001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 */ 018package org.apache.commons.compress.parallel; 019 020import java.io.Closeable; 021import java.io.IOException; 022import java.io.InputStream; 023 024/** 025 * <p>Store intermediate payload in a scatter-gather scenario. 026 * Multiple threads write their payload to a backing store, which can 027 * subsequently be reversed to an {@link InputStream} to be used as input in the 028 * gather phase.</p> 029 * 030 * <p>It is the responsibility of the allocator of an instance of this class 031 * to close this. Closing it should clear off any allocated structures 032 * and preferably delete files.</p> 033 * 034 * @since 1.10 035 */ 036public interface ScatterGatherBackingStore extends Closeable { 037 038 /** 039 * An input stream that contains the scattered payload 040 * 041 * @return An InputStream, should be closed by the caller of this method. 042 * @throws IOException when something fails 043 */ 044 InputStream getInputStream() throws IOException; 045 046 /** 047 * Writes a piece of payload. 048 * 049 * @param data the data to write 050 * @param offset offset inside data to start writing from 051 * @param length the amount of data to write 052 * @throws IOException when something fails 053 */ 054 void writeOut(byte[] data, int offset, int length) throws IOException; 055 056 /** 057 * Closes this backing store for further writing. 058 * @throws IOException when something fails 059 */ 060 void closeForWriting() throws IOException; 061}