org.apache.flink.runtime.operators.testutils.TestData.TupleGenerator Java Examples

private Map<Integer, Collection<String>> collectData(TupleGenerator iter, int num)
throws Exception
{
	Map<Integer, Collection<String>> map = new HashMap<>();
	Tuple2<Integer, String> pair = new Tuple2<>();
	
	for (int i = 0; i < num; i++) {
		iter.next(pair);
		int key = pair.f0;
		
		if (!map.containsKey(key)) {
			map.put(key, new ArrayList<String>());
		}

		Collection<String> values = map.get(key);
		values.add(pair.f1);
	}
	return map;
}
 

/**
 * This test case verifies that hybrid hash join is able to handle multiple probe phases
 * when the build side fits completely into memory.
 */
@Test
public void testDoubleProbeInMemory() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 0, 28, KeyMode.SORTED, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 28, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);

		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

/**
 * Test behavior with overflow buckets (Overflow buckets must be initialized correctly
 * if the input is reopened again)
 */
@Test
public void testOverflow() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 200, 1024, KeyMode.RANDOM, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);
		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

/**
 * Verify proper operation if the build side is spilled to disk.
 */
@Test
public void testDoubleProbeSpilling() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);
		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

private Map<Integer, Collection<String>> collectData(TupleGenerator iter, int num)
throws Exception
{
	Map<Integer, Collection<String>> map = new HashMap<>();
	Tuple2<Integer, String> pair = new Tuple2<>();
	
	for (int i = 0; i < num; i++) {
		iter.next(pair);
		Integer key = pair.f0;
		
		if (!map.containsKey(key)) {
			map.put(key, new ArrayList<String>());
		}

		Collection<String> values = map.get(key);
		values.add(pair.f1);
	}
	return map;
}
 

private Map<Integer, Collection<String>> collectData(TupleGenerator iter, int num)
throws Exception
{
	Map<Integer, Collection<String>> map = new HashMap<>();
	Tuple2<Integer, String> pair = new Tuple2<>();
	
	for (int i = 0; i < num; i++) {
		iter.next(pair);
		int key = pair.f0;
		
		if (!map.containsKey(key)) {
			map.put(key, new ArrayList<String>());
		}

		Collection<String> values = map.get(key);
		values.add(pair.f1);
	}
	return map;
}
 

/**
 * Test behavior with overflow buckets (Overflow buckets must be initialized correctly
 * if the input is reopened again)
 */
@Test
public void testOverflow() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 200, 1024, KeyMode.RANDOM, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);
		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

/**
 * Verify proper operation if the build side is spilled to disk.
 */
@Test
public void testDoubleProbeSpilling() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);
		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

/**
 * This test case verifies that hybrid hash join is able to handle multiple probe phases
 * when the build side fits completely into memory.
 */
@Test
public void testDoubleProbeInMemory() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 0, 28, KeyMode.SORTED, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 28, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);

		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

private Map<Integer, Collection<String>> collectData(TupleGenerator iter, int num)
throws Exception
{
	Map<Integer, Collection<String>> map = new HashMap<>();
	Tuple2<Integer, String> pair = new Tuple2<>();
	
	for (int i = 0; i < num; i++) {
		iter.next(pair);
		Integer key = pair.f0;
		
		if (!map.containsKey(key)) {
			map.put(key, new ArrayList<String>());
		}

		Collection<String> values = map.get(key);
		values.add(pair.f1);
	}
	return map;
}
 

private Map<Integer, Collection<String>> collectData(TupleGenerator iter, int num)
throws Exception
{
	Map<Integer, Collection<String>> map = new HashMap<>();
	Tuple2<Integer, String> pair = new Tuple2<>();
	
	for (int i = 0; i < num; i++) {
		iter.next(pair);
		int key = pair.f0;
		
		if (!map.containsKey(key)) {
			map.put(key, new ArrayList<String>());
		}

		Collection<String> values = map.get(key);
		values.add(pair.f1);
	}
	return map;
}
 

/**
 * Test behavior with overflow buckets (Overflow buckets must be initialized correctly
 * if the input is reopened again)
 */
@Test
public void testOverflow() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 200, 1024, KeyMode.RANDOM, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);
		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

