add tags to individual metrics

1 files changed, 90 insertions, 0 deletions

diff --git a/kamon-spray/src/main/scala/spray/can/client/ClientRequestInstrumentation.scala b/kamon-spray/src/main/scala/spray/can/client/ClientRequestInstrumentation.scala
new file mode 100644
index 00000000..868cbaca
--- /dev/null
+++ b/kamon-spray/src/main/scala/spray/can/client/ClientRequestInstrumentation.scala
@@ -0,0 +1,90 @@
+/* ===================================================
+ * Copyright © 2013 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 spray.can.client
+
+import org.aspectj.lang.annotation._
+import org.aspectj.lang.ProceedingJoinPoint
+import spray.http.{ HttpMessageEnd, HttpRequest }
+import spray.http.HttpHeaders.Host
+import kamon.trace.{ TraceRecorder, SegmentCompletionHandleAware, TraceContextAware }
+import kamon.metrics.TraceMetrics.HttpClientRequest
+import kamon.Kamon
+import kamon.spray.Spray
+
+@Aspect
+class ClientRequestInstrumentation {
+  import ClientRequestInstrumentation._
+
+  @DeclareMixin("spray.can.client.HttpHostConnector.RequestContext")
+  def mixin: SegmentCompletionHandleAware = SegmentCompletionHandleAware.default
+
+  @Pointcut("execution(spray.can.client.HttpHostConnector.RequestContext.new(..)) && this(ctx) && args(request, *, *, *)")
+  def requestContextCreation(ctx: SegmentCompletionHandleAware, request: HttpRequest): Unit = {}
+
+  @After("requestContextCreation(ctx, request)")
+  def afterRequestContextCreation(ctx: SegmentCompletionHandleAware, request: HttpRequest): Unit = {
+    // The RequestContext will be copied when a request needs to be retried but we are only interested in creating the
+    // completion handle the first time we create one.
+
+    // The read to ctx.completionHandle should take care of initializing the aspect timely.
+    if (ctx.segmentCompletionHandle.isEmpty) {
+      TraceRecorder.currentContext.map { traceContext ⇒
+        val requestAttributes = Map[String, String](
+          "host" -> request.header[Host].map(_.value).getOrElse("unknown"),
+          "path" -> request.uri.path.toString(),
+          "method" -> request.method.toString())
+
+        val clientRequestName = Kamon(Spray)(traceContext.system).assignHttpClientRequestName(request)
+        val completionHandle = traceContext.startSegment(HttpClientRequest(clientRequestName, SprayTime), requestAttributes)
+        ctx.segmentCompletionHandle = Some(completionHandle)
+      }
+    }
+  }
+
+  @Pointcut("execution(* spray.can.client.HttpHostConnector.RequestContext.copy(..)) && this(old)")
+  def copyingRequestContext(old: SegmentCompletionHandleAware): Unit = {}
+
+  @Around("copyingRequestContext(old)")
+  def aroundCopyingRequestContext(pjp: ProceedingJoinPoint, old: SegmentCompletionHandleAware): Any = {
+    TraceRecorder.withTraceContext(old.traceContext) {
+      pjp.proceed()
+    }
+  }
+
+  @Pointcut("execution(* spray.can.client.HttpHostConnectionSlot.dispatchToCommander(..)) && args(requestContext, message)")
+  def dispatchToCommander(requestContext: SegmentCompletionHandleAware, message: Any): Unit = {}
+
+  @Around("dispatchToCommander(requestContext, message)")
+  def aroundDispatchToCommander(pjp: ProceedingJoinPoint, requestContext: SegmentCompletionHandleAware, message: Any) = {
+    requestContext.traceContext match {
+      case ctx @ Some(_) ⇒
+        TraceRecorder.withTraceContext(ctx) {
+          if (message.isInstanceOf[HttpMessageEnd])
+            requestContext.segmentCompletionHandle.map(_.finish(Map.empty))
+
+          pjp.proceed()
+        }
+
+      case None ⇒ pjp.proceed()
+    }
+  }
+}
+
+object ClientRequestInstrumentation {
+  val SprayTime = "SprayTime"
+  val UserTime = "UserTime"
+}