpcServer() } fun grpcServer() { val chatService = ChatService() val server = ServerBuilder .forPort(15001) .addService(ProtoReflectionService.newInstance()) .addService(chatService) .build() Runtime.getRuntime().addShutdownHook(Thread { println("Ups, JVM shutdown") chatService.shutdown() server.shutdown() server.awaitTermination() println("Chat service stopped") }) server.start() println("Chat service started") server.awaitTermination() } ================================================ FILE: grpc-kotlin-example-chatserver/src/main/kotlin/io/rouz/grpc/examples/chat/ServerStreaminChatClient.kt ================================================ /*- * -\-\- * simple-kotlin-standalone-example * -- * Copyright (C) 2016 - 2019 rouz.io * -- * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * -/-/- */ package io.rouz.grpc.examples.chat import io.grpc.ManagedChannelBuilder import kotlinx.coroutines.Dispatchers import kotlinx.coroutines.channels.ReceiveChannel import kotlinx.coroutines.launch import kotlinx.coroutines.runBlocking import java.util.concurrent.TimeUnit fun main() = serverStreamingChatClient() fun serverStreamingChatClient() { val channel = ManagedChannelBuilder.forAddress("localhost", 15001) .usePlaintext() .build() val chatService = ChatServiceGrpc.newStub(channel) println("type :q to quit") print("Enter your name: ") val from = readLine() val listen = chatService.listen(WhoAmI.newBuilder().setName(from).build()) runBlocking(Dispatchers.IO) { launch { startPrintLoop(listen) } try { while (true) { print("Message: ") val message = readLine() if (message == null || message == ":q") { break } chatService.say( ChatMessage.newBuilder() .setFrom(from) .setMessage(message) .build() ) } } finally { println("closing") channel.shutdownNow().awaitTermination(1, TimeUnit.SECONDS) println("closed") } } } private suspend fun startPrintLoop(chat: ReceiveChannel) = try { for (responseMessage in chat) { val message = responseMessage.message println("${message.from}: ${message.message}") } println("Server disconnected") } catch (e: Throwable) { println("Server disconnected badly: $e") } ================================================ FILE: grpc-kotlin-example-chatserver/src/main/proto/chat.proto ================================================ syntax = "proto3"; package io.rouz.grpc.examples.chat; import "google/protobuf/timestamp.proto"; import "google/protobuf/empty.proto"; option java_multiple_files = true; option java_package = "io.rouz.grpc.examples.chat"; service ChatService { rpc Chat (stream ChatMessage) returns (stream ChatMessageFromService); rpc GetNames (google.protobuf.Empty) returns (ChatRoom); rpc Say(ChatMessage) returns (google.protobuf.Empty); rpc Listen(WhoAmI) returns (stream ChatMessageFromService); } message ChatRoom { repeated string names = 1; } message WhoAmI { string name = 1; } message ChatMessage { string from = 1; string message = 2; } message ChatMessageFromService { google.protobuf.Timestamp timestamp = 1; ChatMessage message = 2; } ================================================ FILE: grpc-kotlin-gen/pom.xml ================================================ 4.0.0 io.rouz grpc-kotlin-parent 0.1.5-SNAPSHOT grpc-kotlin-gen jar grpc-kotlin-gen 1.25.0 com.salesforce.servicelibs jprotoc 0.9.1 io.grpc grpc-protobuf ${grpc.version} org.springframework.boot spring-boot-maven-plugin 1.5.8.RELEASE repackage io.rouz.grpc.kotlin.GrpcKotlinGenerator JAR com.salesforce.servicelibs canteen-maven-plugin 1.0.0 bootstrap ================================================ FILE: grpc-kotlin-gen/src/main/java/io/rouz/grpc/kotlin/GrpcKotlinGenerator.java ================================================ /*- * -\-\- * grpc-kotlin-gen * -- * Copyright (C) 2016 - 2018 rouz.io * -- * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * -/-/- */ /* * Copyright (c) 2017, salesforce.com, inc. * All rights reserved. * Licensed under the BSD 3-Clause license. * For full license text, see https://opensource.org/licenses/BSD-3-Clause */ package io.rouz.grpc.kotlin; import com.google.common.base.Preconditions; import com.google.common.base.Strings; import com.google.common.html.HtmlEscapers; import com.google.protobuf.DescriptorProtos.FileDescriptorProto; import com.google.protobuf.DescriptorProtos.FileOptions; import com.google.protobuf.DescriptorProtos.MethodDescriptorProto; import com.google.protobuf.DescriptorProtos.ServiceDescriptorProto; import com.google.protobuf.DescriptorProtos.SourceCodeInfo.Location; import com.google.protobuf.compiler.PluginProtos; import com.salesforce.jprotoc.Generator; import com.salesforce.jprotoc.GeneratorException; import com.salesforce.jprotoc.ProtoTypeMap; import com.salesforce.jprotoc.ProtocPlugin; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; import static com.google.protobuf.compiler.PluginProtos.CodeGeneratorRequest; import static com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse; public class GrpcKotlinGenerator extends Generator { private static final int SERVICE_NUMBER_OF_PATHS = 2; private static final int METHOD_NUMBER_OF_PATHS = 4; private static final String CLASS_SUFFIX = "ImplBase"; private static final String STUB_SUFFIX = "StubExt"; private static final String ADAPTERS_FILE_PATH = "io/rouz/grpc/Adapters.kt"; private static final String SERVICE_JAVA_DOC_PREFIX = " "; private static final String METHOD_JAVA_DOC_PREFIX = " "; public static void main(String[] args) { ProtocPlugin.generate(new GrpcKotlinGenerator()); } @Override public List generateFiles(CodeGeneratorRequest request) throws GeneratorException { final ProtoTypeMap typeMap = ProtoTypeMap.of(request.getProtoFileList()); List protosToGenerate = request.getProtoFileList().stream() .filter(protoFile -> request.getFileToGenerateList().contains(protoFile.getName())) .collect(Collectors.toList()); List services = findServices(protosToGenerate, typeMap); return generateFiles(services); } private List findServices(List protos, ProtoTypeMap typeMap) { List contexts = new ArrayList<>(); protos.forEach(fileProto -> { List locations = fileProto.getSourceCodeInfo().getLocationList(); locations.stream() .filter(location -> location.getPathCount() == SERVICE_NUMBER_OF_PATHS && location.getPath(0) == FileDescriptorProto.SERVICE_FIELD_NUMBER) .forEach(location -> { int serviceNumber = location.getPath(SERVICE_NUMBER_OF_PATHS - 1); Context context = context( fileProto.getService(serviceNumber), typeMap, locations, serviceNumber); context.javaDoc = getJavaDoc(getComments(location), SERVICE_JAVA_DOC_PREFIX); context.protoName = fileProto.getName(); context.packageName = extractPackageName(fileProto); contexts.add(context); }); }); return contexts; } private String extractPackageName(FileDescriptorProto proto) { FileOptions options = proto.getOptions(); if (options != null) { String javaPackage = options.getJavaPackage(); if (!Strings.isNullOrEmpty(javaPackage)) { return javaPackage; } } return Strings.nullToEmpty(proto.getPackage()); } private Context context( ServiceDescriptorProto serviceProto, ProtoTypeMap protoTypeMap, List locations, int serviceNumber) { Context context = new Context(); context.serviceName = serviceProto.getName(); context.deprecated = serviceProto.getOptions() != null && serviceProto.getOptions().getDeprecated(); locations.stream() .filter(location -> location.getPathCount() == METHOD_NUMBER_OF_PATHS && location.getPath(0) == FileDescriptorProto.SERVICE_FIELD_NUMBER && location.getPath(1) == serviceNumber && location.getPath(2) == ServiceDescriptorProto.METHOD_FIELD_NUMBER) .forEach(location -> { int methodNumber = location.getPath(METHOD_NUMBER_OF_PATHS - 1); MethodContext methodContext = methodContext( serviceProto.getMethod(methodNumber), protoTypeMap); methodContext.methodNumber = methodNumber; methodContext.javaDoc = getJavaDoc(getComments(location), METHOD_JAVA_DOC_PREFIX); context.methods.add(methodContext); }); return context; } private MethodContext methodContext(MethodDescriptorProto methodProto, ProtoTypeMap typeMap) { MethodContext methodContext = new MethodContext(); methodContext.methodName = lowerCaseFirst(methodProto.getName()); methodContext.inputType = typeMap.toJavaTypeName(methodProto.getInputType()); methodContext.outputType = typeMap.toJavaTypeName(methodProto.getOutputType()); methodContext.deprecated = methodProto.getOptions() != null && methodProto.getOptions().getDeprecated(); methodContext.isManyInput = methodProto.getClientStreaming(); methodContext.isManyOutput = methodProto.getServerStreaming(); if (!methodProto.getClientStreaming() && !methodProto.getServerStreaming()) { methodContext.grpcCallsMethodName = "asyncUnaryCall"; } if (!methodProto.getClientStreaming() && methodProto.getServerStreaming()) { methodContext.grpcCallsMethodName = "asyncServerStreamingCall"; } if (methodProto.getClientStreaming() && !methodProto.getServerStreaming()) { methodContext.grpcCallsMethodName = "asyncClientStreamingCall"; } if (methodProto.getClientStreaming() && methodProto.getServerStreaming()) { methodContext.grpcCallsMethodName = "asyncBidiStreamingCall"; } return methodContext; } private String lowerCaseFirst(String s) { return Character.toLowerCase(s.charAt(0)) + s.substring(1); } private List generateFiles(List services) { List files = new ArrayList<>(); files.add(buildUtilFile()); for (Context service : services) { files.add(buildServiceBaseImpl(service)); files.add(buildStubExtensions(service)); } return files; } private PluginProtos.CodeGeneratorResponse.File buildUtilFile() { UtilContext utilContext = new UtilContext(); String content = applyTemplate("Adapters.mustache", utilContext); return PluginProtos.CodeGeneratorResponse.File .newBuilder() .setName(ADAPTERS_FILE_PATH) .setContent(content) .build(); } private PluginProtos.CodeGeneratorResponse.File buildServiceBaseImpl(Context context) { String content = applyTemplate("ImplBase.mustache", context); String fileName = context.serviceName + CLASS_SUFFIX + ".kt"; return PluginProtos.CodeGeneratorResponse.File .newBuilder() .setName(absoluteFileName(context.packageName, fileName)) .setContent(content) .build(); } PluginProtos.CodeGeneratorResponse.File buildStubExtensions(Context context) { String content = applyTemplate("StubExtensions.mustache", context); String fileName = context.serviceName + STUB_SUFFIX + ".kt"; return PluginProtos.CodeGeneratorResponse.File .newBuilder() .setName(absoluteFileName(context.packageName, fileName)) .setContent(content) .build(); } private static String absoluteFileName(String packageName, String fileName) { Preconditions.checkNotNull(packageName, "packageName"); String dir = packageName.replace('.', '/'); if (Strings.isNullOrEmpty(dir)) { return fileName; } else { return dir + "/" + fileName; } } private String getComments(Location location) { return location.getLeadingComments().isEmpty() ? location.getTrailingComments() : location.getLeadingComments(); } private String getJavaDoc(String comments, String prefix) { if (!comments.isEmpty()) { StringBuilder builder = new StringBuilder("/**\n") .append(prefix).append(" * 
\n");
      Arrays.stream(HtmlEscapers.htmlEscaper().escape(comments).split("\n"))
          // Kotlin allows nested block comments, so any occurrence of '/*' would begin
          // a nested block, breaking the generated code.
          .map(line -> line.replace("/*", "/*"))
          .map(line -> line.replace("*/", "*/"))
          .forEach(line -> builder.append(prefix).append(" * ").append(line).append("\n"));
      builder
          .append(prefix).append(" * 
\n")
          .append(prefix).append(" */");
      return builder.toString();
    }
    return null;
  }