/**
 * Verify proper operation if the build side is spilled to disk.
 */
@Test
public void testDoubleProbeSpilling() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 1024, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);
		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

/**
 * This test case verifies that hybrid hash join is able to handle multiple probe phases
 * when the build side fits completely into memory.
 */
@Test
public void testDoubleProbeInMemory() {

	int buildSize = 1000;
	int probeSize = 1000;
	try {
		TupleGenerator bgen = new TupleGenerator(SEED1, 0, 28, KeyMode.SORTED, ValueMode.FIX_LENGTH);
		TupleGenerator pgen = new TupleGenerator(SEED2, 0, 28, KeyMode.SORTED, ValueMode.FIX_LENGTH);

		final TupleGeneratorIterator buildInput = new TupleGeneratorIterator(bgen, buildSize);
		final TupleGeneratorIterator probeInput = new TupleGeneratorIterator(pgen, probeSize);

		doTest(buildInput,probeInput, bgen, pgen);
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

private Map<Integer, Collection<String>> collectData(TupleGenerator iter, int num)
throws Exception
{
	Map<Integer, Collection<String>> map = new HashMap<>();
	Tuple2<Integer, String> pair = new Tuple2<>();
	
	for (int i = 0; i < num; i++) {
		iter.next(pair);
		Integer key = pair.f0;
		
		if (!map.containsKey(key)) {
			map.put(key, new ArrayList<String>());
		}

		Collection<String> values = map.get(key);
		values.add(pair.f1);
	}
	return map;
}
 

@Test
public void test() throws Exception {
	final TupleGenerator generator1 =
			new TupleGenerator(SEED1, 500, 4096, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);
	final TupleGenerator generator2 =
			new TupleGenerator(SEED2, 500, 2048, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);

	final TestData.TupleGeneratorIterator input1 = new TestData.TupleGeneratorIterator(generator1, INPUT_FIRST_SIZE);
	final TestData.TupleGeneratorIterator input2 = new TestData.TupleGeneratorIterator(generator2, INPUT_SECOND_SIZE);

	// collect expected data
	final Map<Integer, Collection<Match>> expectedMatchesMap = matchValues(
			collectData(input1), collectData(input2));

	// reset the generators
	generator1.reset();
	generator2.reset();
	input1.reset();
	input2.reset();

	StreamOperator operator = getOperator();

	match(expectedMatchesMap, transformToBinary(join(operator, input1, input2)));

	// assert that each expected match was seen
	for (Map.Entry<Integer, Collection<Match>> entry : expectedMatchesMap.entrySet()) {
		Assert.assertTrue("Collection for key " + entry.getKey() + " is not empty", entry.getValue().isEmpty());
	}
}
 

@Test
public void test() throws Exception {
	final TupleGenerator generator1 =
			new TupleGenerator(SEED1, 500, 4096, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);
	final TupleGenerator generator2 =
			new TupleGenerator(SEED2, 500, 2048, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);

	final TestData.TupleGeneratorIterator input1 = new TestData.TupleGeneratorIterator(generator1, INPUT_FIRST_SIZE);
	final TestData.TupleGeneratorIterator input2 = new TestData.TupleGeneratorIterator(generator2, INPUT_SECOND_SIZE);

	// collect expected data
	final Map<Integer, Collection<Match>> expectedMatchesMap = matchValues(
			collectData(input1), collectData(input2));

	// reset the generators
	generator1.reset();
	generator2.reset();
	input1.reset();
	input2.reset();

	StreamOperator operator = getOperator();

	match(expectedMatchesMap, transformToBinary(join(operator, input1, input2)));

	// assert that each expected match was seen
	for (Map.Entry<Integer, Collection<Match>> entry : expectedMatchesMap.entrySet()) {
		Assert.assertTrue("Collection for key " + entry.getKey() + " is not empty", entry.getValue().isEmpty());
	}
}
 

