HW 7 done

src/main/scala/actorbintree/BinaryTreeSet.scala

@@ -58,7 +58,7 @@ class BinaryTreeSet extends Actor {
 
   var root = createRoot
 
-  // optional (used to stash incoming operations during garbage collection)
+  // optional
   var pendingQueue = Queue.empty[Operation]
 
   // optional
@@ -66,15 +66,30 @@ class BinaryTreeSet extends Actor {
 
   // optional
   /** Accepts `Operation` and `GC` messages. */
-  val normal: Receive = { case _ => ??? }
+  val normal: Receive = {
+    case op:Operation => root ! op
+    case GC => {
+      val newRoot = createRoot;
+      root ! CopyTo(newRoot)
+      context.become(garbageCollecting(newRoot))
+    }
+   }
 
   // optional
   /** Handles messages while garbage collection is performed.
     * `newRoot` is the root of the new binary tree where we want to copy
     * all non-removed elements into.
     */
-  def garbageCollecting(newRoot: ActorRef): Receive = ???
-
+  def garbageCollecting(newRoot: ActorRef): Receive = {
+    case op:Operation => pendingQueue = pendingQueue.enqueue(op)
+    case CopyFinished =>
+      pendingQueue.foreach(newRoot ! _) //foreach preserves order of a queue (same as dequeueing)
+      root ! PoisonPill //Will also stop all of its children
+      pendingQueue = Queue.empty
+      root = newRoot;
+      context.become(normal)
+    //Ignore GC messages here
+  }
 }
 
 object BinaryTreeNode {
@@ -84,11 +99,6 @@ object BinaryTreeNode {
   case object Right extends Position
 
   case class CopyTo(treeNode: ActorRef)
-  /**
-   * Acknowledges that a copy has been completed. This message should be sent
-   * from a node to its parent, when this node and all its children nodes have
-   * finished being copied.
-   */
   case object CopyFinished
 
   def props(elem: Int, initiallyRemoved: Boolean) = Props(classOf[BinaryTreeNode],  elem, initiallyRemoved)
@@ -104,15 +114,76 @@ class BinaryTreeNode(val elem: Int, initiallyRemoved: Boolean) extends Actor {
   // optional
   def receive = normal
 
+  def goDownTo(elem : Int) : Position = if(elem < this.elem) Left else Right
   // optional
   /** Handles `Operation` messages and `CopyTo` requests. */
-  val normal: Receive = { case _ => ??? }
+  val normal: Receive = {
+    case Insert  (requester, id, elem) =>
+      if(elem == this.elem && !removed){
+        requester ! OperationFinished(id)
+      }else{
+        val nextPos = goDownTo(elem)
+        
+        subtrees get nextPos match{
+          case Some(node) => node ! Insert(requester, id, elem)
+          case None => {
+              val newActorSubtree = (nextPos, context.actorOf(BinaryTreeNode.props(elem, false)))
+              subtrees = subtrees + newActorSubtree
+              requester ! OperationFinished(id);
+          }
+        }
+      }
+    case Contains(requester, id, elem) =>
+      if(elem == this.elem && !removed)
+        requester ! ContainsResult(id, true)
+      else{
+        //Need to search subtrees
+        subtrees get goDownTo(elem) match{
+          case Some(node) => node ! Contains(requester, id, elem)
+          case None => requester ! ContainsResult(id, false)
+        }
+      }
+        
+    case Remove  (requester, id, elem) => 
+      if(elem == this.elem && !removed){
+        removed = true
+        requester ! OperationFinished(id)
+      }else{
+        subtrees get goDownTo(elem) match{
+          case Some(node) => node ! Remove(requester, id, elem)
+          case None => requester ! OperationFinished(id) // (elem isn't in the tree)
+        }
+      }
+
+    case CopyTo(newRoot) =>
+      //We are already done, nothing to do
+      if(removed && subtrees.isEmpty) context.parent ! CopyFinished
+      else{
+        if(!removed) newRoot ! Insert(self, elem, elem)
+        subtrees.values foreach(_ ! CopyTo(newRoot)) //Copy subtrees elems
+        //val insertConfirmed = if(removed) true else false, hence we can simply pass removed
+        context.become(copying(subtrees.values.toSet, removed))
+      }
+  }
 
   // optional
   /** `expected` is the set of ActorRefs whose replies we are waiting for,
     * `insertConfirmed` tracks whether the copy of this node to the new tree has been confirmed.
     */
-  def copying(expected: Set[ActorRef], insertConfirmed: Boolean): Receive = ???
-
-
-}
+  def copying(expected: Set[ActorRef], insertConfirmed: Boolean): Receive = {
+    //To catch the insert of this node into the new tree beeing finished
+    case OperationFinished(_) => {
+      if(expected.isEmpty) context.parent ! CopyFinished
+      else context.become(copying(expected, true))
+    }
+    
+    case CopyFinished => {
+      val newExp = expected-sender
+      if(insertConfirmed && newExp.isEmpty){
+        context.parent ! CopyFinished
+      }else{
+        context.become(copying(newExp, insertConfirmed))
+      }
+    }
+  }
+}