= core: Inline variant of withTraceContext using macros.

1 files changed, 46 insertions, 0 deletions

diff --git a/kamon-macros/src/main/scala/kamon/macros/InlineTraceContextMacro.scala b/kamon-macros/src/main/scala/kamon/macros/InlineTraceContextMacro.scala
new file mode 100644
index 00000000..ea8cc7b8
--- /dev/null
+++ b/kamon-macros/src/main/scala/kamon/macros/InlineTraceContextMacro.scala
@@ -0,0 +1,46 @@
+/*
+ * =========================================================================================
+ * Copyright © 2013 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.macros
+
+import scala.language.experimental.macros
+import scala.reflect.macros.Context
+
+object InlineTraceContextMacro {
+
+  // Macro to generate an inline version of kamon.trace.TraceRecorder.withTraceContext
+  def withInlineTraceContextImpl[T: c.WeakTypeTag, TC: c.WeakTypeTag](c: Context)(traceCtx: c.Expr[TC])(thunk: c.Expr[T]) = {
+    import c.universe._
+
+    val inlineThunk =
+      Block(
+        List(
+          ValDef(
+            Modifiers(), newTermName("oldContext"), TypeTree(),
+            Select(Ident(newTermName("TraceRecorder")), newTermName("currentContext"))),
+          Apply(
+            Select(Ident(newTermName("TraceRecorder")), newTermName("setContext")),
+            List(traceCtx.tree))),
+        Try(
+          thunk.tree,
+          List(),
+          Apply(
+            Select(Ident(newTermName("TraceRecorder")), newTermName("setContext")),
+            List(Ident(newTermName("oldContext"))))))
+
+    c.Expr[T](inlineThunk)
+  }
+}