@Test
public void testMergeWithHighNumberOfCommonKeys()
{
	// the size of the left and right inputs
	final int INPUT_1_SIZE = 200;
	final int INPUT_2_SIZE = 100;
	
	final int INPUT_1_DUPLICATES = 10;
	final int INPUT_2_DUPLICATES = 4000;
	final int DUPLICATE_KEY = 13;
	
	try {
		final TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);
		final TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);

		final TestData.TupleGeneratorIterator gen1Iter = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator gen2Iter = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);

		final TestData.TupleConstantValueIterator const1Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "LEFT String for Duplicate Keys", INPUT_1_DUPLICATES);
		final TestData.TupleConstantValueIterator const2Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "RIGHT String for Duplicate Keys", INPUT_2_DUPLICATES);

		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList1 = new ArrayList<MutableObjectIterator<Tuple2<Integer, String>>>();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);

		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList2 = new ArrayList<MutableObjectIterator<Tuple2<Integer, String>>>();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		MutableObjectIterator<Tuple2<Integer, String>> input1 = new MergeIterator<Tuple2<Integer, String>>(inList1, comparator1.duplicate());
		MutableObjectIterator<Tuple2<Integer, String>> input2 = new MergeIterator<Tuple2<Integer, String>>(inList2, comparator2.duplicate());
		
		// collect expected data
		final Map<Integer, Collection<Match>> expectedMatchesMap = matchValues(
			collectData(input1),
			collectData(input2));
		
		// re-create the whole thing for actual processing
		
		// reset the generators and iterators
		generator1.reset();
		generator2.reset();
		const1Iter.reset();
		const2Iter.reset();
		gen1Iter.reset();
		gen2Iter.reset();
		
		inList1.clear();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		inList2.clear();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		input1 = new MergeIterator<Tuple2<Integer, String>>(inList1, comparator1.duplicate());
		input2 = new MergeIterator<Tuple2<Integer, String>>(inList2, comparator2.duplicate());
		
		final FlatJoinFunction<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> joinFunction = new MatchRemovingJoiner(expectedMatchesMap);
		
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<Tuple2<Integer, String>>();

		
		// we create this sort-merge iterator with little memory for the block-nested-loops fall-back to make sure it
		// needs to spill for the duplicate keys
		NonReusingMergeInnerJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
			new NonReusingMergeInnerJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>>(
				input1, input2, this.serializer1, this.comparator1, this.serializer2, this.comparator2,
				this.pairComparator, this.memoryManager, this.ioManager, PAGES_FOR_BNLJN, this.parentTask);

		iterator.open();
		
		while (iterator.callWithNextKey(joinFunction, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<Match>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testBuildSecond() {
	try {
		TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		
		final TestData.TupleGeneratorIterator input1 = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator input2 = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);
		
		// collect expected data
		final Map<Integer, Collection<TupleMatch>> expectedMatchesMap = joinTuples(
				collectTupleData(input1),
				collectTupleData(input2));
		
		final TupleMatchRemovingJoin matcher = new TupleMatchRemovingJoin(expectedMatchesMap);
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<>();

		// reset the generators
		generator1.reset();
		generator2.reset();
		input1.reset();
		input2.reset();

		// compare with iterator values			
		NonReusingBuildSecondHashJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
			new NonReusingBuildSecondHashJoinIterator<>(
				input1, input2, this.recordSerializer, this.record1Comparator, 
				this.recordSerializer, this.record2Comparator, this.recordPairComparator,
				this.memoryManager, ioManager, this.parentTask, 1.0, false, false, true);

		iterator.open();
		
		while (iterator.callWithNextKey(matcher, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<TupleMatch>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testBuildSecondAndFullOuterJoin() {
	try {
		TupleGenerator generator1 = new TupleGenerator(SEED1, 1000, 4096, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);

		final TestData.TupleGeneratorIterator input1 = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator input2 = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);

		// collect expected data
		final Map<Integer, Collection<TupleMatch>> expectedMatchesMap = fullOuterJoinTuples(
			collectTupleData(input1),
			collectTupleData(input2));

		final TupleMatchRemovingJoin matcher = new TupleMatchRemovingJoin(expectedMatchesMap);
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<>();

		// reset the generators
		generator1.reset();
		generator2.reset();
		input1.reset();
		input2.reset();

