| /** |
| * 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.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.io.Writable; |
| |
| |
| /** |
| * Common class for storage information. |
| * |
| * TODO namespaceID should be long and computed as hash(address + port) |
| */ |
| @InterfaceAudience.Private |
| public class StorageInfo implements Writable { |
| public int layoutVersion; // layout version of the storage data |
| public int namespaceID; // id of the file system |
| public long cTime; // creation time of the file system state |
| |
| public StorageInfo () { |
| this(0, 0, 0L); |
| } |
| |
| public StorageInfo(int layoutV, int nsID, long cT) { |
| layoutVersion = layoutV; |
| namespaceID = nsID; |
| cTime = cT; |
| } |
| |
| public StorageInfo(StorageInfo from) { |
| setStorageInfo(from); |
| } |
| |
| /** |
| * Layout version of the storage data. |
| */ |
| public int getLayoutVersion(){ return layoutVersion; } |
| |
| /** |
| * Namespace id of the file system.<p> |
| * Assigned to the file system at formatting and never changes after that. |
| * Shared by all file system components. |
| */ |
| public int getNamespaceID() { return namespaceID; } |
| |
| /** |
| * Creation time of the file system state.<p> |
| * Modified during upgrades. |
| */ |
| public long getCTime() { return cTime; } |
| |
| public void setStorageInfo(StorageInfo from) { |
| layoutVersion = from.layoutVersion; |
| namespaceID = from.namespaceID; |
| cTime = from.cTime; |
| } |
| |
| ///////////////////////////////////////////////// |
| // Writable |
| ///////////////////////////////////////////////// |
| public void write(DataOutput out) throws IOException { |
| out.writeInt(getLayoutVersion()); |
| out.writeInt(getNamespaceID()); |
| out.writeLong(getCTime()); |
| } |
| |
| public void readFields(DataInput in) throws IOException { |
| layoutVersion = in.readInt(); |
| namespaceID = in.readInt(); |
| cTime = in.readLong(); |
| } |
| } |