/*
* =========================================================================================
* Copyright © 2013-2016 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.io.ObjectStreamException
import java.util
import kamon.trace.Status.Closed
import kamon.trace.TraceContextAware.DefaultTraceContextAware
import kamon.util.{Function, RelativeNanoTimestamp, SameThreadExecutionContext, Supplier}
import scala.concurrent.Future
trait TraceContext {
def name: String
def token: String
def tags: Map[String, String]
def isEmpty: Boolean
def nonEmpty: Boolean = !isEmpty
def isClosed: Boolean = !(Status.Open == status)
def status: Status
def finish(): Unit
def finishWithError(cause: Throwable): Unit
def rename(newName: String): Unit
def startSegment(segmentName: String, category: String, library: String): Segment
def startSegment(segmentName: String, category: String, library: String, tags: Map[String, String]): Segment
def addMetadata(key: String, value: String): Unit
def addTag(key: String, value: String): Unit
def removeTag(key: String, value: String): Boolean
def startTimestamp: RelativeNanoTimestamp
def collect[T](f: TraceContext ⇒ T): Option[T] =
if (nonEmpty)
Some(f(this))
else None
def collect[T](f: Function[TraceContext, T]): Option[T] =
if (nonEmpty)
Some(f(this))
else None
def withNewSegment[T](segmentName: String, category: String, library: String)(code: ⇒ T): T = {
withNewSegment(segmentName, category, library, Map.empty[String, String])(code)
}
def withNewSegment[T](segmentName: String, category: String, library: String, tags: Map[String, String])(code: ⇒ T): T = {
val segment = startSegment(segmentName, category, library, tags)
try code finally segment.finish()
}
def withNewAsyncSegment[T](segmentName: String, category: String, library: String)(code: ⇒ Future[T]): Future[T] = {
withNewAsyncSegment(segmentName, category, library, Map.empty[String, String])(code)
}
def withNewAsyncSegment[T](segmentName: String, category: String, library: String, tags: Map[String, String])(code: ⇒ Future[T]): Future[T] = {
val segment = startSegment(segmentName, category, library, tags)
val result = code
result.onComplete(_ ⇒ segment.finish())(SameThreadExecutionContext)
result
}
// Java variant.
def withNewSegment[T](segmentName: String, category: String, library: String, code: Supplier[T]): T =
withNewSegment(segmentName, category, library)(code.get)
def withNewSegment[T](segmentName: String, category: String, library: String, tags: util.Map[String, String], code: Supplier[T]): T = {
import scala.collection.JavaConverters._
withNewSegment(segmentName, category, library, tags.asScala.toMap)(code.get)
}
}
trait Segment {
def name: String
def category: String
def library: String
def tags: Map[String, String]
def isEmpty: Boolean
def nonEmpty: Boolean = !isEmpty
def isClosed: Boolean = !(Status.Open == status)
def status: Status
def finish(): Unit
def finishWithError(cause: Throwable): Unit
def rename(newName: String): Unit
def addMetadata(key: String, value: String): Unit
def addTag(key: String, value: String): Unit
def removeTag(key: String, value: String): Boolean
}
case object EmptyTraceContext extends TraceContext {
def name: String = "empty-trace"
def token: String = ""
def tags: Map[String, String] = Map.empty
def isEmpty: Boolean = true
def status: Status = Closed
def finish(): Unit = {}
def finishWithError(cause: Throwable): Unit = {}
def rename(name: String): Unit = {}
def startSegment(segmentName: String, category: String, library: String): Segment = EmptySegment
def startSegment(segmentName: String, category: String, library: String, tags: Map[String, String]): Segment = EmptySegment
def addMetadata(key: String, value: String): Unit = {}
def startTimestamp = new RelativeNanoTimestamp(0L)
def addTag(key: String, value: String): Unit = {}
def removeTag(key: String, value: String): Boolean = false
case object EmptySegment extends Segment {
val name: String = "empty-segment"
val category: String = "empty-category"
val library: String = "empty-library"
def tags: Map[String, String] = Map.empty
def isEmpty: Boolean = true
def status: Status = Closed
def finish(): Unit = {}
def finishWithError(cause: Throwable): Unit = {}
def rename(newName: String): Unit = {}
def addMetadata(key: String, value: String): Unit = {}
def addTag(key: String, value: String): Unit = {}
def removeTag(key: String, value: String): Boolean = false
}
}
object SegmentCategory {
val HttpClient = "http-client"
val Database = "database"
}
class LOD private[trace] (val level: Int) extends AnyVal
object LOD {
val MetricsOnly = new LOD(1)
val SimpleTrace = new LOD(2)
}
sealed trait LevelOfDetail
object LevelOfDetail {
case object MetricsOnly extends LevelOfDetail
case object SimpleTrace extends LevelOfDetail
case object FullTrace extends LevelOfDetail
}
sealed trait Status
object Status {
case object Open extends Status
case object Closed extends Status
case object FinishedWithError extends Status
case object FinishedSuccessfully extends Status
}
trait TraceContextAware extends Serializable {
def traceContext: TraceContext
}
object TraceContextAware {
def default: TraceContextAware = new DefaultTraceContextAware
class DefaultTraceContextAware extends TraceContextAware {
@transient val traceContext = Tracer.currentContext
//
// Beware of this hack, it might bite us in the future!
//
// When using remoting/cluster all messages carry the TraceContext in the envelope in which they
// are sent but that doesn't apply to System Messages. We are certain that the TraceContext is
// available (if any) when the system messages are read and this will make sure that it is correctly
// captured and propagated.
@throws[ObjectStreamException]
private def readResolve: AnyRef = {
new DefaultTraceContextAware
}
}
}
trait TimestampedTraceContextAware extends TraceContextAware {
def captureNanoTime: Long
}
object TimestampedTraceContextAware {
def default: TimestampedTraceContextAware = new DefaultTraceContextAware with TimestampedTraceContextAware {
@transient val captureNanoTime = System.nanoTime()
}
}
trait SegmentAware {
@volatile @transient var segment: Segment = EmptyTraceContext.EmptySegment
}
object SegmentAware {
def default: SegmentAware = new DefaultSegmentAware
class DefaultSegmentAware extends DefaultTraceContextAware with SegmentAware {}
}