/*
 * 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.phoenix.monitoring;

import org.apache.hadoop.conf.Configuration;
import org.apache.phoenix.mapreduce.util.PhoenixConfigurationUtilHelper;
import org.apache.phoenix.query.QueryServices;

/**
 * Histogram for calculating latencies. We read ranges using config property
 * {@link QueryServices#PHOENIX_HISTOGRAM_LATENCY_RANGES}. If this property is not set then it will
 * default to {@link org.apache.hadoop.metrics2.lib.MutableTimeHistogram#RANGES} values.
 */
public class LatencyHistogram extends RangeHistogram {

  // default range of time buckets in milli seconds.
  protected final static long[] DEFAULT_RANGE =
    { 1, 3, 10, 30, 100, 300, 1000, 3000, 10000, 30000, 60000, 120000, 300000, 600000 };

  public LatencyHistogram(String name, String description, Configuration conf) {
    super(initializeRanges(conf), name, description);
  }

  private static long[] initializeRanges(Configuration conf) {
    long[] ranges =
      PhoenixConfigurationUtilHelper.getLongs(conf, QueryServices.PHOENIX_HISTOGRAM_LATENCY_RANGES);
    return ranges != null ? ranges : DEFAULT_RANGE;
  }

}
