Java Code Examples for org.apache.flink.runtime.io.disk.iomanager.BlockChannelReader#deleteChannel()

@Test
public void testWriteReadNotAll() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);
		
		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();
		
		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();
		
		// read and re-generate all records and compare them
		Pair readPair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT / 2; i++) {
			generator.next(pair);
			readPair.read(inView);
			assertEquals("The re-generated and the read record do not match.", pair, readPair);
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testReadTooMany() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);

		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();

		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();

		// read and re-generate all records and compare them
		try {
			Pair readPair = new Pair();
			for (int i = 0; i < NUM_PAIRS_SHORT + 1; i++) {
				generator.next(pair);
				readPair.read(inView);
				assertEquals("The re-generated and the read record do not match.", pair, readPair);
			}
			fail("Expected an EOFException which did not occur.");
		}
		catch (EOFException eofex) {
			// expected
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testWriteAndReadLongRecords() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_LONG_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);
		
		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_LONG; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();
		
		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();
		
		// read and re-generate all records and compare them
		Pair readPair = new Pair();
		for (int i = 0; i < NUM_PAIRS_LONG; i++) {
			generator.next(pair);
			readPair.read(inView);
			assertEquals("The re-generated and the read record do not match.", pair, readPair);
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testWriteReadSmallRecords() {
	try {
		List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);
		
		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();
		
		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();
		
		// read and re-generate all records and compare them
		Pair readPair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			readPair.read(inView);
			assertEquals("The re-generated and the read record do not match.", pair, readPair);
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testWriteReadNotAll() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);
	
	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());
	
	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, outView.getBlockCount(), true);
	generator.reset();
	
	// read and re-generate all records and compare them
	final Tuple2<Integer, String> readRec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT / 2; i++) {
		generator.next(rec);
		serializer.deserialize(readRec, inView);
		
		int k1 = rec.f0;
		String v1 = rec.f1;
		
		int k2 = readRec.f0;
		String v2 = readRec.f1;
		
		Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}
 

@Test
public void testWriteAndReadLongRecords() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_LONG_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);
	
	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_LONG; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());
	
	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, outView.getBlockCount(), true);
	generator.reset();
	
	// read and re-generate all records and compare them
	final Tuple2<Integer, String> readRec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_LONG; i++) {
		generator.next(rec);
		serializer.deserialize(readRec, inView);
		final int k1 = rec.f0;
		final String v1 = rec.f1;
		final int k2 = readRec.f0;
		final String v2 = readRec.f1;
		Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}
 

@Test
public void testWriteReadNotAll() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);
		
		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();
		
		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();
		
		// read and re-generate all records and compare them
		Pair readPair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT / 2; i++) {
			generator.next(pair);
			readPair.read(inView);
			assertEquals("The re-generated and the read record do not match.", pair, readPair);
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testReadTooMany() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);

	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());

	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, outView.getBlockCount(), true);
	generator.reset();

	// read and re-generate all records and compare them
	try {
		final Tuple2<Integer, String> readRec = new Tuple2<>();
		for (int i = 0; i < NUM_PAIRS_SHORT + 1; i++) {
			generator.next(rec);
			serializer.deserialize(readRec, inView);
			final int k1 = rec.f0;
			final String v1 = rec.f1;
			final int k2 = readRec.f0;
			final String v2 = readRec.f1;
			Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
		}
		Assert.fail("Expected an EOFException which did not occur.");
	}
	catch (EOFException eofex) {
		// expected
	}
	catch (Throwable t) {
		// unexpected
		Assert.fail("Unexpected Exception: " + t.getMessage());
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}
 

@Test
public void testWriteAndReadLongRecords() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_LONG_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);
	
	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_LONG; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());
	
	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, outView.getBlockCount(), true);
	generator.reset();
	
	// read and re-generate all records and compare them
	final Tuple2<Integer, String> readRec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_LONG; i++) {
		generator.next(rec);
		serializer.deserialize(readRec, inView);
		final int k1 = rec.f0;
		final String v1 = rec.f1;
		final int k2 = readRec.f0;
		final String v2 = readRec.f1;
		Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}
 

@Test
public void testWriteReadNotAll() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);
		
		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();
		
		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();
		
		// read and re-generate all records and compare them
		Pair readPair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT / 2; i++) {
			generator.next(pair);
			readPair.read(inView);
			assertEquals("The re-generated and the read record do not match.", pair, readPair);
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testWriteReadOneBufferOnly() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), 1);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);
		
		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();
		
		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), 1);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();
		
		// read and re-generate all records and compare them
		Pair readPair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			readPair.read(inView);
			assertEquals("The re-generated and the read record do not match.", pair, readPair);
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testWriteReadOneBufferOnly() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), 1);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);
		
		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();
		
		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), 1);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();
		
		// read and re-generate all records and compare them
		Pair readPair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			readPair.read(inView);
			assertEquals("The re-generated and the read record do not match.", pair, readPair);
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testReadTooMany() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);

		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();

		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();

		// read and re-generate all records and compare them
		try {
			Pair readPair = new Pair();
			for (int i = 0; i < NUM_PAIRS_SHORT + 1; i++) {
				generator.next(pair);
				readPair.read(inView);
				assertEquals("The re-generated and the read record do not match.", pair, readPair);
			}
			fail("Expected an EOFException which did not occur.");
		}
		catch (EOFException eofex) {
			// expected
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testWriteReadOneBufferOnly() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, 1);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);
	
	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());
	
	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, 1);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, outView.getBlockCount(), true);
	generator.reset();
	
