add utility apis for easier usage of Spans in the current context

2 files changed, 18 insertions, 2 deletions

diff --git a/kamon-core-tests/src/test/scala/kamon/trace/TracerSpec.scala b/kamon-core-tests/src/test/scala/kamon/trace/TracerSpec.scala
index 92431470..eec5b428 100644
--- a/kamon-core-tests/src/test/scala/kamon/trace/TracerSpec.scala
+++ b/kamon-core-tests/src/test/scala/kamon/trace/TracerSpec.scala
@@ -65,7 +65,7 @@ class TracerSpec extends WordSpec with Matchers with SpanBuilding with SpanInspe
 
     "automatically take the Span from the current Context as parent" in {
       val parent = tracer.buildSpan("myOperation").start()
-      val child = Kamon.withContext(Context.create(Span.ContextKey, parent)) {
+      val child = Kamon.withSpan(parent) {
         tracer.buildSpan("childOperation").asChildOf(parent).start()
       }
 
@@ -76,7 +76,7 @@ class TracerSpec extends WordSpec with Matchers with SpanBuilding with SpanInspe
 
     "ignore the span from the current context as parent if explicitly requested" in {
       val parent = tracer.buildSpan("myOperation").start()
-      val child = Kamon.withContext(Context.create(Span.ContextKey, parent)) {
+      val child = Kamon.withSpan(parent) {
         tracer.buildSpan("childOperation").ignoreParentFromContext().start()
       }
 
diff --git a/kamon-core/src/main/scala/kamon/Kamon.scala b/kamon-core/src/main/scala/kamon/Kamon.scala
index 6e0a260d..1a9dbe95 100644
--- a/kamon-core/src/main/scala/kamon/Kamon.scala
+++ b/kamon-core/src/main/scala/kamon/Kamon.scala
@@ -122,6 +122,22 @@ object Kamon extends MetricLookup with ReporterRegistry with Tracer {
   def withContextKey[T, K](key: Key[K], value: K)(f: => T): T =
     withContext(currentContext().withKey(key, value))(f)
 
+  def withSpan[T](span: Span)(f: => T): T =
+    withSpan(span, true)(f)
+
+  def withSpan[T](span: Span, finishSpan: Boolean)(f: => T): T = {
+    try {
+      withContextKey(Span.ContextKey, span)(f)
+    } catch {
+      case t: Throwable =>
+        span.addError(t.getMessage, t)
+        throw t
+
+    } finally {
+      if(finishSpan)
+        span.finish()
+    }
+  }
 
   override def loadReportersFromConfig(): Unit =
     _reporterRegistry.loadReportersFromConfig()