Added ScalaKinesisProducer implementation.

Author: Aleksey Nikiforov

src/main/scala/com/contxt/kinesis/ScalaKinesisProducer.scala

@@ -0,0 +1,69 @@
+package com.contxt.kinesis
+
+import com.amazonaws.services.kinesis.producer.{ KinesisProducer, KinesisProducerConfiguration, UserRecordResult }
+import com.google.common.util.concurrent.ListenableFuture
+import java.nio.ByteBuffer
+import scala.concurrent._
+import scala.language.implicitConversions
+import scala.util.Try
+
+/** A lightweight Scala wrapper around Kinesis Producer Library (KPL). */
+trait ScalaKinesisProducer {
+
+  /** Sends a record to a stream. See
+    * [[[com.amazonaws.services.kinesis.producer.KinesisProducer.addUserRecord(String, String, String, ByteBuffer):ListenableFuture[UserRecordResult]*]]].
+    */
+  def send(partitionKey: String, data: ByteBuffer, explicitHashKey: Option[String] = None): Future[UserRecordResult]
+
+  /** Flushes all the outgoing messages, returning a Future that completes when all the flushed messages have been sent.
+    * See [[com.amazonaws.services.kinesis.producer.KinesisProducer.flushSync]].
+    */
+  def flushAll(): Future[Unit]
+
+  /** Performs an orderly shutdown, waiting for all the outgoing messages before destroying the underlying producer. */
+  def shutdown(): Future[Unit]
+}
+
+object ScalaKinesisProducer {
+  def apply(streamName: String, producerConfig: KinesisProducerConfiguration): ScalaKinesisProducer = {
+    val producer = new KinesisProducer(producerConfig)
+    new ScalaKinesisProducerImpl(streamName, producer)
+  }
+
+  private[kinesis] implicit def listenableToScalaFuture[A](listenable: ListenableFuture[A]): Future[A] = {
+    implicit val executionContext: ExecutionContextExecutor = scala.concurrent.ExecutionContext.global
+    val promise = Promise[A]
+    val callback = new Runnable {
+      override def run(): Unit = promise.tryComplete(Try(listenable.get()))
+    }
+    listenable.addListener(callback, executionContext)
+    promise.future
+  }
+}
+
+private[kinesis] class ScalaKinesisProducerImpl(
+  val streamName: String,
+  private val producer: KinesisProducer
+) extends ScalaKinesisProducer {
+  import ScalaKinesisProducer.listenableToScalaFuture
+
+  def send(partitionKey: String, data: ByteBuffer, explicitHashKey: Option[String]): Future[UserRecordResult] = {
+    producer.addUserRecord(streamName, partitionKey, explicitHashKey.orNull, data)
+  }
+
+  def flushAll(): Future[Unit] = {
+    import scala.concurrent.ExecutionContext.Implicits.global
+    Future {
+      blocking {
+        producer.flushSync()
+      }
+    }
+  }
+
+  def shutdown(): Future[Unit] = {
+    import scala.concurrent.ExecutionContext.Implicits.global
+    val allFlushedFuture = flushAll()
+    allFlushedFuture.onComplete(_ => producer.destroy())
+    allFlushedFuture
+  }
+}