  /**
   * Template class for proto Service objects.
   */
  protected final class Context {
    // CHECKSTYLE DISABLE VisibilityModifier FOR 6 LINES
    public String protoName;
    public String packageName;
    public String serviceName;
    public boolean deprecated;
    public String javaDoc;
    public List methods = new ArrayList<>();
  }

  /**
   * Template class for proto RPC objects.
   */
  private class MethodContext {
    // CHECKSTYLE DISABLE VisibilityModifier FOR 10 LINES
    public String methodName;
    public String inputType;
    public String outputType;
    public boolean deprecated;
    public boolean isManyInput;
    public boolean isManyOutput;
    public String grpcCallsMethodName;
    public int methodNumber;
    public String javaDoc;

    // This method mimics the upper-casing method ogf gRPC to ensure compatibility
    // See https://github.com/grpc/grpc-java/blob/v1.8.0/compiler/src/java_plugin/cpp/java_generator.cpp#L58
    public String methodNameUpperUnderscore() {
      StringBuilder s = new StringBuilder();
      for (int i = 0; i < methodName.length(); i++) {
        char c = methodName.charAt(i);
        s.append(Character.toUpperCase(c));
        if ((i < methodName.length() - 1)
            && Character.isLowerCase(c)
            && Character.isUpperCase(methodName.charAt(i + 1))) {
          s.append('_');
        }
      }
      return s.toString();
    }

    public String methodNamePascalCase() {
      return String.valueOf(Character.toUpperCase(methodName.charAt(0))) + methodName.substring(1);
    }
  }

  /**
   * Template class for adapters file.
   */
  private class UtilContext {
  }
}


================================================
FILE: grpc-kotlin-gen/src/main/resources/Adapters.mustache
================================================
package io.rouz.grpc

import io.grpc.Context
import io.grpc.stub.StreamObserver
import kotlin.coroutines.*
import kotlinx.coroutines.*
import kotlinx.coroutines.channels.*

class ManyToOneCall(
    private val request: StreamObserver,
    private val response: Deferred
) : StreamObserverSendAdapter(request),
    Deferred by response

class ManyToManyCall(
    private val request: StreamObserver,
    private val response: ReceiveChannel
) : StreamObserverSendAdapter(request),
    ReceiveChannel by response

open class StreamObserverSendAdapter(private val streamObserver: StreamObserver) {

    fun close(cause: Throwable? = null): Boolean {
        if (cause != null) {
            streamObserver.onError(cause)
        } else {
            streamObserver.onCompleted()
        }

        return true
    }

    fun send(element: E) {
        streamObserver.onNext(element)
    }
}

class ContinuationStreamObserver(
    private val continuation: Continuation
) : StreamObserver {

    override fun onNext(value: E) {
        continuation.resume(value)
    }

    override fun onError(t: Throwable) {
        continuation.resumeWithException(t)
    }

    override fun onCompleted() {}
}

class StreamObserverDeferred(
    private val deferred: CompletableDeferred = CompletableDeferred()
) : StreamObserver, Deferred by deferred {

    override fun onNext(value: E) {
        deferred.complete(value)
    }

    override fun onError(t: Throwable) {
        deferred.completeExceptionally(t)
    }

    override fun onCompleted() { /* nothing */
    }
}

class StreamObserverChannel(
    private val channel: Channel = Channel(Channel.UNLIMITED)
) : StreamObserver, ReceiveChannel by channel {

    override fun onNext(value: E) {
        channel.offer(value)
    }

    override fun onError(t: Throwable?) {
        channel.close(cause = t)
    }

    override fun onCompleted() {
        channel.close(cause = null)
    }
}

class ContextCoroutineContextElement : ThreadContextElement {

    companion object Key : CoroutineContext.Key

    private val grpcContext: Context = Context.current()

    override val key: CoroutineContext.Key
        get() = Key

    override fun updateThreadContext(context: CoroutineContext): Context =
        grpcContext.attach()

    override fun restoreThreadContext(context: CoroutineContext, oldState: Context) =
        grpcContext.detach(oldState)
}


================================================
FILE: grpc-kotlin-gen/src/main/resources/ImplBase.mustache
================================================
{{#packageName}}
package {{packageName}}
{{/packageName}}

import {{packageName}}.{{serviceName}}Grpc.*

import io.grpc.*
import io.grpc.stub.*
import io.rouz.grpc.*

import kotlin.coroutines.*
import kotlinx.coroutines.*
import kotlinx.coroutines.channels.*

{{#javaDoc}}{{{javaDoc}}}{{/javaDoc}}
{{#deprecated}}@Deprecated("deprecated"){{/deprecated}}
@javax.annotation.Generated(
    value = ["by gRPC Kotlin generator"],
    comments = "Source: {{protoName}}"
)
abstract class {{serviceName}}ImplBase(
    coroutineContext: CoroutineContext = Dispatchers.Default
) : BindableService, CoroutineScope {

    private val _coroutineContext: CoroutineContext = coroutineContext

    override val coroutineContext: CoroutineContext
        get() = ContextCoroutineContextElement() + _coroutineContext

