Java Code Examples for org.apache.cassandra.io.util.SequentialWriter#write()

@Test
public void testGetFilePointer() throws IOException {
    final SequentialWriter w = createTempFile("brafGetFilePointer");

    assertEquals(w.getFilePointer(), 0); // initial position should be 0

    w.write(generateByteArray(20));
    assertEquals(w.getFilePointer(), 20); // position 20 after writing 20 bytes

    w.sync();

    RandomAccessReader r = RandomAccessReader.open(w, fs);

    // position should change after skip bytes
    r.seek(0);
    r.skipBytes(15);
    assertEquals(r.getFilePointer(), 15);

    r.read();
    assertEquals(r.getFilePointer(), 16);
    r.read(new byte[4]);
    assertEquals(r.getFilePointer(), 20);

    w.close();
    r.close();
}
 

@Test
public void testBytesRemaining() throws IOException {
    SequentialWriter w = createTempFile("brafBytesRemaining");

    int toWrite = RandomAccessReader.DEFAULT_BUFFER_SIZE + 10;

    w.write(generateByteArray(toWrite));

    w.sync();

    RandomAccessReader r = RandomAccessReader.open(w, fs);

    assertEquals(r.bytesRemaining(), toWrite);

    for (int i = 1; i <= r.length(); i++) {
        r.read();
        assertEquals(r.bytesRemaining(), r.length() - i);
    }

    r.seek(0);
    r.skipBytes(10);
    assertEquals(r.bytesRemaining(), r.length() - 10);

    w.close();
    r.close();
}
 

@Test
public void testLength() throws IOException {
    File tmpFile = File.createTempFile("lengthtest", "bin");
    SequentialWriter w = SequentialWriter.open(tmpFile);
    assertEquals(0, w.length());

    // write a chunk smaller then our buffer, so will not be flushed
    // to disk
    byte[] lessThenBuffer = generateByteArray(RandomAccessReader.DEFAULT_BUFFER_SIZE / 2);
    w.write(lessThenBuffer);
    assertEquals(lessThenBuffer.length, w.length());

    // sync the data and check length
    w.sync();
    assertEquals(lessThenBuffer.length, w.length());

    // write more then the buffer can hold and check length
    byte[] biggerThenBuffer = generateByteArray(RandomAccessReader.DEFAULT_BUFFER_SIZE * 2);
    w.write(biggerThenBuffer);
    assertEquals(biggerThenBuffer.length + lessThenBuffer.length, w.length());

    w.close();

    // will use cachedlength
    RandomAccessReader r = RandomAccessReader.open(new Path(tmpFile.getPath()), fs);
    assertEquals(lessThenBuffer.length + biggerThenBuffer.length, r.length());
    r.close();
}
 

@Test
public void testSeek() throws Exception {
    SequentialWriter w = createTempFile("brafSeek");
    byte[] data = generateByteArray(RandomAccessReader.DEFAULT_BUFFER_SIZE + 20);
    w.write(data);
    w.close();

    final RandomAccessReader file = RandomAccessReader.open(w, fs);

    file.seek(0);
    assertEquals(file.getFilePointer(), 0);
    assertEquals(file.bytesRemaining(), file.length());

    file.seek(20);
    assertEquals(file.getFilePointer(), 20);
    assertEquals(file.bytesRemaining(), file.length() - 20);

    // trying to seek past the end of the file should produce EOFException
    expectException(new Callable<Object>() {
        public Object call() {
            file.seek(file.length() + 30);
            return null;
        }
    }, IllegalArgumentException.class);

    expectException(new Callable<Object>() {
        public Object call() throws IOException {
            file.seek(-1);
            return null;
        }
    }, IllegalArgumentException.class); // throws IllegalArgumentException

    file.close();
}
 

@Test
public void testClose() throws IOException {
    final SequentialWriter w = createTempFile("brafClose");

    byte[] data = generateByteArray(RandomAccessReader.DEFAULT_BUFFER_SIZE + 20);

    w.write(data);
    w.close(); // will flush

    final RandomAccessReader r = RandomAccessReader.open(new Path(new File(w.getPath()).getPath()), fs);

    r.close(); // closing to test read after close

    expectException(new Callable<Object>() {
        public Object call() {
            return r.read();
        }
    }, AssertionError.class);

    expectException(new Callable<Object>() {
        public Object call() throws IOException {
            w.write(generateByteArray(1));
            return null;
        }
    }, ClosedChannelException.class);

