org.apache.giraph.utils.FileUtils.java Source code

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Here is the source code for org.apache.giraph.utils.FileUtils.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.giraph.utils;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

import com.google.common.base.Charsets;
import com.google.common.io.Closeables;
import com.google.common.io.Files;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.Writer;

/**
 * Helper class for filesystem operations during testing
 */
public class FileUtils {

    /**
     * Utility class should not be instantiatable
     */
    private FileUtils() {
    }

    /**
     * Create a temporary folder that will be removed after the test.
     *
     * @param vertexClass Used for generating the folder name.
     * @return File object for the directory.
     */
    public static File createTestDir(Class<?> vertexClass) throws IOException {
        String systemTmpDir = System.getProperty("java.io.tmpdir");
        long simpleRandomLong = (long) (Long.MAX_VALUE * Math.random());
        File testTempDir = new File(systemTmpDir, "giraph-" + vertexClass.getSimpleName() + '-' + simpleRandomLong);
        if (!testTempDir.mkdir()) {
            throw new IOException("Could not create " + testTempDir);
        }
        testTempDir.deleteOnExit();
        return testTempDir;
    }

    /**
     * Make a temporary file.
     *
     * @param parent Parent directory.
     * @param name File name.
     * @return File object to temporary file.
     * @throws IOException
     */
    public static File createTempFile(File parent, String name) throws IOException {
        return createTestTempFileOrDir(parent, name, false);
    }

    /**
     * Make a temporary directory.
     *
     * @param parent Parent directory.
     * @param name Directory name.
     * @return File object to temporary file.
     * @throws IOException
     */
    public static File createTempDir(File parent, String name) throws IOException {
        File dir = createTestTempFileOrDir(parent, name, true);
        dir.delete();
        return dir;
    }

    /**
     * Create a test temp file or directory.
     *
     * @param parent Parent directory
     * @param name Name of file
     * @param dir Is directory?
     * @return File object
     * @throws IOException
     */
    public static File createTestTempFileOrDir(File parent, String name, boolean dir) throws IOException {
        File f = new File(parent, name);
        f.deleteOnExit();
        if (dir && !f.mkdirs()) {
            throw new IOException("Could not make directory " + f);
        }
        return f;
    }

    /**
     * Write lines to a file.
     *
     * @param file File to write lines to
     * @param lines Strings written to the file
     * @throws IOException
     */
    public static void writeLines(File file, String[] lines) throws IOException {
        Writer writer = Files.newWriter(file, Charsets.UTF_8);
        try {
            for (String line : lines) {
                writer.write(line);
                writer.write('\n');
            }
        } finally {
            Closeables.closeQuietly(writer);
        }
    }

    /**
     * Recursively delete a directory
     *
     * @param dir Directory to delete
     */
    public static void delete(File dir) {
        if (dir != null) {
            new DeletingVisitor().accept(dir);
        }
    }

    /**
     * Deletes files.
     */
    private static class DeletingVisitor implements FileFilter {
        @Override
        public boolean accept(File f) {
            if (!f.isFile()) {
                f.listFiles(this);
            }
            f.delete();
            return false;
        }
    }

    /**
     * Helper method to remove a path if it exists.
     *
     * @param conf Configuration to load FileSystem from
     * @param path Path to remove
     * @throws IOException
     */
    public static void deletePath(Configuration conf, String path) throws IOException {
        deletePath(conf, new Path(path));
    }

    /**
     * Helper method to remove a path if it exists.
     *
     * @param conf Configuration to load FileSystem from
     * @param path Path to remove
     * @throws IOException
     */
    public static void deletePath(Configuration conf, Path path) throws IOException {
        FileSystem fs = FileSystem.get(conf);
        fs.delete(path, true);
    }
}