/* =========================================================================================
* Copyright © 2013-2017 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 kamon.trace.IdentityProvider.Identifier
import kamon.trace.SpanContext.{Baggage, SamplingDecision, Source}
/**
*
* @param traceID
* @param spanID
* @param parentID
* @param samplingDecision
* @param baggage
*/
case class SpanContext(traceID: Identifier, spanID: Identifier, parentID: Identifier, samplingDecision: SamplingDecision, baggage: Baggage, source: Source) {
def createChild(childSpanID: Identifier, samplingDecision: SamplingDecision): SpanContext =
this.copy(parentID = this.spanID, spanID = childSpanID)
}
object SpanContext {
sealed trait Source
object Source {
case object Local extends Source
case object Remote extends Source
}
val EmptySpanContext = SpanContext(
traceID = IdentityProvider.NoIdentifier,
spanID = IdentityProvider.NoIdentifier,
parentID = IdentityProvider.NoIdentifier,
samplingDecision = SamplingDecision.DoNotSample,
baggage = Baggage.EmptyBaggage,
source = Source.Local
)
sealed trait SamplingDecision
object SamplingDecision {
/**
* The Trace is sampled, all child Spans should be sampled as well.
*/
case object Sample extends SamplingDecision
/**
* The Trace is not sampled, none of the child Spans should be sampled.
*/
case object DoNotSample extends SamplingDecision
/**
* The sampling decision has not been taken yet, the Tracer is free to decide when creating a Span.
*/
case object Unknown extends SamplingDecision
}
/**
*
*/
sealed trait Baggage {
def add(key: String, value:String): Unit
def get(key: String): Option[String]
def getAll(): Map[String, String]
}
object Baggage {
def apply(): Baggage = new DefaultBaggage()
case object EmptyBaggage extends Baggage {
override def add(key: String, value: String): Unit = {}
override def get(key: String): Option[String] = None
override def getAll: Map[String, String] = Map.empty
}
final class DefaultBaggage extends Baggage {
private var baggage: Map[String, String] = Map.empty
def add(key: String, value: String): Unit = synchronized {
baggage = baggage + (key -> value)
}
def get(key: String): Option[String] =
baggage.get(key)
def getAll: Map[String, String] =
baggage
}
}
}