    {{#methods}}
    {{#javaDoc}}{{{javaDoc}}}{{/javaDoc}}
    {{#deprecated}}@Deprecated("deprecated"){{/deprecated}}
    {{^isManyInput}}
    {{^isManyOutput}}
    {{! == unary req, unary resp == }}
    open suspend fun {{methodName}}(request: {{inputType}}): {{outputType}} {
        throw unimplemented(get{{methodNamePascalCase}}Method()).asRuntimeException()
    }

    internal fun {{methodName}}Internal(
        request: {{inputType}},
        responseObserver: StreamObserver<{{outputType}}>
    ) {
        launch {
            tryCatchingStatus(responseObserver) {
                val response = {{methodName}}(request)
                onNext(response)
            }
        }
    }
    {{/isManyOutput}}
    {{#isManyOutput}}
    {{! == unary req, streaming resp == }}
    open fun {{methodName}}(request: {{inputType}}): ReceiveChannel<{{outputType}}> {
        throw unimplemented(get{{methodNamePascalCase}}Method()).asRuntimeException()
    }

    internal fun {{methodName}}Internal(
        request: {{inputType}},
        responseObserver: StreamObserver<{{outputType}}>
    ) {
        launch {
            tryCatchingStatus(responseObserver) {
                val responses = {{methodName}}(request)
                for (response in responses) {
                    try {
                        onNext(response)
                    } catch (e: Throwable) {
                        responses.cancel()
                        throw e
                    }
                }
            }
        }
    }
    {{/isManyOutput}}
    {{/isManyInput}}
    {{#isManyInput}}
    {{^isManyOutput}}
    {{! == streaming req, unary resp == }}
    open suspend fun {{methodName}}(requests: ReceiveChannel<{{inputType}}>): {{outputType}} {
        throw unimplemented(get{{methodNamePascalCase}}Method()).asRuntimeException()
    }

    internal fun {{methodName}}Internal(
        responseObserver: StreamObserver<{{outputType}}>
    ): StreamObserver<{{inputType}}> {
        val requests = StreamObserverChannel<{{inputType}}>()
        launch {
            tryCatchingStatus(responseObserver) {
                val response = {{methodName}}(requests)
                onNext(response)
            }
        }
        return requests
    }
    {{/isManyOutput}}
    {{#isManyOutput}}
    {{! == streaming req, streaming resp == }}
    open fun {{methodName}}(requests: ReceiveChannel<{{inputType}}>): ReceiveChannel<{{outputType}}> {
        throw unimplemented(get{{methodNamePascalCase}}Method()).asRuntimeException()
    }

    internal fun {{methodName}}Internal(
        responseObserver: StreamObserver<{{outputType}}>
    ): StreamObserver<{{inputType}}> {
        val requests = StreamObserverChannel<{{inputType}}>()
        launch {
            tryCatchingStatus(responseObserver) {
                val responses = {{methodName}}(requests)
                for (response in responses) {
                    try {
                        onNext(response)
                    } catch (e: Throwable) {
                        responses.cancel()
                        throw e
                    }
                }
            }
        }
        return requests
    }
    {{/isManyOutput}}
    {{/isManyInput}}
    {{/methods}}

    override fun bindService(): ServerServiceDefinition {
        return ServerServiceDefinition.builder(getServiceDescriptor())
            {{#methods}}
            .addMethod(
                get{{methodNamePascalCase}}Method(),
                ServerCalls.{{grpcCallsMethodName}}(
                    MethodHandlers(METHODID_{{methodNameUpperUnderscore}})
                )
            )
            {{/methods}}
            .build()
    }

    private fun unimplemented(methodDescriptor: MethodDescriptor<*, *>): Status {
        return Status.UNIMPLEMENTED
            .withDescription("Method ${methodDescriptor.fullMethodName} is unimplemented")
    }

    private fun  handleException(t: Throwable?, responseObserver: StreamObserver) {
        when (t) {
            null -> return
            is CancellationException -> handleException(t.cause, responseObserver)
            is StatusException, is StatusRuntimeException -> responseObserver.onError(t)
            is RuntimeException -> {
                responseObserver.onError(Status.UNKNOWN.asRuntimeException())
                throw t
            }
            is Exception -> {
                responseObserver.onError(Status.UNKNOWN.asException())
                throw t
            }
            else -> {
                responseObserver.onError(Status.INTERNAL.asException())
                throw t
            }
        }
    }

    private suspend fun  tryCatchingStatus(responseObserver: StreamObserver, body: suspend StreamObserver.() -> Unit) {
        try {
            responseObserver.body()
            responseObserver.onCompleted()
        } catch (t: Throwable) {
            handleException(t, responseObserver)
        }
    }

    {{#methods}}
    private val METHODID_{{methodNameUpperUnderscore}} = {{methodNumber}}
    {{/methods}}

    private inner class MethodHandlers internal constructor(
        private val methodId: Int
    ) : ServerCalls.UnaryMethod,
        ServerCalls.ServerStreamingMethod,
        ServerCalls.ClientStreamingMethod,
        ServerCalls.BidiStreamingMethod {

        @Suppress("UNCHECKED_CAST")
        override fun invoke(request: Req, responseObserver: StreamObserver) {
            when (methodId) {
                {{#methods}}
                {{^isManyInput}}
                METHODID_{{methodNameUpperUnderscore}} ->
                    this@{{serviceName}}ImplBase.{{methodName}}Internal(
                        request as {{inputType}},
                        responseObserver as StreamObserver<{{outputType}}>
                    )
                {{/isManyInput}}
                {{/methods}}
                else -> throw AssertionError()
            }
        }

        @Suppress("UNCHECKED_CAST")
        override fun invoke(responseObserver: StreamObserver): StreamObserver {
            when (methodId) {
                {{#methods}}
                {{#isManyInput}}
                METHODID_{{methodNameUpperUnderscore}} ->
                    return this@{{serviceName}}ImplBase.{{methodName}}Internal(
                        responseObserver as StreamObserver<{{outputType}}>
                    ) as StreamObserver
                {{/isManyInput}}
                {{/methods}}
                else -> throw AssertionError()
            }
        }
    }
}


================================================
FILE: grpc-kotlin-gen/src/main/resources/StubExtensions.mustache
================================================
{{#packageName}}
package {{packageName}}
{{/packageName}}

import io.rouz.grpc.*
import {{packageName}}.{{serviceName}}Grpc.{{serviceName}}Stub

import kotlinx.coroutines.channels.ReceiveChannel
import kotlin.coroutines.suspendCoroutine

import io.grpc.Metadata
import io.grpc.stub.MetadataUtils

/**
 * Kotlin extension functions for [{{packageName}}.{{serviceName}}Grpc.{{serviceName}}Stub]
 *
 * Generated by gRPC Kotlin generator
 * Source: {{protoName}}
 */

{{#methods}}
{{#javaDoc}}{{{javaDoc}}}{{/javaDoc}}
{{#deprecated}}@Deprecated("deprecated"){{/deprecated}}
{{^isManyInput}}
{{^isManyOutput}}
{{! == unary req, unary resp == }}
suspend inline fun {{serviceName}}Stub.{{methodName}}(request: {{inputType}}): {{outputType}} {
    return suspendCoroutine {
        {{methodName}}(request, ContinuationStreamObserver(it))
    }
}
{{/isManyOutput}}
{{#isManyOutput}}
{{! == unary req, streaming resp == }}
fun {{serviceName}}Stub.{{methodName}}(request: {{inputType}}): ReceiveChannel<{{outputType}}> {
    val responseChannel = StreamObserverChannel<{{outputType}}>()
    {{methodName}}(request, responseChannel)
    return responseChannel
}
{{/isManyOutput}}
{{/isManyInput}}
{{#isManyInput}}
{{^isManyOutput}}
{{! == streaming req, unary resp == }}
fun {{serviceName}}Stub.{{methodName}}(): ManyToOneCall<{{inputType}}, {{outputType}}> {
    val responseDeferred = StreamObserverDeferred<{{outputType}}>()
    val requestObserver = {{methodName}}(responseDeferred)
    return ManyToOneCall(requestObserver, responseDeferred)
}
{{/isManyOutput}}
{{#isManyOutput}}
{{! == streaming req, streaming resp == }}
fun {{serviceName}}Stub.{{methodName}}(): ManyToManyCall<{{inputType}}, {{outputType}}> {
    val responseChannel = StreamObserverChannel<{{outputType}}>()
    val requestObserver = {{methodName}}(responseChannel)
    return ManyToManyCall(requestObserver, responseChannel)
}
{{/isManyOutput}}
{{/isManyInput}}
{{/methods}}

/**
* Adds new binary header and returns the client
*/
fun {{serviceName}}Stub.addBinaryHeader(
    header: String,
    bytes: ByteArray
): {{serviceName}}Stub {
    val headers = Metadata()
    val key = Metadata.Key.of(header, Metadata.BINARY_BYTE_MARSHALLER)
    headers.put(key, bytes)

    return MetadataUtils.attachHeaders(this, headers)
}


================================================
FILE: grpc-kotlin-gen/src/test/java/io/rouz/grpc/kotlin/GrpcKotlinGeneratorTest.java
================================================
/*-
 * -\-\-
 * grpc-kotlin-gen
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.grpc.kotlin;


import com.google.protobuf.compiler.PluginProtos;
import org.junit.Test;

import static org.junit.Assert.assertTrue;

public class GrpcKotlinGeneratorTest extends GrpcKotlinGenerator {

  @Test
  public void buildStubExtensionsTest() {
    Context ctx = new Context();
    ctx.packageName = "some.package";
    ctx.serviceName = "SomeService";
    PluginProtos.CodeGeneratorResponse.File result = this.buildStubExtensions(ctx);

