network/shuffle/DownloadFile.java

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *    http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 package org.apache.spark.network.shuffle;
0019
0020 import java.io.IOException;
0021
0022 /**
0023  * A handle on the file used when fetching remote data to disk.  Used to ensure the lifecycle of
0024  * writing the data, reading it back, and then cleaning it up is followed.  Specific implementations
0025  * may also handle encryption.  The data can be read only via DownloadFileWritableChannel,
0026  * which ensures data is not read until after the writer is closed.
0027  */
0028 public interface DownloadFile {
0029   /**
0030    * Delete the file.
0031    *
0032    * @return  <code>true</code> if and only if the file or directory is
0033    *          successfully deleted; <code>false</code> otherwise
0034    */
0035   boolean delete();
0036
0037   /**
0038    * A channel for writing data to the file.  This special channel allows access to the data for
0039    * reading, after the channel is closed, via {@link DownloadFileWritableChannel#closeAndRead()}.
0040    */
0041   DownloadFileWritableChannel openForWriting() throws IOException;
0042
0043   /**
0044    * The path of the file, intended only for debug purposes.
0045    */
0046   String path();
0047 }