@Override
public final void reduce(DatumWrapper<ITuple> key, Iterable<NullWritable> values, Context context)
throws IOException, InterruptedException {
try {
Iterator<NullWritable> iterator = values.iterator();
tupleIterator.setIterator(iterator);
ITuple currentTuple = key.datum();
ITuple previousKey = key.previousDatum();
int indexMismatch;
if (firstRun) {
indexMismatch = minDepth;
firstRun = false;
} else {
indexMismatch = indexMismatch(previousKey, currentTuple, 0, maxDepth);
if (indexMismatch < minDepth) {
indexMismatch = minDepth;
}
for (int i = maxDepth; i >= indexMismatch; i--) {
handler.onCloseGroup(
i, groupSchema.getField(i).getName(), previousKey, this.context, collector);
}
}
for (int i = indexMismatch; i <= maxDepth; i++) {
handler.onOpenGroup(
i, groupSchema.getField(i).getName(), currentTuple, this.context, collector);
}
// We set a view over the group fields to the method.
if (isMultipleSources) {
int schemaId = tupleMRConfig.getSchemaIdByName(currentTuple.getSchema().getName());
int[] indexTranslation = serInfo.getGroupSchemaIndexTranslation(schemaId);
groupTuple.setContained(currentTuple, indexTranslation);
} else {
groupTuple.setContained(currentTuple);
}
handler.reduce(groupTuple, tupleIterator, this.context, collector);
// This loop consumes the remaining elements that reduce didn't consume
// The goal of this is to correctly set the last element in the next
// onCloseGroup() call
while (iterator.hasNext()) {
iterator.next();
}
} catch (TupleMRException e) {
throw new RuntimeException(e);
}
}
