ee.ria.xroad.asyncdb.AsyncDBUtil.java Source code

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Here is the source code for ee.ria.xroad.asyncdb.AsyncDBUtil.java

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/**
 * The MIT License
 * Copyright (c) 2015 Estonian Information System Authority (RIA), Population Register Centre (VRK)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package ee.ria.xroad.asyncdb;

import java.io.File;
import java.io.FileOutputStream;
import java.io.RandomAccessFile;
import java.nio.channels.FileLock;
import java.util.concurrent.Callable;

import ee.ria.xroad.common.SystemProperties;
import ee.ria.xroad.common.identifier.ClientId;
import ee.ria.xroad.common.util.CryptoUtils;

import static org.apache.commons.lang3.StringUtils.join;

/**
 * Utility methods specific to asynchronous messages database.
 */
public final class AsyncDBUtil {
    private AsyncDBUtil() {
    }

    /**
     * Returns all the directories under current directory that are not hidden.
     * @param file - directory under which to look for subdirectories
     * @return - list of directory names
     */
    public static String[] getDirectoriesList(File file) {
        return file.list((dir, name) -> new File(dir, name).isDirectory() && !name.startsWith("."));
    }

    /**
     * Performs task under a lock which applies both to different operations and
     * different threads.
     *
     * @param task - action to be performed
     * @param lockFilePath - path to file used for process locking
     * @param lockable - object to be synchronized between threads
     * @param <T> - type of result
     * @return - object returned as a result of operation
     * @throws Exception - when locked operation fails or cannot be performed
     */
    public static <T> T performLocked(Callable<T> task, String lockFilePath, Object lockable) throws Exception {
        try (RandomAccessFile raf = new RandomAccessFile(lockFilePath, "rw");
                FileOutputStream fos = new FileOutputStream(raf.getFD())) {
            synchronized (lockable) {
                FileLock lock = fos.getChannel().lock();
                try {
                    return task.call();
                } finally {
                    lock.release();
                }
            }
        }
    }

    /**
     * Returns path to file that locks all the message queues.
     *
     * @return - absolute path to global lock file
     */
    public static String getGlobalLockFilePath() {
        return makePath(SystemProperties.getAsyncDBPath(), AsyncDB.GLOBAL_LOCK_FILE_NAME);
    }

    /**
     * Creates file path from separate parts
     *
     * @param parts - parts to create file path from
     * @return - file path created
     */
    public static String makePath(String... parts) {
        return join(parts, File.separator);
    }

    /**
     * Makes {@link java.io.File} object from path parts
     *
     * @param parts - path parts
     * @return - file consisting of path parts
     */
    public static File makeFile(String... parts) {
        return new File(makePath(parts));
    }

    /**
     * Returns queue name in hex format for specific provider.
     *
     * @param provider - provider to get queue name for
     * @return - queue name in hex format
     * @throws Exception - when queue name cannot be created
     */
    public static String getQueueName(ClientId provider) throws Exception {
        return CryptoUtils.hexDigest(CryptoUtils.MD5_ID, provider.toShortString());
    }
}