    String expected = "fun SomeServiceStub.addBinaryHeader(\n" +
            "    header: String,\n" +
            "    bytes: ByteArray\n" +
            "): SomeServiceStub {\n" +
            "    val headers = Metadata()\n" +
            "    val key = Metadata.Key.of(header, Metadata.BINARY_BYTE_MARSHALLER)\n" +
            "    headers.put(key, bytes)\n" +
            "\n" +
            "    return MetadataUtils.attachHeaders(this, headers)\n" +
            "}";

    String resultContent = result.getContent().replaceAll("\\r", "");
    assertTrue(resultContent.contains(expected));
  }
}


================================================
FILE: grpc-kotlin-test/pom.xml
================================================


    4.0.0

    
        io.rouz
        grpc-kotlin-parent
        0.1.5-SNAPSHOT
    

    grpc-kotlin-test
    grpc-kotlin-test
    jar

    
        1.3.61
        1.3.3
        1.25.0
        3.10.0
    

    
        
        
            org.jetbrains.kotlin
            kotlin-stdlib
            ${kotlin.version}
        
        
            org.jetbrains.kotlinx
            kotlinx-coroutines-core
            ${kotlinx-coroutines.version}
        

        
            io.grpc
            grpc-netty
            ${grpc.version}
        
        
            io.grpc
            grpc-protobuf
            ${grpc.version}
        
        
            io.grpc
            grpc-stub
            ${grpc.version}
        

        
            io.github.microutils
            kotlin-logging
            1.4.9
        
        
            org.slf4j
            slf4j-simple
            1.7.25
        
        
            javax.annotation
            javax.annotation-api
            1.3.2
        

        
        
            io.grpc
            grpc-testing
            ${grpc.version}
            test
        
    

    
        
            
                kr.motd.maven
                os-maven-plugin
                1.5.0.Final
            
        

        
            
                org.xolstice.maven.plugins
                protobuf-maven-plugin
                0.6.1
                
                    com.google.protobuf:protoc:${protobuf.version}:exe:${os.detected.classifier}
                    
                
                
                    
                        
                            compile
                        
                    
                    
                        grpc-java
                        
                            compile-custom
                        
                        
                            grpc-java
                            io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}
                            
                        
                    
                    
                        grpc-kotlin
                        
                            compile-custom
                        
                        
                            grpc-kotlin
                            io.rouz:grpc-kotlin-gen:${project.version}:exe:${os.detected.classifier}
                        
                    
                
            
            
                kotlin-maven-plugin
                org.jetbrains.kotlin
                ${kotlin.version}
                
                    1.8
                    -Xuse-experimental=kotlin.Experimental
                
                
                    
                        compile
                        compile
                        
                            compile
                        
                        
                            
                                ${project.basedir}/src/main/kotlin
                                ${project.basedir}/target/generated-sources/protobuf/grpc-kotlin
                                ${project.basedir}/target/generated-sources/protobuf/grpc-java
                                ${project.basedir}/target/generated-sources/protobuf/java
                            
                        
                    
                    
                        test-compile
                        
                            test-compile
                        
                        
                            
                                ${project.basedir}/src/test/kotlin
                            
                        
                    
                
            

            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    
                    
                        default-compile
                        none
                    
                    
                    
                        default-testCompile
                        none
                    
                    
                        java-compile
                        compile
                        
                            compile
                        
                    
                    
                        java-test-compile
                        test-compile
                        
                            testCompile
                        
                    
                
            

            
                org.apache.maven.plugins
                maven-deploy-plugin
                2.8.2
                
                    true
                
            
        
    



================================================
FILE: grpc-kotlin-test/src/main/kotlin/io/rouz/greeter/GreeterImpl.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.asCoroutineDispatcher
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.produce
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import mu.KotlinLogging
import java.util.concurrent.Executors.newFixedThreadPool

/**
 * Implementation of coroutine-based gRPC service defined in greeter.proto
 */
@UseExperimental(ExperimentalCoroutinesApi::class)
open class GreeterImpl : GreeterImplBase(
    coroutineContext = newFixedThreadPool(4, threadFactory("server-worker-%d")).asCoroutineDispatcher()
) {

    protected val log = KotlinLogging.logger("server")

    override suspend fun greet(request: GreetRequest): GreetReply {
        log.info(request.greeting)

        return GreetReply.newBuilder()
            .setReply("Hello " + request.greeting)
            .build()
    }

    override fun greetServerStream(request: GreetRequest) = produce {
        log.info(request.greeting)

        send(
            GreetReply.newBuilder()
                .setReply("Hello ${request.greeting}!")
                .build()
        )
        send(
            GreetReply.newBuilder()
                .setReply("Greetings ${request.greeting}!")
                .build()
        )
    }

    override suspend fun greetClientStream(requests: ReceiveChannel): GreetReply {
        val greetings = mutableListOf()

        for (request in requests) {
            log.info(request.greeting)
            greetings.add(request.greeting)
        }

        return GreetReply.newBuilder()
            .setReply("Hi to all of $greetings!")
            .build()
    }

    override fun greetBidirectional(requests: ReceiveChannel) = produce {
        var count = 0

        for (request in requests) {
            val n = count++
            log.info("$n ${request.greeting}")
            launch {
                delay(100)
                send(
                    GreetReply.newBuilder()
                        .setReply("Yo #$n ${request.greeting}")
                        .build()
                )
                log.info("dispatched $n")
            }
        }

        log.info("completing")
    }
}


================================================
FILE: grpc-kotlin-test/src/main/kotlin/io/rouz/greeter/GreeterMain.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import com.google.common.util.concurrent.ThreadFactoryBuilder
import io.grpc.ManagedChannelBuilder
import io.grpc.ServerBuilder
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import mu.KotlinLogging
import java.util.concurrent.ThreadFactory

fun main(args: Array) {
    val log = KotlinLogging.logger("client")
    ServerBuilder.forPort(8080)
        .addService(GreeterImpl())
        .build()
        .start()
    val localhost = ManagedChannelBuilder.forAddress("localhost", 8080)
        .usePlaintext()
        .build()

    val greeter = GreeterGrpc.newStub(localhost)

    runBlocking {
        // === Unary call =============================================================================

        val unaryResponse = greeter.greet(req("Alice"))
        log.info("unary reply = ${unaryResponse.reply}")

        // === Server streaming call ==================================================================

        val serverResponses = greeter.greetServerStream(req("Bob"))
        for (serverResponse in serverResponses) {
            log.info("server response = ${serverResponse.reply}")
        }

        // === Client streaming call ==================================================================

        val manyToOneCall = greeter.greetClientStream()
        manyToOneCall.send(req("Caroline"))
        manyToOneCall.send(req("David"))
        manyToOneCall.close()
        val oneReply = manyToOneCall.await()
        log.info("single reply = ${oneReply.reply}")

        // === Bidirectional call =====================================================================

        val bidiCall = greeter.greetBidirectional()
        launch {
            var n = 0
            for (greetReply in bidiCall) {
                log.info("reply $n = ${greetReply.reply}")
                n++
            }
            log.info("no more replies")
        }

        delay(200)
        bidiCall.send(req("Eve"))

        delay(200)
        bidiCall.send(req("Fred"))

        delay(200)
        bidiCall.send(req("Gina"))
        bidiCall.close()
    }
}

fun req(greeting: String): GreetRequest {
    return GreetRequest.newBuilder().setGreeting(greeting).build()
}

fun threadFactory(threadNameFormat: String): ThreadFactory = ThreadFactoryBuilder()
    .setDaemon(true)
    .setNameFormat(threadNameFormat)
    .build()


================================================
FILE: grpc-kotlin-test/src/main/kotlin/io/rouz/greeter/InfiniteStreamGreeterImpl.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2019 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */


package io.rouz.greeter

import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext
import java.util.concurrent.ConcurrentHashMap
import java.util.concurrent.Semaphore

class InfiniteStreamGreeterImpl : GreeterImpl() {

    val subscribers = ConcurrentHashMap>()
    val startupSync = Semaphore(0)

    override fun greetServerStream(request: GreetRequest): ReceiveChannel =
            Channel(100).also {
                val name = request.greeting
                subscribers[name] = it
                log.info("Subscribed: {}", name)
                startupSync.release()
            }

    suspend fun greetAllSubscribers(word: String) {
        withContext(Dispatchers.IO) {
            subscribers.forEach { (subs, ch) ->
                GreetReply.newBuilder().run {
                    reply = "$word $subs"
                    build()
                }.also {
                    launch {
                        try {
                            ch.send(it)
                            log.info("Message to client: {}", it.reply)
                        } catch (e: Throwable) {
                            log.info("Unsubscribe client: {}", subs)
                            subscribers.remove(subs)
                            ch.close()
                        }
                    }
                }
            }
        }
    }
}


