/*******************************************************************************
* 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.drill.exec.store.dfs;
import org.apache.drill.exec.store.PartitionExplorer;
import org.apache.hadoop.fs.FileStatus;
import java.util.Iterator;
import java.util.List;
public class SubDirectoryList implements Iterable<String>{
final List<FileStatus> fileStatuses;
SubDirectoryList(List<FileStatus> fileStatuses) {
this.fileStatuses = fileStatuses;
}
@Override
public Iterator<String> iterator() {
return new SubDirectoryIterator(fileStatuses.iterator());
}
private class SubDirectoryIterator implements Iterator<String> {
final Iterator<FileStatus> fileStatusIterator;
SubDirectoryIterator(Iterator<FileStatus> fileStatusIterator) {
this.fileStatusIterator = fileStatusIterator;
}
@Override
public boolean hasNext() {
return fileStatusIterator.hasNext();
}
@Override
public String next() {
return fileStatusIterator.next().getPath().toUri().toString();
}
/**
* This class is designed specifically for use in conjunction with the
* {@link org.apache.drill.exec.store.PartitionExplorer} interface.
* This is only designed for accessing partition information, not
* modifying it. To avoid confusing users of the interface this
* method throws UnsupportedOperationException.
*
* @throws UnsupportedOperationException - this is not useful here, the
* list being iterated over should not be used in a way that
* removing an element would be meaningful.
*/
@Override
public void remove() {
throw new UnsupportedOperationException(String.format("Cannot modify partition information through the " +
"%s interface.", PartitionExplorer.class.getSimpleName()));
}
}
}