| /* |
| * 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.impl.prefetch; |
| |
| import java.time.Duration; |
| |
| import org.apache.hadoop.fs.statistics.DurationTracker; |
| |
| import static org.apache.hadoop.fs.statistics.IOStatisticsSupport.stubDurationTracker; |
| |
| /** |
| * Empty implementation of the prefetching statistics interface. |
| */ |
| public final class EmptyPrefetchingStatistics |
| implements PrefetchingStatistics { |
| |
| private static final EmptyPrefetchingStatistics |
| EMPTY_PREFETCHING_STATISTICS = |
| new EmptyPrefetchingStatistics(); |
| |
| private EmptyPrefetchingStatistics() { |
| } |
| |
| public static EmptyPrefetchingStatistics getInstance() { |
| return EMPTY_PREFETCHING_STATISTICS; |
| } |
| |
| @Override |
| public DurationTracker prefetchOperationStarted() { |
| return stubDurationTracker(); |
| } |
| |
| @Override |
| public void blockAddedToFileCache() { |
| |
| } |
| |
| @Override |
| public void blockRemovedFromFileCache() { |
| |
| } |
| |
| @Override |
| public void prefetchOperationCompleted() { |
| |
| } |
| |
| @Override |
| public void executorAcquired(Duration timeInQueue) { |
| |
| } |
| |
| @Override |
| public void memoryAllocated(int size) { |
| |
| } |
| |
| @Override |
| public void memoryFreed(int size) { |
| |
| } |
| } |
| |