Implementation of Hybrid Logical Clock Service.
Change-Id: I52e231433d044f9e6156db7e28bde9fd199118e8
diff --git a/core/api/src/main/java/org/onosproject/core/HybridLogicalTime.java b/core/api/src/main/java/org/onosproject/core/HybridLogicalTime.java
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+/*
+ * Copyright 2016-present 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.core;
+
+import com.google.common.base.MoreObjects;
+
+/**
+ * Time provided by a Hybrid Logical Clock described in
+ * this <a href="http://www.cse.buffalo.edu/tech-reports/2014-04.pdf">paper</a>.
+ */
+public class HybridLogicalTime {
+ private final long logicalTime;
+ private final long logicalCounter;
+
+ public HybridLogicalTime(long logicalTime, long logicalCounter) {
+ this.logicalTime = logicalTime;
+ this.logicalCounter = logicalCounter;
+ }
+
+ /**
+ * Returns the logical time component of a HLT.
+ * @return logical time
+ */
+ public long logicalTime() {
+ return logicalTime;
+ }
+
+ /**
+ * Returns the logical counter component of a HLT.
+ * @return logical counter
+ */
+ public long logicalCounter() {
+ return logicalCounter;
+ }
+
+ /**
+ * Returns the real system time represented by this HLT.
+ * @return real system time
+ */
+ public long time() {
+ return (logicalTime >> 16 << 16) | (logicalCounter << 48 >> 48);
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(getClass())
+ .add("logicalTime", logicalTime)
+ .add("logicalCounter", logicalCounter)
+ .toString();
+ }
+}