@Override
public void coGroup(
Iterator<Record> candidates, Iterator<Record> current, Collector<Record> out)
throws Exception {
if (!current.hasNext()) {
throw new Exception("Error: Id not encountered before.");
}
Record old = current.next();
long oldId = old.getField(1, LongValue.class).getValue();
long minimumComponentID = Long.MAX_VALUE;
while (candidates.hasNext()) {
long candidateComponentID = candidates.next().getField(1, LongValue.class).getValue();
if (candidateComponentID < minimumComponentID) {
minimumComponentID = candidateComponentID;
}
}
if (minimumComponentID < oldId) {
newComponentId.setValue(minimumComponentID);
old.setField(1, newComponentId);
out.collect(old);
}
}
@Override
public Record combineFirst(Iterator<Record> records) {
Record next = null;
long min = Long.MAX_VALUE;
while (records.hasNext()) {
next = records.next();
min = Math.min(min, next.getField(1, LongValue.class).getValue());
}
newComponentId.setValue(min);
next.setField(1, newComponentId);
return next;
}