From 82a110b23ca57286e4e3dd0315c20ed99b5e8f88 Mon Sep 17 00:00:00 2001
From: Ivan Topolnjak <ivantopo@gmail.com>
Date: Wed, 4 Feb 2015 05:32:45 +0100
Subject: ! core: revised semantics of .register on Metrics module to match our
 docs.

---
 .../src/main/scala/kamon/metric/EntityRecorder.scala       |  2 +-
 .../src/main/scala/kamon/metric/MetricsExtension.scala     | 10 +++++++---
 .../scala/kamon/util/TriemapAtomicGetOrElseUpdate.scala    | 14 +++++++++++++-
 3 files changed, 21 insertions(+), 5 deletions(-)

(limited to 'kamon-core/src/main/scala/kamon')

diff --git a/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala b/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala
index a7bba2e1..6e0a4248 100644
--- a/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala
+++ b/kamon-core/src/main/scala/kamon/metric/EntityRecorder.scala
@@ -38,7 +38,7 @@ abstract class GenericEntityRecorder(instrumentFactory: InstrumentFactory) exten
 
   private val _instruments = TrieMap.empty[MetricKey, Instrument]
   private def register[T <: Instrument](key: MetricKey, instrument: ⇒ T): T =
-    _instruments.atomicGetOrElseUpdate(key, instrument).asInstanceOf[T]
+    _instruments.atomicGetOrElseUpdate(key, instrument, _.cleanup).asInstanceOf[T]
 
   protected def histogram(name: String): Histogram =
     register(HistogramKey(name), instrumentFactory.createHistogram(name))
diff --git a/kamon-core/src/main/scala/kamon/metric/MetricsExtension.scala b/kamon-core/src/main/scala/kamon/metric/MetricsExtension.scala
index c14d4e16..88352e21 100644
--- a/kamon-core/src/main/scala/kamon/metric/MetricsExtension.scala
+++ b/kamon-core/src/main/scala/kamon/metric/MetricsExtension.scala
@@ -86,14 +86,18 @@ class MetricsExtensionImpl(system: ExtendedActorSystem) extends MetricsExtension
 
     if (shouldTrack(entity)) {
       val instrumentFactory = settings.instrumentFactories.get(recorderFactory.category).getOrElse(settings.defaultInstrumentFactory)
-      val recorder = _trackedEntities.atomicGetOrElseUpdate(entity, recorderFactory.createRecorder(instrumentFactory)).asInstanceOf[T]
+      val recorder = _trackedEntities.atomicGetOrElseUpdate(entity, recorderFactory.createRecorder(instrumentFactory), _.cleanup).asInstanceOf[T]
+
       Some(EntityRegistration(entity, recorder))
     } else None
   }
 
   def register[T <: EntityRecorder](entity: Entity, recorder: T): EntityRegistration[T] = {
-    import TriemapAtomicGetOrElseUpdate.Syntax
-    EntityRegistration(entity, _trackedEntities.atomicGetOrElseUpdate(entity, recorder).asInstanceOf[T])
+    _trackedEntities.put(entity, recorder).map { oldRecorder ⇒
+      oldRecorder.cleanup
+    }
+
+    EntityRegistration(entity, recorder)
   }
 
   def unregister(entity: Entity): Unit =
diff --git a/kamon-core/src/main/scala/kamon/util/TriemapAtomicGetOrElseUpdate.scala b/kamon-core/src/main/scala/kamon/util/TriemapAtomicGetOrElseUpdate.scala
index 5ad43c34..d1197a5a 100644
--- a/kamon-core/src/main/scala/kamon/util/TriemapAtomicGetOrElseUpdate.scala
+++ b/kamon-core/src/main/scala/kamon/util/TriemapAtomicGetOrElseUpdate.scala
@@ -24,10 +24,22 @@ object TriemapAtomicGetOrElseUpdate {
    *  why this is necessary can be found at [[https://issues.scala-lang.org/browse/SI-7943]].
    */
   implicit class Syntax[K, V](val trieMap: TrieMap[K, V]) extends AnyVal {
+
     def atomicGetOrElseUpdate(key: K, op: ⇒ V): V =
+      atomicGetOrElseUpdate(key, op, { v: V ⇒ Unit })
+
+    def atomicGetOrElseUpdate(key: K, op: ⇒ V, cleanup: V ⇒ Unit): V =
       trieMap.get(key) match {
         case Some(v) ⇒ v
-        case None    ⇒ val d = op; trieMap.putIfAbsent(key, d).getOrElse(d)
+        case None ⇒
+          val d = op
+          trieMap.putIfAbsent(key, d).map { oldValue ⇒
+            // If there was an old value then `d` was never added
+            // and thus need to be cleanup.
+            cleanup(d)
+            oldValue
+
+          } getOrElse (d)
       }
   }
 }
-- 
cgit v1.2.3