Added initial (very much non-complete) version of failure detection management system.

Signed-off-by: Jonas Bonér <jonas@jonasboner.com>

akka-cluster/src/main/scala/akka/cluster/FailureDetector.scala

@@ -0,0 +1,118 @@
+/**
+ * Copyright (C) 2009-2011 Typesafe Inc. <http://www.typesafe.com>
+ */
+
+package akka.cluster
+
+import akka.actor.Actor
+import akka.cluster._
+import akka.dispatch.Dispatchers
+import akka.util.ListenerManagement
+
+import scala.collection.mutable.{ HashMap, Set }
+
+import java.net.InetSocketAddress
+
+object FailureDetector {
+
+  private sealed trait FailureDetectorEvent
+  private case class Register(strategy: FailOverStrategy, address: InetSocketAddress) extends FailureDetectorEvent
+  private case class Unregister(strategy: FailOverStrategy, address: InetSocketAddress) extends FailureDetectorEvent
+
+  private[akka] val registry = Actor.localActorOf[Registry].start()
+
+  def register(strategy: FailOverStrategy, address: InetSocketAddress) = registry ! Register(strategy, address)
+
+  def unregister(strategy: FailOverStrategy, address: InetSocketAddress) = registry ! Unregister(strategy, address)
+
+  private class Registry extends Actor {
+    self.dispatcher = Dispatchers.newPinnedDispatcher(self)
+
+    val strategies = new HashMap[InetSocketAddress, Set[FailOverStrategy]]() {
+      override def default(k: InetSocketAddress) = Set.empty[FailOverStrategy]
+    }
+
+    def receive = {
+      case event: RemoteClientLifeCycleEvent ⇒
+        strategies(event.remoteAddress) foreach (_ notify event)
+
+      case event: RemoteServerLifeCycleEvent ⇒ // FIXME handle RemoteServerLifeCycleEvent
+
+      case Register(strategy, address) ⇒
+        strategies(address) += strategy
+
+      case Unregister(strategy, address) ⇒
+        strategies(address) -= strategy
+
+      case _ ⇒ //ignore other
+    }
+  }
+
+  trait FailOverStrategy {
+
+    def notify(event: RemoteLifeCycleEvent) = event match {
+      case RemoteClientWriteFailed(request, cause, client, address) ⇒
+        remoteClientWriteFailed(request, cause, client, address)
+        println("--------->>> RemoteClientWriteFailed")
+      case RemoteClientError(cause, client, address) ⇒
+        println("--------->>> RemoteClientError")
+        remoteClientError(cause, client, address)
+      case RemoteClientDisconnected(client, address) ⇒
+        remoteClientDisconnected(client, address)
+        println("--------->>> RemoteClientDisconnected")
+      case RemoteClientShutdown(client, address) ⇒
+        remoteClientShutdown(client, address)
+        println("--------->>> RemoteClientShutdown")
+      case RemoteServerWriteFailed(request, cause, server, clientAddress) ⇒
+        remoteServerWriteFailed(request, cause, server, clientAddress)
+      case RemoteServerError(cause, server) ⇒
+        remoteServerError(cause, server)
+      case RemoteServerShutdown(server) ⇒
+        remoteServerShutdown(server)
+    }
+
+    def remoteClientWriteFailed(request: AnyRef, cause: Throwable, client: RemoteClientModule, address: InetSocketAddress) {}
+
+    def remoteClientError(cause: Throwable, client: RemoteClientModule, address: InetSocketAddress) {}
+
+    def remoteClientDisconnected(client: RemoteClientModule, address: InetSocketAddress) {}
+
+    def remoteClientShutdown(client: RemoteClientModule, address: InetSocketAddress) {}
+
+    def remoteServerWriteFailed(request: AnyRef, cause: Throwable, server: RemoteServerModule, clientAddress: Option[InetSocketAddress]) {}
+
+    def remoteServerError(cause: Throwable, server: RemoteServerModule) {}
+
+    def remoteServerShutdown(server: RemoteServerModule) {}
+  }
+
+  trait RemoveConnectionOnFirstFailureFailOverStrategy extends FailOverStrategy {
+
+    override def remoteClientWriteFailed(request: AnyRef, cause: Throwable, client: RemoteClientModule, address: InetSocketAddress) {
+      removeConnection(address)
+    }
+
+    override def remoteClientError(cause: Throwable, client: RemoteClientModule, address: InetSocketAddress) {
+      removeConnection(address)
+    }
+
+    override def remoteClientDisconnected(client: RemoteClientModule, address: InetSocketAddress) {
+      removeConnection(address)
+    }
+
+    override def remoteClientShutdown(client: RemoteClientModule, address: InetSocketAddress) {
+      removeConnection(address)
+    }
+
+    private def removeConnection(address: InetSocketAddress) = {} //connections.get(address) foreach (remove(connection))
+  }
+
+  trait LinearBackoffFailOverStrategy extends FailOverStrategy {
+  }
+
+  trait ExponentialBackoffFailOverStrategy extends FailOverStrategy {
+  }
+
+  trait CircuitBreakerFailOverStrategy extends FailOverStrategy {
+  }
+}