separate metrics from instruments and add default instrument for metrics

1 files changed, 161 insertions, 0 deletions

diff --git a/kamon-core/src/main/scala/kamon/metric/Metric.scala b/kamon-core/src/main/scala/kamon/metric/Metric.scala
new file mode 100644
index 00000000..58386353
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/metric/Metric.scala
@@ -0,0 +1,161 @@
+/* =========================================================================================
+ * 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
+package metric
+
+import java.util.concurrent.atomic.AtomicReference
+
+import kamon.metric.InstrumentFactory.InstrumentType
+import kamon.metric.InstrumentFactory.InstrumentTypes._
+import kamon.util.MeasurementUnit
+
+import scala.collection.concurrent.TrieMap
+import scala.concurrent.duration.Duration
+
+
+
+trait Metric[T] {
+  def name: String
+  def unit: MeasurementUnit
+
+  def refine(tags: Tags): T
+  def refine(tags: (String, String)*): T
+  def refine(tag: String, value: String): T
+}
+
+trait HistogramMetric extends Metric[Histogram] with Histogram
+trait MinMaxCounterMetric extends Metric[MinMaxCounter] with MinMaxCounter
+trait GaugeMetric extends Metric[Gauge] with Gauge
+trait CounterMetric extends Metric[Counter] with Counter
+
+
+abstract sealed class BaseMetric[T, S](val instrumentType: InstrumentType) extends Metric[T] {
+  private val instruments = TrieMap.empty[Tags, T]
+  protected lazy val baseInstrument: T = instruments.atomicGetOrElseUpdate(Map.empty, createInstrument(Map.empty))
+
+  def refine(tag: String, value: String): T = {
+    val instrumentTags = Map(tag -> value)
+    instruments.atomicGetOrElseUpdate(instrumentTags, createInstrument(instrumentTags))
+  }
+
+  def refine(tags: Map[String, String]): T =
+    instruments.atomicGetOrElseUpdate(tags, createInstrument(tags))
+
+  def refine(tags: (String, String)*): T =
+    refine(tags.toMap)
+
+
+  private[kamon] def snapshot(): Seq[S] =
+    instruments.values.map(createSnapshot).toSeq
+
+  protected def createInstrument(tags: Tags): T
+
+  protected def createSnapshot(instrument: T): S
+}
+
+
+private[kamon] final class HistogramMetricImpl(val name: String, val unit: MeasurementUnit, customDynamicRange: Option[DynamicRange],
+    factory: AtomicReference[InstrumentFactory]) extends BaseMetric[Histogram, MetricDistribution](Histogram) with HistogramMetric {
+
+  def dynamicRange: DynamicRange =
+    baseInstrument.dynamicRange
+
+  override def record(value: Long): Unit =
+    baseInstrument.record(value)
+
+  override def record(value: Long, times: Long): Unit =
+    baseInstrument.record(value, times)
+
+  override protected def createInstrument(tags: Tags): Histogram =
+    factory.get().buildHistogram(customDynamicRange)(name, tags, unit)
+
+  override protected def createSnapshot(instrument: Histogram): MetricDistribution =
+    instrument.asInstanceOf[SnapshotableHistogram].snapshot()
+}
+
+private[kamon] final class MinMaxCounterMetricImpl(val name: String, val unit: MeasurementUnit, customDynamicRange: Option[DynamicRange],
+    customSampleInterval: Option[Duration], factory: AtomicReference[InstrumentFactory])
+  extends BaseMetric[MinMaxCounter, MetricDistribution](MinMaxCounter) with MinMaxCounterMetric {
+
+  def dynamicRange: DynamicRange =
+    baseInstrument.dynamicRange
+
+  override def sampleInterval: Duration =
+    baseInstrument.sampleInterval
+
+  override def increment(): Unit =
+    baseInstrument.increment()
+
+  override def increment(times: Long): Unit =
+    baseInstrument.increment(times)
+
+  override def decrement(): Unit =
+    baseInstrument.decrement()
+
+  override def decrement(times: Long): Unit =
+    baseInstrument.decrement(times)
+
+  override def sample(): Unit =
+    baseInstrument.sample()
+
+  override protected def createInstrument(tags: Tags): MinMaxCounter =
+    factory.get().buildMinMaxCounter(customDynamicRange, customSampleInterval)(name, tags, unit)
+
+  override protected def createSnapshot(instrument: MinMaxCounter): MetricDistribution =
+    instrument.asInstanceOf[SnapshotableMinMaxCounter].snapshot()
+}
+
+
+private[kamon] final class CounterMetricImpl(val name: String, val unit: MeasurementUnit, factory: AtomicReference[InstrumentFactory])
+  extends BaseMetric[Counter, MetricValue](Counter) with CounterMetric {
+
+  override def increment(): Unit =
+    baseInstrument.increment()
+
+  override def increment(times: Long): Unit =
+    baseInstrument.increment(times)
+
+  override protected def createInstrument(tags: Tags): Counter =
+    factory.get().buildCounter(name, tags, unit)
+
+  override protected def createSnapshot(instrument: Counter): MetricValue =
+    instrument.asInstanceOf[SnapshotableCounter].snapshot()
+}
+
+private[kamon] final class GaugeMetricImpl(val name: String, val unit: MeasurementUnit, factory: AtomicReference[InstrumentFactory])
+  extends BaseMetric[Gauge, MetricValue](Gauge) with GaugeMetric {
+
+  override def increment(): Unit =
+    baseInstrument.increment()
+
+  override def increment(times: Long): Unit =
+    baseInstrument.increment(times)
+
+  override def decrement(): Unit =
+    baseInstrument.decrement()
+
+  override def decrement(times: Long): Unit =
+    baseInstrument.decrement(times)
+
+  override def set(value: Long): Unit =
+    baseInstrument.set(value)
+
+  override protected def createInstrument(tags: Tags): Gauge =
+    factory.get().buildGauge(name, tags, unit)
+
+  override protected def createSnapshot(instrument: Gauge): MetricValue =
+    instrument.asInstanceOf[SnapshotableGauge].snapshot()
+}
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