001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.metrics;
019
020import org.apache.hadoop.hbase.HBaseInterfaceAudience;
021import org.apache.yetus.audience.InterfaceAudience;
022import org.apache.yetus.audience.InterfaceStability;
023
024/**
025 * A metric which measures the distribution of values.
026 */
027@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
028@InterfaceStability.Evolving
029public interface Histogram extends Metric {
030
031  /**
032   * Adds a new value to the distribution.
033   *
034   * @param value The value to add
035   */
036  void update(int value);
037
038  /**
039   * Adds a new value to the distribution.
040   *
041   * @param value The value to add
042   */
043  void update(long value);
044
045  /**
046   * Return the total number of values added to the histogram.
047   * @return the total number of values.
048   */
049  long getCount();
050
051  /**
052   * Snapshot the current values in the Histogram
053   * @return a Snapshot of the distribution.
054   */
055  @InterfaceAudience.Private
056  Snapshot snapshot();
057
058}