= core: first simple approach to providing traces and a subscription mechanism.

1 files changed, 45 insertions, 0 deletions

diff --git a/kamon-core/src/main/scala/kamon/trace/Incubator.scala b/kamon-core/src/main/scala/kamon/trace/Incubator.scala
new file mode 100644
index 00000000..d363d771
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/trace/Incubator.scala
@@ -0,0 +1,45 @@
+package kamon.trace
+
+import akka.actor.{ Props, Actor, ActorRef }
+import kamon.trace.Incubator.{ CheckForCompletedTraces, IncubatingTrace }
+import scala.annotation.tailrec
+import scala.collection.immutable.Queue
+import scala.concurrent.duration._
+
+class Incubator(subscriptions: ActorRef, maxIncubationNanoTime: Long) extends Actor {
+  import context.dispatcher
+  val checkSchedule = context.system.scheduler.schedule(100 millis, 100 millis, self, CheckForCompletedTraces)
+  var incubating = Queue.empty[IncubatingTrace]
+
+  def receive = {
+    case CheckForCompletedTraces ⇒ dispatchCompleted()
+    case tc: TracingContext      ⇒ incubating = incubating.enqueue(IncubatingTrace(tc))
+  }
+
+  @tailrec private def dispatchCompleted(): Unit = {
+    if (incubating.nonEmpty) {
+      val it = incubating.head
+      if (!it.tc.shouldIncubate || it.incubationNanoTime >= maxIncubationNanoTime) {
+        it.tc.generateTraceInfo.map(subscriptions ! _)
+        incubating = incubating.tail
+        dispatchCompleted()
+      }
+    }
+  }
+
+  override def postStop(): Unit = {
+    super.postStop()
+    checkSchedule.cancel()
+  }
+}
+
+object Incubator {
+
+  def props(subscriptions: ActorRef, maxIncubationNanoTime: Long): Props = Props(new Incubator(subscriptions, maxIncubationNanoTime))
+
+  case object CheckForCompletedTraces
+  case class IncubatingTrace(tc: TracingContext) {
+    private val incubationStartNanoTime = System.nanoTime()
+    def incubationNanoTime: Long = System.nanoTime() - incubationStartNanoTime
+  }
+}