cc.recommenders.io.ZipFolder.java Source code

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Here is the source code for cc.recommenders.io.ZipFolder.java

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/**
 * Copyright 2016 Technische Universitt Darmstadt
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package cc.recommenders.io;

import java.io.File;
import java.io.IOException;
import java.nio.file.Paths;
import java.util.List;
import java.util.Set;

import javax.annotation.Nonnull;

import org.apache.commons.io.FileUtils;

import com.google.common.collect.Lists;

import cc.recommenders.assertions.Asserts;

public class ZipFolder {

    public static final String MARKER_FILE_NAME = ".zipfolder";

    private final String _root;
    private final String _metaData;

    private int _fileCounter;

    public ZipFolder(@Nonnull String root) {
        this(root, "");
    }

    public ZipFolder(@Nonnull String root, @Nonnull String metaData) {
        File f = new File(root);
        Asserts.assertTrue(f.exists() && f.isDirectory());
        _root = root;
        _metaData = metaData;
    }

    public WritingArchive createNewArchive() {
        createMarker();
        File fileName = createNextUnusedFileName();
        return new WritingArchive(fileName);
    }

    private void createMarker() {
        File markerName = new File(_root, MARKER_FILE_NAME);
        if (!markerName.exists()) {
            try {
                FileUtils.writeStringToFile(markerName, _metaData);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    }

    private File createNextUnusedFileName() {
        File fileName = CreateNextFileName();
        while (fileName.exists()) {
            fileName = CreateNextFileName();
        }
        return fileName;
    }

    private File CreateNextFileName() {
        return new File(_root, String.format("%d.zip", _fileCounter++));
    }

    public int getNumArchives() {
        return findFiles().size();
    }

    private Set<String> findFiles() {
        return new Directory(_root).findFiles(f -> f.endsWith(".zip"));
    }

    public List<ReadingArchive> openAll() {
        List<ReadingArchive> archives = Lists.newLinkedList();
        for (String zip : findFiles()) {
            archives.add(open(zip));
        }
        return archives;
    }

    public ReadingArchive open(String relPath) {
        File f = Paths.get(_root, relPath).toFile();
        return new ReadingArchive(f);
    }
}