add timer utility metric, based on histograms

1 files changed, 100 insertions, 0 deletions

diff --git a/kamon-core/src/main/scala/kamon/metric/Timer.scala b/kamon-core/src/main/scala/kamon/metric/Timer.scala
new file mode 100644
index 00000000..4750856d
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/metric/Timer.scala
@@ -0,0 +1,100 @@
+/* =========================================================================================
+ * Copyright © 2013-2017 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.metric
+
+import kamon.Tags
+import kamon.util.MeasurementUnit
+
+trait Timer extends Histogram {
+  def start(): StartedTimer
+}
+
+trait StartedTimer {
+  def stop(): Unit
+}
+
+object StartedTimer {
+
+  def createFor(histogram: Histogram): StartedTimer = new StartedTimer {
+    var running = true
+    val startTimestamp = System.nanoTime()
+
+    override def stop(): Unit = synchronized {
+      if(running) {
+        histogram.record(System.nanoTime() - startTimestamp)
+        running = false
+      }
+    }
+  }
+}
+
+private[kamon] final class TimerImpl(val histogram: Histogram) extends Timer {
+
+  override def unit: MeasurementUnit =
+    histogram.unit
+
+  override def dynamicRange: DynamicRange =
+    histogram.dynamicRange
+
+  override def record(value: Long): Unit =
+    histogram.record(value)
+
+  override def record(value: Long, times: Long): Unit =
+    histogram.record(value, times)
+
+  override def start(): StartedTimer =
+    StartedTimer.createFor(histogram)
+}
+
+
+private[kamon] final class TimerMetricImpl(val underlyingHistogram: HistogramMetric) extends TimerMetric {
+
+  override def unit: MeasurementUnit =
+    underlyingHistogram.unit
+
+  override def dynamicRange: DynamicRange =
+    underlyingHistogram.dynamicRange
+
+  override def record(value: Long): Unit =
+    underlyingHistogram.record(value)
+
+  override def record(value: Long, times: Long): Unit =
+    underlyingHistogram.record(value, times)
+
+  override def name: String =
+    underlyingHistogram.name
+
+  override def refine(tags: Tags): Timer =
+    new TimerImpl(underlyingHistogram.refine(tags))
+
+  override def refine(tags: (String, String)*): Timer =
+    new TimerImpl(underlyingHistogram.refine(tags: _*))
+
+  override def refine(tag: String, value: String): Timer =
+    new TimerImpl(underlyingHistogram.refine(Map(tag -> value)))
+
+  override def remove(tags: Tags): Boolean =
+    underlyingHistogram.remove(tags)
+
+  override def remove(tags: (String, String)*): Boolean =
+    underlyingHistogram.remove(tags: _*)
+
+  override def remove(tag: String, value: String): Boolean =
+    underlyingHistogram.remove(tag, value)
+
+  override def start(): StartedTimer =
+    StartedTimer.createFor(underlyingHistogram)
+}
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