Merge branch 'wip/improve-metric-recorders-infrastructure'

Conflicts:
	kamon-system-metrics/src/main/scala/kamon/system/SystemMetricsCollector.scala

1 files changed, 49 insertions, 0 deletions

diff --git a/kamon-core/src/main/scala/kamon/metric/TickMetricSnapshotBuffer.scala b/kamon-core/src/main/scala/kamon/metric/TickMetricSnapshotBuffer.scala
new file mode 100644
index 00000000..b9127118
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/metric/TickMetricSnapshotBuffer.scala
@@ -0,0 +1,49 @@
+package kamon.metric
+
+import akka.actor.{ Props, Actor, ActorRef }
+import kamon.Kamon
+import kamon.metric.SubscriptionsDispatcher.TickMetricSnapshot
+import kamon.metric.TickMetricSnapshotBuffer.FlushBuffer
+import kamon.metric.instrument.CollectionContext
+import kamon.util.MapMerge
+
+import scala.concurrent.duration.FiniteDuration
+
+class TickMetricSnapshotBuffer(flushInterval: FiniteDuration, receiver: ActorRef) extends Actor {
+  import MapMerge.Syntax
+
+  val flushSchedule = context.system.scheduler.schedule(flushInterval, flushInterval, self, FlushBuffer)(context.dispatcher)
+  val collectionContext: CollectionContext = Kamon(Metrics)(context.system).buildDefaultCollectionContext
+
+  def receive = empty
+
+  def empty: Actor.Receive = {
+    case tick: TickMetricSnapshot ⇒ context become (buffering(tick))
+    case FlushBuffer              ⇒ // Nothing to flush.
+  }
+
+  def buffering(buffered: TickMetricSnapshot): Actor.Receive = {
+    case TickMetricSnapshot(_, to, tickMetrics) ⇒
+      val combinedMetrics = buffered.metrics.merge(tickMetrics, (l, r) ⇒ l.merge(r, collectionContext))
+      val combinedSnapshot = TickMetricSnapshot(buffered.from, to, combinedMetrics)
+
+      context become (buffering(combinedSnapshot))
+
+    case FlushBuffer ⇒
+      receiver ! buffered
+      context become (empty)
+
+  }
+
+  override def postStop(): Unit = {
+    flushSchedule.cancel()
+    super.postStop()
+  }
+}
+
+object TickMetricSnapshotBuffer {
+  case object FlushBuffer
+
+  def props(flushInterval: FiniteDuration, receiver: ActorRef): Props =
+    Props[TickMetricSnapshotBuffer](new TickMetricSnapshotBuffer(flushInterval, receiver))
+}