+ core: MinMaxCounter for actor mailbox size

2 files changed, 81 insertions, 0 deletions

diff --git a/kamon-core/src/main/scala/kamon/metrics/instruments/counter/MinMaxCounter.scala b/kamon-core/src/main/scala/kamon/metrics/instruments/counter/MinMaxCounter.scala
new file mode 100644
index 00000000..052c7bcd
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/metrics/instruments/counter/MinMaxCounter.scala
@@ -0,0 +1,57 @@
+package kamon.metrics.instruments.counter
+/*
+ * =========================================================================================
+ * 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.
+ * =========================================================================================
+ */
+
+import java.lang.Math._
+import jsr166e.LongMaxUpdater
+import kamon.util.PaddedAtomicLong
+
+sealed trait Counter {
+  def increment(value: Long = 1L): Unit
+  def decrement(value: Long = 1L): Unit
+  def collect(): (Long, Long, Long)
+}
+
+class MinMaxCounter extends Counter {
+  private val min = new LongMaxUpdater
+  private val max = new LongMaxUpdater
+  private val sum = new PaddedAtomicLong
+
+  min.update(0L)
+  max.update(0L)
+
+  def increment(value: Long = 1L): Unit = {
+    val currentValue = sum.addAndGet(value)
+    max.update(currentValue)
+  }
+
+  def decrement(value: Long = 1L): Unit = {
+    val currentValue = sum.addAndGet(-value)
+    min.update(-currentValue)
+  }
+
+  def collect(): (Long, Long, Long) = {
+    val currentValue = sum.get()
+    val result = (abs(min.max()), max.max(), currentValue)
+    max.update(currentValue)
+    min.update(-currentValue)
+    result
+  }
+}
+
+object MinMaxCounter {
+  def apply(): Counter = new MinMaxCounter()
+}
diff --git a/kamon-core/src/main/scala/kamon/util/PaddedAtomicLong.scala b/kamon-core/src/main/scala/kamon/util/PaddedAtomicLong.scala
new file mode 100644
index 00000000..9c926372
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/util/PaddedAtomicLong.scala
@@ -0,0 +1,24 @@
+package kamon.util
+/*
+ * =========================================================================================
+ * 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.
+ * =========================================================================================
+ */
+
+import java.util.concurrent.atomic.AtomicLong
+
+class PaddedAtomicLong(value: Long = 0) extends AtomicLong(value) {
+  @volatile var p1, p2, p3, p4, p5, p6 = 7L
+
+  protected def sumPaddingToPreventOptimisation() = p1 + p2 + p3 + p4 + p5 + p6
+}
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