= core: minor cleanup of metric keys and units of measurements.

5 files changed, 42 insertions, 44 deletions

diff --git a/kamon-core/src/main/scala/kamon/metric/MetricKey.scala b/kamon-core/src/main/scala/kamon/metric/MetricKey.scala
index 2c710a19..0d4e0163 100644
--- a/kamon-core/src/main/scala/kamon/metric/MetricKey.scala
+++ b/kamon-core/src/main/scala/kamon/metric/MetricKey.scala
@@ -16,42 +16,32 @@
 
 package kamon.metric
 
-import kamon.metric.instrument.{ InstrumentTypes, InstrumentType, UnitOfMeasurement }
+import kamon.metric.instrument.UnitOfMeasurement
 
 /**
- *  MetricKeys are used to identify a given metric in entity recorders and snapshots. MetricKeys can be used to encode
- *  additional metadata for a metric being recorded, as well as the unit of measurement of the data being recorder.
+ *  MetricKeys are used to identify a given metric in entity recorders and snapshots.
  */
 sealed trait MetricKey {
   def name: String
   def unitOfMeasurement: UnitOfMeasurement
-  def instrumentType: InstrumentType
 }
 
 /**
  *  MetricKey for all Histogram-based metrics.
  */
-private[kamon] case class HistogramKey(name: String, unitOfMeasurement: UnitOfMeasurement) extends MetricKey {
-  val instrumentType = InstrumentTypes.Histogram
-}
+private[kamon] case class HistogramKey(name: String, unitOfMeasurement: UnitOfMeasurement) extends MetricKey
 
 /**
  *  MetricKey for all MinMaxCounter-based metrics.
  */
-case class MinMaxCounterKey(name: String, unitOfMeasurement: UnitOfMeasurement) extends MetricKey {
-  val instrumentType = InstrumentTypes.MinMaxCounter
-}
+private[kamon] case class MinMaxCounterKey(name: String, unitOfMeasurement: UnitOfMeasurement) extends MetricKey
 
 /**
  *  MetricKey for all Gauge-based metrics.
  */
-case class GaugeKey(name: String, unitOfMeasurement: UnitOfMeasurement) extends MetricKey {
-  val instrumentType = InstrumentTypes.Gauge
-}
+private[kamon] case class GaugeKey(name: String, unitOfMeasurement: UnitOfMeasurement) extends MetricKey
 
 /**
  *  MetricKey for all Counter-based metrics.
  */
-case class CounterKey(name: String, unitOfMeasurement: UnitOfMeasurement) extends MetricKey {
-  val instrumentType = InstrumentTypes.Counter
-}
+private[kamon] case class CounterKey(name: String, unitOfMeasurement: UnitOfMeasurement) extends MetricKey
diff --git a/kamon-core/src/main/scala/kamon/metric/Metrics.scala b/kamon-core/src/main/scala/kamon/metric/Metrics.scala
index 05f333ab..11166127 100644
--- a/kamon-core/src/main/scala/kamon/metric/Metrics.scala
+++ b/kamon-core/src/main/scala/kamon/metric/Metrics.scala
@@ -245,7 +245,7 @@ private[kamon] class MetricsImpl(config: Config) extends Metrics {
   def registerHistogram(name: String, tags: Map[String, String], unitOfMeasurement: Option[UnitOfMeasurement],
     dynamicRange: Option[DynamicRange]): Histogram = {
 
-    val histogramEntity = Entity(name, "histogram", tags)
+    val histogramEntity = Entity(name, SingleInstrumentEntityRecorder.Histogram, tags)
     val recorder = _trackedEntities.atomicGetOrElseUpdate(histogramEntity, {
       val factory = instrumentFactory(histogramEntity.category)
       HistogramRecorder(HistogramKey(histogramEntity.category, unitOfMeasurement.getOrElse(UnitOfMeasurement.Unknown)),
@@ -256,12 +256,12 @@ private[kamon] class MetricsImpl(config: Config) extends Metrics {
   }
 
   def removeHistogram(name: String, tags: Map[String, String]): Boolean =
-    _trackedEntities.remove(Entity(name, "histogram", tags)).isDefined
+    _trackedEntities.remove(Entity(name, SingleInstrumentEntityRecorder.Histogram, tags)).isDefined
 
   def registerMinMaxCounter(name: String, tags: Map[String, String], unitOfMeasurement: Option[UnitOfMeasurement], dynamicRange: Option[DynamicRange],
     refreshInterval: Option[FiniteDuration]): MinMaxCounter = {
 
