48 lines
1.5 KiB
Scala
48 lines
1.5 KiB
Scala
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package akka.contrib.pattern
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import akka.actor.Actor
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/**
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* Trait implementing Receive Pipeline Pattern. Mixin this trait
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* for configuring a chain of interceptors to be applied around
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* Actor's current behavior.
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*/
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trait ReceivePipeline extends Actor {
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private var pipeline: Vector[Receive ⇒ Receive] = Vector.empty
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private var aroundCache: Option[(Receive, Receive)] = None
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/**
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* Adds an inner interceptor, it will be applied lastly, near to Actor's original behavior
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* @param around A Receive decorator. Gets by parameter the next Receive in the chain
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* and has to return a new Receive with the decoration applied
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*/
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def pipelineInner(around: Receive ⇒ Receive): Unit = {
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pipeline :+= around
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aroundCache = None
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}
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/**
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* Adds an outer interceptor, it will be applied firstly, far from Actor's original behavior
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* @param around A Receive decorator. Gets by parameter the next Receive in the chain
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* and has to return a new Receive with the decoration applied
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*/
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def pipelineOuter(around: Receive ⇒ Receive): Unit = {
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pipeline +:= around
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aroundCache = None
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}
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/**
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* INTERNAL API.
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*/
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override protected[akka] def aroundReceive(receive: Receive, msg: Any): Unit = {
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val around = aroundCache match {
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case Some((`receive`, cached)) ⇒ cached
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case _ ⇒
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val zipped = pipeline.foldRight(receive)((outer, inner) ⇒ outer(inner) orElse inner)
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aroundCache = Some((receive, zipped))
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zipped
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}
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super.aroundReceive(around, msg)
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}
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}
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