Java Code Examples for org.apache.flink.api.common.functions.FlatJoinFunction#join()

/**
 * Crosses a single value from the second side with N values, all sharing a common key.
 * Effectively realizes a <i>N:1</i> join.
 *
 * @param val1      The value form the <i>1</i> side.
 * @param firstValN The first of the values from the <i>N</i> side.
 * @param valsN     Iterator over remaining <i>N</i> side values.
 * @throws Exception Forwards all exceptions thrown by the stub.
 */
private void crossSecond1withNValues(T2 val1, T1 firstValN,
									Iterator<T1> valsN, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception {
	T2 copy2 = createCopy(serializer2, val1, this.copy2);
	joinFunction.join(firstValN, copy2, collector);

	// set copy and join first element
	boolean more = true;
	do {
		final T1 nRec = valsN.next();

		if (valsN.hasNext()) {
			copy2 = createCopy(serializer2, val1, this.copy2);
			joinFunction.join(nRec, copy2, collector);
		} else {
			joinFunction.join(nRec, val1, collector);
			more = false;
		}
	}
	while (more);
}
 

/**
 * Crosses a single value from the first input with N values, all sharing a common key.
 * Effectively realizes a <i>1:N</i> join.
 *
 * @param val1      The value form the <i>1</i> side.
 * @param firstValN The first of the values from the <i>N</i> side.
 * @param valsN     Iterator over remaining <i>N</i> side values.
 * @throws Exception Forwards all exceptions thrown by the stub.
 */
private void crossFirst1withNValues(final T1 val1, final T2 firstValN,
									final Iterator<T2> valsN, final FlatJoinFunction<T1, T2, O> joinFunction, final Collector<O> collector)
		throws Exception {
	T1 copy1 = createCopy(serializer1, val1, this.copy1);
	joinFunction.join(copy1, firstValN, collector);

	// set copy and join first element
	boolean more = true;
	do {
		final T2 nRec = valsN.next();

		if (valsN.hasNext()) {
			copy1 = createCopy(serializer1, val1, this.copy1);
			joinFunction.join(copy1, nRec, collector);
		} else {
			joinFunction.join(val1, nRec, collector);
			more = false;
		}
	}
	while (more);
}
 

/**
 * Crosses a single value from the first input with N values, all sharing a common key.
 * Effectively realizes a <i>1:N</i> join.
 *
 * @param val1      The value form the <i>1</i> side.
 * @param firstValN The first of the values from the <i>N</i> side.
 * @param valsN     Iterator over remaining <i>N</i> side values.
 * @throws Exception Forwards all exceptions thrown by the stub.
 */
private void crossFirst1withNValues(final T1 val1, final T2 firstValN,
									final Iterator<T2> valsN, final FlatJoinFunction<T1, T2, O> joinFunction, final Collector<O> collector)
		throws Exception {
	T1 copy1 = createCopy(serializer1, val1, this.copy1);
	joinFunction.join(copy1, firstValN, collector);

	// set copy and join first element
	boolean more = true;
	do {
		final T2 nRec = valsN.next();

		if (valsN.hasNext()) {
			copy1 = createCopy(serializer1, val1, this.copy1);
			joinFunction.join(copy1, nRec, collector);
		} else {
			joinFunction.join(val1, nRec, collector);
			more = false;
		}
	}
	while (more);
}
 

/**
 * Crosses a single value from the second side with N values, all sharing a common key.
 * Effectively realizes a <i>N:1</i> join.
 *
 * @param val1      The value form the <i>1</i> side.
 * @param firstValN The first of the values from the <i>N</i> side.
 * @param valsN     Iterator over remaining <i>N</i> side values.
 * @throws Exception Forwards all exceptions thrown by the stub.
 */
private void crossSecond1withNValues(T2 val1, T1 firstValN,
									Iterator<T1> valsN, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception {
	T2 copy2 = createCopy(serializer2, val1, this.copy2);
	joinFunction.join(firstValN, copy2, collector);

	// set copy and join first element
	boolean more = true;
	do {
		final T1 nRec = valsN.next();

		if (valsN.hasNext()) {
			copy2 = createCopy(serializer2, val1, this.copy2);
			joinFunction.join(nRec, copy2, collector);
		} else {
			joinFunction.join(nRec, val1, collector);
			more = false;
		}
	}
	while (more);
}
 

