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

package kamon.metric

import akka.actor.ExtendedActorSystem
import com.typesafe.config.Config
import kamon.metric.instrument.{ RefreshScheduler, InstrumentFactory, DefaultInstrumentSettings, InstrumentCustomSettings }
import kamon.util.GlobPathFilter

import scala.concurrent.duration.FiniteDuration

/**
 *  Configuration settings for the Metrics extension, as read from the `kamon.metric` configuration key.
 */
case class MetricsExtensionSettings(
  tickInterval: FiniteDuration,
  defaultCollectionContextBufferSize: Int,
  trackUnmatchedEntities: Boolean,
  entityFilters: Map[String, EntityFilter],
  instrumentFactories: Map[String, InstrumentFactory],
  defaultInstrumentFactory: InstrumentFactory,
  metricCollectionDispatcher: String,
  refreshSchedulerDispatcher: String,
  refreshScheduler: RefreshScheduler)

/**
 *
 */
case class EntityFilter(includes: List[GlobPathFilter], excludes: List[GlobPathFilter]) {
  def accept(name: String): Boolean =
    includes.exists(_.accept(name)) && !excludes.exists(_.accept(name))
}

object MetricsExtensionSettings {
  import kamon.util.ConfigTools.Syntax
  import scala.concurrent.duration._

  def apply(system: ExtendedActorSystem): MetricsExtensionSettings = {
    val metricConfig = system.settings.config.getConfig("kamon.metric")

    val tickInterval = metricConfig.getFiniteDuration("tick-interval")
    val collectBufferSize = metricConfig.getInt("default-collection-context-buffer-size")
    val trackUnmatchedEntities = metricConfig.getBoolean("track-unmatched-entities")
    val entityFilters = loadFilters(metricConfig.getConfig("filters"))
    val defaultInstrumentSettings = DefaultInstrumentSettings.fromConfig(metricConfig.getConfig("default-instrument-settings"))
    val metricCollectionDispatcher = metricConfig.getString("dispatchers.metric-collection")
    val refreshSchedulerDispatcher = metricConfig.getString("dispatchers.refresh-scheduler")

    val refreshScheduler = RefreshScheduler(system.scheduler, system.dispatchers.lookup(refreshSchedulerDispatcher))
    val instrumentFactories = loadInstrumentFactories(metricConfig.getConfig("instrument-settings"), defaultInstrumentSettings, refreshScheduler)
    val defaultInstrumentFactory = new InstrumentFactory(Map.empty, defaultInstrumentSettings, refreshScheduler)

    MetricsExtensionSettings(tickInterval, collectBufferSize, trackUnmatchedEntities, entityFilters, instrumentFactories,
      defaultInstrumentFactory, metricCollectionDispatcher, refreshSchedulerDispatcher, refreshScheduler)
  }

  /**
   *  Load all the default filters configured under the `kamon.metric.filters` configuration key. All filters are
   *  defined with the entity category as a sub-key of the `kamon.metric.filters` key and two sub-keys to it: includes
   *  and excludes with lists of string glob patterns as values. Example:
   *
   *  {{{
   *
   *    kamon.metrics.filters {
   *      actor {
   *        includes = ["user/test-actor", "user/service/worker-*"]
   *        excludes = ["user/IO-*"]
   *      }
   *    }
   *
   *  }}}
   *
   *  @return a Map from category name to corresponding entity filter.
   */
  def loadFilters(filtersConfig: Config): Map[String, EntityFilter] = {
    import scala.collection.JavaConverters._

    filtersConfig.firstLevelKeys map { category: String ⇒
      val includes = filtersConfig.getStringList(s"$category.includes").asScala.map(inc ⇒ new GlobPathFilter(inc)).toList
      val excludes = filtersConfig.getStringList(s"$category.excludes").asScala.map(exc ⇒ new GlobPathFilter(exc)).toList

      (category, EntityFilter(includes, excludes))
    } toMap
  }

  /**
   *  Load any custom configuration settings defined under the `kamon.metric.instrument-settings` configuration key and
   *  create InstrumentFactories for them.
   *
   * @return a Map from category name to InstrumentFactory.
   */
  def loadInstrumentFactories(instrumentSettings: Config, defaults: DefaultInstrumentSettings, refreshScheduler: RefreshScheduler): Map[String, InstrumentFactory] = {
    instrumentSettings.firstLevelKeys.map { category ⇒
      val categoryConfig = instrumentSettings.getConfig(category)
      val customSettings = categoryConfig.firstLevelKeys.map { instrumentName ⇒
        (instrumentName, InstrumentCustomSettings.fromConfig(categoryConfig.getConfig(instrumentName)))
      } toMap

      (category, new InstrumentFactory(customSettings, defaults, refreshScheduler))
    } toMap
  }
}