1 files changed, 53 insertions, 0 deletions
diff --git a/framework/src/onos/core/api/src/main/java/org/onosproject/store/Timestamp.java b/framework/src/onos/core/api/src/main/java/org/onosproject/store/Timestamp.java
new file mode 100644
index 00000000..44238ff2
--- /dev/null
+++ b/framework/src/onos/core/api/src/main/java/org/onosproject/store/Timestamp.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2014-2015 Open Networking Laboratory
+ *
+ * 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 org.onosproject.store;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Opaque version structure.
+ * <p>
+ * Classes implementing this interface must also implement
+ * {@link #hashCode()} and {@link #equals(Object)}.
+ */
+public interface Timestamp extends Comparable<Timestamp> {
+
+    @Override
+    int hashCode();
+
+    @Override
+    boolean equals(Object obj);
+
+    /**
+     * Tests if this timestamp is newer than the specified timestamp.
+     *
+     * @param other timestamp to compare against
+     * @return true if this instance is newer
+     */
+    default boolean isNewerThan(Timestamp other) {
+        return this.compareTo(checkNotNull(other)) > 0;
+    }
+
+    /**
+     * Tests if this timestamp is older than the specified timestamp.
+     *
+     * @param other timestamp to compare against
+     * @return true if this instance is older
+     */
+    default boolean isOlderThan(Timestamp other) {
+        return this.compareTo(checkNotNull(other)) < 0;
+    }
+}