package kamon.testkit
import kamon.trace.{Span, SpanContext}
import kamon.trace.Span.FinishedSpan
import kamon.util.Clock
import scala.reflect.ClassTag
import scala.util.Try
class SpanInspector(span: Span) {
private val (realSpan, spanData) = Try {
val realSpan = span match {
case _: Span.Local => span
}
val spanData = invoke[Span.Local, FinishedSpan](realSpan, "toFinishedSpan", classOf[Long] -> Long.box(Clock.microTimestamp()))
(realSpan, spanData)
}.getOrElse((null, null))
def isEmpty: Boolean =
realSpan == null
def spanTag(key: String): Option[Span.TagValue] =
spanData.tags.get(key)
def spanTags(): Map[String, Span.TagValue] =
spanData.tags
def metricTags(): Map[String, String] =
getField[Span.Local, Map[String, String]](realSpan, "customMetricTags")
def startTimestamp(): Long =
getField[Span.Local, Long](realSpan, "startTimestampMicros")
def context(): SpanContext =
spanData.context
def operationName(): String =
spanData.operationName
private def getField[T, R](target: Any, fieldName: String)(implicit classTag: ClassTag[T]): R = {
val toFinishedSpanMethod = classTag.runtimeClass.getDeclaredField(fieldName)
toFinishedSpanMethod.setAccessible(true)
toFinishedSpanMethod.get(target).asInstanceOf[R]
}
private def invoke[T, R](target: Any, fieldName: String, parameters: (Class[_], AnyRef)*)(implicit classTag: ClassTag[T]): R = {
val parameterClasses = parameters.map(_._1)
val parameterInstances = parameters.map(_._2)
val toFinishedSpanMethod = classTag.runtimeClass.getDeclaredMethod(fieldName, parameterClasses: _*)
toFinishedSpanMethod.setAccessible(true)
toFinishedSpanMethod.invoke(target, parameterInstances: _*).asInstanceOf[R]
}
}
object SpanInspector {
def apply(span: Span): SpanInspector = new SpanInspector(span)
}