/**
* 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.namenode;
import org.apache.hadoop.hdfs.util.LightWeightGSet;
/**
* A lighter weight implementation of LightWeightGSet optimized for inode query by id
*
*/
public class INodeMap extends LightWeightGSet<INode, INode>{
public INodeMap(int recommended_length) {
super(recommended_length);
}
/**
* This has to be consistent with {@link INode#hashCode()}
* @param inodeId
* @return
*/
private int getIndex(final long inodeId) {
return INode.getHashCode(inodeId) & hash_mask;
}
public INode get(long inodeId) {
//find element
final int index = getIndex(inodeId);
for(LinkedElement e = entries[index]; e != null; e = e.getNext()) {
INode n = (INode)e;
if (n.getId() == inodeId) {
return n;
}
}
//element not found
return null;
}
}