67 lines
1.8 KiB
Java
67 lines
1.8 KiB
Java
/*
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* Copyright (C) 2011 The Guava Authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.google.common.base;
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import com.google.common.annotations.Beta;
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import com.google.common.annotations.GwtCompatible;
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/**
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* A time source; returns a time value representing the number of nanoseconds
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* elapsed since some fixed but arbitrary point in time. Note that most users
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* should use {@link Stopwatch} instead of interacting with this class directly.
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*
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* <p>
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* <b>Warning:</b> this interface can only be used to measure elapsed time, not
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* wall time.
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*
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* @author Kevin Bourrillion
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* @since 10.0
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* (<a href="http://code.google.com/p/guava-libraries/wiki/Compatibility"
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* >mostly source-compatible</a> since 9.0)
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*/
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@Beta
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@GwtCompatible
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public abstract class Ticker {
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/**
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* Constructor for use by subclasses.
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*/
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protected Ticker() {
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}
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/**
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* Returns the number of nanoseconds elapsed since this ticker's fixed point of
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* reference.
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*/
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public abstract long read();
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/**
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* A ticker that reads the current time using {@link System#nanoTime}.
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*
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* @since 10.0
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*/
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public static Ticker systemTicker() {
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return SYSTEM_TICKER;
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}
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private static final Ticker SYSTEM_TICKER = new Ticker() {
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@Override
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public long read() {
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return Platform.systemNanoTime();
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}
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};
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}
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