remake of trace context and allow different tracing levels

1 files changed, 69 insertions, 0 deletions

diff --git a/kamon-core/src/main/scala/kamon/trace/TraceRecorder.scala b/kamon-core/src/main/scala/kamon/trace/TraceRecorder.scala
new file mode 100644
index 00000000..3e3bb19f
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/trace/TraceRecorder.scala
@@ -0,0 +1,69 @@
+/*
+ * =========================================================================================
+ * 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 kamon.trace
+
+import java.util.concurrent.atomic.AtomicLong
+import scala.util.Try
+import java.net.InetAddress
+import akka.actor.ActorSystem
+import kamon.trace.TraceContext.SegmentIdentity
+
+object TraceRecorder {
+  private val traceContextStorage = new ThreadLocal[Option[TraceContext]] {
+    override def initialValue(): Option[TraceContext] = None
+  }
+
+  private val tokenCounter = new AtomicLong
+  private val hostnamePrefix = Try(InetAddress.getLocalHost.getHostName).getOrElse("unknown-localhost")
+
+  def newToken = "%s-%s".format(hostnamePrefix, tokenCounter.incrementAndGet())
+
+  private def newTraceContext(name: String, token: Option[String], metadata: Map[String, String],
+                              system: ActorSystem): TraceContext = {
+
+    // In the future this should select between implementations.
+    val finalToken = token.getOrElse(newToken)
+    new SimpleMetricCollectionContext(name, finalToken, metadata, system)
+  }
+
+  def setContext(context: Option[TraceContext]): Unit = traceContextStorage.set(context)
+
+  def clearContext: Unit = traceContextStorage.set(None)
+
+  def currentContext: Option[TraceContext] = traceContextStorage.get()
+
+  def start(name: String, token: Option[String] = None, metadata: Map[String, String] = Map.empty)(implicit system: ActorSystem) = {
+    val ctx = newTraceContext(name, token, metadata, system)
+    traceContextStorage.set(Some(ctx))
+  }
+
+  def startSegment(identity: SegmentIdentity, metadata: Map[String, String]): Option[SegmentCompletionHandle] =
+    currentContext.map(_.startSegment(identity, metadata))
+
+  def withNewTraceContext[T](name: String, token: Option[String] = None, metadata: Map[String, String] = Map.empty)(thunk: ⇒ T)(implicit system: ActorSystem): T =
+    withTraceContext(Some(newTraceContext(name, token, metadata, system)))(thunk)
+
+  def withTraceContext[T](context: Option[TraceContext])(thunk: ⇒ T): T = {
+    val oldContext = currentContext
+    setContext(context)
+
+    try thunk finally setContext(oldContext)
+  }
+
+  def finish(metadata: Map[String, String] = Map.empty): Unit = currentContext.map(_.finish(metadata))
+
+}