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.implcore.internal; 18 19 import io.opencensus.common.Clock; 20 import io.opencensus.common.Timestamp; 21 import javax.annotation.concurrent.Immutable; 22 23 /** 24 * This class provides a mechanism for converting {@link System#nanoTime() nanoTime} values to 25 * {@link Timestamp}. 26 */ 27 @Immutable 28 public final class TimestampConverter { 29 private final Timestamp timestamp; 30 private final long nanoTime; 31 32 // Returns a WallTimeConverter initialized to now. 33 public static TimestampConverter now(Clock clock) { 34 return new TimestampConverter(clock.now(), clock.nowNanos()); 35 } 36 37 /** 38 * Converts a {@link System#nanoTime() nanoTime} value to {@link Timestamp}. 39 * 40 * @param nanoTime value to convert. 41 * @return the {@code Timestamp} representation of the {@code time}. 42 */ 43 public Timestamp convertNanoTime(long nanoTime) { 44 return timestamp.addNanos(nanoTime - this.nanoTime); 45 } 46 47 private TimestampConverter(Timestamp timestamp, long nanoTime) { 48 this.timestamp = timestamp; 49 this.nanoTime = nanoTime; 50 } 51 } 52