		// compare with iterator values
		NonReusingBuildSecondHashJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
			new NonReusingBuildSecondHashJoinIterator<>(
				input1, input2, this.recordSerializer, this.record1Comparator,
				this.recordSerializer, this.record2Comparator, this.recordPairComparator,
				this.memoryManager, ioManager, this.parentTask, 1.0, true, true, false);

		iterator.open();

		while (iterator.callWithNextKey(matcher, collector));

		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<TupleMatch>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testBuildFirstWithHighNumberOfCommonKeys()
{
	// the size of the left and right inputs
	final int INPUT_1_SIZE = 200;
	final int INPUT_2_SIZE = 100;
	
	final int INPUT_1_DUPLICATES = 10;
	final int INPUT_2_DUPLICATES = 2000;
	final int DUPLICATE_KEY = 13;
	
	try {
		TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		
		final TestData.TupleGeneratorIterator gen1Iter = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator gen2Iter = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);
		
		final TestData.TupleConstantValueIterator const1Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "LEFT String for Duplicate Keys", INPUT_1_DUPLICATES);
		final TestData.TupleConstantValueIterator const2Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "RIGHT String for Duplicate Keys", INPUT_2_DUPLICATES);
		
		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList1 = new ArrayList<>();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList2 = new ArrayList<>();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);
		
		MutableObjectIterator<Tuple2<Integer, String>> input1 = new UnionIterator<>(inList1);
		MutableObjectIterator<Tuple2<Integer, String>> input2 = new UnionIterator<>(inList2);
		
		
		// collect expected data
		final Map<Integer, Collection<TupleMatch>> expectedMatchesMap = joinTuples(
				collectTupleData(input1),
				collectTupleData(input2));
		
		// re-create the whole thing for actual processing
		
		// reset the generators and iterators
		generator1.reset();
		generator2.reset();
		const1Iter.reset();
		const2Iter.reset();
		gen1Iter.reset();
		gen2Iter.reset();
		
		inList1.clear();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		inList2.clear();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		input1 = new UnionIterator<>(inList1);
		input2 = new UnionIterator<>(inList2);
		
		final TupleMatchRemovingJoin matcher = new TupleMatchRemovingJoin(expectedMatchesMap);
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<>();

		NonReusingBuildFirstHashJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
				new NonReusingBuildFirstHashJoinIterator<>(
					input1, input2, this.recordSerializer, this.record1Comparator, 
					this.recordSerializer, this.record2Comparator, this.recordPairComparator,
					this.memoryManager, ioManager, this.parentTask, 1.0, false, false, true);

		iterator.open();
		
		while (iterator.callWithNextKey(matcher, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<TupleMatch>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testBuildFirst() {
	try {
		TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		
		final TestData.TupleGeneratorIterator input1 = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator input2 = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);
		
		// collect expected data
		final Map<Integer, Collection<TupleMatch>> expectedMatchesMap = joinTuples(
				collectTupleData(input1),
				collectTupleData(input2));
		
		final TupleMatchRemovingJoin matcher = new TupleMatchRemovingJoin(expectedMatchesMap);
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<Tuple2<Integer, String>>();

		// reset the generators
		generator1.reset();
		generator2.reset();
		input1.reset();
		input2.reset();

		// compare with iterator values
		NonReusingBuildFirstHashJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
				new NonReusingBuildFirstHashJoinIterator<>(
					input1, input2, this.recordSerializer, this.record1Comparator, 
					this.recordSerializer, this.record2Comparator, this.recordPairComparator,
					this.memoryManager, ioManager, this.parentTask, 1.0, false, false, true);
		
		iterator.open();

		//noinspection StatementWithEmptyBody
		while (iterator.callWithNextKey(matcher, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<TupleMatch>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testBuildFirst() {
	try {
		TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		
		final TestData.TupleGeneratorIterator input1 = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator input2 = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);
		
		// collect expected data
		final Map<Integer, Collection<TupleMatch>> expectedMatchesMap = joinTuples(
				collectTupleData(input1),
				collectTupleData(input2));
		
		final TupleMatchRemovingJoin matcher = new TupleMatchRemovingJoin(expectedMatchesMap);
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<Tuple2<Integer, String>>();

