/*
* =========================================================================================
* 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.metric
import akka.actor._
import kamon.metric.Subscriptions._
import kamon.util.GlobPathFilter
import scala.concurrent.duration.{ FiniteDuration, Duration }
import java.util.concurrent.TimeUnit
import kamon.Kamon
import kamon.metric.TickMetricSnapshotBuffer.FlushBuffer
class Subscriptions extends Actor {
import context.system
val flushMetricsSchedule = scheduleFlushMessage()
val collectionContext = Kamon(Metrics).buildDefaultCollectionContext
var lastTick: Long = System.currentTimeMillis()
var oneShotSubscriptions: Map[ActorRef, MetricSelectionFilter] = Map.empty
var permanentSubscriptions: Map[ActorRef, MetricSelectionFilter] = Map.empty
def receive = {
case Subscribe(category, selection, subscriber, permanent) ⇒ subscribe(category, selection, subscriber, permanent)
case Unsubscribe(subscriber) ⇒ unsubscribe(subscriber)
case Terminated(subscriber) ⇒ unsubscribe(subscriber)
case FlushMetrics ⇒ flush()
}
def subscribe(category: MetricGroupCategory, selection: String, subscriber: ActorRef, permanent: Boolean): Unit = {
context.watch(subscriber)
val newFilter: MetricSelectionFilter = GroupAndPatternFilter(category, new GlobPathFilter(selection))
if (permanent) {
permanentSubscriptions = permanentSubscriptions.updated(subscriber, newFilter combine {
permanentSubscriptions.getOrElse(subscriber, MetricSelectionFilter.empty)
})
} else {
oneShotSubscriptions = oneShotSubscriptions.updated(subscriber, newFilter combine {
oneShotSubscriptions.getOrElse(subscriber, MetricSelectionFilter.empty)
})
}
}
def unsubscribe(subscriber: ActorRef): Unit = {
if (permanentSubscriptions.contains(subscriber))
permanentSubscriptions = permanentSubscriptions - subscriber
if (oneShotSubscriptions.contains(subscriber))
oneShotSubscriptions = oneShotSubscriptions - subscriber
}
def flush(): Unit = {
val currentTick = System.currentTimeMillis()
val snapshots = collectAll()
dispatchSelectedMetrics(lastTick, currentTick, permanentSubscriptions, snapshots)
dispatchSelectedMetrics(lastTick, currentTick, oneShotSubscriptions, snapshots)
lastTick = currentTick
oneShotSubscriptions = Map.empty
}
def collectAll(): Map[MetricGroupIdentity, MetricGroupSnapshot] = {
val allMetrics = Kamon(Metrics).storage
val builder = Map.newBuilder[MetricGroupIdentity, MetricGroupSnapshot]
allMetrics.foreach {
case (identity, recorder) ⇒ builder += ((identity, recorder.collect(collectionContext)))
}
builder.result()
}
def dispatchSelectedMetrics(lastTick: Long, currentTick: Long, subscriptions: Map[ActorRef, MetricSelectionFilter],
snapshots: Map[MetricGroupIdentity, MetricGroupSnapshot]): Unit = {
for ((subscriber, filter) ← subscriptions) {
val selection = snapshots.filter(group ⇒ filter.accept(group._1))
val tickMetrics = TickMetricSnapshot(lastTick, currentTick, selection)
subscriber ! tickMetrics
}
}
def scheduleFlushMessage(): Cancellable = {
val config = context.system.settings.config
val tickInterval = Duration(config.getDuration("kamon.metrics.tick-interval", TimeUnit.NANOSECONDS), TimeUnit.NANOSECONDS)
context.system.scheduler.schedule(tickInterval, tickInterval, self, FlushMetrics)(context.dispatcher)
}
}
object Subscriptions {
case object FlushMetrics
case class Unsubscribe(subscriber: ActorRef)
case class Subscribe(category: MetricGroupCategory, selection: String, subscriber: ActorRef, permanently: Boolean = false)
case class TickMetricSnapshot(from: Long, to: Long, metrics: Map[MetricGroupIdentity, MetricGroupSnapshot])
trait MetricSelectionFilter {
def accept(identity: MetricGroupIdentity): Boolean
}
object MetricSelectionFilter {
val empty = new MetricSelectionFilter {
def accept(identity: MetricGroupIdentity): Boolean = false
}
implicit class CombinableMetricSelectionFilter(msf: MetricSelectionFilter) {
def combine(that: MetricSelectionFilter): MetricSelectionFilter = new MetricSelectionFilter {
def accept(identity: MetricGroupIdentity): Boolean = msf.accept(identity) || that.accept(identity)
}
}
}
case class GroupAndPatternFilter(category: MetricGroupCategory, globFilter: GlobPathFilter) extends MetricSelectionFilter {
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)
val collectionContext = Kamon(Metrics)(context.system).buildDefaultCollectionContext
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) = left.merge(right.asInstanceOf[left.GroupSnapshotType], collectionContext).asInstanceOf[MetricGroupSnapshot] // ??? //Combined(combineMaps(left.metrics, right.metrics)((l, r) ⇒ l.merge(r, collectionContext)))
}
object TickMetricSnapshotBuffer {
case object FlushBuffer
def props(flushInterval: FiniteDuration, receiver: ActorRef): Props =
Props[TickMetricSnapshotBuffer](new TickMetricSnapshotBuffer(flushInterval, receiver))
}