path: root/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala

/*
 * =========================================================================================
 * Copyright © 2013-2015 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.metric.instrument.Gauge.CurrentValueCollector
import kamon.metric.instrument.Histogram.DynamicRange
import kamon.metric.instrument._
import kamon.util.Function

import scala.collection.concurrent.TrieMap
import scala.concurrent.duration.FiniteDuration

trait EntityRecorder {
  def collect(collectionContext: CollectionContext): EntitySnapshot
  def cleanup: Unit
}

trait EntityRecorderFactory[T <: EntityRecorder] {
  def category: String
  def createRecorder(instrumentFactory: InstrumentFactory): T
}

abstract class EntityRecorderFactoryCompanion[T <: EntityRecorder](val category: String, builder: (InstrumentFactory) ⇒ T)
    extends EntityRecorderFactory[T] {

  def createRecorder(instrumentFactory: InstrumentFactory): T = builder(instrumentFactory)
}

object EntityRecorderFactory {
  def apply[T <: EntityRecorder](entityCategory: String, factory: InstrumentFactory ⇒ T): EntityRecorderFactory[T] =
    new EntityRecorderFactory[T] {
      def category: String = entityCategory
      def createRecorder(instrumentFactory: InstrumentFactory): T = factory(instrumentFactory)
    }

  def create[T <: EntityRecorder](entityCategory: String, factory: Function[InstrumentFactory, T]): EntityRecorderFactory[T] =
    new EntityRecorderFactory[T] {
      def category: String = entityCategory
      def createRecorder(instrumentFactory: InstrumentFactory): T = factory(instrumentFactory)
    }
}

private[kamon] sealed trait SingleInstrumentEntityRecorder extends EntityRecorder {
  def key: MetricKey
  def instrument: Instrument

  def collect(collectionContext: CollectionContext): EntitySnapshot =
    new DefaultEntitySnapshot(Map(key → instrument.collect(collectionContext)))

  def cleanup: Unit = instrument.cleanup
}

object SingleInstrumentEntityRecorder {
  val Histogram = "histogram"
  val MinMaxCounter = "min-max-counter"
  val Gauge = "gauge"
  val Counter = "counter"

  val AllCategories = List("histogram", "gauge", "counter", "min-max-counter")
}

/**
 *  Entity recorder for a single Counter instrument.
 */
case class CounterRecorder(key: MetricKey, instrument: Counter) extends SingleInstrumentEntityRecorder

/**
 *  Entity recorder for a single Histogram instrument.
 */
case class HistogramRecorder(key: MetricKey, instrument: Histogram) extends SingleInstrumentEntityRecorder

/**
 *  Entity recorder for a single MinMaxCounter instrument.
 */
case class MinMaxCounterRecorder(key: MetricKey, instrument: MinMaxCounter) extends SingleInstrumentEntityRecorder

/**
 *  Entity recorder for a single Gauge instrument.
 */
case class GaugeRecorder(key: MetricKey, instrument: Gauge) extends SingleInstrumentEntityRecorder

/**
 *  Base class with plenty of utility methods to facilitate the creation of [[EntityRecorder]] implementations.
 *  It is not required to use this base class for defining a custom [[EntityRecorder]], but it is certainly
 *  the most convenient way to do it and the preferred approach throughout the Kamon codebase.
 */
abstract class GenericEntityRecorder(instrumentFactory: InstrumentFactory) extends EntityRecorder {
  import kamon.util.TriemapAtomicGetOrElseUpdate.Syntax

  private val _instruments = TrieMap.empty[MetricKey, Instrument]
  private def register[T <: Instrument](key: MetricKey, instrument: ⇒ T): T =
    _instruments.atomicGetOrElseUpdate(key, instrument, _.cleanup).asInstanceOf[T]

  protected def histogram(name: String): Histogram =
    register(HistogramKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createHistogram(name))

  protected def histogram(name: String, dynamicRange: DynamicRange): Histogram =
    register(HistogramKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createHistogram(name, Some(dynamicRange)))

  protected def histogram(name: String, unitOfMeasurement: UnitOfMeasurement): Histogram =
    register(HistogramKey(name, unitOfMeasurement), instrumentFactory.createHistogram(name))

