| /** |
| * 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.ozone.container.common.impl; |
| |
| import com.google.common.base.Preconditions; |
| import org.apache.hadoop.hdds.scm.container.common.helpers |
| .StorageContainerException; |
| import org.apache.hadoop.hdfs.DFSUtil; |
| import org.apache.hadoop.ozone.container.common.interfaces |
| .ContainerDeletionChoosingPolicy; |
| import org.apache.hadoop.ozone.container.keyvalue.KeyValueContainerData; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** |
| * Randomly choosing containers for block deletion. |
| */ |
| public class RandomContainerDeletionChoosingPolicy |
| implements ContainerDeletionChoosingPolicy { |
| private static final Logger LOG = |
| LoggerFactory.getLogger(RandomContainerDeletionChoosingPolicy.class); |
| |
| @Override |
| public List<ContainerData> chooseContainerForBlockDeletion(int count, |
| Map<Long, ContainerData> candidateContainers) |
| throws StorageContainerException { |
| Preconditions.checkNotNull(candidateContainers, |
| "Internal assertion: candidate containers cannot be null"); |
| |
| int currentCount = 0; |
| List<ContainerData> result = new LinkedList<>(); |
| ContainerData[] values = new ContainerData[candidateContainers.size()]; |
| // to get a shuffle list |
| for (ContainerData entry : DFSUtil.shuffle( |
| candidateContainers.values().toArray(values))) { |
| if (currentCount < count) { |
| result.add(entry); |
| currentCount++; |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Select container {} for block deletion, " |
| + "pending deletion blocks num: {}.", |
| entry.getContainerID(), |
| ((KeyValueContainerData) entry).getNumPendingDeletionBlocks()); |
| } |
| } else { |
| break; |
| } |
| } |
| |
| return result; |
| } |
| } |