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 */ 018 019package org.apache.hadoop.mapreduce.counters; 020 021import org.apache.hadoop.classification.InterfaceAudience; 022import org.apache.hadoop.classification.InterfaceAudience.Private; 023import org.apache.hadoop.classification.InterfaceStability; 024import org.apache.hadoop.io.Writable; 025import org.apache.hadoop.mapreduce.Counter; 026 027/** 028 * The common counter group interface. 029 * 030 * @param <T> type of the counter for the group 031 */ 032@InterfaceAudience.Public 033@InterfaceStability.Evolving 034public interface CounterGroupBase<T extends Counter> 035 extends Writable, Iterable<T> { 036 037 /** 038 * Get the internal name of the group 039 * @return the internal name 040 */ 041 String getName(); 042 043 /** 044 * Get the display name of the group. 045 * @return the human readable name 046 */ 047 String getDisplayName(); 048 049 /** 050 * Set the display name of the group 051 * @param displayName of the group 052 */ 053 void setDisplayName(String displayName); 054 055 /** Add a counter to this group. 056 * @param counter to add 057 */ 058 void addCounter(T counter); 059 060 /** 061 * Add a counter to this group 062 * @param name of the counter 063 * @param displayName of the counter 064 * @param value of the counter 065 * @return the counter 066 */ 067 T addCounter(String name, String displayName, long value); 068 069 /** 070 * Find a counter in the group. 071 * @param counterName the name of the counter 072 * @param displayName the display name of the counter 073 * @return the counter that was found or added 074 */ 075 T findCounter(String counterName, String displayName); 076 077 /** 078 * Find a counter in the group 079 * @param counterName the name of the counter 080 * @param create create the counter if not found if true 081 * @return the counter that was found or added or null if create is false 082 */ 083 T findCounter(String counterName, boolean create); 084 085 /** 086 * Find a counter in the group. 087 * @param counterName the name of the counter 088 * @return the counter that was found or added 089 */ 090 T findCounter(String counterName); 091 092 /** 093 * @return the number of counters in this group. 094 */ 095 int size(); 096 097 /** 098 * Increment all counters by a group of counters 099 * @param rightGroup the group to be added to this group 100 */ 101 void incrAllCounters(CounterGroupBase<T> rightGroup); 102 103 @Private 104 /** 105 * Exposes the underlying group type if a facade. 106 * @return the underlying object that this object is wrapping up. 107 */ 108 CounterGroupBase<T> getUnderlyingGroup(); 109}