1 files changed, 45 insertions, 0 deletions
diff --git a/kamon-core/src/legacy-main/scala/kamon/util/TriemapAtomicGetOrElseUpdate.scala b/kamon-core/src/legacy-main/scala/kamon/util/TriemapAtomicGetOrElseUpdate.scala
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+++ b/kamon-core/src/legacy-main/scala/kamon/util/TriemapAtomicGetOrElseUpdate.scala
@@ -0,0 +1,45 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2015 the kamon project <http://kamon.io/>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the
+ * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ * =========================================================================================
+ */
+package kamon.util
+
+import scala.collection.concurrent.TrieMap
+
+object TriemapAtomicGetOrElseUpdate {
+
+  /**
+   *  Workaround to the non thread-safe [[scala.collection.concurrent.TrieMap#getOrElseUpdate]] method. More details on
+   *  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).map { oldValue ⇒
+            // If there was an old value then `d` was never added
+            // and thus need to be cleanup.
+            cleanup(d)
+            oldValue
+
+          } getOrElse (d)
+      }
+  }
+}