		// reset the generators
		generator1.reset();
		generator2.reset();
		input1.reset();
		input2.reset();

		// compare with iterator values
		NonReusingBuildFirstHashJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
				new NonReusingBuildFirstHashJoinIterator<>(
					input1, input2, this.recordSerializer, this.record1Comparator, 
					this.recordSerializer, this.record2Comparator, this.recordPairComparator,
					this.memoryManager, ioManager, this.parentTask, 1.0, false, false, true);
		
		iterator.open();

		//noinspection StatementWithEmptyBody
		while (iterator.callWithNextKey(matcher, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<TupleMatch>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testBuildFirstWithHighNumberOfCommonKeys()
{
	// the size of the left and right inputs
	final int INPUT_1_SIZE = 200;
	final int INPUT_2_SIZE = 100;
	
	final int INPUT_1_DUPLICATES = 10;
	final int INPUT_2_DUPLICATES = 2000;
	final int DUPLICATE_KEY = 13;
	
	try {
		TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		
		final TestData.TupleGeneratorIterator gen1Iter = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator gen2Iter = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);
		
		final TestData.TupleConstantValueIterator const1Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "LEFT String for Duplicate Keys", INPUT_1_DUPLICATES);
		final TestData.TupleConstantValueIterator const2Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "RIGHT String for Duplicate Keys", INPUT_2_DUPLICATES);
		
		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList1 = new ArrayList<>();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList2 = new ArrayList<>();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);
		
		MutableObjectIterator<Tuple2<Integer, String>> input1 = new UnionIterator<>(inList1);
		MutableObjectIterator<Tuple2<Integer, String>> input2 = new UnionIterator<>(inList2);
		
		
		// collect expected data
		final Map<Integer, Collection<TupleMatch>> expectedMatchesMap = joinTuples(
				collectTupleData(input1),
				collectTupleData(input2));
		
		// re-create the whole thing for actual processing
		
		// reset the generators and iterators
		generator1.reset();
		generator2.reset();
		const1Iter.reset();
		const2Iter.reset();
		gen1Iter.reset();
		gen2Iter.reset();
		
		inList1.clear();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		inList2.clear();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		input1 = new UnionIterator<>(inList1);
		input2 = new UnionIterator<>(inList2);
		
		final TupleMatchRemovingJoin matcher = new TupleMatchRemovingJoin(expectedMatchesMap);
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<>();

		NonReusingBuildFirstHashJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
				new NonReusingBuildFirstHashJoinIterator<>(
					input1, input2, this.recordSerializer, this.record1Comparator, 
					this.recordSerializer, this.record2Comparator, this.recordPairComparator,
					this.memoryManager, ioManager, this.parentTask, 1.0, false, false, true);

		iterator.open();
		
		while (iterator.callWithNextKey(matcher, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<TupleMatch>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testMergeWithHighNumberOfCommonKeys() {
	// the size of the left and right inputs
	final int input1Size = 200;
	final int input2Size = 100;

	final int input1Duplicates = 10;
	final int input2Duplicates = 4000;
	final int duplicateKey = 13;

	try {
		final TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);
		final TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);

		final TestData.TupleGeneratorIterator gen1Iter = new TestData.TupleGeneratorIterator(generator1, input1Size);
		final TestData.TupleGeneratorIterator gen2Iter = new TestData.TupleGeneratorIterator(generator2, input2Size);

		final TestData.TupleConstantValueIterator const1Iter = new TestData.TupleConstantValueIterator(duplicateKey, "LEFT String for Duplicate Keys", input1Duplicates);
		final TestData.TupleConstantValueIterator const2Iter = new TestData.TupleConstantValueIterator(duplicateKey, "RIGHT String for Duplicate Keys", input2Duplicates);

		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList1 = new ArrayList<>();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);

		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList2 = new ArrayList<>();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		MutableObjectIterator<Tuple2<Integer, String>> input1 = new MergeIterator<>(inList1, comparator1.duplicate());
		MutableObjectIterator<Tuple2<Integer, String>> input2 = new MergeIterator<>(inList2, comparator2.duplicate());

