Method Next

iterator.go:229–287

Next returns ErrIteratorDone if the iterator is done.

()

// Next returns ErrIteratorDone if the iterator is done.
func (iter *iterator) Next() error {
	if len(iter.cursors) <= 0 {
		return ErrIteratorDone
	}

	lastK := iter.cursors[0].k

	for len(iter.cursors) > 0 {
		next := iter.cursors[0]

		if next.ssIndex < 0 && next.sc == nil {
			err := iter.lowerLevelIter.Next()
			if err == nil {
				next.k, next.v, err = iter.lowerLevelIter.Current()
				if err == nil && len(iter.cursors) > 1 {
					heap.Fix(iter, 0)
				}
			}

			if err != nil {
				iter.lowerLevelIter.Close()
				iter.lowerLevelIter = nil

				heap.Pop(iter)
			}
		} else {
			err := next.sc.Next()
			if err != nil {
				if err != ErrIteratorDone {
					return err
				}
				heap.Pop(iter)
			} else {
				next.op, next.k, next.v = next.sc.Current()
				if next.op == 0 {
					heap.Pop(iter)
				} else if len(iter.cursors) > 1 {
					heap.Fix(iter, 0)
				}
			}
		}

		if len(iter.cursors) <= 0 {
			return ErrIteratorDone
		}

		if !iteratorBytesEqual(iter.cursors[0].k, lastK) {
			if !iter.iteratorOptions.IncludeDeletions &&
				iter.cursors[0].op == OperationDel {
				lastK = iter.cursors[0].k
				continue
			}

			return nil
		}
	}

	return ErrIteratorDone