| /* |
| * 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.hadoop.fs.statistics; |
| |
| import java.util.Map; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| /** |
| * IO Statistics. |
| * <p> |
| * These are low-cost per-instance statistics provided by any Hadoop |
| * I/O class instance. |
| * <p> |
| * Consult the filesystem specification document for the requirements |
| * of an implementation of this interface. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Unstable |
| public interface IOStatistics { |
| |
| /** |
| * Map of counters. |
| * @return the current map of counters. |
| */ |
| Map<String, Long> counters(); |
| |
| /** |
| * Map of gauges. |
| * @return the current map of gauges. |
| */ |
| Map<String, Long> gauges(); |
| |
| /** |
| * Map of minimums. |
| * @return the current map of minimums. |
| */ |
| Map<String, Long> minimums(); |
| |
| /** |
| * Map of maximums. |
| * @return the current map of maximums. |
| */ |
| Map<String, Long> maximums(); |
| |
| /** |
| * Map of meanStatistics. |
| * @return the current map of MeanStatistic statistics. |
| */ |
| Map<String, MeanStatistic> meanStatistics(); |
| |
| /** |
| * Value when a minimum value has never been set. |
| */ |
| long MIN_UNSET_VALUE = -1; |
| |
| /** |
| * Value when a max value has never been set. |
| */ |
| long MAX_UNSET_VALUE = -1; |
| } |