		// collect expected data
		final Map<Integer, Collection<Match>> expectedMatchesMap = matchValues(
				collectData(input1),
				collectData(input2));

		// re-create the whole thing for actual processing

		// reset the generators and iterators
		generator1.reset();
		generator2.reset();
		const1Iter.reset();
		const2Iter.reset();
		gen1Iter.reset();
		gen2Iter.reset();

		inList1.clear();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);

		inList2.clear();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		input1 = new MergeIterator<>(inList1, comparator1.duplicate());
		input2 = new MergeIterator<>(inList2, comparator2.duplicate());

		StreamOperator operator = getOperator();

		match(expectedMatchesMap, transformToBinary(join(operator, input1, input2)));

		// assert that each expected match was seen
		for (Map.Entry<Integer, Collection<Match>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@SuppressWarnings("unchecked, rawtypes")
protected void testOuterJoinWithHighNumberOfCommonKeys(
		FlinkJoinType outerJoinType, int input1Size, int input1Duplicates, int input1ValueLength,
		float input1KeyDensity, int input2Size, int input2Duplicates, int input2ValueLength,
		float input2KeyDensity) {
	TypeComparator<Tuple2<Integer, String>> comparator1 = new TupleComparator<>(
			new int[]{0},
			new TypeComparator<?>[]{new IntComparator(true)},
			new TypeSerializer<?>[]{IntSerializer.INSTANCE}
	);
	TypeComparator<Tuple2<Integer, String>> comparator2 = new TupleComparator<>(
			new int[]{0},
			new TypeComparator<?>[]{new IntComparator(true)},
			new TypeSerializer<?>[]{IntSerializer.INSTANCE}
	);

	final int duplicateKey = 13;

	try {
		final TupleGenerator generator1 = new TupleGenerator(SEED1, 500, input1KeyDensity, input1ValueLength, KeyMode.SORTED_SPARSE, ValueMode.RANDOM_LENGTH, null);
		final TupleGenerator generator2 = new TupleGenerator(SEED2, 500, input2KeyDensity, input2ValueLength, KeyMode.SORTED_SPARSE, ValueMode.RANDOM_LENGTH, null);

		final TupleGeneratorIterator gen1Iter = new TupleGeneratorIterator(generator1, input1Size);
		final TupleGeneratorIterator gen2Iter = new TupleGeneratorIterator(generator2, input2Size);

		final TupleConstantValueIterator const1Iter = new TupleConstantValueIterator(duplicateKey, "LEFT String for Duplicate Keys", input1Duplicates);
		final TupleConstantValueIterator const2Iter = new TupleConstantValueIterator(duplicateKey, "RIGHT String for Duplicate Keys", input2Duplicates);

		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList1 = new ArrayList<>();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);

		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList2 = new ArrayList<>();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		MutableObjectIterator<Tuple2<Integer, String>> input1 = new MergeIterator<>(inList1, comparator1.duplicate());
		MutableObjectIterator<Tuple2<Integer, String>> input2 = new MergeIterator<>(inList2, comparator2.duplicate());

		// collect expected data
		final Map<Integer, Collection<Match>> expectedMatchesMap = joinValues(
				RandomSortMergeInnerJoinTest.collectData(input1),
				RandomSortMergeInnerJoinTest.collectData(input2),
				outerJoinType);

		// re-create the whole thing for actual processing

		// reset the generators and iterators
		generator1.reset();
		generator2.reset();
		const1Iter.reset();
		const2Iter.reset();
		gen1Iter.reset();
		gen2Iter.reset();

		inList1.clear();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);

		inList2.clear();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		input1 = new MergeIterator<>(inList1, comparator1.duplicate());
		input2 = new MergeIterator<>(inList2, comparator2.duplicate());

		StreamOperator operator = getOperator(outerJoinType);
		RandomSortMergeInnerJoinTest.match(expectedMatchesMap,
				RandomSortMergeInnerJoinTest.transformToBinary(myJoin(operator, input1, input2)));

		// assert that each expected match was seen
		for (Entry<Integer, Collection<Match>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	} catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testBuildSecond() {
	try {
		TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		
		final TestData.TupleGeneratorIterator input1 = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator input2 = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);
		
