Add closing functionality to tracers

1 files changed, 13 insertions, 0 deletions

diff --git a/src/main/scala/Tracer.scala b/src/main/scala/Tracer.scala
index 00a1fbf..3d82489 100644
--- a/src/main/scala/Tracer.scala
+++ b/src/main/scala/Tracer.scala
@@ -1,5 +1,18 @@
 package xyz.driver.tracing
 
+import scala.concurrent.Future
+
+/** Interface to tracing aggregation backends. */
 trait Tracer {
+
+  /** Submit a span to be sent to the aggregation backend.
+    *
+    * Note that submission typically happens asynchronously. Exact semantics are
+    * implementation-specific, however to guarantee of successful submission is
+    * made when this method returns. */
   def submit(span: Span): Unit
+
+  /** Aggregate any potentially queued submissions and perform any cleanup logic. */
+  def close(): Future[_] = Future.unit
+
 }