Time.java

// =================================================================================================
// Copyright 2011 Twitter, Inc.
// -------------------------------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this work except in compliance with the License.
// You may obtain a copy of the License in the LICENSE file, or 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 com.twitter.common.quantity;

import java.util.concurrent.TimeUnit;

/**
 * Provides a unit to allow conversions and unambiguous passing around of time {@link Amount}s.
 *
 * @author John Sirois
 */
public enum Time implements Unit<Time> {
  NANOSECONDS(1, TimeUnit.NANOSECONDS, "ns"),
  MICROSECONDS(1000, NANOSECONDS, TimeUnit.MICROSECONDS, "us"),
  MILLISECONDS(1000, MICROSECONDS, TimeUnit.MILLISECONDS, "ms"),
  SECONDS(1000, MILLISECONDS, TimeUnit.SECONDS, "secs"),
  MINUTES(60, SECONDS, TimeUnit.MINUTES, "mins"),
  HOURS(60, MINUTES, TimeUnit.HOURS, "hrs"),
  DAYS(24, HOURS, TimeUnit.DAYS, "days");

  private final double multiplier;
  private final TimeUnit timeUnit;
  private final String display;

  private Time(double multiplier, TimeUnit timeUnit, String display) {
    this.multiplier = multiplier;
    this.timeUnit = timeUnit;
    this.display = display;
  }

  private Time(double multiplier, Time base, TimeUnit timeUnit, String display) {
    this(multiplier * base.multiplier, timeUnit, display);
  }

  @Override
  public double multiplier() {
    return multiplier;
  }

  /**
   * Returns the equivalent {@code TimeUnit}.
   */
  public TimeUnit getTimeUnit() {
    return timeUnit;
  }

  @Override
  public String toString() {
    return display;
  }
}