		// collect expected data
		final Map<Integer, Collection<TupleMatch>> expectedMatchesMap = joinTuples(
				collectTupleData(input1),
				collectTupleData(input2));
		
		final TupleMatchRemovingJoin matcher = new TupleMatchRemovingJoin(expectedMatchesMap);
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<>();

		// reset the generators
		generator1.reset();
		generator2.reset();
		input1.reset();
		input2.reset();

		// compare with iterator values			
		NonReusingBuildSecondHashJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
			new NonReusingBuildSecondHashJoinIterator<>(
				input1, input2, this.recordSerializer, this.record1Comparator, 
				this.recordSerializer, this.record2Comparator, this.recordPairComparator,
				this.memoryManager, ioManager, this.parentTask, 1.0, false, false, true);

		iterator.open();
		
		while (iterator.callWithNextKey(matcher, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<TupleMatch>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testMergeWithHighNumberOfCommonKeys()
{
	// the size of the left and right inputs
	final int INPUT_1_SIZE = 200;
	final int INPUT_2_SIZE = 100;

	final int INPUT_1_DUPLICATES = 10;
	final int INPUT_2_DUPLICATES = 4000;
	final int DUPLICATE_KEY = 13;

	try {
		final TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);
		final TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);
		
		final TestData.TupleGeneratorIterator gen1Iter = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator gen2Iter = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);
		
		final TestData.TupleConstantValueIterator const1Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "LEFT String for Duplicate Keys", INPUT_1_DUPLICATES);
		final TestData.TupleConstantValueIterator const2Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "RIGHT String for Duplicate Keys", INPUT_2_DUPLICATES);
		
		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList1 = new ArrayList<MutableObjectIterator<Tuple2<Integer, String>>>();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList2 = new ArrayList<MutableObjectIterator<Tuple2<Integer, String>>>();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);
		
		MutableObjectIterator<Tuple2<Integer, String>> input1 = new MergeIterator<Tuple2<Integer, String>>(inList1, comparator1.duplicate());
		MutableObjectIterator<Tuple2<Integer, String>> input2 = new MergeIterator<Tuple2<Integer, String>>(inList2, comparator2.duplicate());
		
		// collect expected data
		final Map<Integer, Collection<Match>> expectedMatchesMap = matchValues(
			collectData(input1),
			collectData(input2));
		
		// re-create the whole thing for actual processing
		
		// reset the generators and iterators
		generator1.reset();
		generator2.reset();
		const1Iter.reset();
		const2Iter.reset();
		gen1Iter.reset();
		gen2Iter.reset();
		
		inList1.clear();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		inList2.clear();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		input1 = new MergeIterator<Tuple2<Integer, String>>(inList1, comparator1.duplicate());
		input2 = new MergeIterator<Tuple2<Integer, String>>(inList2, comparator2.duplicate());
		
		final FlatJoinFunction<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> matcher = new MatchRemovingJoiner(expectedMatchesMap);
		
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<Tuple2<Integer, String>>();

		
		// we create this sort-merge iterator with little memory for the block-nested-loops fall-back to make sure it
		// needs to spill for the duplicate keys
		ReusingMergeInnerJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
			new ReusingMergeInnerJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>>(
				input1, input2, this.serializer1, this.comparator1, this.serializer2, this.comparator2,
				this.pairComparator, this.memoryManager, this.ioManager, PAGES_FOR_BNLJN, this.parentTask);

		iterator.open();
		
		while (iterator.callWithNextKey(matcher, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<Match>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testBuildSecondWithHighNumberOfCommonKeys()
{
	// the size of the left and right inputs
	final int INPUT_1_SIZE = 200;
	final int INPUT_2_SIZE = 100;
	
	final int INPUT_1_DUPLICATES = 10;
	final int INPUT_2_DUPLICATES = 2000;
	final int DUPLICATE_KEY = 13;
	
	try {
		TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.RANDOM, ValueMode.RANDOM_LENGTH);
		
		final TestData.TupleGeneratorIterator gen1Iter = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator gen2Iter = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);
		
		final TestData.TupleConstantValueIterator const1Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "LEFT String for Duplicate Keys", INPUT_1_DUPLICATES);
		final TestData.TupleConstantValueIterator const2Iter = new TestData.TupleConstantValueIterator(DUPLICATE_KEY, "RIGHT String for Duplicate Keys", INPUT_2_DUPLICATES);
		
