1 files changed, 64 insertions, 0 deletions
diff --git a/kamon-core/src/legacy-main/scala/kamon/trace/TraceLocal.scala b/kamon-core/src/legacy-main/scala/kamon/trace/TraceLocal.scala
new file mode 100644
index 00000000..460e4b22
--- /dev/null
+++ b/kamon-core/src/legacy-main/scala/kamon/trace/TraceLocal.scala
@@ -0,0 +1,64 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013-2014 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.trace
+
+import kamon.trace.TraceLocal.TraceLocalKey
+import kamon.util.Supplier
+import scala.collection.concurrent.TrieMap
+
+object TraceLocal {
+
+  trait TraceLocalKey[T]
+
+  trait AvailableToMdc extends TraceLocalKey[String] {
+    def mdcKey: String
+  }
+
+  object AvailableToMdc {
+    case class DefaultKeyAvailableToMdc(mdcKey: String) extends AvailableToMdc
+
+    def fromKey(mdcKey: String): AvailableToMdc = DefaultKeyAvailableToMdc(mdcKey)
+    def apply(mdcKey: String): AvailableToMdc = fromKey(mdcKey)
+  }
+
+  def store[T](key: TraceLocalKey[T])(value: Any): Unit = Tracer.currentContext match {
+    case ctx: MetricsOnlyContext ⇒ ctx.traceLocalStorage.store(key)(value)
+    case EmptyTraceContext       ⇒ // Can't store in the empty context.
+  }
+
+  def retrieve[T](key: TraceLocalKey[T]): Option[T] = Tracer.currentContext match {
+    case ctx: MetricsOnlyContext ⇒ ctx.traceLocalStorage.retrieve(key)
+    case EmptyTraceContext       ⇒ None // Can't retrieve anything from the empty context.
+  }
+
+  // Java variant
+  @throws(classOf[NoSuchElementException])
+  def get[T](key: TraceLocalKey[T]): T = retrieve(key).get
+
+  def getOrElse[T](key: TraceLocalKey[T], code: Supplier[T]): T = retrieve(key).getOrElse(code.get)
+
+  def storeForMdc(key: String, value: String): Unit = store(AvailableToMdc.fromKey(key))(value)
+
+  def newTraceLocalKey[T]: TraceLocalKey[T] = new TraceLocalKey[T] {}
+}
+
+class TraceLocalStorage {
+  val underlyingStorage = TrieMap[TraceLocalKey[_], Any]()
+
+  def store[T](key: TraceLocalKey[T])(value: Any): Unit = underlyingStorage.put(key, value)
+  def retrieve[T](key: TraceLocalKey[T]): Option[T] = underlyingStorage.get(key).map(_.asInstanceOf[T])
+}