= core: avoid unnecesary allocation when askPatternTimeoutWarning is off

5 files changed, 54 insertions, 17 deletions

diff --git a/kamon-core/src/main/resources/reference.conf b/kamon-core/src/main/resources/reference.conf
index df5534a4..da09f500 100644
--- a/kamon-core/src/main/resources/reference.conf
+++ b/kamon-core/src/main/resources/reference.conf
@@ -172,13 +172,18 @@ kamon {
       max-incubation-time = 20 seconds
     }
 
-    # If ask-pattern-tracing is enabled, a WARN level log message will be generated if a future generated by the `ask`
+    # Default dispatcher for all trace operations
+    dispatcher = ${kamon.default-dispatcher}
+  }
+
+  akka {
+    # If ask-pattern-timeout-warning is enabled, a WARN level log message will be generated if a future generated by the `ask`
     # pattern fails with a `AskTimeoutException` and the log message will contain information depending of the strategy selected.
     # strategies:
     #   - off: nothing to do.
     #   - lightweight: logs the warning when a timeout is reached using org.aspectj.lang.reflect.SourceLocation.
     #   - heavyweight: logs the warning when a timeout is reached using a stack trace captured at the moment the future was created.
-    ask-pattern-tracing = off
+    ask-pattern-timeout-warning = off
 
     # Default dispatcher for all trace operations
     dispatcher = ${kamon.default-dispatcher}
diff --git a/kamon-core/src/main/scala/kamon/akka/AkkaExtension.scala b/kamon-core/src/main/scala/kamon/akka/AkkaExtension.scala
new file mode 100644
index 00000000..2fc7395e
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/akka/AkkaExtension.scala
@@ -0,0 +1,32 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 the kamon project <http://kamon.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 kamon.extension.akka
+
+import akka.actor
+import akka.actor._
+import kamon._
+
+class AkkaExtension(system: ExtendedActorSystem) extends Kamon.Extension {
+  val config = system.settings.config.getConfig("kamon.akka")
+  val askPatternTimeoutWarning = config.getString("ask-pattern-timeout-warning")
+  val dispatcher = system.dispatchers.lookup(config.getString("dispatcher"))
+}
+
+object Akka extends ExtensionId[AkkaExtension] with ExtensionIdProvider {
+  def lookup(): ExtensionId[_ <: actor.Extension] = Akka
+  def createExtension(system: ExtendedActorSystem): AkkaExtension = new AkkaExtension(system)
+}
\ No newline at end of file
diff --git a/kamon-core/src/main/scala/kamon/instrumentation/akka/AskPatternInstrumentation.scala b/kamon-core/src/main/scala/kamon/instrumentation/akka/AskPatternInstrumentation.scala
index efce169d..93b53764 100644
--- a/kamon-core/src/main/scala/kamon/instrumentation/akka/AskPatternInstrumentation.scala
+++ b/kamon-core/src/main/scala/kamon/instrumentation/akka/AskPatternInstrumentation.scala
@@ -17,7 +17,8 @@
 package akka.kamon.instrumentation
 
 import kamon.Kamon
-import kamon.trace.{ Trace, TraceContextAware }
+import kamon.extension.akka.Akka
+import kamon.trace.TraceContextAware
 import akka.actor.{ ActorSystem, ActorRef }
 import akka.event.Logging.Warning
 import akka.pattern.AskTimeoutException
@@ -41,17 +42,18 @@ class AskPatternInstrumentation {
   @Around("askableActorRefAsk(ctx, actor)")
   def hookAskTimeoutWarning(pjp: ProceedingJoinPoint, ctx: TraceContextAware, actor: ActorRef): AnyRef = {
     implicit val system = ctx.traceContext.system
-    val traceExtension = Kamon(Trace)(system)
+    val akkaExtension = Kamon(Akka)(system)
 
     val future = pjp.proceed().asInstanceOf[Future[AnyRef]]
 
-    val handler = traceExtension.askPatternTracing match {
-      case "off"         ⇒ errorHandler()
-      case "lightweight" ⇒ errorHandler(callInfo = Some(CallInfo(s"${actor.path.name} ?", pjp.getSourceLocation)))
-      case "heavyweight" ⇒ errorHandler(stack = Some(new StackTraceCaptureException))
+    val handler = akkaExtension.askPatternTimeoutWarning match {
+      case "off"         ⇒ None
+      case "lightweight" ⇒ Some(errorHandler(callInfo = Some(CallInfo(s"${actor.path.name} ?", pjp.getSourceLocation))))
+      case "heavyweight" ⇒ Some(errorHandler(stack = Some(new StackTraceCaptureException)))
     }
 
-    future.onFailure(handler)(traceExtension.defaultDispatcher)
+    handler.map(h ⇒ future.onFailure(h)(akkaExtension.dispatcher))
+
     future
   }
 
@@ -64,10 +66,9 @@ class AskPatternInstrumentation {
       publish(message)
   }
 
-  def publish(message: Option[String])(implicit system: ActorSystem) = message map {
-    msg ⇒
-      system.eventStream.publish(Warning("AskPatternTracing", classOf[AskPatternInstrumentation],
-        s"Timeout triggered for ask pattern registered at: $msg"))
+  def publish(message: Option[String])(implicit system: ActorSystem) = message map { msg ⇒
+    system.eventStream.publish(Warning("AskPatternTracing", classOf[AskPatternInstrumentation],
+      s"Timeout triggered for ask pattern registered at: $msg"))
   }
 }
 
diff --git a/kamon-core/src/main/scala/kamon/trace/TraceExtension.scala b/kamon-core/src/main/scala/kamon/trace/TraceExtension.scala
index c227ce58..41f022d0 100644
--- a/kamon-core/src/main/scala/kamon/trace/TraceExtension.scala
+++ b/kamon-core/src/main/scala/kamon/trace/TraceExtension.scala
@@ -27,8 +27,7 @@ import kamon.util.GlobPathFilter
 
 class TraceExtension(system: ExtendedActorSystem) extends Kamon.Extension {
   val config = system.settings.config.getConfig("kamon.trace")
-  val askPatternTracing = config.getString("ask-pattern-tracing")
-  val defaultDispatcher = system.dispatchers.lookup(config.getString("dispatcher"))
+  val dispatcher = system.dispatchers.lookup(config.getString("dispatcher"))
 
   val detailLevel: LevelOfDetail = config.getString("level") match {
     case "metrics-only" ⇒ LevelOfDetail.MetricsOnly
diff --git a/kamon-core/src/test/scala/kamon/instrumentation/akka/AskPatternInstrumentationSpec.scala b/kamon-core/src/test/scala/kamon/instrumentation/akka/AskPatternInstrumentationSpec.scala
index e0c861cb..471cbd4d 100644
--- a/kamon-core/src/test/scala/kamon/instrumentation/akka/AskPatternInstrumentationSpec.scala
+++ b/kamon-core/src/test/scala/kamon/instrumentation/akka/AskPatternInstrumentationSpec.scala
@@ -31,8 +31,8 @@ class AskPatternInstrumentationSpec extends TestKitBase with WordSpecLike with M
   implicit lazy val system: ActorSystem = ActorSystem("ask-pattern-tracing-spec", ConfigFactory.parseString(
     """
       |kamon {
-      |  trace {
-      |    ask-pattern-tracing = heavyweight
+      |  akka {
+      |     ask-pattern-timeout-warning = heavyweight
       |  }
       |}
     """.stripMargin))