		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList1 = new ArrayList<>();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		final List<MutableObjectIterator<Tuple2<Integer, String>>> inList2 = new ArrayList<>();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);
		
		MutableObjectIterator<Tuple2<Integer, String>> input1 = new UnionIterator<>(inList1);
		MutableObjectIterator<Tuple2<Integer, String>> input2 = new UnionIterator<>(inList2);
		
		
		// collect expected data
		final Map<Integer, Collection<TupleMatch>> expectedMatchesMap = joinTuples(
				collectTupleData(input1),
				collectTupleData(input2));
		
		// re-create the whole thing for actual processing
		
		// reset the generators and iterators
		generator1.reset();
		generator2.reset();
		const1Iter.reset();
		const2Iter.reset();
		gen1Iter.reset();
		gen2Iter.reset();
		
		inList1.clear();
		inList1.add(gen1Iter);
		inList1.add(const1Iter);
		
		inList2.clear();
		inList2.add(gen2Iter);
		inList2.add(const2Iter);

		input1 = new UnionIterator<>(inList1);
		input2 = new UnionIterator<>(inList2);
		
		final TupleMatchRemovingJoin matcher = new TupleMatchRemovingJoin(expectedMatchesMap);
		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<>();

		NonReusingBuildSecondHashJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
			new NonReusingBuildSecondHashJoinIterator<>(
				input1, input2, this.recordSerializer, this.record1Comparator, 
				this.recordSerializer, this.record2Comparator, this.recordPairComparator,
				this.memoryManager, ioManager, this.parentTask, 1.0, false, false, true);
		
		iterator.open();
		
		while (iterator.callWithNextKey(matcher, collector));
		
		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<TupleMatch>> entry : expectedMatchesMap.entrySet()) {
			if (!entry.getValue().isEmpty()) {
				Assert.fail("Collection for key " + entry.getKey() + " is not empty");
			}
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}
 

@Test
public void testMerge() {
	try {

		final TupleGenerator generator1 = new TupleGenerator(SEED1, 500, 4096, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);
		final TupleGenerator generator2 = new TupleGenerator(SEED2, 500, 2048, KeyMode.SORTED, ValueMode.RANDOM_LENGTH);

		final TestData.TupleGeneratorIterator input1 = new TestData.TupleGeneratorIterator(generator1, INPUT_1_SIZE);
		final TestData.TupleGeneratorIterator input2 = new TestData.TupleGeneratorIterator(generator2, INPUT_2_SIZE);

		// collect expected data
		final Map<Integer, Collection<Match>> expectedMatchesMap = matchValues(
			collectData(input1),
			collectData(input2));

		final FlatJoinFunction<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> joinFunction =
				new MatchRemovingJoiner(expectedMatchesMap);

		final Collector<Tuple2<Integer, String>> collector = new DiscardingOutputCollector<Tuple2<Integer, String>>();

		// reset the generators
		generator1.reset();
		generator2.reset();
		input1.reset();
		input2.reset();

		// compare with iterator values
		ReusingMergeInnerJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>> iterator =
			new ReusingMergeInnerJoinIterator<Tuple2<Integer, String>, Tuple2<Integer, String>, Tuple2<Integer, String>>(
				input1, input2, this.serializer1, this.comparator1, this.serializer2, this.comparator2,
				this.pairComparator, this.memoryManager, this.ioManager, PAGES_FOR_BNLJN, this.parentTask);

		iterator.open();

		while (iterator.callWithNextKey(joinFunction, collector));

		iterator.close();

		// assert that each expected match was seen
		for (Entry<Integer, Collection<Match>> entry : expectedMatchesMap.entrySet()) {
			Assert.assertTrue("Collection for key " + entry.getKey() + " is not empty", entry.getValue().isEmpty());
		}
	}
	catch (Exception e) {
		e.printStackTrace();
		Assert.fail("An exception occurred during the test: " + e.getMessage());
	}
}