From b00857368a56474e818fabe8a06b4873ab57d234 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=A0est=C3=A1k=20V=C3=ADt?= <Vit.Sestak@ysoft.com>
Date: Wed, 21 Jun 2017 10:18:39 +0200
Subject: [PATCH] Added throttling to reduce Bamboo peak load and number of
 concurrent connections

---
 app/com/ysoft/odc/BambooDownloader.scala      |  7 ++++--
 .../VulnerabilityNotificationService.scala    | 15 -------------
 app/services/throttlers.scala                 | 22 +++++++++++++++++++
 3 files changed, 27 insertions(+), 17 deletions(-)
 create mode 100644 app/services/throttlers.scala

diff --git a/app/com/ysoft/odc/BambooDownloader.scala b/app/com/ysoft/odc/BambooDownloader.scala
index 5f2ad1c..38b647b 100644
--- a/app/com/ysoft/odc/BambooDownloader.scala
+++ b/app/com/ysoft/odc/BambooDownloader.scala
@@ -4,6 +4,7 @@ import com.google.inject.Inject
 import com.google.inject.name.Named
 import org.ccil.cowan.tagsoup.jaxp.SAXFactoryImpl
 import play.api.libs.ws.{WS, WSClient}
+import services.SingleFutureExecutionThrottler
 import upickle.default._
 
 import scala.concurrent.{ExecutionContext, Future}
@@ -64,6 +65,8 @@ final case class FlatArtifactDirectory(name: String, items: Seq[(String, String)
 
 final class BambooDownloader @Inject()(@Named("bamboo-server-url") val server: String, @Named("bamboo-authentication") auth: AtlassianAuthentication)(implicit executionContext: ExecutionContext, wSClient: WSClient) extends Downloader {
 
+  private val throttler = new SingleFutureExecutionThrottler()
+
   private object ArtifactKeys{
     val BuildLog = "Build log"
     val ResultsHtml = "Report results-HTML"
@@ -76,7 +79,7 @@ final class BambooDownloader @Inject()(@Named("bamboo-server-url") val server: S
   }
 
   private def downloadArtifact(url: String, name: String)(implicit wSClient: WSClient): Future[FlatArtifactItem] = {
-    bambooUrl(url).get().map{response =>
+    throttler.throttle(bambooUrl(url).get()).map{response =>
       response.header("Content-Disposition") match{
         case Some(_) => ArtifactFile(name = name, data = response.bodyAsBytes)
         case None =>
@@ -149,7 +152,7 @@ final class BambooDownloader @Inject()(@Named("bamboo-server-url") val server: S
 
   private def downloadProjectReport(project: String, versionOption: Option[Int]): Future[(String, Try[(Build, ArtifactItem, ArtifactFile)])] = {
     val url = s"$server/rest/api/latest/result/$project-${versionOption.getOrElse("latest")}.json?expand=artifacts"
-    val resultFuture = (bambooUrl(url).get().flatMap { response =>
+    val resultFuture = (throttler.throttle(bambooUrl(url).get()).flatMap { response =>
       val build = read[Build](response.body)
       val artifactMap: Map[String, Artifact] = build.artifacts.artifact.map(x => x.name -> x).toMap
       val logFuture = downloadArtifact(artifactMap, ArtifactKeys.BuildLog).map(_.asInstanceOf[ArtifactFile])
diff --git a/app/services/VulnerabilityNotificationService.scala b/app/services/VulnerabilityNotificationService.scala
index 6f9e074..a205624 100644
--- a/app/services/VulnerabilityNotificationService.scala
+++ b/app/services/VulnerabilityNotificationService.scala
@@ -14,21 +14,6 @@ import slick.jdbc.TransactionIsolation
 
 import scala.concurrent.{ExecutionContext, Future}
 
-final class SingleFutureExecutionThrottler() (implicit executionContext: ExecutionContext){
-  private var nextFuture: Future[_] = Future.successful(null)
-
-  def throttle[T](f: => Future[T]): Future[T] = synchronized{
-    val newFuture = nextFuture.recover{ case _ => null}.flatMap(_ => f)
-    nextFuture = newFuture
-    newFuture
-  }
-
-}
-
-final class NoThrottler() (implicit executionContext: ExecutionContext){
-  def throttle[T](f: => Future[T]): Future[T] = f
-}
-
 class VulnerabilityNotificationService @Inject() (protected val dbConfigProvider: DatabaseConfigProvider)(implicit executionContext: ExecutionContext) extends HasDatabaseConfigProvider[models.profile.type]{
   import dbConfig.driver.api._
   import models.tables._
diff --git a/app/services/throttlers.scala b/app/services/throttlers.scala
new file mode 100644
index 0000000..9dddb80
--- /dev/null
+++ b/app/services/throttlers.scala
@@ -0,0 +1,22 @@
+package services
+
+import scala.concurrent.{ExecutionContext, Future}
+
+trait Throttler {
+  def throttle[T](f: => Future[T]): Future[T]
+}
+
+final class SingleFutureExecutionThrottler() (implicit executionContext: ExecutionContext) extends Throttler{
+  private var nextFuture: Future[_] = Future.successful(null)
+
+  def throttle[T](f: => Future[T]): Future[T] = synchronized{
+    val newFuture = nextFuture.recover{ case _ => null}.flatMap(_ => f)
+    nextFuture = newFuture
+    newFuture
+  }
+
+}
+
+final class NoThrottler() (implicit executionContext: ExecutionContext) extends Throttler{
+  def throttle[T](f: => Future[T]): Future[T] = f
+}