Coroutine builder for service call

coroutine-service-call/pom.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>lagomkotlin</artifactId>
+        <groupId>org.cakesolutions</groupId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>coroutine-service-call</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.lightbend.lagom</groupId>
+            <artifactId>lagom-javadsl-server_2.11</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-stdlib</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlinx</groupId>
+            <artifactId>kotlinx-coroutines-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlinx</groupId>
+            <artifactId>kotlinx-coroutines-jdk8</artifactId>
+        </dependency>
+    </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>kotlin-maven-plugin</artifactId>
+                <groupId>org.jetbrains.kotlin</groupId>
+            </plugin>
+        </plugins>
+    </build>
+</project>

coroutine-service-call/src/main/kotlin/org/cakesolutions/coroutine/ServicelCallBuilders.kt

@@ -0,0 +1,68 @@
+package org.cakesolutions.coroutine
+
+import com.lightbend.lagom.javadsl.api.ServiceCall
+import com.lightbend.lagom.javadsl.api.transport.RequestHeader
+import com.lightbend.lagom.javadsl.api.transport.ResponseHeader
+import com.lightbend.lagom.javadsl.server.HeaderServiceCall
+import com.lightbend.lagom.javadsl.server.ServerServiceCall
+import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.CoroutineStart
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.future.future
+
+/**
+ * @author Alex Mihailov {@literal <[email protected]>}.
+ */
+
+/**
+ * Starts new coroutine and returns its result as an implementation of [ServiceCall].
+ *
+ * @param context additional to [CoroutineScope.coroutineContext] context of the coroutine.
+ * @param start coroutine start option. The default value is [CoroutineStart.DEFAULT].
+ * @param block the coroutine code.
+ */
+fun <Request, Response> serviceCall(
+    context: CoroutineContext = EmptyCoroutineContext,
+    start: CoroutineStart = CoroutineStart.DEFAULT,
+    block: suspend CoroutineScope.(request: Request) -> Response
+) = ServiceCall<Request, Response> {
+    CoroutineScope(Dispatchers.Unconfined).future(context, start) {
+        block(it)
+    }
+}
+
+/**
+ * Starts new coroutine and returns its result as an implementation of [ServerServiceCall].
+ *
+ * @param context additional to [CoroutineScope.coroutineContext] context of the coroutine.
+ * @param start coroutine start option. The default value is [CoroutineStart.DEFAULT].
+ * @param block the coroutine code.
+ */
+fun <Request, Response> serverServiceCall(
+    context: CoroutineContext = EmptyCoroutineContext,
+    start: CoroutineStart = CoroutineStart.DEFAULT,
+    block: suspend CoroutineScope.(request: Request) -> Response
+) = ServerServiceCall<Request, Response> {
+    CoroutineScope(Dispatchers.Unconfined).future(context, start) {
+        block(it)
+    }
+}
+
+/**
+ * Starts new coroutine and returns its result as an implementation of [HeaderServiceCall].
+ *
+ * @param context additional to [CoroutineScope.coroutineContext] context of the coroutine.
+ * @param start coroutine start option. The default value is [CoroutineStart.DEFAULT].
+ * @param block the coroutine code.
+ */
+fun <Request, Response> headerServiceCall(
+    context: CoroutineContext = EmptyCoroutineContext,
+    start: CoroutineStart = CoroutineStart.DEFAULT,
+    block: suspend CoroutineScope.(requestHeader: RequestHeader, request: Request) -> akka.japi.Pair<ResponseHeader, Response>
+) = HeaderServiceCall<Request, Response> { requestHeader, request ->
+    CoroutineScope(Dispatchers.Unconfined).future(context, start) {
+        block(requestHeader, request)
+    }
+}

hello-impl/pom.xml

@@ -15,9 +15,14 @@
 
     <dependencies>
         <dependency>
-            <groupId>org.cakesolutions</groupId>
+            <groupId>${project.groupId}</groupId>
             <artifactId>hello-api</artifactId>
-            <version>1.0-SNAPSHOT</version>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>coroutine-service-call</artifactId>
+            <version>${project.version}</version>
         </dependency>
         <dependency>
             <groupId>com.lightbend.lagom</groupId>

hello-impl/src/main/kotlin/org/cakesolutions/hello/impl/KHelloServiceImpl.kt

@@ -4,6 +4,8 @@ import akka.Done
 import akka.NotUsed
 import com.lightbend.lagom.javadsl.api.ServiceCall
 import com.lightbend.lagom.javadsl.persistence.PersistentEntityRegistry
+import kotlinx.coroutines.future.await
+import org.cakesolutions.coroutine.serviceCall
 import org.cakesolutions.hello.api.KGreetingMessage
 import org.cakesolutions.hello.api.KHelloService
 import java.util.Optional
@@ -16,17 +18,13 @@ class KHelloServiceImpl @Inject constructor(private val persistentEntityRegistry
 		persistentEntityRegistry.register(KHelloEntity::class.java)
 	}
 