  protected def histogram(name: String, dynamicRange: DynamicRange, unitOfMeasurement: UnitOfMeasurement): Histogram =
    register(HistogramKey(name, unitOfMeasurement), instrumentFactory.createHistogram(name, Some(dynamicRange)))

  protected def removeHistogram(name: String): Unit =
    _instruments.remove(HistogramKey(name, UnitOfMeasurement.Unknown))

  protected def removeHistogram(name: String, unitOfMeasurement: UnitOfMeasurement): Unit =
    _instruments.remove(HistogramKey(name, unitOfMeasurement))

  protected def minMaxCounter(name: String): MinMaxCounter =
    register(MinMaxCounterKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createMinMaxCounter(name))

  protected def minMaxCounter(name: String, dynamicRange: DynamicRange): MinMaxCounter =
    register(MinMaxCounterKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createMinMaxCounter(name, Some(dynamicRange)))

  protected def minMaxCounter(name: String, refreshInterval: FiniteDuration): MinMaxCounter =
    register(MinMaxCounterKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createMinMaxCounter(name, refreshInterval = Some(refreshInterval)))

  protected def minMaxCounter(name: String, unitOfMeasurement: UnitOfMeasurement): MinMaxCounter =
    register(MinMaxCounterKey(name, unitOfMeasurement), instrumentFactory.createMinMaxCounter(name))

  protected def minMaxCounter(name: String, dynamicRange: DynamicRange, refreshInterval: FiniteDuration): MinMaxCounter =
    register(MinMaxCounterKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createMinMaxCounter(name, Some(dynamicRange), Some(refreshInterval)))

  protected def minMaxCounter(name: String, dynamicRange: DynamicRange, unitOfMeasurement: UnitOfMeasurement): MinMaxCounter =
    register(MinMaxCounterKey(name, unitOfMeasurement), instrumentFactory.createMinMaxCounter(name, Some(dynamicRange)))

  protected def minMaxCounter(name: String, refreshInterval: FiniteDuration, unitOfMeasurement: UnitOfMeasurement): MinMaxCounter =
    register(MinMaxCounterKey(name, unitOfMeasurement), instrumentFactory.createMinMaxCounter(name, refreshInterval = Some(refreshInterval)))

  protected def minMaxCounter(name: String, dynamicRange: DynamicRange, refreshInterval: FiniteDuration, unitOfMeasurement: UnitOfMeasurement): MinMaxCounter =
    register(MinMaxCounterKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createMinMaxCounter(name, Some(dynamicRange), Some(refreshInterval)))

  protected def minMaxCounter(key: MinMaxCounterKey): MinMaxCounter =
    register(key, instrumentFactory.createMinMaxCounter(key.name))

  protected def minMaxCounter(key: MinMaxCounterKey, dynamicRange: DynamicRange): MinMaxCounter =
    register(key, instrumentFactory.createMinMaxCounter(key.name, Some(dynamicRange)))

  protected def minMaxCounter(key: MinMaxCounterKey, refreshInterval: FiniteDuration): MinMaxCounter =
    register(key, instrumentFactory.createMinMaxCounter(key.name, refreshInterval = Some(refreshInterval)))

  protected def minMaxCounter(key: MinMaxCounterKey, dynamicRange: DynamicRange, refreshInterval: FiniteDuration): MinMaxCounter =
    register(key, instrumentFactory.createMinMaxCounter(key.name, Some(dynamicRange), Some(refreshInterval)))

  protected def removeMinMaxCounter(name: String): Unit =
    _instruments.remove(MinMaxCounterKey(name, UnitOfMeasurement.Unknown))

  protected def removeMinMaxCounter(key: MinMaxCounterKey): Unit =
    _instruments.remove(key)

  protected def gauge(name: String, valueCollector: CurrentValueCollector): Gauge =
    register(GaugeKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createGauge(name, valueCollector = valueCollector))

  protected def gauge(name: String, dynamicRange: DynamicRange, valueCollector: CurrentValueCollector): Gauge =
    register(GaugeKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createGauge(name, Some(dynamicRange), valueCollector = valueCollector))

