restor the HasContext mixin

1 files changed, 36 insertions, 0 deletions

diff --git a/kamon-core/src/main/scala/kamon/instrumentation/Mixin.scala b/kamon-core/src/main/scala/kamon/instrumentation/Mixin.scala
new file mode 100644
index 00000000..f5a5e63b
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/instrumentation/Mixin.scala
@@ -0,0 +1,36 @@
+package kamon.instrumentation
+
+import kamon.Kamon
+import kamon.context.Context
+
+/**
+  * Common mixins used across multiple instrumentation modules.
+  */
+object Mixin {
+
+  /**
+    * Utility trait that marks objects carrying a reference to a Context instance.
+    *
+    */
+  trait HasContext {
+    def context: Context
+  }
+
+  object HasContext {
+    private case class Default(context: Context) extends HasContext
+
+    /**
+      * Construct a HasSpan instance that references the provided Context.
+      *
+      */
+    def from(context: Context): HasContext =
+      Default(context)
+
+    /**
+      * Construct a HasContext instance with the current Kamon from Kamon's default context storage.
+      *
+      */
+    def fromCurrentContext(): HasContext =
+      Default(Kamon.currentContext())
+  }
+}