-	override fun hello(id: String): ServiceCall<NotUsed, String> {
-		return ServiceCall {
-			val ref = persistentEntityRegistry.refFor(KHelloEntity::class.java, id)
-			ref.ask(KHelloCommand.Hello(id, Optional.empty()))
-		}
+	override fun hello(id: String): ServiceCall<NotUsed, String> = serviceCall {
+		val ref = persistentEntityRegistry.refFor(KHelloEntity::class.java, id)
+		ref.ask<String, KHelloCommand.Hello>(KHelloCommand.Hello(id, Optional.empty())).await()
 	}
 
-	override fun useGreeting(id: String): ServiceCall<KGreetingMessage, Done> {
-		return ServiceCall { request ->
-			val ref = persistentEntityRegistry.refFor(KHelloEntity::class.java, id)
-			ref.ask(KHelloCommand.UserGreetingMessage(request.message))
-		}
+	override fun useGreeting(id: String): ServiceCall<KGreetingMessage, Done> = serviceCall { request ->
+		val ref = persistentEntityRegistry.refFor(KHelloEntity::class.java, id)
+		ref.ask<Done, KHelloCommand.UserGreetingMessage>(KHelloCommand.UserGreetingMessage(request.message)).await()
 	}
 }

pom.xml

@@ -16,6 +16,7 @@
         <module>stream-impl</module>
         <module>integration-tests</module>
         <module>cassandra-config</module>
+        <module>coroutine-service-call</module>
     </modules>
 
     <build>
@@ -205,6 +206,16 @@
                 <artifactId>kotlin-reflect</artifactId>
                 <version>${kotlin.version}</version>
             </dependency>
+            <dependency>
+                <groupId>org.jetbrains.kotlinx</groupId>
+                <artifactId>kotlinx-coroutines-core</artifactId>
+                <version>${kotlin.coroutines.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>org.jetbrains.kotlinx</groupId>
+                <artifactId>kotlinx-coroutines-jdk8</artifactId>
+                <version>${kotlin.coroutines.version}</version>
+            </dependency>
         </dependencies>
     </dependencyManagement>
 
@@ -215,9 +226,10 @@
         <play.version>2.5.10</play.version>
         <akka.version>2.4.16</akka.version>
         <conductr.lib.name>lagom10-conductr-bundle-lib_2.11</conductr.lib.name>
-        <kotlin.version>1.2.71</kotlin.version>
+        <kotlin.version>1.3.50</kotlin.version>
         <kotlin.compiler.incremental>true</kotlin.compiler.incremental>
-        <kotlin.compiler.languageVersion>1.2</kotlin.compiler.languageVersion>
+        <kotlin.compiler.languageVersion>1.3</kotlin.compiler.languageVersion>
         <kotlin.compiler.jvmTarget>1.8</kotlin.compiler.jvmTarget>
+        <kotlin.coroutines.version>1.3.2</kotlin.coroutines.version>
     </properties>
 </project>

stream-impl/pom.xml

@@ -24,6 +24,11 @@
             <artifactId>hello-api</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>coroutine-service-call</artifactId>
+            <version>${project.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.lightbend.lagom</groupId>
             <artifactId>lagom-javadsl-server_2.11</artifactId>

stream-impl/src/main/kotlin/org/cakesolutions/stream/impl/KStreamServiceImpl.kt

@@ -3,19 +3,17 @@ package org.cakesolutions.stream.impl
 import akka.NotUsed
 import akka.stream.javadsl.Source
 import com.lightbend.lagom.javadsl.api.ServiceCall
+import org.cakesolutions.coroutine.serviceCall
 import org.cakesolutions.hello.api.KHelloService
 import org.cakesolutions.stream.api.KStreamService
-import java.util.concurrent.CompletableFuture.completedFuture
 import javax.inject.Inject
 
 
 class KStreamServiceImpl @Inject
 constructor(private val helloService: KHelloService) : KStreamService {
-	override fun stream(): ServiceCall<Source<String, NotUsed>, Source<String, NotUsed>> {
-		return ServiceCall { hellos ->
-			completedFuture(hellos.mapAsync(8){ name ->
-				helloService.hello(name)()
-			})
+	override fun stream(): ServiceCall<Source<String, NotUsed>, Source<String, NotUsed>> = serviceCall { hellos ->
+		hellos.mapAsync(8) { name ->
+			helloService.hello(name)()
 		}
 	}
 }