Examples with FileChannel java.nio.channels.FileChannel used on opensource projects

Example 11 with FileChannel

use of java.nio.channels.FileChannel in project kafka by apache.

the class Utils method readFileAsString.

/**
     * Attempt to read a file as a string
     * @throws IOException
     */
public static String readFileAsString(String path, Charset charset) throws IOException {
    if (charset == null)
        charset = Charset.defaultCharset();
    try (FileInputStream stream = new FileInputStream(new File(path))) {
        FileChannel fc = stream.getChannel();
        MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
        return charset.decode(bb).toString();
    }
}

Example 12 with FileChannel

use of java.nio.channels.FileChannel in project kafka by apache.

the class StateDirectory method lock.

/**
     * Get the lock for the {@link TaskId}s directory if it is available
     * @param taskId
     * @param retry
     * @return true if successful
     * @throws IOException
     */
boolean lock(final TaskId taskId, int retry) throws IOException {
    // we already have the lock so bail out here
    if (locks.containsKey(taskId)) {
        return true;
    }
    final File lockFile = new File(directoryForTask(taskId), LOCK_FILE_NAME);
    final FileChannel channel;
    try {
        channel = getOrCreateFileChannel(taskId, lockFile.toPath());
    } catch (NoSuchFileException e) {
        // file, in this case we will return immediately indicating locking failed.
        return false;
    }
    final FileLock lock = tryLock(retry, channel);
    if (lock != null) {
        locks.put(taskId, lock);
    }
    return lock != null;
}

Example 13 with FileChannel

use of java.nio.channels.FileChannel in project kafka by apache.

the class StateDirectoryTest method shouldUnlockGlobalStateDirectory.

@Test
public void shouldUnlockGlobalStateDirectory() throws Exception {
    final FileChannel channel = FileChannel.open(new File(directory.globalStateDir(), StateDirectory.LOCK_FILE_NAME).toPath(), StandardOpenOption.CREATE, StandardOpenOption.WRITE);
    directory.lockGlobalState(1);
    directory.unlockGlobalState();
    // should lock without any exceptions
    channel.lock();
}

Example 14 with FileChannel

use of java.nio.channels.FileChannel in project kafka by apache.

the class StateDirectoryTest method shouldReleaseTaskStateDirectoryLock.

@Test
public void shouldReleaseTaskStateDirectoryLock() throws Exception {
    final TaskId taskId = new TaskId(0, 0);
    final File taskDirectory = directory.directoryForTask(taskId);
    directory.lock(taskId, 1);
    directory.unlock(taskId);
    final FileChannel channel = FileChannel.open(new File(taskDirectory, StateDirectory.LOCK_FILE_NAME).toPath(), StandardOpenOption.CREATE, StandardOpenOption.WRITE);
    channel.tryLock();
}

Example 15 with FileChannel

use of java.nio.channels.FileChannel in project kafka by apache.

the class StateDirectoryTest method shouldLockMulitpleTaskDirectories.

@Test
public void shouldLockMulitpleTaskDirectories() throws Exception {
    final TaskId taskId = new TaskId(0, 0);
    final File task1Dir = directory.directoryForTask(taskId);
    final TaskId taskId2 = new TaskId(1, 0);
    final File task2Dir = directory.directoryForTask(taskId2);
    directory.lock(taskId, 0);
    directory.lock(taskId2, 0);
    final FileChannel channel1 = FileChannel.open(new File(task1Dir, StateDirectory.LOCK_FILE_NAME).toPath(), StandardOpenOption.CREATE, StandardOpenOption.WRITE);
    final FileChannel channel2 = FileChannel.open(new File(task2Dir, StateDirectory.LOCK_FILE_NAME).toPath(), StandardOpenOption.CREATE, StandardOpenOption.WRITE);
    try {
        channel1.tryLock();
        channel2.tryLock();
        fail("shouldn't be able to lock already locked directory");
    } catch (OverlappingFileLockException e) {
    // pass
    }
}