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36 package gr.grnet.aquarium.user.actor
38 import org.apache.solr.util.ConcurrentLRUCache
39 import akka.actor.ActorRef
40 import gr.grnet.aquarium.util.{Loggable, Lifecycle}
43 * This class holds an LRU cache for the user actors.
45 * The underlying implementation is borrowed from the Apache lucene+solr project(s).
47 * The provided collections-like API is neither Java- nor Scala-oriented.
49 * @author Christos KK Loverdos <loverdos@gmail.com>
52 class UserActorsLRU(val upperWaterMark: Int, val lowerWatermark: Int) extends Lifecycle {
53 private[this] val _cache = new ConcurrentLRUCache[String, ActorRef](
56 ((upperWaterMark + lowerWatermark).toLong / 2).toInt,
57 (3L * upperWaterMark / 4).toInt,
62 def put(userId: String, userActor: ActorRef): Unit = {
63 _cache.put(userId, userActor)
66 def get(userId: String): Option[ActorRef] = {
67 _cache.get(userId) match {
69 case actorRef ⇒ Some(actorRef)
73 def size: Int = _cache.size()
74 def clear: Unit = _cache.clear()
82 private[this] object EvictionListener extends ConcurrentLRUCache.EvictionListener[String, ActorRef] with Loggable {
83 def evictedEntry(userId: String, userActor: ActorRef): Unit = {
84 logger.debug("Parking UserActor for userId = %s".format(userId))
85 userActor ! UserActorPark
86 // hopefully no need to further track these actors as they now enter a state machine which ultimately leads
87 // to their shutting down