@Override
protected List<OUT> executeOnCollections(List<IN1> leftInput, List<IN2> rightInput, RuntimeContext runtimeContext, ExecutionConfig executionConfig) throws Exception {
	TypeInformation<IN1> leftInformation = getOperatorInfo().getFirstInputType();
	TypeInformation<IN2> rightInformation = getOperatorInfo().getSecondInputType();
	TypeInformation<OUT> outInformation = getOperatorInfo().getOutputType();

	TypeComparator<IN1> leftComparator = buildComparatorFor(0, executionConfig, leftInformation);
	TypeComparator<IN2> rightComparator = buildComparatorFor(1, executionConfig, rightInformation);

	TypeSerializer<IN1> leftSerializer = leftInformation.createSerializer(executionConfig);
	TypeSerializer<IN2> rightSerializer = rightInformation.createSerializer(executionConfig);

	OuterJoinListIterator<IN1, IN2> outerJoinIterator =
			new OuterJoinListIterator<>(leftInput, leftSerializer, leftComparator,
					rightInput, rightSerializer, rightComparator, outerJoinType);

	// --------------------------------------------------------------------
	// Run UDF
	// --------------------------------------------------------------------
	FlatJoinFunction<IN1, IN2, OUT> function = userFunction.getUserCodeObject();

	FunctionUtils.setFunctionRuntimeContext(function, runtimeContext);
	FunctionUtils.openFunction(function, this.parameters);

	List<OUT> result = new ArrayList<>();
	Collector<OUT> collector = new CopyingListCollector<>(result, outInformation.createSerializer(executionConfig));

	while (outerJoinIterator.next()) {
		IN1 left = outerJoinIterator.getLeft();
		IN2 right = outerJoinIterator.getRight();
		function.join(left == null ? null : leftSerializer.copy(left), right == null ? null : rightSerializer.copy(right), collector);
	}

	FunctionUtils.closeFunction(function);

	return result;
}
 

protected void crossMatchingGroup(Iterator<T1> values1, Iterator<T2> values2, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception {
	final T1 firstV1 = values1.next();
	final T2 firstV2 = values2.next();

	final boolean v1HasNext = values1.hasNext();
	final boolean v2HasNext = values2.hasNext();

	// check if one side is already empty
	// this check could be omitted if we put this in MatchTask.
	// then we can derive the local strategy (with build side).

	if (v1HasNext) {
		if (v2HasNext) {
			// both sides contain more than one value
			// TODO: Decide which side to spill and which to block!
			crossMwithNValues(firstV1, values1, firstV2, values2, joinFunction, collector);
		} else {
			crossSecond1withNValues(firstV2, firstV1, values1, joinFunction, collector);
		}
	} else {
		if (v2HasNext) {
			crossFirst1withNValues(firstV1, firstV2, values2, joinFunction, collector);
		} else {
			// both sides contain only one value
			joinFunction.join(firstV1, firstV2, collector);
		}
	}
}
 

private void joinRightKeyValuesWithNull(Iterator<T2> values, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception {
	while (values.hasNext()) {
		T2 next = values.next();
		this.copy2 = createCopy(serializer2, next, copy2);
		joinFunction.join(null, copy2, collector);
	}
}
 

private void joinLeftKeyValuesWithNull(Iterator<T1> values, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception {
	while (values.hasNext()) {
		T1 next = values.next();
		this.copy1 = createCopy(serializer1, next, copy1);
		joinFunction.join(copy1, null, collector);
	}
}
 

@Override
public boolean callWithNextKey(FlatJoinFunction<V1, V2, O> matchFunction, Collector<O> collector)
throws Exception
{
	if (this.hashJoin.nextRecord())
	{
		// we have a next record, get the iterators to the probe and build side values
		final MutableObjectIterator<V2> buildSideIterator = this.hashJoin.getBuildSideIterator();
		final V1 probeRecord = this.hashJoin.getCurrentProbeRecord();
		V2 nextBuildSideRecord = buildSideIterator.next(this.nextBuildSideObject);

		if (probeRecord != null && nextBuildSideRecord != null) {
			matchFunction.join(probeRecord, nextBuildSideRecord, collector);

			while (this.running && ((nextBuildSideRecord = buildSideIterator.next(nextBuildSideRecord)) != null)) {
				matchFunction.join(probeRecord, nextBuildSideRecord, collector);
			}
		} else {
			if (probeSideOuterJoin && probeRecord != null && nextBuildSideRecord == null) {
				matchFunction.join(probeRecord, null, collector);
			}

