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}