    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.File;
    020import java.io.FileNotFoundException;
    021import java.io.IOException;
    022import java.io.InputStream;
    023import java.io.OutputStream;
    024import java.io.UncheckedIOException;
    025import java.nio.file.Files;
    026import java.nio.file.Path;
    027
    028/**
    029 * ScatterGatherBackingStore that is backed by a path.
    030 *
    031 * @since 1.10
    032 */
    033public class FileBasedScatterGatherBackingStore implements ScatterGatherBackingStore {
    034    private final Path target;
    035    private final OutputStream outputStream;
    036    private boolean closed;
    037
    038    public FileBasedScatterGatherBackingStore(final File target) throws FileNotFoundException {
    039        this(target.toPath());
    040    }
    041
    042    /**
    043     * Constructs a new instance for the given path.
    044     *
    045     * @param target The path to offload compressed data into.
    046     * @throws FileNotFoundException if the file doesn't exist
    047     * @since 1.22
    048     */
    049    public FileBasedScatterGatherBackingStore(final Path target) throws FileNotFoundException {
    050        this.target = target;
    051        try {
    052            outputStream = Files.newOutputStream(target);
    053        } catch (final FileNotFoundException ex) {
    054            throw ex;
    055        } catch (final IOException ex) {
    056            // must convert exception to stay backwards compatible with Compress 1.10 to 1.13
    057            throw new UncheckedIOException(ex); // NOSONAR
    058        }
    059    }
    060
    061    @Override
    062    public void close() throws IOException {
    063        try {
    064            closeForWriting();
    065        } finally {
    066            Files.deleteIfExists(target);
    067        }
    068    }
    069
    070    @Override
    071    public void closeForWriting() throws IOException {
    072        if (!closed) {
    073            outputStream.close();
    074            closed = true;
    075        }
    076    }
    077
    078    @Override
    079    public InputStream getInputStream() throws IOException {
    080        return Files.newInputStream(target);
    081    }
    082
    083    @Override
    084    public void writeOut(final byte[] data, final int offset, final int length) throws IOException {
    085        outputStream.write(data, offset, length);
    086    }
    087}