-    val minMaxCounterEntity = Entity(name, "min-max-counter", tags)
+    val minMaxCounterEntity = Entity(name, SingleInstrumentEntityRecorder.MinMaxCounter, tags)
     val recorder = _trackedEntities.atomicGetOrElseUpdate(minMaxCounterEntity, {
       val factory = instrumentFactory(minMaxCounterEntity.category)
       MinMaxCounterRecorder(MinMaxCounterKey(minMaxCounterEntity.category, unitOfMeasurement.getOrElse(UnitOfMeasurement.Unknown)),
@@ -272,13 +272,13 @@ private[kamon] class MetricsImpl(config: Config) extends Metrics {
   }
 
   def removeMinMaxCounter(name: String, tags: Map[String, String]): Boolean =
-    _trackedEntities.remove(Entity(name, "min-max-counter", tags)).isDefined
+    _trackedEntities.remove(Entity(name, SingleInstrumentEntityRecorder.MinMaxCounter, tags)).isDefined
 
   def registerGauge(name: String, valueCollector: CurrentValueCollector, tags: Map[String, String] = Map.empty,
     unitOfMeasurement: Option[UnitOfMeasurement] = None, dynamicRange: Option[DynamicRange] = None,
     refreshInterval: Option[FiniteDuration] = None): Gauge = {
 
-    val gaugeEntity = Entity(name, "gauge", tags)
+    val gaugeEntity = Entity(name, SingleInstrumentEntityRecorder.Gauge, tags)
     val recorder = _trackedEntities.atomicGetOrElseUpdate(gaugeEntity, {
       val factory = instrumentFactory(gaugeEntity.category)
       GaugeRecorder(MinMaxCounterKey(gaugeEntity.category, unitOfMeasurement.getOrElse(UnitOfMeasurement.Unknown)),
@@ -289,12 +289,12 @@ private[kamon] class MetricsImpl(config: Config) extends Metrics {
   }
 
   def removeGauge(name: String, tags: Map[String, String]): Boolean =
-    _trackedEntities.remove(Entity(name, "gauge", tags)).isDefined
+    _trackedEntities.remove(Entity(name, SingleInstrumentEntityRecorder.Gauge, tags)).isDefined
 
   def registerCounter(name: String, tags: Map[String, String] = Map.empty, unitOfMeasurement: Option[UnitOfMeasurement] = None,
     dynamicRange: Option[DynamicRange] = None): Counter = {
 
-    val counterEntity = Entity(name, "counter", tags)
+    val counterEntity = Entity(name, SingleInstrumentEntityRecorder.Counter, tags)
     val recorder = _trackedEntities.atomicGetOrElseUpdate(counterEntity, {
       val factory = instrumentFactory(counterEntity.category)
       CounterRecorder(CounterKey(counterEntity.category, unitOfMeasurement.getOrElse(UnitOfMeasurement.Unknown)),
@@ -305,7 +305,7 @@ private[kamon] class MetricsImpl(config: Config) extends Metrics {
   }
 
   def removeCounter(name: String, tags: Map[String, String]): Boolean =
-    _trackedEntities.remove(Entity(name, "counter", tags)).isDefined
+    _trackedEntities.remove(Entity(name, SingleInstrumentEntityRecorder.Counter, tags)).isDefined
 
   def entity[T <: EntityRecorder](recorderFactory: EntityRecorderFactory[T], entity: Entity): T = {
     _trackedEntities.atomicGetOrElseUpdate(entity, {
diff --git a/kamon-core/src/main/scala/kamon/metric/instrument/Instrument.scala b/kamon-core/src/main/scala/kamon/metric/instrument/Instrument.scala
index 59b4b443..089dbeec 100644
--- a/kamon-core/src/main/scala/kamon/metric/instrument/Instrument.scala
+++ b/kamon-core/src/main/scala/kamon/metric/instrument/Instrument.scala
@@ -33,14 +33,6 @@ trait InstrumentSnapshot {
   def merge(that: InstrumentSnapshot, context: CollectionContext): InstrumentSnapshot
 }
 
