basic separation of concerns between sub-projects

1 files changed, 56 insertions, 0 deletions

diff --git a/kamon-spray/src/main/scala/spray/can/server/ServerRequestTracing.scala b/kamon-spray/src/main/scala/spray/can/server/ServerRequestTracing.scala
new file mode 100644
index 00000000..d5e21f35
--- /dev/null
+++ b/kamon-spray/src/main/scala/spray/can/server/ServerRequestTracing.scala
@@ -0,0 +1,56 @@
+package spray.can.server
+
+import org.aspectj.lang.annotation.{After, Pointcut, DeclareMixin, Aspect}
+import kamon.trace.{Trace, TraceContext, ContextAware}
+import spray.http.HttpRequest
+import akka.actor.ActorSystem
+import akka.event.Logging.Warning
+
+
+@Aspect
+class ServerRequestTracing {
+
+  @DeclareMixin("spray.can.server.OpenRequestComponent.DefaultOpenRequest")
+  def mixinContextAwareToOpenRequest: ContextAware = ContextAware.default
+
+
+  @Pointcut("execution(spray.can.server.OpenRequestComponent$DefaultOpenRequest.new(..)) && this(openRequest) && args(*, request, *, *)")
+  def openRequestInit(openRequest: ContextAware, request: HttpRequest): Unit = {}
+
+  @After("openRequestInit(openRequest, request)")
+  def afterInit(openRequest: ContextAware, request: HttpRequest): Unit = {
+    val system: ActorSystem = openRequest.asInstanceOf[OpenRequest].context.actorContext.system
+    val defaultTraceName: String = request.method.value + ": " + request.uri.path
+
+    Trace.start(defaultTraceName)(system)
+
+    // Necessary to force initialization of traceContext when initiating the request.
+    openRequest.traceContext
+  }
+
+  @Pointcut("execution(* spray.can.server.OpenRequestComponent$DefaultOpenRequest.handleResponseEndAndReturnNextOpenRequest(..)) && target(openRequest)")
+  def openRequestCreation(openRequest: ContextAware): Unit = {}
+
+  @After("openRequestCreation(openRequest)")
+  def afterFinishingRequest(openRequest: ContextAware): Unit = {
+    val storedContext = openRequest.traceContext
+    val incomingContext = Trace.finish()
+
+    for(original <- storedContext) {
+      incomingContext match {
+        case Some(incoming) if original.id != incoming.id =>
+          publishWarning(s"Different ids when trying to close a Trace, original: [$original] - incoming: [$incoming]")
+
+        case Some(_) => // nothing to do here.
+          
+        case None =>
+          publishWarning(s"Trace context not present while closing the Trace: [$original]")
+      }
+    }
+
+    def publishWarning(text: String): Unit = {
+      val system: ActorSystem = openRequest.asInstanceOf[OpenRequest].context.actorContext.system
+      system.eventStream.publish(Warning("", classOf[ServerRequestTracing], text))
+    }
+  }
+}