			if (buildSideOuterJoin && probeRecord == null && nextBuildSideRecord != null) {
				matchFunction.join(null, nextBuildSideRecord, collector);
				while (this.running && ((nextBuildSideRecord = buildSideIterator.next(nextBuildSideRecord)) != null)) {
					matchFunction.join(null, nextBuildSideRecord, collector);
				}
			}
		}

		return true;
	}
	else {
		return false;
	}
}
 

@Override
protected List<OUT> executeOnCollections(List<IN1> leftInput, List<IN2> rightInput, RuntimeContext runtimeContext, ExecutionConfig executionConfig) throws Exception {
	TypeInformation<IN1> leftInformation = getOperatorInfo().getFirstInputType();
	TypeInformation<IN2> rightInformation = getOperatorInfo().getSecondInputType();
	TypeInformation<OUT> outInformation = getOperatorInfo().getOutputType();

	TypeComparator<IN1> leftComparator = buildComparatorFor(0, executionConfig, leftInformation);
	TypeComparator<IN2> rightComparator = buildComparatorFor(1, executionConfig, rightInformation);

	TypeSerializer<IN1> leftSerializer = leftInformation.createSerializer(executionConfig);
	TypeSerializer<IN2> rightSerializer = rightInformation.createSerializer(executionConfig);

	OuterJoinListIterator<IN1, IN2> outerJoinIterator =
			new OuterJoinListIterator<>(leftInput, leftSerializer, leftComparator,
					rightInput, rightSerializer, rightComparator, outerJoinType);

	// --------------------------------------------------------------------
	// Run UDF
	// --------------------------------------------------------------------
	FlatJoinFunction<IN1, IN2, OUT> function = userFunction.getUserCodeObject();

	FunctionUtils.setFunctionRuntimeContext(function, runtimeContext);
	FunctionUtils.openFunction(function, this.parameters);

	List<OUT> result = new ArrayList<>();
	Collector<OUT> collector = new CopyingListCollector<>(result, outInformation.createSerializer(executionConfig));

	while (outerJoinIterator.next()) {
		IN1 left = outerJoinIterator.getLeft();
		IN2 right = outerJoinIterator.getRight();
		function.join(left == null ? null : leftSerializer.copy(left), right == null ? null : rightSerializer.copy(right), collector);
	}

	FunctionUtils.closeFunction(function);

	return result;
}
 

protected void crossMatchingGroup(Iterator<T1> values1, Iterator<T2> values2, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception {
	final T1 firstV1 = values1.next();
	final T2 firstV2 = values2.next();

	final boolean v1HasNext = values1.hasNext();
	final boolean v2HasNext = values2.hasNext();

	// check if one side is already empty
	// this check could be omitted if we put this in MatchTask.
	// then we can derive the local strategy (with build side).

	if (v1HasNext) {
		if (v2HasNext) {
			// both sides contain more than one value
			// TODO: Decide which side to spill and which to block!
			crossMwithNValues(firstV1, values1, firstV2, values2, joinFunction, collector);
		} else {
			crossSecond1withNValues(firstV2, firstV1, values1, joinFunction, collector);
		}
	} else {
		if (v2HasNext) {
			crossFirst1withNValues(firstV1, firstV2, values2, joinFunction, collector);
		} else {
			// both sides contain only one value
			joinFunction.join(firstV1, firstV2, collector);
		}
	}
}
 

private void joinRightKeyValuesWithNull(Iterator<T2> values, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception {
	while (values.hasNext()) {
		T2 next = values.next();
		this.copy2 = createCopy(serializer2, next, copy2);
		joinFunction.join(null, copy2, collector);
	}
}
 

private void joinLeftKeyValuesWithNull(Iterator<T1> values, FlatJoinFunction<T1, T2, O> joinFunction, Collector<O> collector) throws Exception {
	while (values.hasNext()) {
		T1 next = values.next();
		this.copy1 = createCopy(serializer1, next, copy1);
		joinFunction.join(copy1, null, collector);
	}
}
 

