1 /* 2 * Copyright 2017, OpenCensus Authors 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 17 package io.opencensus.internal; 18 19 import io.opencensus.common.Clock; 20 import io.opencensus.common.Timestamp; 21 import javax.annotation.concurrent.Immutable; 22 23 /** A {@link Clock} that always returns 0. */ 24 @Immutable 25 public final class ZeroTimeClock extends Clock { 26 private static final ZeroTimeClock INSTANCE = new ZeroTimeClock(); 27 private static final Timestamp ZERO_TIMESTAMP = Timestamp.create(0, 0); 28 29 private ZeroTimeClock() {} 30 31 /** 32 * Returns a {@code ZeroTimeClock}. 33 * 34 * @return a {@code ZeroTimeClock}. 35 */ 36 public static ZeroTimeClock getInstance() { 37 return INSTANCE; 38 } 39 40 @Override 41 public Timestamp now() { 42 return ZERO_TIMESTAMP; 43 } 44 45 @Override 46 public long nowNanos() { 47 return 0; 48 } 49 } 50
