Akka/Scala example source code file (FileDescriptorMetricSet.scala)

This example Akka source code file (FileDescriptorMetricSet.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

akka, filedescriptormetricset, gauge, long, map, metric, metrics, metricset, operatingsystemmxbean, string, test, testing, testkit

The FileDescriptorMetricSet.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.testkit.metrics

import java.util
import collection.JavaConverters._
import java.lang.management.{ OperatingSystemMXBean, ManagementFactory }
import com.codahale.metrics.{ Gauge, Metric, MetricSet }
import com.codahale.metrics.MetricRegistry._
import com.codahale.metrics.jvm.FileDescriptorRatioGauge

/**
 * MetricSet exposing number of open and maximum file descriptors used by the JVM process.
 */
private[akka] class FileDescriptorMetricSet(os: OperatingSystemMXBean = ManagementFactory.getOperatingSystemMXBean) extends MetricSet {

  override def getMetrics: util.Map[String, Metric] = {
    Map[String, Metric](

      name("file-descriptors", "open") -> new Gauge[Long] {
        override def getValue: Long = invoke("getOpenFileDescriptorCount")
      },

      name("file-descriptors", "max") -> new Gauge[Long] {
        override def getValue: Long = invoke("getMaxFileDescriptorCount")
      },

      name("file-descriptors", "ratio") -> new FileDescriptorRatioGauge(os)).asJava
  }

  private def invoke(name: String): Long = {
    val method = os.getClass.getDeclaredMethod(name)
    method.setAccessible(true)
    method.invoke(os).asInstanceOf[Long]
  }
}