    RandomAccessReader copy = RandomAccessReader.open(new Path(new File(r.getPath()).getPath()), fs);
    ByteBuffer contents = copy.readBytes((int) copy.length());

    assertEquals(contents.limit(), data.length);
    assertEquals(ByteBufferUtil.compare(contents, data), 0);
}
 

@Test
public void testMarkAndReset() throws IOException {
    SequentialWriter w = createTempFile("brafTestMark");
    w.write(new byte[30]);

    w.close();

    RandomAccessReader file = RandomAccessReader.open(w, fs);

    file.seek(10);
    FileMark mark = file.mark();

    file.seek(file.length());
    assertTrue(file.isEOF());

    file.reset();
    assertEquals(file.bytesRemaining(), 20);

    file.seek(file.length());
    assertTrue(file.isEOF());

    file.reset(mark);
    assertEquals(file.bytesRemaining(), 20);

    file.seek(file.length());
    assertEquals(file.bytesPastMark(), 20);
    assertEquals(file.bytesPastMark(mark), 20);

    file.reset(mark);
    assertEquals(file.bytesPastMark(), 0);

    file.close();
}
 

@Test(expected = AssertionError.class)
public void testAssertionErrorWhenBytesPastMarkIsNegative() throws IOException {
    SequentialWriter w = createTempFile("brafAssertionErrorWhenBytesPastMarkIsNegative");
    w.write(new byte[30]);
    w.close();

    RandomAccessReader r = RandomAccessReader.open(w, fs);
    r.seek(10);
    r.mark();

    r.seek(0);
    r.bytesPastMark();
}
 

@Test
public void testReadOnly() throws IOException {
    SequentialWriter file = createTempFile("brafReadOnlyTest");

    byte[] data = new byte[20];
    for (int i = 0; i < data.length; i++)
        data[i] = 'c';

    file.write(data);
    file.sync(); // flushing file to the disk

    // read-only copy of the file, with fixed file length
    final RandomAccessReader copy = RandomAccessReader.open(new Path(file.getPath()), fs);

    copy.seek(copy.length());
    assertTrue(copy.bytesRemaining() == 0 && copy.isEOF());

    // can't seek past the end of the file for read-only files
    expectException(new Callable<Object>() {
        public Object call() {
            copy.seek(copy.length() + 1);
            return null;
        }
    }, IllegalArgumentException.class);

    // Any write() call should fail
    expectException(new Callable<Object>() {
        public Object call() throws IOException {
            copy.write(1);
            return null;
        }
    }, UnsupportedOperationException.class);

    expectException(new Callable<Object>() {
        public Object call() throws IOException {
            copy.write(new byte[1]);
            return null;
        }
    }, UnsupportedOperationException.class);

    expectException(new Callable<Object>() {
        public Object call() throws IOException {
            copy.write(new byte[3], 0, 2);
            return null;
        }
    }, UnsupportedOperationException.class);

    copy.seek(0);
    copy.skipBytes(5);

    assertEquals(copy.bytesRemaining(), 15);
    assertEquals(copy.getFilePointer(), 5);
    assertTrue(!copy.isEOF());

    copy.seek(0);
    ByteBuffer contents = copy.readBytes((int) copy.length());

    assertEquals(contents.limit(), copy.length());
    assertTrue(ByteBufferUtil.compare(contents, data) == 0);

    copy.seek(0);

    int count = 0;
    while (!copy.isEOF()) {
        assertEquals((byte) copy.read(), 'c');
        count++;
    }

    assertEquals(count, copy.length());

    copy.seek(0);
    byte[] content = new byte[10];
    copy.read(content);

    assertEquals(new String(content), "cccccccccc");

    file.close();
    copy.close();
}