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

Example 41 with FileChannel

use of java.nio.channels.FileChannel in project j2objc by google.

the class FileChannelTest method useFileChannel.

private void useFileChannel() throws IOException {
    File file = File.createTempFile("j2objc", "tmp");
    ChannelGetter channelGetter = new ChannelGetter();
    channelGetter.createChannel(file);
    // The FileOutputStream used to create the channel is released at this point.
    FileChannel channel = channelGetter.get();
    FileLock lock = channel.lock();
    lock.close();
    channel.close();
    assertTrue(file.delete());
}

Example 42 with FileChannel

use of java.nio.channels.FileChannel in project jimfs by google.

the class JimfsUnixLikeFileSystemTest method testRegularFileAccessAndModifiedTimeUpdates.

@Test
public void testRegularFileAccessAndModifiedTimeUpdates() throws IOException {
    Path foo = path("foo");
    Files.createFile(foo);
    FileTimeTester tester = new FileTimeTester(foo);
    tester.assertAccessTimeDidNotChange();
    tester.assertModifiedTimeDidNotChange();
    Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
    try (FileChannel channel = FileChannel.open(foo, READ)) {
        // opening READ channel does not change times
        tester.assertAccessTimeDidNotChange();
        tester.assertModifiedTimeDidNotChange();
        Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
        channel.read(ByteBuffer.allocate(100));
        // read call on channel does
        tester.assertAccessTimeChanged();
        tester.assertModifiedTimeDidNotChange();
        Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
        channel.read(ByteBuffer.allocate(100));
        tester.assertAccessTimeChanged();
        tester.assertModifiedTimeDidNotChange();
        Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
        try {
            channel.write(ByteBuffer.wrap(new byte[] { 0, 1, 2, 3 }));
        } catch (NonWritableChannelException ignore) {
        }
        // failed write on non-readable channel does not change times
        tester.assertAccessTimeDidNotChange();
        tester.assertModifiedTimeDidNotChange();
        Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
    }
    // closing channel does not change times
    tester.assertAccessTimeDidNotChange();
    tester.assertModifiedTimeDidNotChange();
    Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
    try (FileChannel channel = FileChannel.open(foo, WRITE)) {
        // opening WRITE channel does not change times
        tester.assertAccessTimeDidNotChange();
        tester.assertModifiedTimeDidNotChange();
        Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
        channel.write(ByteBuffer.wrap(new byte[] { 0, 1, 2, 3 }));
        // write call on channel does
        tester.assertAccessTimeDidNotChange();
        tester.assertModifiedTimeChanged();
        Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
        channel.write(ByteBuffer.wrap(new byte[] { 4, 5, 6, 7 }));
        tester.assertAccessTimeDidNotChange();
        tester.assertModifiedTimeChanged();
        Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
        try {
            channel.read(ByteBuffer.allocate(100));
        } catch (NonReadableChannelException ignore) {
        }
        // failed read on non-readable channel does not change times
        tester.assertAccessTimeDidNotChange();
        tester.assertModifiedTimeDidNotChange();
        Uninterruptibles.sleepUninterruptibly(1, MILLISECONDS);
    }
    // closing channel does not change times
    tester.assertAccessTimeDidNotChange();
    tester.assertModifiedTimeDidNotChange();
}

Example 43 with FileChannel

use of java.nio.channels.FileChannel in project jimfs by google.

the class JimfsUnixLikeFileSystemTest method testChannels.

@Test
public void testChannels() throws IOException {
    try (FileChannel channel = FileChannel.open(path("/test.txt"), CREATE_NEW, WRITE)) {
        ByteBuffer buf1 = UTF_8.encode("hello");
        ByteBuffer buf2 = UTF_8.encode(" world");
        while (buf1.hasRemaining() || buf2.hasRemaining()) {
            channel.write(new ByteBuffer[] { buf1, buf2 });
        }
        assertEquals(11, channel.position());
        assertEquals(11, channel.size());
        channel.write(UTF_8.encode("!"));
        assertEquals(12, channel.position());
        assertEquals(12, channel.size());
    }
    try (SeekableByteChannel channel = Files.newByteChannel(path("/test.txt"), READ)) {
        assertEquals(0, channel.position());
        assertEquals(12, channel.size());
        ByteBuffer buffer = ByteBuffer.allocate(100);
        while (channel.read(buffer) != -1) {
        }
        buffer.flip();
        assertEquals("hello world!", UTF_8.decode(buffer).toString());
    }
    byte[] bytes = preFilledBytes(100);
    Files.write(path("/test"), bytes);
    try (SeekableByteChannel channel = Files.newByteChannel(path("/test"), READ, WRITE)) {
        ByteBuffer buffer = ByteBuffer.wrap(preFilledBytes(50));
        channel.position(50);
        channel.write(buffer);
        buffer.flip();
        channel.write(buffer);
        channel.position(0);
        ByteBuffer readBuffer = ByteBuffer.allocate(150);
        while (readBuffer.hasRemaining()) {
            channel.read(readBuffer);
        }
        byte[] expected = Bytes.concat(preFilledBytes(50), preFilledBytes(50), preFilledBytes(50));
        assertArrayEquals(expected, readBuffer.array());
    }
    try (FileChannel channel = FileChannel.open(path("/test"), READ, WRITE)) {
        assertEquals(150, channel.size());
        channel.truncate(10);
        assertEquals(10, channel.size());
        ByteBuffer buffer = ByteBuffer.allocate(20);
        assertEquals(10, channel.read(buffer));
        buffer.flip();
        byte[] expected = new byte[20];
        System.arraycopy(preFilledBytes(10), 0, expected, 0, 10);
        assertArrayEquals(expected, buffer.array());
    }
}

Example 44 with FileChannel

use of java.nio.channels.FileChannel in project jimfs by google.

the class JimfsUnixLikeFileSystemTest method testOpenFile_withReadAndTruncateExisting_doesNotTruncateFile.

@Test
public void testOpenFile_withReadAndTruncateExisting_doesNotTruncateFile() throws IOException {
    byte[] bytes = bytes(1, 2, 3, 4);
    Files.write(path("/test"), bytes);
    try (FileChannel channel = FileChannel.open(path("/test"), READ, TRUNCATE_EXISTING)) {
        // TRUNCATE_EXISTING ignored when opening for read
        byte[] readBytes = new byte[4];
        channel.read(ByteBuffer.wrap(readBytes));
        assertThat(Bytes.asList(readBytes)).isEqualTo(Bytes.asList(bytes));
    }
}

Example 45 with FileChannel

use of java.nio.channels.FileChannel in project jimfs by google.

the class JimfsFileChannelTest method testAsynchronousClose.

@Test
public void testAsynchronousClose() throws Exception {
    RegularFile file = regularFile(10);
    final FileChannel channel = channel(file, READ, WRITE);
    // ensure all operations on the channel will block
    file.writeLock().lock();
    ExecutorService executor = Executors.newCachedThreadPool();
    CountDownLatch latch = new CountDownLatch(BLOCKING_OP_COUNT);
    List<Future<?>> futures = queueAllBlockingOperations(channel, executor, latch);
    // wait for all the threads to have started running
    latch.await();
    // then ensure time for operations to start blocking
    Uninterruptibles.sleepUninterruptibly(20, MILLISECONDS);
    // close channel on this thread
    channel.close();
    // AsynchronousCloseException
    for (Future<?> future : futures) {
        try {
            future.get();
            fail();
        } catch (ExecutionException expected) {
            assertThat(expected.getCause()).named("blocking thread exception").isInstanceOf(AsynchronousCloseException.class);
        }
    }
}