com.google.gerrit.common.FileUtil.java Source code

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Here is the source code for com.google.gerrit.common.FileUtil.java

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// Copyright (C) 2014 The Android Open Source Project
//
// 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 com.google.gerrit.common;

import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.storage.file.FileBasedConfig;
import org.eclipse.jgit.util.IO;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Arrays;

public class FileUtil {
    public static boolean modified(FileBasedConfig cfg) throws IOException {
        byte[] curVers;
        try {
            curVers = IO.readFully(cfg.getFile());
        } catch (FileNotFoundException notFound) {
            return true;
        }

        byte[] newVers = Constants.encode(cfg.toText());
        return !Arrays.equals(curVers, newVers);
    }

    public static void mkdir(final File path) {
        if (!path.isDirectory() && !path.mkdir()) {
            throw new Die("Cannot make directory " + path);
        }
    }

    public static void chmod(final int mode, final Path path) {
        // TODO(dborowitz): Is there a portable way to do this with NIO?
        chmod(mode, path.toFile());
    }

    public static void chmod(final int mode, final File path) {
        path.setReadable(false, false /* all */);
        path.setWritable(false, false /* all */);
        path.setExecutable(false, false /* all */);

        path.setReadable((mode & 0400) == 0400, true /* owner only */);
        path.setWritable((mode & 0200) == 0200, true /* owner only */);
        if (path.isDirectory() || (mode & 0100) == 0100) {
            path.setExecutable(true, true /* owner only */);
        }

        if ((mode & 0044) == 0044) {
            path.setReadable(true, false /* all */);
        }
        if ((mode & 0011) == 0011) {
            path.setExecutable(true, false /* all */);
        }
    }

    /**
     * Get the last modified time of a path.
     * <p>
     * Equivalent to {@code File#lastModified()}, returning 0 on errors, including
     * file not found. Callers that prefer exceptions can use {@link
     * Files#getLastModifiedTime(Path, java.nio.file.LinkOption...)}.
     *
     * @param p path.
     * @return last modified time, in milliseconds since epoch.
     */
    public static long lastModified(Path p) {
        try {
            return Files.getLastModifiedTime(p).toMillis();
        } catch (IOException e) {
            return 0;
        }
    }

    public static Path mkdirsOrDie(Path p, String errMsg) {
        try {
            Files.createDirectories(p);
            return p;
        } catch (IOException e) {
            throw new Die(errMsg + ": " + p, e);
        }
    }

    private FileUtil() {
    }
}