1 files changed, 15 insertions, 0 deletions
diff --git a/container-search/src/main/java/com/yahoo/vespa/streamingvisitors/tracing/MonotonicNanoClock.java b/container-search/src/main/java/com/yahoo/vespa/streamingvisitors/tracing/MonotonicNanoClock.java
new file mode 100644
index 00000000000..1b3d766e266
--- /dev/null
+++ b/container-search/src/main/java/com/yahoo/vespa/streamingvisitors/tracing/MonotonicNanoClock.java
@@ -0,0 +1,15 @@
+// Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.streamingvisitors.tracing;
+
+/*
+ * Clock which returns a monotonically increasing timestamp from an undefined epoch.
+ * The epoch is guaranteed to be stable within a single JVM execution, but not across
+ * processes. Should therefore only be used for relative duration tracking, not absolute
+ * wall clock time events.
+ */
+@FunctionalInterface
+public interface MonotonicNanoClock {
+
+    long nanoTimeNow();
+
+}