| /** |
| * 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.IOException; |
| |
| import org.apache.crunch.ReadableData; |
| import org.apache.crunch.Source; |
| import org.apache.hadoop.conf.Configuration; |
| |
| /** |
| * An extension of the {@code Source} interface that indicates that a |
| * {@code Source} instance may be read as a series of records by the client |
| * code. This is used to determine whether a {@code PCollection} instance can be |
| * materialized. |
| */ |
| public interface ReadableSource<T> extends Source<T> { |
| |
| /** |
| * Returns an {@code Iterable} that contains the contents of this source. |
| * |
| * @param conf The current {@code Configuration} instance |
| * @return the contents of this {@code Source} as an {@code Iterable} instance |
| * @throws IOException |
| */ |
| Iterable<T> read(Configuration conf) throws IOException; |
| |
| /** |
| * @return a {@code ReadableData} instance containing the data referenced by this |
| * {@code ReadableSource}. |
| */ |
| ReadableData<T> asReadable(); |
| } |