ambari-metrics-common/src/main/java/org/apache/hadoop/metrics2/sink/timeline/Precision.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License 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 org.apache.hadoop.metrics2.sink.timeline;

/**
 * Is used to determine metrics aggregate table.
 *
 */
public enum Precision {
  SECONDS,
  MINUTES,
  HOURS,
  DAYS;

  public static class PrecisionFormatException extends IllegalArgumentException {
    public PrecisionFormatException(String message, Throwable cause) {
      super(message, cause);
    }
  }

  public static Precision getPrecision(String precision) throws PrecisionFormatException {
    if (precision == null || precision.isEmpty()) {
      return null;
    }
    try {
      return Precision.valueOf(precision.toUpperCase());
    } catch (IllegalArgumentException e) {
      throw new PrecisionFormatException("precision should be seconds, " +
        "minutes, hours or days", e);
    }
  }

  public static Precision getPrecision(long startTime, long endTime) {
    long HOUR = 3600000; // 1 hour
    long DAY = 86400000; // 1 day
    long timeRange = endTime - startTime;
    if (timeRange > 30 * DAY) {
      return Precision.DAYS;
    } else if (timeRange > 1 * DAY) {
      return Precision.HOURS;
    } else if (timeRange > 2 * HOUR) {
      return Precision.MINUTES;
    } else {
      return Precision.SECONDS;
    }
  }

  public static Precision getHigherPrecision(Precision precision) {

    if (precision == null)
      return null;

    if (precision.equals(Precision.SECONDS)) {
      return Precision.MINUTES;
    } else if (precision.equals(Precision.MINUTES)) {
      return Precision.HOURS;
    } else if (precision.equals(Precision.HOURS)) {
      return Precision.DAYS;
    } else {
      return null;
    }
  }
}