1 files changed, 77 insertions, 0 deletions
diff --git a/kamon-system-metrics/src/main/scala/kamon/system/GcMetricsCollector.scala b/kamon-system-metrics/src/main/scala/kamon/system/GcMetricsCollector.scala
new file mode 100644
index 00000000..ae2f50cf
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+++ b/kamon-system-metrics/src/main/scala/kamon/system/GcMetricsCollector.scala
@@ -0,0 +1,77 @@
+/*
+ * =========================================================================================
+ * 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.system
+
+import java.lang.management.GarbageCollectorMXBean
+
+import akka.actor.{ Actor, Props }
+import kamon.metrics.GCMetrics.GCMetricRecorder
+
+import scala.concurrent.duration.FiniteDuration
+
+class GcMetricsCollector(collectInterval: FiniteDuration, recorder: Option[GCMetricRecorder], extractor: GcMetricExtractor) extends Actor {
+  import kamon.system.GcMetricsCollector._
+
+  val collectSchedule = context.system.scheduler.schedule(collectInterval, collectInterval, self, Collect)(SystemMetrics(context.system).dispatcher)
+
+  def receive: Receive = {
+    case Collect ⇒ collectMetrics()
+  }
+
+  override def postStop() = collectSchedule.cancel()
+
+  def collectMetrics(): Unit = recorder.map(recordGc)
+
+  private def recordGc(gcr: GCMetricRecorder) = {
+    val gcMeasure = extractor.extract()
+
+    gcr.count.record(gcMeasure.collectionCount)
+    gcr.time.record(gcMeasure.collectionTime)
+  }
+}
+
+object GcMetricsCollector {
+  case object Collect
+
+  def props(collectInterval: FiniteDuration, recorder: Option[GCMetricRecorder], extractor: GcMetricExtractor): Props = Props(classOf[GcMetricsCollector], collectInterval, recorder, extractor)
+}
+
+case class GcMeasure(collectionCount: Long, collectionTime: Long)
+
+case class GcMetricExtractor(gc: GarbageCollectorMXBean) {
+  var previousGcCount = 0L
+  var previousGcTime = 0L
+
+  def extract(): GcMeasure = {
+    var diffCollectionCount = 0L
+    var diffCollectionTime = 0L
+
+    val collectionCount = gc.getCollectionCount
+    val collectionTime = gc.getCollectionTime
+
+    if (collectionCount > 0)
+      diffCollectionCount = collectionCount - previousGcCount
+
+    if (collectionTime > 0)
+      diffCollectionTime = collectionTime - previousGcTime
+
+    previousGcCount = collectionCount
+    previousGcTime = collectionTime
+
+    GcMeasure(diffCollectionCount, diffCollectionTime)
+  }
+}
+\ No newline at end of file