1 files changed, 32 insertions, 0 deletions
diff --git a/kamon-core/src/main/scala/kamon/metric/Counter.scala b/kamon-core/src/main/scala/kamon/metric/Counter.scala
new file mode 100644
index 00000000..38d312f0
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/metric/Counter.scala
@@ -0,0 +1,32 @@
+package kamon.metric
+
+import java.util.concurrent.atomic.LongAdder
+
+import com.typesafe.scalalogging.StrictLogging
+import kamon.util.MeasurementUnit
+
+trait Counter {
+  def measurementUnit: MeasurementUnit
+
+  def increment(): Unit
+  def increment(times: Long): Unit
+}
+
+class LongAdderCounter(name: String, tags: Map[String, String], val measurementUnit: MeasurementUnit)
+    extends SnapshotableCounter with StrictLogging {
+
+  private val adder = new LongAdder()
+
+  def increment(): Unit =
+    adder.increment()
+
+  def increment(times: Long): Unit = {
+    if (times >= 0)
+      adder.add(times)
+    else
+      logger.warn(s"Ignored attempt to decrement counter [$name]")
+  }
+
+  def snapshot(): MetricValue =
+    MetricValue(name, tags, measurementUnit, adder.sumThenReset())
+}