public Tuple next()

in tajo-core/tajo-core-backend/src/main/java/org/apache/tajo/engine/planner/physical/MergeJoinExec.java [98:169]
62 lines of code
19 McCabe index (conditional complexity)

  public Tuple next() throws IOException {
    Tuple previous;

    for (;;) {
      if (!outerIterator.hasNext() && !innerIterator.hasNext()) {
        if(end){
          return null;
        }

        if(outerTuple == null){
          outerTuple = leftChild.next();
        }
        if(innerTuple == null){
          innerTuple = rightChild.next();
        }

        outerTupleSlots.clear();
        innerTupleSlots.clear();

        int cmp;
        while ((cmp = joincomparator.compare(outerTuple, innerTuple)) != 0) {
          if (cmp > 0) {
            innerTuple = rightChild.next();
          } else if (cmp < 0) {
            outerTuple = leftChild.next();
          }
          if (innerTuple == null || outerTuple == null) {
            return null;
          }
        }

        try {
          previous = outerTuple.clone();
          do {
            outerTupleSlots.add(outerTuple.clone());
            outerTuple = leftChild.next();
            if (outerTuple == null) {
              end = true;
              break;
            }
          } while (tupleComparator[0].compare(previous, outerTuple) == 0);
          outerIterator = outerTupleSlots.iterator();
          outerNext = outerIterator.next();

          previous = innerTuple.clone();
          do {
            innerTupleSlots.add(innerTuple.clone());
            innerTuple = rightChild.next();
            if (innerTuple == null) {
              end = true;
              break;
            }
          } while (tupleComparator[1].compare(previous, innerTuple) == 0);
          innerIterator = innerTupleSlots.iterator();
        } catch (CloneNotSupportedException e) {

        }
      }

      if(!innerIterator.hasNext()){
        outerNext = outerIterator.next();
        innerIterator = innerTupleSlots.iterator();
      }

      frameTuple.set(outerNext, innerIterator.next());

      if (joinQual.eval(inSchema, frameTuple).isTrue()) {
        projector.eval(frameTuple, outTuple);
        return outTuple;
      }
    }
  }