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 InputStream getInputStream() throws IOException {
064        return Files.newInputStream(target);
065    }
066
067    @Override
068    public void closeForWriting() throws IOException {
069        if (!closed) {
070            outputStream.close();
071            closed = true;
072        }
073    }
074
075    @Override
076    public void writeOut(final byte[] data, final int offset, final int length) throws IOException {
077        outputStream.write(data, offset, length);
078    }
079
080    @Override
081    public void close() throws IOException {
082        try {
083            closeForWriting();
084        } finally {
085            Files.deleteIfExists(target);
086        }
087    }
088}