org.apache.sentry.core.common.utils.PolicyFiles.java Source code

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Here is the source code for org.apache.sentry.core.common.utils.PolicyFiles.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.sentry.core.common.utils;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;

import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.shiro.config.Ini;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Joiner;
import com.google.common.collect.Lists;
import com.google.common.io.ByteStreams;
import com.google.common.io.Resources;

public final class PolicyFiles {

    private static final Logger LOGGER = LoggerFactory.getLogger(PolicyFiles.class);
    private static final String NL = System.getProperty("line.separator", "\n");

    public static void copyToDir(File dest, String... resources) throws FileNotFoundException, IOException {
        for (String resource : resources) {
            LOGGER.debug("Copying " + resource + " to " + dest);
            try (OutputStream output = Files.newOutputStream(new File(dest, resource).toPath())) {
                Resources.copy(Resources.getResource(resource), output);
            }
        }
    }

    public static void copyToDir(FileSystem fs, Path dest, String... resources)
            throws FileNotFoundException, IOException {
        for (String resource : resources) {
            InputStream in = Resources.getResource(resource).openStream();
            FSDataOutputStream out = fs.create(new Path(dest, resource));
            long bytes = ByteStreams.copy(in, out);
            in.close();
            out.hflush();
            out.close();
            LOGGER.debug("Copying " + resource + " to " + dest + ", bytes " + bytes);
        }
    }

    public static void copyFilesToDir(FileSystem fs, Path dest, File inputFile) throws IOException {
        try (InputStream input = Files.newInputStream(inputFile.toPath());
                FSDataOutputStream out = fs.create(new Path(dest, inputFile.getName()))) {
            ByteStreams.copy(input, out);
            out.hflush();
            out.close();
        }
    }

    public static Ini loadFromPath(FileSystem fileSystem, Path path) throws IOException {
        InputStream inputStream = null;
        try {
            LOGGER.debug("Opening " + path);
            inputStream = fileSystem.open(path);
            Ini ini = new Ini();
            ini.load(inputStream);
            return ini;
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    LOGGER.warn("Error closing " + inputStream);
                }
            }
        }
    }

    /**
     * Save the specified Sentry configuration file to the desired location
     *
     * @param iniFile The Sentry configuration ini file to be saved
     * @param fileSystem The {@linkplain FileSystem} instance to be used
     * @param path The path on the {@linkplain FileSystem} where the configuration file should be stored.
     * @throws IOException in case of I/O errors
     */
    public static void writeToPath(Ini iniFile, FileSystem fileSystem, Path path) throws IOException {
        if (fileSystem.exists(path)) {
            throw new IllegalArgumentException("The specified path " + path + " already exist!");
        }

        List<String> sectionStrs = new ArrayList<>();
        for (String sectionName : PolicyFileConstants.SECTION_NAMES) {
            sectionStrs.add(toString(sectionName, iniFile.getSection(sectionName)));
        }

        String contents = Joiner.on(NL).join(sectionStrs.iterator());
        try (OutputStream out = fileSystem.create(path)) {
            ByteArrayInputStream in = new ByteArrayInputStream(contents.getBytes(StandardCharsets.UTF_8));
            IOUtils.copyBytes(in, out, fileSystem.getConf());
        }
    }

    private static String toString(String name, Ini.Section mapping) {
        if (mapping == null || mapping.isEmpty()) {
            return "";
        }
        Joiner kvJoiner = Joiner.on(" = ");
        List<String> lines = Lists.newArrayList();
        lines.add(NL);
        lines.add("[" + name + "]");
        for (String key : mapping.keySet()) {
            lines.add(kvJoiner.join(key, mapping.get(key)));
        }
        return Joiner.on(NL).join(lines);
    }

    private PolicyFiles() {
        // Make constructor private to avoid instantiation
    }
}