/**
* 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;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.server.datanode.FSDataset.ActiveFile;
import org.apache.hadoop.hdfs.server.datanode.FSDataset.FSVolume;
/**
* Maintains the replicas map.
*/
class VolumeMap {
// Map of block Id to DatanodeBlockInfo, indexed by namespace
private Map<Integer, Map<Block, DatanodeBlockInfo>> namespaceMap;
private Map<Integer, Map<Block, ActiveFile>> ongoingCreates;
VolumeMap(int numNamespaces) {
namespaceMap = new HashMap<Integer, Map<Block, DatanodeBlockInfo>>(numNamespaces);
ongoingCreates = new HashMap<Integer, Map<Block, ActiveFile>>(numNamespaces);
}
/**
* Returns an immutable instance of the volume map for a given namespace.
* @param namespaceID the namespaceID for which the volume map needs to be
* returned.
*/
public Map <Block, DatanodeBlockInfo> getNamespaceMap(int namespaceID) {
return Collections.unmodifiableMap(namespaceMap.get(namespaceID));
}
synchronized Integer[] getNamespaceList() {
return namespaceMap.keySet().toArray(
new Integer[namespaceMap.keySet().size()]);
}
private void checkBlock(Block b) {
if (b == null) {
throw new IllegalArgumentException("Block is null");
}
}
synchronized int removeUnhealthyVolumes(Collection<FSVolume> failed_vols) {
int removed_blocks = 0;
for (Integer namespaceId : namespaceMap.keySet()) {
Map<Block, DatanodeBlockInfo> m = namespaceMap.get(namespaceId);
Iterator<Entry<Block, DatanodeBlockInfo>> dbi = m.entrySet().iterator();
while (dbi.hasNext()) {
Entry<Block, DatanodeBlockInfo> entry = dbi.next();
for (FSVolume v : failed_vols) {
if (entry.getValue().getVolume() == v) {
DataNode.LOG.warn("removing block " + entry.getKey().getBlockId()
+ " from vol " + v.toString() + ", form namespace: "
+ namespaceId);
dbi.remove();
removed_blocks++;
break;
}
}
}
}
return removed_blocks;
}
/**
* Get the meta information of the replica that matches both block id and
* generation stamp
*
* @param namespaceId
* @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
*/
DatanodeBlockInfo get(int namespaceId, Block block) {
checkBlock(block);
synchronized(this){
Map<Block, DatanodeBlockInfo> m = namespaceMap.get(namespaceId);
return m != null ? m.get(block) : null;
}
}
/**
* Add a replica's meta information into the map
*
* @param namespaceId
* @param replicaInfo
* a replica's meta information
* @return previous meta information of the replica
* @throws IllegalArgumentException
* if the input parameter is null
*/
DatanodeBlockInfo add(int namespaceId, Block block,
DatanodeBlockInfo replicaInfo) {
checkBlock(block);
synchronized(this){
Map<Block, DatanodeBlockInfo> m = namespaceMap.get(namespaceId);
return m.put(block, replicaInfo);
}
}
DatanodeBlockInfo update(int namespaceId, Block oldB, Block newB) {
Map<Block, DatanodeBlockInfo> m = namespaceMap.get(namespaceId);
if (m == null) {
return null;
}
DatanodeBlockInfo bi = m.remove(oldB);
if (bi != null) {
m.put(newB, bi);
}
return bi;
}
/**
* Remove the replica's meta information from the map that matches the input
* block's id and generation stamp
*
* @param namespaceId
* @param block
* block with its id as the key
* @return the removed replica's meta information
* @throws IllegalArgumentException
* if the input block is null
*/
DatanodeBlockInfo remove(int namespaceId, Block block) {
checkBlock(block);
synchronized(this){
Map<Block, DatanodeBlockInfo> m = namespaceMap.get(namespaceId);
return m != null ? m.remove(block) : null;
}
}
/**
* Get the size of the map for given namespace
*
* @param namespaceId
* @return the number of replicas in the map
*/
synchronized int size(int namespaceId) {
Map<Block, DatanodeBlockInfo> m = namespaceMap.get(namespaceId);
return m != null ? m.size() : 0;
}
synchronized void initNamespace(int namespaceId) {
Map<Block, DatanodeBlockInfo> m = namespaceMap.get(namespaceId);
if(m != null){
return;
}
m = new HashMap<Block, DatanodeBlockInfo>();
namespaceMap.put(namespaceId, m);
Map<Block, ActiveFile> oc = new HashMap<Block, ActiveFile>();
ongoingCreates.put(namespaceId, oc);
}
synchronized void removeNamespace(int namespaceId){
namespaceMap.remove(namespaceId);
ongoingCreates.remove(namespaceId);
}
// for ongoing creates
ActiveFile getOngoingCreates(int namespaceId, Block block) {
checkBlock(block);
synchronized(this){
Map<Block, ActiveFile> m = ongoingCreates.get(namespaceId);
return m != null ? m.get(block) : null;
}
}
ActiveFile removeOngoingCreates(int namespaceId, Block block) {
checkBlock(block);
synchronized(this){
Map<Block, ActiveFile> m = ongoingCreates.get(namespaceId);
return m != null ? m.remove(block) : null;
}
}
ActiveFile addOngoingCreates(int namespaceId, Block block, ActiveFile af) {
checkBlock(block);
synchronized(this){
Map<Block, ActiveFile> m = ongoingCreates.get(namespaceId);
return m.put(block, af);
}
}
/**
* If there is an ActiveFile object for the block, create a copy of the
* old one and replace the old one. This is to make sure that the VisibleLength
* applied to the old object will have no impact to the local map. In
* that way, BlockReceiver can directly update visible length without
* holding the lock.
*
* @param namespaceId
* @param block
* @throws CloneNotSupportedException
*/
void copyOngoingCreates(int namespaceId, Block block) throws CloneNotSupportedException {
checkBlock(block);
synchronized(this){
Map<Block, ActiveFile> m = ongoingCreates.get(namespaceId);
ActiveFile af = m.get(block);
if (af == null) {
return;
}
m.put(block, af.getClone());
}
}
public synchronized String toString() {
String ret = "VolumeMap: ";
for (Integer namespaceId : namespaceMap.keySet()) {
ret += namespaceMap.get(namespaceId).toString();
ret += "\n---\n";
ret += ongoingCreates.get(namespaceId).toString();
}
return ret;
}
}