@Override
public boolean callWithNextKey(FlatJoinFunction<V1, V2, O> matchFunction, Collector<O> collector)
throws Exception
{
	if (this.hashJoin.nextRecord())
	{
		// we have a next record, get the iterators to the probe and build side values
		final MutableObjectIterator<V2> buildSideIterator = this.hashJoin.getBuildSideIterator();
		final V1 probeRecord = this.hashJoin.getCurrentProbeRecord();
		V2 nextBuildSideRecord = buildSideIterator.next(this.nextBuildSideObject);

		if (probeRecord != null && nextBuildSideRecord != null) {
			matchFunction.join(probeRecord, nextBuildSideRecord, collector);

			while (this.running && ((nextBuildSideRecord = buildSideIterator.next(nextBuildSideRecord)) != null)) {
				matchFunction.join(probeRecord, nextBuildSideRecord, collector);
			}
		} else {
			if (probeSideOuterJoin && probeRecord != null && nextBuildSideRecord == null) {
				matchFunction.join(probeRecord, null, collector);
			}

			if (buildSideOuterJoin && probeRecord == null && nextBuildSideRecord != null) {
				matchFunction.join(null, nextBuildSideRecord, collector);
				while (this.running && ((nextBuildSideRecord = buildSideIterator.next(nextBuildSideRecord)) != null)) {
					matchFunction.join(null, nextBuildSideRecord, collector);
				}
			}
		}

		return true;
	}
	else {
		return false;
	}
}
 

@Override
public boolean callWithNextKey(FlatJoinFunction<V1, V2, O> matchFunction, Collector<O> collector)
throws Exception
{
	if (this.hashJoin.nextRecord())
	{
		// we have a next record, get the iterators to the probe and build side values
		final MutableObjectIterator<V2> buildSideIterator = this.hashJoin.getBuildSideIterator();

		final V1 probeRecord = this.hashJoin.getCurrentProbeRecord();
		V2 nextBuildSideRecord = buildSideIterator.next();

		if (probeRecord != null && nextBuildSideRecord != null) {
			V2 tmpRec;

			// check if there is another build-side value
			if ((tmpRec = buildSideIterator.next()) != null) {
				// more than one build-side value --> copy the probe side
				V1 probeCopy;
				probeCopy = this.probeSideSerializer.copy(probeRecord);

				// call match on the first pair
				matchFunction.join(probeCopy, nextBuildSideRecord, collector);
				
				// call match on the second pair
				probeCopy = this.probeSideSerializer.copy(probeRecord);
				matchFunction.join(probeCopy, tmpRec, collector);
				
				while (this.running && ((nextBuildSideRecord = buildSideIterator.next()) != null)) {
					// call match on the next pair
					// make sure we restore the value of the probe side record
					probeCopy = this.probeSideSerializer.copy(probeRecord);
					matchFunction.join(probeCopy, nextBuildSideRecord, collector);
				}
			}
			else {
				// only single pair matches
				matchFunction.join(probeRecord, nextBuildSideRecord, collector);
			}
		} else {
			// while probe side outer join, join current probe record with null.
			if (probeSideOuterJoin && probeRecord != null && nextBuildSideRecord == null) {
				matchFunction.join(probeRecord, null, collector);
			}

			// while build side outer join, iterate all build records which have not been probed before,
			// and join with null.
			if (buildSideOuterJoin && probeRecord == null && nextBuildSideRecord != null) {
				matchFunction.join(null, nextBuildSideRecord, collector);
				while (this.running && ((nextBuildSideRecord = buildSideIterator.next()) != null)) {
					matchFunction.join(null, nextBuildSideRecord, collector);
				}
			}
		}

		return true;
	}
	else {
		return false;
	}
}
 

@Override
public final boolean callWithNextKey(FlatJoinFunction<V1, V2, O> matchFunction, Collector<O> collector)
throws Exception
{
	if (this.hashJoin.nextRecord())
	{
		// we have a next record, get the iterators to the probe and build side values
		final MutableObjectIterator<V1> buildSideIterator = this.hashJoin.getBuildSideIterator();
		final V2 probeRecord = this.hashJoin.getCurrentProbeRecord();
		V1 nextBuildSideRecord = buildSideIterator.next();

		// get the first build side value
		if (probeRecord != null && nextBuildSideRecord != null) {
			V1 tmpRec;

			// check if there is another build-side value
			if ((tmpRec = buildSideIterator.next()) != null) {
				// more than one build-side value --> copy the probe side
				V2 probeCopy;
				probeCopy = this.probeSideSerializer.copy(probeRecord);
				
				// call match on the first pair
				matchFunction.join(nextBuildSideRecord, probeCopy, collector);
				