	// read and re-generate all records and compare them
	final Tuple2<Integer, String> readRec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.deserialize(readRec, inView);
		
		int k1 = rec.f0;
		String v1 = rec.f1;
		
		int k2 = readRec.f0;
		String v2 = readRec.f1;
		
		Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}
 

@Test
public void testWriteReadSmallRecords() {
	try {
		List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);
		
		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();
		
		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();
		
		// read and re-generate all records and compare them
		Pair readPair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			readPair.read(inView);
			assertEquals("The re-generated and the read record do not match.", pair, readPair);
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testWriteReadSmallRecords() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);
	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());
	
	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, outView.getBlockCount(), true);
	generator.reset();
	
	// read and re-generate all records and compare them
	final Tuple2<Integer, String> readRec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.deserialize(readRec, inView);
		
		int k1 = rec.f0;
		String v1 = rec.f1;
		
		int k2 = readRec.f0;
		String v2 = readRec.f1;
		
		Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}
 

@Test
public void testWriteReadOneBufferOnly() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, 1);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);
	
	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());
	
	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, 1);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, outView.getBlockCount(), true);
	generator.reset();
	
	// read and re-generate all records and compare them
	final Tuple2<Integer, String> readRec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.deserialize(readRec, inView);
		
		int k1 = rec.f0;
		String v1 = rec.f1;
		
		int k2 = readRec.f0;
		String v2 = readRec.f1;
		
		Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}
 

@Test
public void testReadTooMany() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);

	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());

	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, outView.getBlockCount(), true);
	generator.reset();

	// read and re-generate all records and compare them
	try {
		final Tuple2<Integer, String> readRec = new Tuple2<>();
		for (int i = 0; i < NUM_PAIRS_SHORT + 1; i++) {
			generator.next(rec);
			serializer.deserialize(readRec, inView);
			final int k1 = rec.f0;
			final String v1 = rec.f1;
			final int k2 = readRec.f0;
			final String v2 = readRec.f1;
			Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
		}
		Assert.fail("Expected an EOFException which did not occur.");
	}
	catch (EOFException eofex) {
		// expected
	}
	catch (Throwable t) {
		// unexpected
		Assert.fail("Unexpected Exception: " + t.getMessage());
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}
 

@Test
public void testReadTooMany() {
	try {
		final List<MemorySegment> memory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final PairGenerator generator = new PairGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		final FileIOChannel.ID channel = this.ioManager.createChannel();
		
		// create the writer output view
		final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
		final FileChannelOutputView outView = new FileChannelOutputView(writer, memManager, memory, MEMORY_PAGE_SIZE);

		// write a number of pairs
		Pair pair = new Pair();
		for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
			generator.next(pair);
			pair.write(outView);
		}
		outView.close();

		// create the reader input view
		List<MemorySegment> readMemory = memManager.allocatePages(new DummyInvokable(), NUM_MEMORY_SEGMENTS);
		
		final BlockChannelReader<MemorySegment> reader = ioManager.createBlockChannelReader(channel);
		final FileChannelInputView inView = new FileChannelInputView(reader, memManager, readMemory, outView.getBytesInLatestSegment());
		generator.reset();

		// read and re-generate all records and compare them
		try {
			Pair readPair = new Pair();
			for (int i = 0; i < NUM_PAIRS_SHORT + 1; i++) {
				generator.next(pair);
				readPair.read(inView);
				assertEquals("The re-generated and the read record do not match.", pair, readPair);
			}
			fail("Expected an EOFException which did not occur.");
		}
		catch (EOFException eofex) {
			// expected
		}
		
		inView.close();
		reader.deleteChannel();
	}
	catch (Exception e) {
		e.printStackTrace();
		fail(e.getMessage());
	}
}
 

@Test
public void testReadWithoutKnownBlockCount() throws Exception
{
	final TestData.TupleGenerator generator = new TestData.TupleGenerator(SEED, KEY_MAX, VALUE_SHORT_LENGTH, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
	final FileIOChannel.ID channel = this.ioManager.createChannel();
	final TypeSerializer<Tuple2<Integer, String>> serializer = TestData.getIntStringTupleSerializer();
	
	// create the writer output view
	List<MemorySegment> memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelWriter<MemorySegment> writer = this.ioManager.createBlockChannelWriter(channel);
	final ChannelWriterOutputView outView = new ChannelWriterOutputView(writer, memory, MEMORY_PAGE_SIZE);
	
	// write a number of pairs
	final Tuple2<Integer, String> rec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.serialize(rec, outView);
	}
	this.memoryManager.release(outView.close());
	
	// create the reader input view
	memory = this.memoryManager.allocatePages(this.parentTask, NUM_MEMORY_SEGMENTS);
	final BlockChannelReader<MemorySegment> reader = this.ioManager.createBlockChannelReader(channel);
	final ChannelReaderInputView inView = new ChannelReaderInputView(reader, memory, true);
	generator.reset();
	
	// read and re-generate all records and compare them
	final Tuple2<Integer, String> readRec = new Tuple2<>();
	for (int i = 0; i < NUM_PAIRS_SHORT; i++) {
		generator.next(rec);
		serializer.deserialize(readRec, inView);
		
		int k1 = rec.f0;
		String v1 = rec.f1;
		
		int k2 = readRec.f0;
		String v2 = readRec.f1;
		
		Assert.assertTrue("The re-generated and the read record do not match.", k1 == k2 && v1.equals(v2));
	}
	
	this.memoryManager.release(inView.close());
	reader.deleteChannel();
}