1 files changed, 134 insertions, 0 deletions
diff --git a/kamon-core/src/main/scala/kamon/metric/MetricsExtension.scala b/kamon-core/src/main/scala/kamon/metric/MetricsExtension.scala
new file mode 100644
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+++ b/kamon-core/src/main/scala/kamon/metric/MetricsExtension.scala
@@ -0,0 +1,134 @@
+/*
+ * =========================================================================================
+ * 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.event.Logging.Error
+import akka.event.EventStream
+
+import scala.collection.concurrent.TrieMap
+import akka.actor._
+import com.typesafe.config.Config
+import kamon.util.GlobPathFilter
+import kamon.Kamon
+import akka.actor
+import kamon.metric.Metrics.MetricGroupFilter
+import kamon.metric.Subscriptions.{ Unsubscribe, Subscribe }
+import java.util.concurrent.TimeUnit
+
+class MetricsExtension(system: ExtendedActorSystem) extends Kamon.Extension {
+  val metricsExtConfig = system.settings.config.getConfig("kamon.metrics")
+  printInitializationMessage(system.eventStream, metricsExtConfig.getBoolean("disable-aspectj-weaver-missing-error"))
+
+  /** Configured Dispatchers */
+  val metricSubscriptionsDispatcher = system.dispatchers.lookup(metricsExtConfig.getString("dispatchers.metric-subscriptions"))
+  val gaugeRecordingsDispatcher = system.dispatchers.lookup(metricsExtConfig.getString("dispatchers.gauge-recordings"))
+
+  /** Configuration Settings */
+  val gaugeRecordingInterval = metricsExtConfig.getDuration("gauge-recording-interval", TimeUnit.MILLISECONDS)
+
+  val storage = TrieMap[MetricGroupIdentity, MetricGroupRecorder]()
+  val filters = loadFilters(metricsExtConfig)
+  lazy val subscriptions = system.actorOf(Props[Subscriptions], "kamon-metrics-subscriptions")
+
+  def register(identity: MetricGroupIdentity, factory: MetricGroupFactory): Option[factory.GroupRecorder] = {
+    if (shouldTrack(identity))
+      Some(storage.getOrElseUpdate(identity, factory.create(metricsExtConfig, system)).asInstanceOf[factory.GroupRecorder])
+    else
+      None
+  }
+
+  def unregister(identity: MetricGroupIdentity): Unit = {
+    storage.remove(identity)
+  }
+
+  def subscribe[C <: MetricGroupCategory](category: C, selection: String, subscriber: ActorRef, permanently: Boolean = false): Unit =
+    subscriptions.tell(Subscribe(category, selection, subscriber, permanently), subscriber)
+
+  def unsubscribe(subscriber: ActorRef): Unit =
+    subscriptions.tell(Unsubscribe(subscriber), subscriber)
+
+  def scheduleGaugeRecorder(body: ⇒ Unit): Cancellable = {
+    import scala.concurrent.duration._
+
+    system.scheduler.schedule(gaugeRecordingInterval milliseconds, gaugeRecordingInterval milliseconds) {
+      body
+    }(gaugeRecordingsDispatcher)
+  }
+
+  private def shouldTrack(identity: MetricGroupIdentity): Boolean = {
+    filters.get(identity.category.name).map(filter ⇒ filter.accept(identity.name)).getOrElse(true)
+  }
+
+  def loadFilters(config: Config): Map[String, MetricGroupFilter] = {
+    import scala.collection.JavaConverters._
+
+    val filters = config.getObjectList("filters").asScala
+
+    val allFilters =
+      for (
+        filter ← filters;
+        entry ← filter.entrySet().asScala
+      ) yield {
+        val key = entry.getKey
+        val keyBasedConfig = entry.getValue.atKey(key)
+
+        val includes = keyBasedConfig.getStringList(s"$key.includes").asScala.map(inc ⇒ new GlobPathFilter(inc)).toList
+        val excludes = keyBasedConfig.getStringList(s"$key.excludes").asScala.map(exc ⇒ new GlobPathFilter(exc)).toList
+
+        (key, MetricGroupFilter(includes, excludes))
+      }
+
+    allFilters.toMap
+  }
+
+  def buildDefaultCollectionContext: CollectionContext =
+    CollectionContext(metricsExtConfig.getInt("default-collection-context-buffer-size"))
+
+  def printInitializationMessage(eventStream: EventStream, disableWeaverMissingError: Boolean): Unit = {
+    if (!disableWeaverMissingError) {
+      val weaverMissingMessage =
+        """
+          |
+          |  ___                           _      ___   _    _                                 ___  ___ _            _
+          | / _ \                         | |    |_  | | |  | |                                |  \/  |(_)          (_)
+          |/ /_\ \ ___  _ __    ___   ___ | |_     | | | |  | |  ___   __ _ __   __ ___  _ __  | .  . | _  ___  ___  _  _ __    __ _
+          ||  _  |/ __|| '_ \  / _ \ / __|| __|    | | | |/\| | / _ \ / _` |\ \ / // _ \| '__| | |\/| || |/ __|/ __|| || '_ \  / _` |
+          || | | |\__ \| |_) ||  __/| (__ | |_ /\__/ / \  /\  /|  __/| (_| | \ V /|  __/| |    | |  | || |\__ \\__ \| || | | || (_| |
+          |\_| |_/|___/| .__/  \___| \___| \__|\____/   \/  \/  \___| \__,_|  \_/  \___||_|    \_|  |_/|_||___/|___/|_||_| |_| \__, |
+          |            | |                                                                                                      __/ |
+          |            |_|                                                                                                     |___/
+          |
+          | It seems like your application wasn't started with the -javaagent:/path-to-aspectj-weaver.jar option. Without that Kamon might
+          | not work properly, if you need help on setting up the weaver go to http://kamon.io/introduction/get-started/ for more info. If
+          | you are sure that you don't need the weaver (e.g. you are only using KamonStandalone) then you can disable this error message
+          | by changing the kamon.metrics.disable-aspectj-weaver-missing-error setting in your configuration file.
+          |
+        """.stripMargin
+
+      eventStream.publish(Error("MetricsExtension", classOf[MetricsExtension], weaverMissingMessage))
+    }
+  }
+}
+
+object Metrics extends ExtensionId[MetricsExtension] with ExtensionIdProvider {
+  def lookup(): ExtensionId[_ <: actor.Extension] = Metrics
+  def createExtension(system: ExtendedActorSystem): MetricsExtension = new MetricsExtension(system)
+
+  case class MetricGroupFilter(includes: List[GlobPathFilter], excludes: List[GlobPathFilter]) {
+    def accept(name: String): Boolean = includes.exists(_.accept(name)) && !excludes.exists(_.accept(name))
+  }
+}