-class InstrumentType private[kamon] (val id: Int) extends AnyVal
-object InstrumentTypes {
-  val Histogram = new InstrumentType(1)
-  val MinMaxCounter = new InstrumentType(2)
-  val Gauge = new InstrumentType(3)
-  val Counter = new InstrumentType(4)
-}
-
 trait CollectionContext {
   def buffer: LongBuffer
 }
@@ -51,3 +43,11 @@ object CollectionContext {
   }
 }
 
+sealed trait InstrumentType
+
+object InstrumentTypes {
+  case object Histogram extends InstrumentType
+  case object MinMaxCounter extends InstrumentType
+  case object Gauge extends InstrumentType
+  case object Counter extends InstrumentType
+}
diff --git a/kamon-core/src/main/scala/kamon/metric/instrument/UnitOfMeasurement.scala b/kamon-core/src/main/scala/kamon/metric/instrument/UnitOfMeasurement.scala
index f2a061d1..c5a1b81a 100644
--- a/kamon-core/src/main/scala/kamon/metric/instrument/UnitOfMeasurement.scala
+++ b/kamon-core/src/main/scala/kamon/metric/instrument/UnitOfMeasurement.scala
@@ -16,17 +16,20 @@
 
 package kamon.metric.instrument
 
+/**
+ *  A UnitOfMeasurement implementation describes the magnitude of a quantity being measured, such as Time and computer
+ *  Memory space. Kamon uses UnitOfMeasurement implementations just as a informative companion to metrics inside entity
+ *  recorders and might be used to scale certain kinds of measurements in metric backends.
+ */
 trait UnitOfMeasurement {
   def name: String
   def label: String
-  def factor: Double
 }
 
 object UnitOfMeasurement {
   case object Unknown extends UnitOfMeasurement {
     val name = "unknown"
     val label = "unknown"
-    val factor = 1D
   }
 
   def isUnknown(uom: UnitOfMeasurement): Boolean =
@@ -35,19 +38,18 @@ object UnitOfMeasurement {
   def isTime(uom: UnitOfMeasurement): Boolean =
     uom.isInstanceOf[Time]
 
+  def isMemory(uom: UnitOfMeasurement): Boolean =
+    uom.isInstanceOf[Memory]
+
 }
 
+/**
+ *  UnitOfMeasurement representing time.
+ */
 case class Time(factor: Double, label: String) extends UnitOfMeasurement {
   val name = "time"
 
-  /**
-   *  Scale a value from this scale factor to a different scale factor.
-   *
-   * @param toUnit Time unit of the expected result.
-   * @param value Value to scale.
-   * @return Equivalent of value on the target time unit.
-   */
-  def scale(toUnit: Time)(value: Long): Double =
+  def scale(toUnit: Time)(value: Double): Double =
     (value * factor) / toUnit.factor
 }
 
@@ -58,8 +60,14 @@ object Time {
   val Seconds = Time(1, "s")
 }
 
+/**
+ *  UnitOfMeasurement representing computer memory space.
+ */
 case class Memory(factor: Double, label: String) extends UnitOfMeasurement {
   val name = "bytes"
+
+  def scale(toUnit: Memory)(value: Double): Double =
+    (value * factor) / toUnit.factor
 }
 
 object Memory {
diff --git a/kamon-newrelic/src/main/scala/kamon/newrelic/Metric.scala b/kamon-newrelic/src/main/scala/kamon/newrelic/Metric.scala
index 20204b79..6fb645f5 100644
--- a/kamon-newrelic/src/main/scala/kamon/newrelic/Metric.scala
+++ b/kamon-newrelic/src/main/scala/kamon/newrelic/Metric.scala
@@ -18,9 +18,9 @@ case class MetricData(callCount: Long, total: Double, totalExclusive: Double, mi
 
 object Metric {
 
-  def scaleFunction(uom: UnitOfMeasurement): Long ⇒ Double = uom match {
+  def scaleFunction(uom: UnitOfMeasurement): Double ⇒ Double = uom match {
     case time: Time ⇒ time.scale(Time.Seconds)
-    case other      ⇒ _.toDouble
+    case other      ⇒ a ⇒ a
   }
 
   def apply(snapshot: InstrumentSnapshot, snapshotUnit: UnitOfMeasurement, name: String, scope: Option[String]): Metric = {