| /** |
| * 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.crunch.io; |
| |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| import java.util.Collections; |
| import java.util.Iterator; |
| |
| import org.apache.hadoop.fs.FileStatus; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.fs.PathFilter; |
| |
| import com.google.common.collect.UnmodifiableIterator; |
| |
| public class CompositePathIterable<T> implements Iterable<T> { |
| |
| private final FileStatus[] stati; |
| private final FileSystem fs; |
| private final FileReaderFactory<T> readerFactory; |
| |
| private static final PathFilter FILTER = new PathFilter() { |
| @Override |
| public boolean accept(Path path) { |
| String name = path.getName(); |
| return !name.startsWith("_") && !name.startsWith("."); |
| } |
| }; |
| |
| public static <S> Iterable<S> create(FileSystem fs, Path path, FileReaderFactory<S> readerFactory) throws IOException { |
| |
| if (!fs.exists(path)) { |
| throw new IOException("No files found to materialize at: " + path); |
| } |
| |
| FileStatus[] stati = null; |
| try { |
| stati = fs.listStatus(path, FILTER); |
| } catch (FileNotFoundException e) { |
| stati = null; |
| } |
| if (stati == null) { |
| throw new IOException("No files found to materialize at: " + path); |
| } |
| |
| if (stati.length == 0) { |
| return Collections.emptyList(); |
| } else { |
| return new CompositePathIterable<S>(stati, fs, readerFactory); |
| } |
| |
| } |
| |
| private CompositePathIterable(FileStatus[] stati, FileSystem fs, FileReaderFactory<T> readerFactory) { |
| this.stati = stati; |
| this.fs = fs; |
| this.readerFactory = readerFactory; |
| } |
| |
| @Override |
| public Iterator<T> iterator() { |
| |
| return new UnmodifiableIterator<T>() { |
| private int index = 0; |
| private Iterator<T> iter = readerFactory.read(fs, stati[index++].getPath()); |
| |
| @Override |
| public boolean hasNext() { |
| if (!iter.hasNext()) { |
| while (index < stati.length) { |
| iter = readerFactory.read(fs, stati[index++].getPath()); |
| if (iter.hasNext()) { |
| return true; |
| } |
| } |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public T next() { |
| return iter.next(); |
| } |
| }; |
| } |
| } |