				// call match on the second pair
				probeCopy = this.probeSideSerializer.copy(probeRecord);
				matchFunction.join(tmpRec, probeCopy, collector);
				
				while (this.running && ((nextBuildSideRecord = buildSideIterator.next()) != null)) {
					// call match on the next pair
					// make sure we restore the value of the probe side record
					probeCopy = this.probeSideSerializer.copy(probeRecord);
					matchFunction.join(nextBuildSideRecord, probeCopy, collector);
				}
			}
			else {
				// only single pair matches
				matchFunction.join(nextBuildSideRecord, probeRecord, collector);
			}
		} else {
			// while probe side outer join, join current probe record with null.
			if (probeSideOuterJoin && probeRecord != null && nextBuildSideRecord == null) {
				matchFunction.join(null, probeRecord, collector);
			}

			// while build side outer join, iterate all build records which have not been probed before,
			// and join with null.
			if (buildSideOuterJoin && probeRecord == null && nextBuildSideRecord != null) {
				matchFunction.join(nextBuildSideRecord, null, collector);

				while (this.running && ((nextBuildSideRecord = buildSideIterator.next()) != null)) {
					matchFunction.join(nextBuildSideRecord, null, collector);
				}
			}
		}

		return true;
	}
	else {
		return false;
	}
}
 

@Override
public final boolean callWithNextKey(FlatJoinFunction<V1, V2, O> matchFunction, Collector<O> collector)
throws Exception
{
	if (this.hashJoin.nextRecord())
	{
		// we have a next record, get the iterators to the probe and build side values
		final MutableObjectIterator<V1> buildSideIterator = this.hashJoin.getBuildSideIterator();

		final V2 probeRecord = this.hashJoin.getCurrentProbeRecord();
		V1 nextBuildSideRecord = buildSideIterator.next(this.nextBuildSideObject);

		if (probeRecord != null && nextBuildSideRecord != null) {
			matchFunction.join(nextBuildSideRecord, probeRecord, collector);

			while (this.running && ((nextBuildSideRecord = buildSideIterator.next(nextBuildSideRecord)) != null)) {
				matchFunction.join(nextBuildSideRecord, probeRecord, collector);
			}
		} else {
			if (probeSideOuterJoin && probeRecord != null && nextBuildSideRecord == null) {
				matchFunction.join(null, probeRecord, collector);
			}

			if (buildSideOuterJoin && probeRecord == null && nextBuildSideRecord != null) {
				// call match on the first pair
				matchFunction.join(nextBuildSideRecord, null, collector);

				while (this.running && ((nextBuildSideRecord = buildSideIterator.next(nextBuildSideRecord)) != null)) {
					// call match on the next pair
					// make sure we restore the value of the probe side record
					matchFunction.join(nextBuildSideRecord, null, collector);
				}
			}
		}

		return true;
	}
	else {
		return false;
	}
}
 

@Override
public final boolean callWithNextKey(FlatJoinFunction<V1, V2, O> matchFunction, Collector<O> collector)
throws Exception
{
	if (this.hashJoin.nextRecord())
	{
		// we have a next record, get the iterators to the probe and build side values
		final MutableObjectIterator<V1> buildSideIterator = this.hashJoin.getBuildSideIterator();

		final V2 probeRecord = this.hashJoin.getCurrentProbeRecord();
		V1 nextBuildSideRecord = buildSideIterator.next(this.nextBuildSideObject);

		if (probeRecord != null && nextBuildSideRecord != null) {
			matchFunction.join(nextBuildSideRecord, probeRecord, collector);

			while (this.running && ((nextBuildSideRecord = buildSideIterator.next(nextBuildSideRecord)) != null)) {
				matchFunction.join(nextBuildSideRecord, probeRecord, collector);
			}
		} else {
			if (probeSideOuterJoin && probeRecord != null && nextBuildSideRecord == null) {
				matchFunction.join(null, probeRecord, collector);
			}

			if (buildSideOuterJoin && probeRecord == null && nextBuildSideRecord != null) {
				// call match on the first pair
				matchFunction.join(nextBuildSideRecord, null, collector);

				while (this.running && ((nextBuildSideRecord = buildSideIterator.next(nextBuildSideRecord)) != null)) {
					// call match on the next pair
					// make sure we restore the value of the probe side record
					matchFunction.join(nextBuildSideRecord, null, collector);
				}
			}
		}

		return true;
	}
	else {
		return false;
	}
}
 

@Override
public final boolean callWithNextKey(FlatJoinFunction<V1, V2, O> matchFunction, Collector<O> collector)
throws Exception
{
	if (this.hashJoin.nextRecord())
	{
		// we have a next record, get the iterators to the probe and build side values
		final MutableObjectIterator<V1> buildSideIterator = this.hashJoin.getBuildSideIterator();
		final V2 probeRecord = this.hashJoin.getCurrentProbeRecord();
		V1 nextBuildSideRecord = buildSideIterator.next();

