    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 */
    017package org.apache.commons.compress.parallel;
    018
    019import java.io.Closeable;
    020import java.io.IOException;
    021import java.io.InputStream;
    022
    023/**
    024 * <p>
    025 * Store intermediate payload in a scatter-gather scenario. Multiple threads write their payload to a backing store, which can subsequently be reversed to an
    026 * {@link InputStream} to be used as input in the gather phase.
    027 * </p>
    028 *
    029 * <p>
    030 * It is the responsibility of the allocator of an instance of this class to close this. Closing it should clear off any allocated structures and preferably
    031 * delete files.
    032 * </p>
    033 *
    034 * @since 1.10
    035 */
    036public interface ScatterGatherBackingStore extends Closeable {
    037
    038    /**
    039     * Closes this backing store for further writing.
    040     *
    041     * @throws IOException when something fails
    042     */
    043    void closeForWriting() throws IOException;
    044
    045    /**
    046     * An input stream that contains the scattered payload
    047     *
    048     * @return An InputStream, should be closed by the caller of this method.
    049     * @throws IOException when something fails
    050     */
    051    InputStream getInputStream() throws IOException;
    052
    053    /**
    054     * Writes a piece of payload.
    055     *
    056     * @param data   the data to write
    057     * @param offset offset inside data to start writing from
    058     * @param length the amount of data to write
    059     * @throws IOException when something fails
    060     */
    061    void writeOut(byte[] data, int offset, int length) throws IOException;
    062}