Class AbstractVisitingPrefixTreeFilter.VisitorTemplate

An abstract class designed to make it easy to implement predicates or other operations on a SpatialPrefixTree indexed field. An instance of this class is not designed to be re-used across AtomicReaderContext instances so simply create a new one for each call to, say a GetDocIdSet(AtomicReaderContext, IBits). The GetDocIdSet() method here starts the work. It first checks that there are indexed terms; if not it quickly returns null. Then it calls Start() so a subclass can set up a return value, like an FixedBitSet. Then it starts the traversal process, calling FindSubCellsToVisit(Cell) which by default finds the top cells that intersect queryShape. If there isn't an indexed cell for a corresponding cell returned for this method then it's short-circuited until it finds one, at which point Visit(Cell) is called. At some depths, of the tree, the algorithm switches to a scanning mode that calls VisitScanned(Cell) for each leaf cell found.

@lucene.internal