================================================
FILE: grpc-kotlin-test/src/main/proto/io/rouz/greeter.proto
================================================
syntax = "proto3";
package io.rouz.greeter;

option java_package = "io.rouz.greeter";
option java_multiple_files = true;

message GreetRequest {
    string greeting = 1;
}

message GreetReply {
    string reply = 1;
}

service Greeter {
    // Adding some comments to ensure correct parsing with respect to kotlin nested block comments
    // /* That should get escaped so that it doesn't start a block comment
    // */ That should also get escaped so that it doesn't terminate a javadoc comment block
    rpc Greet (GreetRequest) returns (GreetReply);
    rpc GreetServerStream (GreetRequest) returns (stream GreetReply);
    rpc GreetClientStream (stream GreetRequest) returns (GreetReply);
    rpc GreetBidirectional (stream GreetRequest) returns (stream GreetReply);
}


================================================
FILE: grpc-kotlin-test/src/main/proto/io/rouz/kvs.proto
================================================
syntax = "proto3";
package io.rouz.kvs;

import "io/rouz/greeter.proto";

option java_package = "io.rouz.kvs";

message KvsMessage {
    string msg = 1;
}

service KeyValueStore {
    rpc GetKeyForGreeting (io.rouz.greeter.GreetRequest) returns (io.rouz.greeter.GreetReply);
    rpc Dummy (KvsMessage) returns (KvsMessage);
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/ClientAbandonTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2019 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import io.grpc.ManagedChannel
import io.grpc.ManagedChannelBuilder
import io.grpc.netty.NettyServerBuilder
import kotlinx.coroutines.joinAll
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import kotlinx.coroutines.yield
import mu.KotlinLogging
import org.junit.After
import org.junit.Assert.assertEquals
import org.junit.Assert.assertTrue
import org.junit.Test
import org.junit.runner.RunWith
import org.junit.runners.JUnit4
import java.util.concurrent.TimeUnit.SECONDS
import kotlin.coroutines.resume
import kotlin.coroutines.suspendCoroutine


@RunWith(JUnit4::class)
class ClientAbandonTest {
    private val log = KotlinLogging.logger {}

    private val svc = InfiniteStreamGreeterImpl()

    private fun server() =
            NettyServerBuilder.forPort(16565)
                    .addService(svc)
                    .build()
                    .start()

    private fun getChannel() = ManagedChannelBuilder
            .forAddress("localhost", 16565)
            .usePlaintext()
            .build().also {
                channels.add(it)
            }


    private fun dumpSubscribers() =
            log.info("Current subscribers: {}", svc.subscribers.keys)

    private val serv = server()
    private val channels: MutableList = mutableListOf()

    @After
    fun tearDown() {
        channels.forEach { ch ->
            if (!ch.shutdownNow().awaitTermination(1, SECONDS)) {
                error("Failed to shutdown channel")
            }
        }
        if (!serv.shutdownNow().awaitTermination(1, SECONDS)) {
            error("Failed to shutdown server")
        }
    }

    @Test
    fun infiniteServerStreamingToSubscribers() {
        // Create two subscribers & subscribe them
        val rouzStub = GreeterGrpc.newStub(getChannel())
        val igorStub = GreeterGrpc.newStub(getChannel())

        val rouzCh = rouzStub.greetServerStream(req("rouz"))
        val igorCh = igorStub.greetServerStream(req("igor"))
        svc.startupSync.acquire(2)

        runBlocking {
            dumpSubscribers()
            assertEquals(setOf("rouz", "igor"), svc.subscribers.keys)

            // Publish greeting to all
            val rouzJob = launch {
                rouzCh.receive().also {
                    assertEquals("Hello rouz", it.reply)
                }
            }

            val igorJob = launch {
                igorCh.receive().also {
                    assertEquals("Hello igor", it.reply)
                }
            }

            val sendJob = launch {
                svc.greetAllSubscribers("Hello")
            }

            joinAll(rouzJob, igorJob, sendJob)
            assertEquals(setOf("rouz", "igor"), svc.subscribers.keys)

            // One client disconnects
            suspendCoroutine {
                val ch = igorStub.channel as ManagedChannel
                ch.shutdownNow()
                it.resume(assertTrue(ch.awaitTermination(1, SECONDS)))
            }

            // Continue publishing of new greetings
            val rouzJob2 = launch {
                repeat(4) {
                    assertEquals("Hola $it rouz", rouzCh.receive().reply)
                }
            }

            // One of the first invocations should close the channel of Igor, the next one should remove subscription.
            val senderJob2 = launch {
                repeat(4) {
                    svc.greetAllSubscribers("Hola $it")
                    yield()
                }
            }

            joinAll(rouzJob2, senderJob2)

            // Check that subscription of Igor has gone
            dumpSubscribers()
            assertEquals(setOf("rouz"), svc.subscribers.keys)
        }
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/ClosingStatusExceptionTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.produce

class ClosingStatusExceptionTest : StatusExceptionTestBase() {

    override val service: GreeterImplBase
        get() = StatusThrowingGreeter()

    @UseExperimental(ExperimentalCoroutinesApi::class)
    private inner class StatusThrowingGreeter : GreeterImplBase(collectExceptions) {

        override suspend fun greet(request: GreetRequest): GreetReply {
            throw notFound("uni")
        }

        override fun greetServerStream(request: GreetRequest) = produce {
            close(notFound("sstream"))
        }

        override suspend fun greetClientStream(requests: ReceiveChannel): GreetReply {
            throw notFound("cstream")
        }

        override fun greetBidirectional(requests: ReceiveChannel) = produce {
            close(notFound("bidi"))
        }
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/ContextBasedGreeterTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import io.grpc.Context
import io.grpc.Contexts
import io.grpc.Metadata
import io.grpc.ServerCall
import io.grpc.ServerCallHandler
import io.grpc.ServerInterceptor
import io.grpc.stub.MetadataUtils
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.produce
import kotlinx.coroutines.channels.toList
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import org.junit.Assert
import org.junit.Test

class ContextBasedGreeterTest : GrpcTestBase() {

    companion object {
        private val userContextKey = Context.key("user name")
        private val userMetadataKey = Metadata.Key.of("User-Name", Metadata.ASCII_STRING_MARSHALLER)
    }

    @Test
    fun contextValueMissing() {
        val stub = startServer(ContextGreeter())

        runBlocking {
            val reply = stub.greet(req("rouz"))

            Assert.assertEquals("Hello anonymous", reply.reply)
        }
    }

    @Test
    fun contextValuePresent() {
        val stub = MetadataUtils.attachHeaders(
            startServer(ContextGreeter()),
            Metadata().apply { put(userMetadataKey, "Chad") }
        )

        runBlocking {
            val reply = stub.greet(req("rouz"))

            Assert.assertEquals("Hello Chad", reply.reply)
        }
    }

    @Test
    fun contextTransferredAcrossThreads() {
        /*
         * This test is intended to ensure that the context gets transferred as expected to child coroutines and multiple
         * threads. We ensure this by having the service include the thread ID in the reply and verifying that more than
         * one thread issued replies.
         */
        val stub = MetadataUtils.attachHeaders(
            startServer(ContextGreeter()),
            Metadata().apply { put(userMetadataKey, "Jordan") }
        )

        runBlocking {
            val replies = stub.greetServerStream(req("rouz")).toList()

            val regex = Regex("Hi #\\d{1,3} Jordan from (\\d+)")
            val threadIds = replies
                .map { regex.matchEntire(it.reply) }
                .onEach { Assert.assertNotNull("Reply did not match '${regex.pattern}'", it) }.filterNotNull()
                .map { it.groups[1]?.value }
                .onEach { Assert.assertNotNull(it) }.filterNotNull()
                .toSet()
            Assert.assertNotEquals("All messages were dispatched by a single thread", 1, threadIds.size)
        }
    }

    override fun serverInterceptor(): ServerInterceptor = ServerNameInterceptor

    inner class ContextGreeter : GreeterImplBase() {
        override suspend fun greet(request: GreetRequest): GreetReply =
            repl("Hello ${userContextKey.get() ?: "anonymous"}")

        @ExperimentalCoroutinesApi
        override fun greetServerStream(request: GreetRequest): ReceiveChannel = produce {
            for (i in 0..99) {
                launch {
                    send(repl("Hi #$i ${userContextKey.get()} from ${Thread.currentThread().id}"))
                }
            }
        }
    }

    object ServerNameInterceptor : ServerInterceptor {
        override fun  interceptCall(
            call: ServerCall,
            headers: Metadata,
            next: ServerCallHandler
        ): ServerCall.Listener = headers[userMetadataKey]
            ?.let {
                Contexts.interceptCall(
                    Context.current().withValue(userContextKey, it),
                    call,
                    headers,
                    next
                )
            } ?: next.startCall(call, headers)
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/DelayedClosingStatusExceptionTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.async
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.SendChannel
import kotlinx.coroutines.channels.produce
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch

class DelayedClosingStatusExceptionTest : StatusExceptionTestBase() {

    override val service: GreeterImplBase
        get() = StatusThrowingGreeter()

