3 files changed, 31 insertions, 0 deletions
diff --git a/kamon-core/src/main/scala/kamon/util/Clock.scala b/kamon-core/src/main/scala/kamon/util/Clock.scala
new file mode 100644
index 00000000..55bb529a
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/util/Clock.scala
@@ -0,0 +1,9 @@
+package kamon.util
+
+trait Clock {
+  def nanoTimestamp(): Long
+  def microTimestamp(): Long
+  def milliTimestamp(): Long
+
+  def relativeNanoTimestamp(): Long
+}
diff --git a/kamon-core/src/main/scala/kamon/util/EntityFilter.scala b/kamon-core/src/main/scala/kamon/util/EntityFilter.scala
new file mode 100644
index 00000000..a8456689
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/util/EntityFilter.scala
@@ -0,0 +1,7 @@
+package kamon.util
+
+import kamon.metric.Entity
+
+trait EntityFilter {
+  def accept(entity: Entity): Boolean
+}
diff --git a/kamon-core/src/main/scala/kamon/util/MeasurementUnit.scala b/kamon-core/src/main/scala/kamon/util/MeasurementUnit.scala
new file mode 100644
index 00000000..4130fa50
--- /dev/null
+++ b/kamon-core/src/main/scala/kamon/util/MeasurementUnit.scala
@@ -0,0 +1,15 @@
+package kamon.util
+
+trait MeasurementUnit {
+  def dimension: Dimension
+  def magnitude: Magnitude
+}
+
+trait Magnitude {
+  def name: String
+}
+
+trait Dimension {
+  def name: String
+  def scale(value: Long, from: Magnitude, to: Magnitude): Double
+}