		// get the first build side value
		if (probeRecord != null && nextBuildSideRecord != null) {
			V1 tmpRec;

			// check if there is another build-side value
			if ((tmpRec = buildSideIterator.next()) != null) {
				// more than one build-side value --> copy the probe side
				V2 probeCopy;
				probeCopy = this.probeSideSerializer.copy(probeRecord);
				
				// call match on the first pair
				matchFunction.join(nextBuildSideRecord, probeCopy, collector);
				
				// call match on the second pair
				probeCopy = this.probeSideSerializer.copy(probeRecord);
				matchFunction.join(tmpRec, probeCopy, collector);
				
				while (this.running && ((nextBuildSideRecord = buildSideIterator.next()) != null)) {
					// call match on the next pair
					// make sure we restore the value of the probe side record
					probeCopy = this.probeSideSerializer.copy(probeRecord);
					matchFunction.join(nextBuildSideRecord, probeCopy, collector);
				}
			}
			else {
				// only single pair matches
				matchFunction.join(nextBuildSideRecord, probeRecord, collector);
			}
		} else {
			// while probe side outer join, join current probe record with null.
			if (probeSideOuterJoin && probeRecord != null && nextBuildSideRecord == null) {
				matchFunction.join(null, probeRecord, collector);
			}

			// while build side outer join, iterate all build records which have not been probed before,
			// and join with null.
			if (buildSideOuterJoin && probeRecord == null && nextBuildSideRecord != null) {
				matchFunction.join(nextBuildSideRecord, null, collector);

				while (this.running && ((nextBuildSideRecord = buildSideIterator.next()) != null)) {
					matchFunction.join(nextBuildSideRecord, null, collector);
				}
			}
		}

		return true;
	}
	else {
		return false;
	}
}
 

@Override
public boolean callWithNextKey(FlatJoinFunction<V1, V2, O> matchFunction, Collector<O> collector)
throws Exception
{
	if (this.hashJoin.nextRecord())
	{
		// we have a next record, get the iterators to the probe and build side values
		final MutableObjectIterator<V2> buildSideIterator = this.hashJoin.getBuildSideIterator();

		final V1 probeRecord = this.hashJoin.getCurrentProbeRecord();
		V2 nextBuildSideRecord = buildSideIterator.next();

		if (probeRecord != null && nextBuildSideRecord != null) {
			V2 tmpRec;

			// check if there is another build-side value
			if ((tmpRec = buildSideIterator.next()) != null) {
				// more than one build-side value --> copy the probe side
				V1 probeCopy;
				probeCopy = this.probeSideSerializer.copy(probeRecord);

				// call match on the first pair
				matchFunction.join(probeCopy, nextBuildSideRecord, collector);
				
				// call match on the second pair
				probeCopy = this.probeSideSerializer.copy(probeRecord);
				matchFunction.join(probeCopy, tmpRec, collector);
				
				while (this.running && ((nextBuildSideRecord = buildSideIterator.next()) != null)) {
					// call match on the next pair
					// make sure we restore the value of the probe side record
					probeCopy = this.probeSideSerializer.copy(probeRecord);
					matchFunction.join(probeCopy, nextBuildSideRecord, collector);
				}
			}
			else {
				// only single pair matches
				matchFunction.join(probeRecord, nextBuildSideRecord, collector);
			}
		} else {
			// while probe side outer join, join current probe record with null.
			if (probeSideOuterJoin && probeRecord != null && nextBuildSideRecord == null) {
				matchFunction.join(probeRecord, null, collector);
			}

			// while build side outer join, iterate all build records which have not been probed before,
			// and join with null.
			if (buildSideOuterJoin && probeRecord == null && nextBuildSideRecord != null) {
				matchFunction.join(null, nextBuildSideRecord, collector);
				while (this.running && ((nextBuildSideRecord = buildSideIterator.next()) != null)) {
					matchFunction.join(null, nextBuildSideRecord, collector);
				}
			}
		}

		return true;
	}
	else {
		return false;
	}
}