    @UseExperimental(ExperimentalCoroutinesApi::class)
    private inner class StatusThrowingGreeter : GreeterImplBase(collectExceptions) {

        override suspend fun greet(request: GreetRequest): GreetReply {
            async {
                delay(10)
                throw notFound("uni")
            }.await()
        }

        override fun greetServerStream(request: GreetRequest) = produce {
            launch {
                delay(10)
                close(notFound("sstream"))
            }
        }

        override suspend fun greetClientStream(requests: ReceiveChannel): GreetReply {
            async {
                delay(10)
                throw notFound("cstream")
            }.await()
        }

        override fun greetBidirectional(requests: ReceiveChannel) = produce {
            launch {
                delay(10)
                close(notFound("bidi"))
            }
        }
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/DelayedThrowingStatusExceptionTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.async
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.produce
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch

@UseExperimental(ExperimentalCoroutinesApi::class)
class DelayedThrowingStatusExceptionTest : StatusExceptionTestBase() {

    override val service: GreeterImplBase
        get() = StatusThrowingGreeter()

    @UseExperimental(ExperimentalCoroutinesApi::class)
    private inner class StatusThrowingGreeter : GreeterImplBase(collectExceptions) {

        override suspend fun greet(request: GreetRequest): GreetReply {
            async {
                delay(10)
                throw notFound("uni")
            }.await()
        }

        override fun greetServerStream(request: GreetRequest) = produce {
            launch {
                delay(10)
                throw notFound("sstream")
            }
        }

        override suspend fun greetClientStream(requests: ReceiveChannel): GreetReply {
            async {
                delay(10)
                throw notFound("cstream")
            }.await()
        }

        override fun greetBidirectional(requests: ReceiveChannel) = produce {
            launch {
                delay(10)
                throw notFound("bidi")
            }
        }
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/ExceptionPropagationTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import io.grpc.StatusRuntimeException
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.produce
import kotlinx.coroutines.runBlocking
import org.junit.Rule
import org.junit.Test
import org.junit.rules.ExpectedException
import org.junit.runner.RunWith
import org.junit.runners.JUnit4
import java.lang.Thread.sleep

@RunWith(JUnit4::class)
class ExceptionPropagationTest : GrpcTestBase() {

    @Rule
    @JvmField
    val expect = ExpectedException.none()

    @Test
    fun unaryException() {
        val stub = startServer(CustomThrowingGreeter())

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("UNKNOWN")

        runBlocking {
            stub.greet(req("joe"))
        }
    }

    @Test
    fun serverStreamingException() {
        val stub = startServer(CustomThrowingGreeter())

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("UNKNOWN")

        runBlocking {
            stub.greetServerStream(req("joe")).receive()
        }
    }

    @Test
    fun clientStreamingException() {
        val stub = startServer(CustomThrowingGreeter())

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("UNKNOWN")

        runBlocking {
            stub.greetClientStream().await()
        }
    }

    @Test
    fun bidirectionalException() {
        val stub = startServer(CustomThrowingGreeter())

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("UNKNOWN")

        runBlocking {
            stub.greetBidirectional().receive()
        }
    }

    @Test
    fun unaryPropagateCustomException() {
        val stub = startServer(CustomThrowingGreeter())

        expect.expect(CustomThrowingGreeter.CustomException::class.java)
        expect.expectMessage("my app broke uni")

        try {
            runBlocking {
                stub.greet(req("joe"))
            }
        } catch (t: Throwable) { // silence
        }

        sleep(100) // wait for worker threads to invoke exception handler
        throw seenExceptions[0]
    }

    @Test
    fun serverStreamingPropagateCustomException() {
        val stub = startServer(CustomThrowingGreeter())

        expect.expect(CustomThrowingGreeter.CustomException::class.java)
        expect.expectMessage("my app broke sstream")

        try {
            runBlocking {
                stub.greetServerStream(req("jow")).receive()
            }
        } catch (t: Throwable) { // silence
        }

        sleep(100) // wait for worker threads to invoke exception handler
        throw seenExceptions[0]
    }

    @Test
    fun clientStreamingPropagateCustomException() {
        val stub = startServer(CustomThrowingGreeter())

        expect.expect(CustomThrowingGreeter.CustomException::class.java)
        expect.expectMessage("my app broke cstream")

        try {
            runBlocking {
                stub.greetClientStream().await()
            }
        } catch (t: Throwable) { // silence
        }

        sleep(100) // wait for worker threads to invoke exception handler
        throw seenExceptions[0]
    }

    @Test
    fun bidirectionalPropagateCustomException() {
        val stub = startServer(CustomThrowingGreeter())

        expect.expect(CustomThrowingGreeter.CustomException::class.java)
        expect.expectMessage("my app broke bidi")

        try {
            runBlocking {
                stub.greetBidirectional().receive()
            }
        } catch (t: Throwable) { // silence
        }

        sleep(100) // wait for worker threads to invoke exception handler
        throw seenExceptions[0]
    }

    @UseExperimental(ExperimentalCoroutinesApi::class)
    private inner class CustomThrowingGreeter : GreeterImplBase(collectExceptions) {

        override suspend fun greet(request: GreetRequest): GreetReply {
            throw broke("uni")
        }

        override fun greetServerStream(request: GreetRequest) = produce {
            throw broke("sstream")
        }

        override suspend fun greetClientStream(requests: ReceiveChannel): GreetReply {
            throw broke("cstream")
        }

        override fun greetBidirectional(requests: ReceiveChannel) = produce {
            throw broke("bidi")
        }

        private fun broke(description: String): Exception {
            return CustomException("my app broke $description")
        }

        inner class CustomException(message: String) : Exception(message)
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/GrpcTestBase.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import io.grpc.ClientInterceptor
import io.grpc.ClientInterceptors
import io.grpc.ServerInterceptor
import io.grpc.ServerInterceptors
import io.grpc.testing.GrpcServerRule
import io.rouz.greeter.GreeterGrpc.GreeterStub
import kotlinx.coroutines.CoroutineExceptionHandler
import mu.KotlinLogging
import org.junit.Rule

open class GrpcTestBase {

    val log = KotlinLogging.logger("GreeterImplBase")

    @Rule
    @JvmField
    val grpcServer: GrpcServerRule = GrpcServerRule().directExecutor()

    protected val seenExceptions = mutableListOf()
    protected val collectExceptions = CoroutineExceptionHandler { _, t ->
        seenExceptions += t
        log.info("Caught exception in exception handler: $t")
    }

    protected fun startServer(service: GreeterImplBase): GreeterStub {
        val serviceDefinition = serverInterceptor()?.let {
            ServerInterceptors.intercept(service, it)
        } ?: service.bindService()
        grpcServer.serviceRegistry.addService(serviceDefinition)

        val channel = clientInterceptor()?.let {
            ClientInterceptors.intercept(grpcServer.channel, it)
        } ?: grpcServer.channel

        return GreeterGrpc.newStub(channel)
    }

    protected open fun serverInterceptor(): ServerInterceptor? = null

    protected open fun clientInterceptor(): ClientInterceptor? = null

    fun req(greeting: String): GreetRequest {
        return GreetRequest.newBuilder().setGreeting(greeting).build()
    }

    fun repl(reply: String): GreetReply {
        return GreetReply.newBuilder().setReply(reply).build()
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/NoStatusExceptionPropagationTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.produce
import org.junit.After

class NoStatusExceptionPropagationTest : StatusExceptionTestBase() {

    override val service: GreeterImplBase
        get() = StatusThrowingGreeter()

    @After
    fun tearDown() {
        assert(seenExceptions.isEmpty()) {
            "Status exceptions should not reach context handler"
        }
    }

    @UseExperimental(ExperimentalCoroutinesApi::class)
    private inner class StatusThrowingGreeter : GreeterImplBase(collectExceptions) {

        override suspend fun greet(request: GreetRequest): GreetReply {
            throw notFound("uni")
        }

        override fun greetServerStream(request: GreetRequest) = produce {
            throw notFound("sstream")
        }

        override suspend fun greetClientStream(requests: ReceiveChannel): GreetReply {
            throw notFound("cstream")
        }

        override fun greetBidirectional(requests: ReceiveChannel) = produce {
            throw notFound("bidi")
        }
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/ServiceCallsTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import kotlinx.coroutines.runBlocking
import org.junit.Assert.assertEquals
import org.junit.Test
import org.junit.runner.RunWith
import org.junit.runners.JUnit4

