/*
* =========================================================================================
* Copyright © 2013 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.metrics
import akka.actor.{ Props, ActorRef, Actor }
import kamon.metrics.Subscriptions.{ MetricGroupFilter, FlushMetrics, TickMetricSnapshot, Subscribe }
import kamon.util.GlobPathFilter
import scala.concurrent.duration.{ FiniteDuration, Duration }
import java.util.concurrent.TimeUnit
import kamon.Kamon
import kamon.metrics.TickMetricSnapshotBuffer.{ Combined, FlushBuffer }
class Subscriptions extends Actor {
import context.system
val config = context.system.settings.config
val tickInterval = Duration(config.getNanoseconds("kamon.metrics.tick-interval"), TimeUnit.NANOSECONDS)
val flushMetricsSchedule = context.system.scheduler.schedule(tickInterval, tickInterval, self, FlushMetrics)(context.dispatcher)
var lastTick: Long = System.currentTimeMillis()
var subscribedPermanently: Map[MetricGroupFilter, List[ActorRef]] = Map.empty
var subscribedForOneShot: Map[MetricGroupFilter, List[ActorRef]] = Map.empty
def receive = {
case Subscribe(category, selection, permanent) ⇒ subscribe(category, selection, permanent)
case FlushMetrics ⇒ flush()
}
def subscribe(category: MetricGroupCategory, selection: String, permanent: Boolean): Unit = {
val filter = MetricGroupFilter(category, new GlobPathFilter(selection))
if (permanent) {
val receivers = subscribedPermanently.get(filter).getOrElse(Nil)
subscribedPermanently = subscribedPermanently.updated(filter, sender :: receivers)
} else {
val receivers = subscribedForOneShot.get(filter).getOrElse(Nil)
subscribedForOneShot = subscribedForOneShot.updated(filter, sender :: receivers)
}
}
def flush(): Unit = {
val currentTick = System.currentTimeMillis()
val snapshots = Kamon(Metrics).collect
dispatchSelectedMetrics(lastTick, currentTick, subscribedPermanently, snapshots)
dispatchSelectedMetrics(lastTick, currentTick, subscribedForOneShot, snapshots)
lastTick = currentTick
subscribedForOneShot = Map.empty
}
def dispatchSelectedMetrics(lastTick: Long, currentTick: Long, subscriptions: Map[MetricGroupFilter, List[ActorRef]],
snapshots: Map[MetricGroupIdentity, MetricGroupSnapshot]): Unit = {
for ((filter, receivers) ← subscriptions) yield {
val selection = snapshots.filter(group ⇒ filter.accept(group._1))
val tickMetrics = TickMetricSnapshot(lastTick, currentTick, selection)
receivers.foreach(_ ! tickMetrics)
}
}
}
object Subscriptions {
case object FlushMetrics
case class Subscribe(category: MetricGroupCategory, selection: String, permanently: Boolean = false)
case class TickMetricSnapshot(from: Long, to: Long, metrics: Map[MetricGroupIdentity, MetricGroupSnapshot])
case class MetricGroupFilter(category: MetricGroupCategory, globFilter: GlobPathFilter) {
def accept(identity: MetricGroupIdentity): Boolean = {
category.equals(identity.category) && globFilter.accept(identity.name)
}
}
}
class TickMetricSnapshotBuffer(flushInterval: FiniteDuration, receiver: ActorRef) extends Actor {
val flushSchedule = context.system.scheduler.schedule(flushInterval, flushInterval, self, FlushBuffer)(context.dispatcher)
def receive = empty
def empty: Actor.Receive = {
case tick: TickMetricSnapshot ⇒ context become (buffering(tick))
case FlushBuffer ⇒ // Nothing to flush.
}
def buffering(buffered: TickMetricSnapshot): Actor.Receive = {
case TickMetricSnapshot(_, to, tickMetrics) ⇒
val combinedMetrics = combineMaps(buffered.metrics, tickMetrics)(mergeMetricGroup)
val combinedSnapshot = TickMetricSnapshot(buffered.from, to, combinedMetrics)
context become (buffering(combinedSnapshot))
case FlushBuffer ⇒
receiver ! buffered
context become (empty)
}
override def postStop(): Unit = {
flushSchedule.cancel()
super.postStop()
}
def mergeMetricGroup(left: MetricGroupSnapshot, right: MetricGroupSnapshot) = Combined(combineMaps(left.metrics, right.metrics)((l, r) ⇒ l.merge(r)))
}
object TickMetricSnapshotBuffer {
case object FlushBuffer
case class Combined(metrics: Map[MetricIdentity, MetricSnapshotLike]) extends MetricGroupSnapshot
def props(flushInterval: FiniteDuration, receiver: ActorRef): Props =
Props[TickMetricSnapshotBuffer](new TickMetricSnapshotBuffer(flushInterval, receiver))
}