| /** |
| * 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.common; |
| |
| import java.io.IOException; |
| import java.util.SortedSet; |
| import java.util.TreeSet; |
| |
| import org.apache.hadoop.hdfs.protocol.FSConstants; |
| import org.apache.hadoop.util.StringUtils; |
| |
| /** |
| * Collection of upgrade objects. |
| * |
| * Upgrade objects should be registered here before they can be used. |
| */ |
| public class UpgradeObjectCollection { |
| static { |
| initialize(); |
| // Registered distributed upgrade objects here |
| // registerUpgrade(new UpgradeObject()); |
| } |
| |
| static class UOSignature implements Comparable<UOSignature> { |
| int version; |
| HdfsConstants.NodeType type; |
| String className; |
| |
| UOSignature(Upgradeable uo) { |
| this.version = uo.getVersion(); |
| this.type = uo.getType(); |
| this.className = uo.getClass().getCanonicalName(); |
| } |
| |
| int getVersion() { |
| return version; |
| } |
| |
| HdfsConstants.NodeType getType() { |
| return type; |
| } |
| |
| String getClassName() { |
| return className; |
| } |
| |
| Upgradeable instantiate() throws IOException { |
| try { |
| return (Upgradeable)Class.forName(getClassName()).newInstance(); |
| } catch(ClassNotFoundException e) { |
| throw new IOException(StringUtils.stringifyException(e)); |
| } catch(InstantiationException e) { |
| throw new IOException(StringUtils.stringifyException(e)); |
| } catch(IllegalAccessException e) { |
| throw new IOException(StringUtils.stringifyException(e)); |
| } |
| } |
| |
| public int compareTo(UOSignature o) { |
| if(this.version != o.version) |
| return (version < o.version ? -1 : 1); |
| int res = this.getType().toString().compareTo(o.getType().toString()); |
| if(res != 0) |
| return res; |
| return className.compareTo(o.className); |
| } |
| |
| public boolean equals(Object o) { |
| if (!(o instanceof UOSignature)) { |
| return false; |
| } |
| return this.compareTo((UOSignature)o) == 0; |
| } |
| |
| public int hashCode() { |
| return version ^ ((type==null)?0:type.hashCode()) |
| ^ ((className==null)?0:className.hashCode()); |
| } |
| } |
| |
| /** |
| * Static collection of upgrade objects sorted by version. |
| * Layout versions are negative therefore newer versions will go first. |
| */ |
| static SortedSet<UOSignature> upgradeTable; |
| |
| static final void initialize() { |
| upgradeTable = new TreeSet<UOSignature>(); |
| } |
| |
| static void registerUpgrade(Upgradeable uo) { |
| // Registered distributed upgrade objects here |
| upgradeTable.add(new UOSignature(uo)); |
| } |
| |
| public static SortedSet<Upgradeable> getDistributedUpgrades(int versionFrom, |
| HdfsConstants.NodeType type |
| ) throws IOException { |
| assert FSConstants.LAYOUT_VERSION <= versionFrom : "Incorrect version " |
| + versionFrom + ". Expected to be <= " + FSConstants.LAYOUT_VERSION; |
| SortedSet<Upgradeable> upgradeObjects = new TreeSet<Upgradeable>(); |
| for(UOSignature sig : upgradeTable) { |
| if(sig.getVersion() < FSConstants.LAYOUT_VERSION) |
| continue; |
| if(sig.getVersion() > versionFrom) |
| break; |
| if(sig.getType() != type ) |
| continue; |
| upgradeObjects.add(sig.instantiate()); |
| } |
| if(upgradeObjects.size() == 0) |
| return null; |
| return upgradeObjects; |
| } |
| } |