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   * @param value The value to add
034   */
035  void update(int value);
036
037  /**
038   * Adds a new value to the distribution.
039   * @param value The value to add
040   */
041  void update(long value);
042
043  /**
044   * Return the total number of values added to the histogram.
045   * @return the total number of values.
046   */
047  long getCount();
048
049  /**
050   * Snapshot the current values in the Histogram
051   * @return a Snapshot of the distribution.
052   */
053  @InterfaceAudience.Private
054  Snapshot snapshot();
055
056}