Improvements and finalization of dynamically resizable routers, replaces ActorPool. See 1557

* resize on nth message instead of always each message
* improved pressure evaluation
* more tests
* documentation
* removed ActorPool

akka-docs/scala/code/akka/docs/routing/ActorPoolExample.scala

@@ -1,24 +0,0 @@
-/**
- * Copyright (C) 2009-2011 Typesafe Inc. <http://www.typesafe.com>
- */
-package akka.docs.routing
-
-import akka.routing.{ BasicNoBackoffFilter, SmallestMailboxSelector, DefaultActorPool }
-import akka.actor.{ ActorRef, Props, Actor }
-
-//#testPool
-class TestPool extends Actor with DefaultActorPool with SmallestMailboxSelector with BasicNoBackoffFilter {
-
-  def capacity(delegates: Seq[ActorRef]) = 5
-  protected def receive = _route
-  def rampupRate = 0.1
-  def selectionCount = 1
-  def partialFill = true
-
-  def instance(defaults: Props) = context.actorOf(defaults.withCreator(new Actor {
-    def receive = {
-      case _ ⇒ // do something
-    }
-  }))
-}
-//#testPool

akka-docs/scala/code/akka/docs/routing/BoundedCapacitorExample.scala

@@ -1,26 +0,0 @@
-/**
- * Copyright (C) 2009-2011 Typesafe Inc. <http://www.typesafe.com>
- */
-package akka.docs.routing
-
-import akka.actor.ActorRef
-
-//#boundedCapacitor
-trait BoundedCapacitor {
-  def lowerBound: Int
-  def upperBound: Int
-
-  def capacity(delegates: Seq[ActorRef]): Int = {
-    val current = delegates length
-    var delta = _eval(delegates)
-    val proposed = current + delta
-
-    if (proposed < lowerBound) delta += (lowerBound - proposed)
-    else if (proposed > upperBound) delta -= (proposed - upperBound)
-
-    delta
-  }
-
-  protected def _eval(delegates: Seq[ActorRef]): Int
-}
-//#boundedCapacitor

akka-docs/scala/code/akka/docs/routing/CapacityStrategyExample.scala

@@ -1,19 +0,0 @@
-/**
- * Copyright (C) 2009-2011 Typesafe Inc. <http://www.typesafe.com>
- */
-package akka.docs.routing
-
-import akka.routing.ActorPool
-import akka.actor.ActorRef
-
-//#capacityStrategy
-trait CapacityStrategy {
-  import ActorPool._
-
-  def pressure(delegates: Seq[ActorRef]): Int
-  def filter(pressure: Int, capacity: Int): Int
-
-  protected def _eval(delegates: Seq[ActorRef]): Int =
-    filter(pressure(delegates), delegates.size)
-}
-//#capacityStrategy

akka-docs/scala/code/akka/docs/routing/RouterViaConfigExample.scala

@@ -25,6 +25,17 @@ object RouterWithConfigExample extends App {
       }
     }
     //#config
+    //#config-resize
+    akka.actor.deployment {
+      /router2 {
+        router = round-robin
+        resizer {
+          lower-bound = 2
+          upper-bound = 15
+        }
+      }
+    }
+    //#config-resize
       """)
   val system = ActorSystem("Example", config)
   //#configurableRouting
@@ -32,4 +43,10 @@ object RouterWithConfigExample extends App {
     "router")
   //#configurableRouting
   1 to 10 foreach { i ⇒ router ! Message(i) }
+
+  //#configurableRoutingWithResizer
+  val router2 = system.actorOf(Props[ExampleActor].withRouter(FromConfig()),
+    "router2")
+  //#configurableRoutingWithResizer
+  1 to 10 foreach { i ⇒ router2 ! Message(i) }
 }

akka-docs/scala/code/akka/docs/routing/RouterViaProgramExample.scala

@@ -5,6 +5,7 @@ package akka.docs.routing
 
 import akka.routing.RoundRobinRouter
 import akka.actor.{ ActorRef, Props, Actor, ActorSystem }
+import akka.routing.DefaultResizer
 
 case class Message1(nbr: Int)
 
@@ -31,4 +32,12 @@ object RoutingProgrammaticallyExample extends App {
     RoundRobinRouter(routees = routees)))
   //#programmaticRoutingRoutees
   1 to 6 foreach { i ⇒ router2 ! Message1(i) }
+
+  //#programmaticRoutingWithResizer
+  val resizer = DefaultResizer(lowerBound = 2, upperBound = 15)
+  val router3 = system.actorOf(Props[ExampleActor1].withRouter(
+    RoundRobinRouter(resizer = Some(resizer))))
+  //#programmaticRoutingWithResizer
+  1 to 6 foreach { i ⇒ router3 ! Message1(i) }
+
 }