gerrit.opnfv Code Review - onosfw.git/blob

   1 /*
   2  * Copyright 2015 Open Networking Laboratory
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.onosproject.store.trivial;
  17
  18 import com.google.common.base.MoreObjects;
  19 import com.google.common.collect.ComparisonChain;
  20 import org.onosproject.store.Timestamp;
  21
  22 import java.util.Objects;
  23
  24 import static com.google.common.base.Preconditions.checkArgument;
  25
  26 /**
  27  * A Timestamp that derives its value from the system clock time (in ns)
  28  * on the controller where it is generated.
  29  */
  30 public class SystemClockTimestamp implements Timestamp {
  31
  32     private final long nanoTimestamp;
  33
  34     public SystemClockTimestamp() {
  35         nanoTimestamp = System.nanoTime();
  36     }
  37
  38     public SystemClockTimestamp(long timestamp) {
  39         nanoTimestamp = timestamp;
  40     }
  41
  42     @Override
  43     public int compareTo(Timestamp o) {
  44         checkArgument(o instanceof SystemClockTimestamp,
  45                 "Must be SystemClockTimestamp", o);
  46         SystemClockTimestamp that = (SystemClockTimestamp) o;
  47
  48         return ComparisonChain.start()
  49                 .compare(this.nanoTimestamp, that.nanoTimestamp)
  50                 .result();
  51     }
  52     @Override
  53     public int hashCode() {
  54         return Objects.hash(nanoTimestamp);
  55     }
  56
  57     @Override
  58     public boolean equals(Object obj) {
  59         if (this == obj) {
  60             return true;
  61         }
  62         if (!(obj instanceof SystemClockTimestamp)) {
  63             return false;
  64         }
  65         SystemClockTimestamp that = (SystemClockTimestamp) obj;
  66         return Objects.equals(this.nanoTimestamp, that.nanoTimestamp);
  67     }
  68
  69     @Override
  70     public String toString() {
  71         return MoreObjects.toStringHelper(getClass())
  72                     .add("nanoTimestamp", nanoTimestamp)
  73                     .toString();
  74     }
  75
  76     public long nanoTimestamp() {
  77         return nanoTimestamp;
  78     }
  79
  80     public long systemTimestamp() {
  81         return nanoTimestamp / 1_000_000; // convert ns to ms
  82     }
  83 }