| /** |
| * 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.hdfs.server.datanode.fsdataset.impl; |
| |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.hadoop.HadoopIllegalArgumentException; |
| import org.apache.hadoop.hdfs.protocol.Block; |
| import org.apache.hadoop.hdfs.server.datanode.ReplicaInfo; |
| |
| /** |
| * Maintains the replica map. |
| */ |
| class ReplicaMap { |
| // Object using which this class is synchronized |
| private final Object mutex; |
| |
| // Map of block pool Id to another map of block Id to ReplicaInfo. |
| private Map<String, Map<Long, ReplicaInfo>> map = |
| new HashMap<String, Map<Long, ReplicaInfo>>(); |
| |
| ReplicaMap(Object mutex) { |
| if (mutex == null) { |
| throw new HadoopIllegalArgumentException( |
| "Object to synchronize on cannot be null"); |
| } |
| this.mutex = mutex; |
| } |
| |
| String[] getBlockPoolList() { |
| synchronized(mutex) { |
| return map.keySet().toArray(new String[map.keySet().size()]); |
| } |
| } |
| |
| private void checkBlockPool(String bpid) { |
| if (bpid == null) { |
| throw new IllegalArgumentException("Block Pool Id is null"); |
| } |
| } |
| |
| private void checkBlock(Block b) { |
| if (b == null) { |
| throw new IllegalArgumentException("Block is null"); |
| } |
| } |
| |
| /** |
| * Get the meta information of the replica that matches both block id |
| * and generation stamp |
| * @param bpid block pool id |
| * @param block block with its id as the key |
| * @return the replica's meta information |
| * @throws IllegalArgumentException if the input block or block pool is null |
| */ |
| ReplicaInfo get(String bpid, Block block) { |
| checkBlockPool(bpid); |
| checkBlock(block); |
| ReplicaInfo replicaInfo = get(bpid, block.getBlockId()); |
| if (replicaInfo != null && |
| block.getGenerationStamp() == replicaInfo.getGenerationStamp()) { |
| return replicaInfo; |
| } |
| return null; |
| } |
| |
| |
| /** |
| * Get the meta information of the replica that matches the block id |
| * @param bpid block pool id |
| * @param blockId a block's id |
| * @return the replica's meta information |
| */ |
| ReplicaInfo get(String bpid, long blockId) { |
| checkBlockPool(bpid); |
| synchronized(mutex) { |
| Map<Long, ReplicaInfo> m = map.get(bpid); |
| return m != null ? m.get(blockId) : null; |
| } |
| } |
| |
| /** |
| * Add a replica's meta information into the map |
| * |
| * @param bpid block pool id |
| * @param replicaInfo a replica's meta information |
| * @return previous meta information of the replica |
| * @throws IllegalArgumentException if the input parameter is null |
| */ |
| ReplicaInfo add(String bpid, ReplicaInfo replicaInfo) { |
| checkBlockPool(bpid); |
| checkBlock(replicaInfo); |
| synchronized(mutex) { |
| Map<Long, ReplicaInfo> m = map.get(bpid); |
| if (m == null) { |
| // Add an entry for block pool if it does not exist already |
| m = new HashMap<Long, ReplicaInfo>(); |
| map.put(bpid, m); |
| } |
| return m.put(replicaInfo.getBlockId(), replicaInfo); |
| } |
| } |
| |
| /** |
| * Remove the replica's meta information from the map that matches |
| * the input block's id and generation stamp |
| * @param bpid block pool id |
| * @param block block with its id as the key |
| * @return the removed replica's meta information |
| * @throws IllegalArgumentException if the input block is null |
| */ |
| ReplicaInfo remove(String bpid, Block block) { |
| checkBlockPool(bpid); |
| checkBlock(block); |
| synchronized(mutex) { |
| Map<Long, ReplicaInfo> m = map.get(bpid); |
| if (m != null) { |
| Long key = Long.valueOf(block.getBlockId()); |
| ReplicaInfo replicaInfo = m.get(key); |
| if (replicaInfo != null && |
| block.getGenerationStamp() == replicaInfo.getGenerationStamp()) { |
| return m.remove(key); |
| } |
| } |
| } |
| |
| return null; |
| } |
| |
| /** |
| * Remove the replica's meta information from the map if present |
| * @param bpid block pool id |
| * @param the block id of the replica to be removed |
| * @return the removed replica's meta information |
| */ |
| ReplicaInfo remove(String bpid, long blockId) { |
| checkBlockPool(bpid); |
| synchronized(mutex) { |
| Map<Long, ReplicaInfo> m = map.get(bpid); |
| if (m != null) { |
| return m.remove(blockId); |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Get the size of the map for given block pool |
| * @param bpid block pool id |
| * @return the number of replicas in the map |
| */ |
| int size(String bpid) { |
| Map<Long, ReplicaInfo> m = null; |
| synchronized(mutex) { |
| m = map.get(bpid); |
| return m != null ? m.size() : 0; |
| } |
| } |
| |
| /** |
| * Get a collection of the replicas for given block pool |
| * This method is <b>not synchronized</b>. It needs to be synchronized |
| * externally using the mutex, both for getting the replicas |
| * values from the map and iterating over it. Mutex can be accessed using |
| * {@link #getMutext()} method. |
| * |
| * @param bpid block pool id |
| * @return a collection of the replicas belonging to the block pool |
| */ |
| Collection<ReplicaInfo> replicas(String bpid) { |
| Map<Long, ReplicaInfo> m = null; |
| m = map.get(bpid); |
| return m != null ? m.values() : null; |
| } |
| |
| void initBlockPool(String bpid) { |
| checkBlockPool(bpid); |
| synchronized(mutex) { |
| Map<Long, ReplicaInfo> m = map.get(bpid); |
| if (m == null) { |
| // Add an entry for block pool if it does not exist already |
| m = new HashMap<Long, ReplicaInfo>(); |
| map.put(bpid, m); |
| } |
| } |
| } |
| |
| void cleanUpBlockPool(String bpid) { |
| checkBlockPool(bpid); |
| synchronized(mutex) { |
| map.remove(bpid); |
| } |
| } |
| |
| /** |
| * Give access to mutex used for synchronizing ReplicasMap |
| * @return object used as lock |
| */ |
| Object getMutext() { |
| return mutex; |
| } |
| } |