    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.File;
    021import java.io.FileNotFoundException;
    022import java.io.IOException;
    023import java.io.InputStream;
    024import java.io.OutputStream;
    025import java.io.UncheckedIOException;
    026import java.nio.file.Files;
    027import java.nio.file.Path;
    028
    029/**
    030 * ScatterGatherBackingStore that is backed by a path.
    031 *
    032 * @since 1.10
    033 */
    034public class FileBasedScatterGatherBackingStore implements ScatterGatherBackingStore {
    035    private final Path target;
    036    private final OutputStream outputStream;
    037    private boolean closed;
    038
    039    public FileBasedScatterGatherBackingStore(final File target) throws FileNotFoundException {
    040        this(target.toPath());
    041    }
    042
    043    /**
    044     * Constructs a new instance for the given path.
    045     *
    046     * @param target The path to offload compressed data into.
    047     * @throws FileNotFoundException if the file doesn't exist
    048     * @since 1.22
    049     */
    050    public FileBasedScatterGatherBackingStore(final Path target) throws FileNotFoundException {
    051        this.target = target;
    052        try {
    053            outputStream = Files.newOutputStream(target);
    054        } catch (final FileNotFoundException ex) {
    055            throw ex;
    056        } catch (final IOException ex) {
    057            // must convert exception to stay backwards compatible with Compress 1.10 to 1.13
    058            throw new UncheckedIOException(ex); // NOSONAR
    059        }
    060    }
    061
    062    @Override
    063    public void close() throws IOException {
    064        try {
    065            closeForWriting();
    066        } finally {
    067            Files.deleteIfExists(target);
    068        }
    069    }
    070
    071    @Override
    072    public void closeForWriting() throws IOException {
    073        if (!closed) {
    074            outputStream.close();
    075            closed = true;
    076        }
    077    }
    078
    079    @Override
    080    public InputStream getInputStream() throws IOException {
    081        return Files.newInputStream(target);
    082    }
    083
    084    @Override
    085    public void writeOut(final byte[] data, final int offset, final int length) throws IOException {
    086        outputStream.write(data, offset, length);
    087    }
    088}