@RunWith(JUnit4::class)
class ServiceCallsTest : GrpcTestBase() {

    @Test
    fun unaryGreet() {
        val stub = startServer(GreeterImpl())

        runBlocking {
            val reply = stub.greet(req("rouz"))

            assertEquals("Hello rouz", reply.reply)
        }
    }

    @Test
    fun serverStreamingGreet() {
        val stub = startServer(GreeterImpl())

        runBlocking {
            val replies = stub.greetServerStream(req("rouz"))

            assertEquals("Hello rouz!", replies.receive().reply)
            assertEquals("Greetings rouz!", replies.receive().reply)
        }
    }

    @Test
    fun clientStreamingGreet() {
        val stub = startServer(GreeterImpl())

        runBlocking {
            val call = stub.greetClientStream()

            call.send(req("rouz"))
            call.send(req("delavari"))
            call.close()

            val reply = call.await()

            assertEquals("Hi to all of [rouz, delavari]!", reply.reply)
        }
    }

    @Test
    fun bidirectionalGreet() {
        val stub = startServer(GreeterImpl())

        runBlocking {
            val call = stub.greetBidirectional()

            call.send(req("rouz"))
            val reply1 = call.receive()
            assertEquals("Yo #0 rouz", reply1.reply)

            call.send(req("delavari"))
            val reply2 = call.receive()
            assertEquals("Yo #1 delavari", reply2.reply)

            call.close()
        }
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/StatusExceptionTestBase.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import io.grpc.Status
import io.grpc.StatusRuntimeException
import kotlinx.coroutines.runBlocking
import org.junit.Rule
import org.junit.Test
import org.junit.rules.ExpectedException

abstract class StatusExceptionTestBase : GrpcTestBase() {

    @Rule
    @JvmField
    val expect = ExpectedException.none()

    abstract val service: GreeterImplBase

    @Test
    fun unaryStatus() {
        val stub = startServer(service)

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("NOT_FOUND: uni")

        runBlocking {
            stub.greet(req("joe"))
        }
    }

    @Test
    fun serverStreamingStatus() {
        val stub = startServer(service)

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("NOT_FOUND: sstream")

        runBlocking {
            stub.greetServerStream(req("joe")).receive()
        }
    }

    @Test
    fun clientStreamingStatus() {
        val stub = startServer(service)

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("NOT_FOUND: cstream")

        runBlocking {
            stub.greetClientStream().await()
        }
    }

    @Test
    fun bidirectionalStatus() {
        val stub = startServer(service)

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("NOT_FOUND: bidi")

        runBlocking {
            stub.greetBidirectional().receive()
        }
    }

    protected fun notFound(description: String): StatusRuntimeException {
        return Status.NOT_FOUND.withDescription(description).asRuntimeException()
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/ThrowingStatusExceptionTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.produce

class ThrowingStatusExceptionTest : StatusExceptionTestBase() {

    override val service: GreeterImplBase
        get() = StatusThrowingGreeter()

    @UseExperimental(ExperimentalCoroutinesApi::class)
    private inner class StatusThrowingGreeter : GreeterImplBase(collectExceptions) {

        override suspend fun greet(request: GreetRequest): GreetReply {
            throw notFound("uni")
        }

        override fun greetServerStream(request: GreetRequest) = produce {
            throw notFound("sstream")
        }

        override suspend fun greetClientStream(requests: ReceiveChannel): GreetReply {
            throw notFound("cstream")
        }

        override fun greetBidirectional(requests: ReceiveChannel) = produce {
            throw notFound("bidi")
        }
    }
}


================================================
FILE: grpc-kotlin-test/src/test/kotlin/io/rouz/greeter/UnimplementedStatusTest.kt
================================================
/*-
 * -\-\-
 * grpc-kotlin-test
 * --
 * Copyright (C) 2016 - 2018 rouz.io
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */

package io.rouz.greeter

import io.grpc.StatusRuntimeException
import kotlinx.coroutines.runBlocking
import org.junit.Rule
import org.junit.Test
import org.junit.rules.ExpectedException

class UnimplementedStatusTest : GrpcTestBase() {

    @Rule
    @JvmField
    val expect = ExpectedException.none()

    @Test
    fun unaryUnimplemented() {
        val stub = startServer(UnimplementedGreeter())

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("UNIMPLEMENTED: Method io.rouz.greeter.Greeter/Greet is unimplemented")

        runBlocking {
            stub.greet(req("anyone there?"))
        }
    }

    @Test
    fun clientStreamingUnimplemented() {
        val stub = startServer(UnimplementedGreeter())

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("UNIMPLEMENTED: Method io.rouz.greeter.Greeter/GreetClientStream is unimplemented")

        runBlocking {
            stub.greetClientStream().await()
        }
    }

    @Test
    fun serverStreamingUnimplemented() {
        val stub = startServer(UnimplementedGreeter())

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("UNIMPLEMENTED: Method io.rouz.greeter.Greeter/GreetServerStream is unimplemented")

        runBlocking {
            stub.greetServerStream(req("anyone there?")).receive()
        }
    }

    @Test
    fun bidirectionalUnimplemented() {
        val stub = startServer(UnimplementedGreeter())

        expect.expect(StatusRuntimeException::class.java)
        expect.expectMessage("UNIMPLEMENTED: Method io.rouz.greeter.Greeter/GreetBidirectional is unimplemented")

        runBlocking {
            stub.greetBidirectional().receive()
        }
    }

    inner class UnimplementedGreeter : GreeterImplBase(collectExceptions)
}


================================================
FILE: mvnw
================================================
#!/bin/sh
# ----------------------------------------------------------------------------
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
# ----------------------------------------------------------------------------

# ----------------------------------------------------------------------------
# Maven2 Start Up Batch script
#
# Required ENV vars:
# ------------------
#   JAVA_HOME - location of a JDK home dir
#
# Optional ENV vars
# -----------------
#   M2_HOME - location of maven2's installed home dir
#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
#     e.g. to debug Maven itself, use
#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
# ----------------------------------------------------------------------------

if [ -z "$MAVEN_SKIP_RC" ] ; then

  if [ -f /etc/mavenrc ] ; then
    . /etc/mavenrc
  fi

  if [ -f "$HOME/.mavenrc" ] ; then
    . "$HOME/.mavenrc"
  fi

fi

# OS specific support.  $var _must_ be set to either true or false.
cygwin=false;
darwin=false;
mingw=false
case "`uname`" in
  CYGWIN*) cygwin=true ;;
  MINGW*) mingw=true;;
  Darwin*) darwin=true
    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
    if [ -z "$JAVA_HOME" ]; then
      if [ -x "/usr/libexec/java_home" ]; then
        export JAVA_HOME="`/usr/libexec/java_home`"
      else
        export JAVA_HOME="/Library/Java/Home"
      fi
    fi
    ;;
esac

if [ -z "$JAVA_HOME" ] ; then
  if [ -r /etc/gentoo-release ] ; then
    JAVA_HOME=`java-config --jre-home`
  fi
fi

if [ -z "$M2_HOME" ] ; then
  ## resolve links - $0 may be a link to maven's home
  PRG="$0"

  # need this for relative symlinks
  while [ -h "$PRG" ] ; do
    ls=`ls -ld "$PRG"`
    link=`expr "$ls" : '.*-> \(.*\)$'`
    if expr "$link" : '/.*' > /dev/null; then
      PRG="$link"
    else
      PRG="`dirname "$PRG"`/$link"
    fi
  done

  saveddir=`pwd`

  M2_HOME=`dirname "$PRG"`/..

  # make it fully qualified
  M2_HOME=`cd "$M2_HOME" && pwd`

  cd "$saveddir"
  # echo Using m2 at $M2_HOME
fi

# For Cygwin, ensure paths are in UNIX format before anything is touched
if $cygwin ; then
  [ -n "$M2_HOME" ] &&
    M2_HOME=`cygpath --unix "$M2_HOME"`
  [ -n "$JAVA_HOME" ] &&
    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
  [ -n "$CLASSPATH" ] &&
    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
fi

# For Mingw, ensure paths are in UNIX format before anything is touched
if $mingw ; then
  [ -n "$M2_HOME" ] &&
    M2_HOME="`(cd "$M2_HOME"; pwd)`"
  [ -n "$JAVA_HOME" ] &&
    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
  # TODO classpath?
fi

if [ -z "$JAVA_HOME" ]; then
  javaExecutable="`which javac`"
  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
    # readlink(1) is not available as standard on Solaris 10.
    readLink=`which readlink`
    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
      if $darwin ; then
        javaHome="`dirname \"$javaExecutable\"`"
        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
      else
        javaExecutable="`readlink -f \"$javaExecutable\"`"
      fi
      javaHome="`dirname \"$javaExecutable\"`"
      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
      JAVA_HOME="$javaHome"
      export JAVA_HOME
    fi
  fi
fi

if [ -z "$JAVACMD" ] ; then
  if [ -n "$JAVA_HOME"  ] ; then
    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
      # IBM's JDK on AIX uses strange locations for the executables
      JAVACMD="$JAVA_HOME/jre/sh/java"
    else
      JAVACMD="$JAVA_HOME/bin/java"
    fi
  else
    JAVACMD="`which java`"
  fi
fi

if [ ! -x "$JAVACMD" ] ; then
  echo "Error: JAVA_HOME is not defined correctly." >&2
  echo "  We cannot execute $JAVACMD" >&2
  exit 1
fi

if [ -z "$JAVA_HOME" ] ; then
  echo "Warning: JAVA_HOME environment variable is not set."
fi

CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher

# traverses directory structure from process work directory to filesystem root
# first directory with .mvn subdirectory is considered project base directory
find_maven_basedir() {

  if [ -z "$1" ]
  then
    echo "Path not specified to find_maven_basedir"
    return 1
  fi

  basedir="$1"
  wdir="$1"
  while [ "$wdir" != '/' ] ; do
    if [ -d "$wdir"/.mvn ] ; then
      basedir=$wdir
      break
    fi
    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
    if [ -d "${wdir}" ]; then
      wdir=`cd "$wdir/.."; pwd`
    fi
    # end of workaround
  done
  echo "${basedir}"
}

# concatenates all lines of a file
concat_lines() {
  if [ -f "$1" ]; then
    echo "$(tr -s '\n' ' ' < "$1")"
  fi
}

BASE_DIR=`find_maven_basedir "$(pwd)"`
if [ -z "$BASE_DIR" ]; then
  exit 1;
fi

##########################################################################################
# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
# This allows using the maven wrapper in projects that prohibit checking in binary data.
##########################################################################################
if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
    if [ "$MVNW_VERBOSE" = true ]; then
      echo "Found .mvn/wrapper/maven-wrapper.jar"
    fi
else
    if [ "$MVNW_VERBOSE" = true ]; then
      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
    fi
    jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar"
    while IFS="=" read key value; do
      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
      esac
    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
    if [ "$MVNW_VERBOSE" = true ]; then
      echo "Downloading from: $jarUrl"
    fi
    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"

    if command -v wget > /dev/null; then
        if [ "$MVNW_VERBOSE" = true ]; then
          echo "Found wget ... using wget"
        fi
        wget "$jarUrl" -O "$wrapperJarPath"
    elif command -v curl > /dev/null; then
        if [ "$MVNW_VERBOSE" = true ]; then
          echo "Found curl ... using curl"
        fi
        curl -o "$wrapperJarPath" "$jarUrl"
    else
        if [ "$MVNW_VERBOSE" = true ]; then
          echo "Falling back to using Java to download"
        fi
        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
        if [ -e "$javaClass" ]; then
            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
                if [ "$MVNW_VERBOSE" = true ]; then
                  echo " - Compiling MavenWrapperDownloader.java ..."
                fi
                # Compiling the Java class
                ("$JAVA_HOME/bin/javac" "$javaClass")
            fi
            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
                # Running the downloader
                if [ "$MVNW_VERBOSE" = true ]; then
                  echo " - Running MavenWrapperDownloader.java ..."
                fi
                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
            fi
        fi
    fi
fi
##########################################################################################
# End of extension
##########################################################################################

export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
if [ "$MVNW_VERBOSE" = true ]; then
  echo $MAVEN_PROJECTBASEDIR
fi
MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"

# For Cygwin, switch paths to Windows format before running java
if $cygwin; then
  [ -n "$M2_HOME" ] &&
    M2_HOME=`cygpath --path --windows "$M2_HOME"`
  [ -n "$JAVA_HOME" ] &&
    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
  [ -n "$CLASSPATH" ] &&
    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
fi

WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain

exec "$JAVACMD" \
  $MAVEN_OPTS \
  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"


================================================
FILE: mvnw.cmd
================================================
@REM ----------------------------------------------------------------------------
@REM Licensed to the Apache Software Foundation (ASF) under one
@REM or more contributor license agreements.  See the NOTICE file
@REM distributed with this work for additional information
@REM regarding copyright ownership.  The ASF licenses this file
@REM to you under the Apache License, Version 2.0 (the
@REM "License"); you may not use this file except in compliance
@REM with the License.  You may obtain a copy of the License at
@REM
@REM    http://www.apache.org/licenses/LICENSE-2.0
@REM
@REM Unless required by applicable law or agreed to in writing,
@REM software distributed under the License is distributed on an
@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
@REM KIND, either express or implied.  See the License for the
@REM specific language governing permissions and limitations
@REM under the License.
@REM ----------------------------------------------------------------------------

@REM ----------------------------------------------------------------------------
@REM Maven2 Start Up Batch script
@REM
@REM Required ENV vars:
@REM JAVA_HOME - location of a JDK home dir
@REM
@REM Optional ENV vars
@REM M2_HOME - location of maven2's installed home dir
@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a key stroke before ending
@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
@REM     e.g. to debug Maven itself, use
@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
@REM ----------------------------------------------------------------------------

@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
@echo off
@REM set title of command window
title %0
@REM enable echoing my setting MAVEN_BATCH_ECHO to 'on'
@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%

@REM set %HOME% to equivalent of $HOME
if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")

@REM Execute a user defined script before this one
if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
@REM check for pre script, once with legacy .bat ending and once with .cmd ending
if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
:skipRcPre

@setlocal

set ERROR_CODE=0

@REM To isolate internal variables from possible post scripts, we use another setlocal
@setlocal

@REM ==== START VALIDATION ====
if not "%JAVA_HOME%" == "" goto OkJHome

echo.
echo Error: JAVA_HOME not found in your environment. >&2
echo Please set the JAVA_HOME variable in your environment to match the >&2
echo location of your Java installation. >&2
echo.
goto error

:OkJHome
if exist "%JAVA_HOME%\bin\java.exe" goto init

echo.
echo Error: JAVA_HOME is set to an invalid directory. >&2
echo JAVA_HOME = "%JAVA_HOME%" >&2
echo Please set the JAVA_HOME variable in your environment to match the >&2
echo location of your Java installation. >&2
echo.
goto error

@REM ==== END VALIDATION ====

:init

@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
@REM Fallback to current working directory if not found.

set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir

set EXEC_DIR=%CD%
set WDIR=%EXEC_DIR%
:findBaseDir
IF EXIST "%WDIR%"\.mvn goto baseDirFound
cd ..
IF "%WDIR%"=="%CD%" goto baseDirNotFound
set WDIR=%CD%
goto findBaseDir

:baseDirFound
set MAVEN_PROJECTBASEDIR=%WDIR%
cd "%EXEC_DIR%"
goto endDetectBaseDir

:baseDirNotFound
set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
cd "%EXEC_DIR%"

:endDetectBaseDir

IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig

@setlocal EnableExtensions EnableDelayedExpansion
for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%

:endReadAdditionalConfig

SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain

set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar"
FOR /F "tokens=1,2 delims==" %%A IN (%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties) DO (
	IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B 
)

@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
if exist %WRAPPER_JAR% (
    echo Found %WRAPPER_JAR%
) else (
    echo Couldn't find %WRAPPER_JAR%, downloading it ...
	echo Downloading from: %DOWNLOAD_URL%
    powershell -Command "(New-Object Net.WebClient).DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"
    echo Finished downloading %WRAPPER_JAR%
)
@REM End of extension

%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
if ERRORLEVEL 1 goto error
goto end

:error
set ERROR_CODE=1

:end
@endlocal & set ERROR_CODE=%ERROR_CODE%

if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
@REM check for post script, once with legacy .bat ending and once with .cmd ending
if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
:skipRcPost

@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
if "%MAVEN_BATCH_PAUSE%" == "on" pause

if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%

exit /B %ERROR_CODE%


================================================
FILE: pom.xml
================================================


    4.0.0

    
        io.rouz
        root
        2
    

    grpc-kotlin-parent
    0.1.5-SNAPSHOT
    pom

    grpc-kotlin
    https://github.com/rouzwawi/grpc-kotlin

    
        
            The Apache Software License, Version 2.0
            http://www.apache.org/licenses/LICENSE-2.0.txt
            repo
        
    

    
        
            rouz
            me@rouz.io
            Rouzbeh Delavari
        
    

    
        https://github.com/rouzwawi/grpc-kotlin
        scm:git:git@github.com:rouzwawi/grpc-kotlin.git
        scm:git:git@github.com:rouzwawi/grpc-kotlin.git
        HEAD
    

    
    

    
        grpc-kotlin-gen
        grpc-kotlin-test
        grpc-kotlin-example-chatserver
    

    
        

        
        
            junit
            junit
            4.12
            test
        
    

    
        
            
                maven-enforcer-plugin
            
            
                maven-failsafe-plugin
            
            
                org.apache.maven.plugins
                maven-jar-plugin
                3.1.0
            
            
                maven-surefire-plugin
                
                    0