1 files changed, 70 insertions, 0 deletions
diff --git a/kamon-play/src/main/scala/kamon/play/instrumentation/LoggerLikeInstrumentation.scala b/kamon-play/src/main/scala/kamon/play/instrumentation/LoggerLikeInstrumentation.scala
new file mode 100644
index 00000000..b7afeb76
--- /dev/null
+++ b/kamon-play/src/main/scala/kamon/play/instrumentation/LoggerLikeInstrumentation.scala
@@ -0,0 +1,70 @@
+/* =========================================================================================
+ * 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.play.instrumentation
+
+import kamon.trace.{ TraceContext, TraceContextAware }
+import org.aspectj.lang.ProceedingJoinPoint
+import org.aspectj.lang.annotation._
+import org.slf4j.MDC
+
+@Aspect
+class LoggerLikeInstrumentation {
+
+  import LoggerLikeInstrumentation._
+
+  @DeclareMixin("play.api.LoggerLike+")
+  def mixinContextAwareToLoggerLike: TraceContextAware = TraceContextAware.default
+
+  @Pointcut("execution(* play.api.LoggerLike+.info(..))")
+  def infoPointcut(): Unit = {}
+
+  @Pointcut("execution(* play.api.LoggerLike+.warn(..))")
+  def warnPointcut(): Unit = {}
+
+  @Pointcut("execution(* play.api.LoggerLike+.error(..))")
+  def errorPointcut(): Unit = {}
+
+  @Pointcut("execution(* play.api.LoggerLike+.trace(..))")
+  def tracePointcut(): Unit = {}
+
+  @Around("(infoPointcut() || warnPointcut() || errorPointcut() || tracePointcut()) && this(logger)")
+  def aroundLog(pjp: ProceedingJoinPoint, logger: TraceContextAware): Any = {
+    withMDC(logger.traceContext) {
+      pjp.proceed()
+    }
+  }
+}
+
+object LoggerLikeInstrumentation {
+  def withMDC[A](currentContext: Option[TraceContext])(block: ⇒ A): A = {
+    val keys = currentContext.map(extractProperties).map(putAndExtractKeys)
+
+    try block finally keys.map(k ⇒ k.foreach(MDC.remove(_)))
+  }
+
+  def putAndExtractKeys(values: Iterable[Map[String, Any]]): Iterable[String] = values.map {
+    value ⇒ value.map { case (key, value) ⇒ MDC.put(key, value.toString); key }
+  }.flatten
+
+  def extractProperties(ctx: TraceContext): Iterable[Map[String, Any]] = ctx.traceLocalStorage.underlyingStorage.values.map {
+    case traceLocalValue @ (p: Product) ⇒ {
+      val properties = p.productIterator
+      traceLocalValue.getClass.getDeclaredFields.filter(field ⇒ field.getName != "$outer").map(_.getName -> properties.next).toMap
+    }
+    case anything ⇒ Map.empty[String, Any]
+  }
+}
+