  protected def gauge(name: String, refreshInterval: FiniteDuration, valueCollector: CurrentValueCollector): Gauge =
    register(GaugeKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createGauge(name, refreshInterval = Some(refreshInterval), valueCollector = valueCollector))

  protected def gauge(name: String, unitOfMeasurement: UnitOfMeasurement, valueCollector: CurrentValueCollector): Gauge =
    register(GaugeKey(name, unitOfMeasurement), instrumentFactory.createGauge(name, valueCollector = valueCollector))

  protected def gauge(name: String, dynamicRange: DynamicRange, refreshInterval: FiniteDuration, valueCollector: CurrentValueCollector): Gauge =
    register(GaugeKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createGauge(name, Some(dynamicRange), Some(refreshInterval), valueCollector = valueCollector))

  protected def gauge(name: String, dynamicRange: DynamicRange, unitOfMeasurement: UnitOfMeasurement, valueCollector: CurrentValueCollector): Gauge =
    register(GaugeKey(name, unitOfMeasurement), instrumentFactory.createGauge(name, Some(dynamicRange), valueCollector = valueCollector))

  protected def gauge(name: String, refreshInterval: FiniteDuration, unitOfMeasurement: UnitOfMeasurement, valueCollector: CurrentValueCollector): Gauge =
    register(GaugeKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createGauge(name, refreshInterval = Some(refreshInterval), valueCollector = valueCollector))

  protected def gauge(name: String, dynamicRange: DynamicRange, refreshInterval: FiniteDuration, unitOfMeasurement: UnitOfMeasurement, valueCollector: CurrentValueCollector): Gauge =
    register(GaugeKey(name, unitOfMeasurement), instrumentFactory.createGauge(name, Some(dynamicRange), Some(refreshInterval), valueCollector))

  protected def gauge(key: GaugeKey, valueCollector: CurrentValueCollector): Gauge =
    register(key, instrumentFactory.createGauge(key.name, valueCollector = valueCollector))

  protected def gauge(key: GaugeKey, dynamicRange: DynamicRange, valueCollector: CurrentValueCollector): Gauge =
    register(key, instrumentFactory.createGauge(key.name, Some(dynamicRange), valueCollector = valueCollector))

  protected def gauge(key: GaugeKey, refreshInterval: FiniteDuration, valueCollector: CurrentValueCollector): Gauge =
    register(key, instrumentFactory.createGauge(key.name, refreshInterval = Some(refreshInterval), valueCollector = valueCollector))

  protected def gauge(key: GaugeKey, dynamicRange: DynamicRange, refreshInterval: FiniteDuration, valueCollector: CurrentValueCollector): Gauge =
    register(key, instrumentFactory.createGauge(key.name, Some(dynamicRange), Some(refreshInterval), valueCollector = valueCollector))

  protected def removeGauge(name: String): Unit =
    _instruments.remove(GaugeKey(name, UnitOfMeasurement.Unknown))

  protected def removeGauge(key: GaugeKey): Unit =
    _instruments.remove(key)

  protected def counter(name: String): Counter =
    register(CounterKey(name, UnitOfMeasurement.Unknown), instrumentFactory.createCounter())

  protected def counter(name: String, unitOfMeasurement: UnitOfMeasurement): Counter =
    register(CounterKey(name, unitOfMeasurement), instrumentFactory.createCounter())

  protected def counter(key: CounterKey): Counter =
    register(key, instrumentFactory.createCounter())

  protected def removeCounter(name: String): Unit =
    _instruments.remove(CounterKey(name, UnitOfMeasurement.Unknown))

  protected def removeCounter(key: CounterKey): Unit =
    _instruments.remove(key)

  def collect(collectionContext: CollectionContext): EntitySnapshot = {
    val snapshots = Map.newBuilder[MetricKey, InstrumentSnapshot]
    _instruments.foreach {
      case (key, instrument) ⇒ snapshots += key → instrument.collect(collectionContext)
    }

    new DefaultEntitySnapshot(snapshots.result())
  }

  def cleanup: Unit = _instruments.values.foreach(_.cleanup)
}