Lift runtime stats snippet

RuntimeStats.scala

/*
 * Copyright 2007-2013 WorldWide Conferencing, LLC
 *
 * 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 net.liftweb.example.snippet

import _root_.net.liftweb._
import http._
import util._
import Helpers._

import _root_.java.text.NumberFormat
import _root_.scala.xml.Text

object RuntimeStats extends DispatchSnippet {
  @volatile
  var totalMem = Runtime.getRuntime.totalMemory
  @volatile
  var freeMem = Runtime.getRuntime.freeMemory

  @volatile
  var sessions = 1

  @volatile
  var lastUpdate = now

  val startedAt = now

  private def nf(in: Long): String = NumberFormat.getInstance.format(in)

  def dispatch = {
    case "total_mem" => i => Text(nf(totalMem))
    case "free_mem" => i => Text(nf(freeMem))
    case "sessions" => i => Text(sessions.toString)
    case "updated_at" => i => Text(lastUpdate.toString)
    case "started_at" => i => Text(startedAt.toString)
  }
}

stats.html

<div>
    Lift version <span data-lift="version_info.lift"></span> built on <br data-lift="version_info.date">.
    <br>
    Stats: 
    Total Memory: <span data-lift="runtime_stats.total_mem"></span>
    Free Memory: <span data-lift="runtime_stats.free_mem"></span>
    Open Sessions: <span data-lift="runtime_stats.sessions"></span>
    <br>
    Updated At: <span data-lift="runtime_stats.updated_at"></span>
    Started At: <span data-lift="runtime_stats.started_at"></span>
</div>

Origin:
https://github.com/fmpwizard/lift_25_samples/blob/master/src/main/scala/net/liftweb/example/snippet/RuntimeStats.scala