/*
* =========================================================================================
* 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] = Map.empty): Option[SegmentCompletionHandle] =
currentContext.map(_.startSegment(identity, metadata))
def rename(name: String): Unit = currentContext.map(_.rename(name))
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))
}