Package org.apache.lucene.spatial.prefix.tree

Interface Cell

All Known Subinterfaces:
CellCanPrune
All Known Implementing Classes:
LegacyCell, NumberRangePrefixTree.NRCell, PackedQuadPrefixTree.PackedQuadCell, QuadPrefixTree.QuadCell
public interface Cell
Represents a grid cell. Cell instances are generally very transient and may be re-used internally. To get an instance, you could start with SpatialPrefixTree.getWorldCell(). And from there you could either traverse down the tree with getNextLevelCells(org.locationtech.spatial4j.shape.Shape), or you could read an indexed term via SpatialPrefixTree.readCell(org.apache.lucene.util.BytesRef,Cell). When a cell is read from a term, it is comprised of just the base bytes plus optionally a leaf flag.
WARNING: This API is experimental and might change in incompatible ways in the next release.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    compareToNoLeaf(Cell fromCell)
    Equivalent to this.getTokenBytesNoLeaf(null).compareTo(fromCell.getTokenBytesNoLeaf(null)).
    int
    getLevel()
    Level 0 is the world (and has no parent), from then on a higher level means a smaller cell than the level before it.
    CellIterator
    getNextLevelCells(org.locationtech.spatial4j.shape.Shape shapeFilter)
    Gets the cells at the next grid cell level underneath this one, optionally filtered by shapeFilter.
    org.locationtech.spatial4j.shape.Shape
    getShape()
    Gets the shape for this cell; typically a Rectangle.
    org.locationtech.spatial4j.shape.SpatialRelation
    getShapeRel()
    Gets the relationship this cell has with the shape from which it was filtered from, assuming it came from a CellIterator.
    BytesRef
    getTokenBytesNoLeaf(BytesRef result)
    Returns the bytes for this cell, without a leaf set.
    BytesRef
    getTokenBytesWithLeaf(BytesRef result)
    Returns the bytes for this cell, with a leaf byte if this is a leaf cell.
    boolean
    isLeaf()
    Some cells are flagged as leaves, which are indexed as such.
    boolean
    isPrefixOf(Cell c)
    Returns if the target term is within/underneath this cell; not necessarily a direct descendant.
    void
    setLeaf()
    Set this cell to be a leaf.
    void
    setShapeRel(org.locationtech.spatial4j.shape.SpatialRelation rel)
    See getShapeRel().

  • Method Details

    • getShapeRel

      org.locationtech.spatial4j.shape.SpatialRelation getShapeRel()
      Gets the relationship this cell has with the shape from which it was filtered from, assuming it came from a CellIterator. Arguably it belongs there but it's very convenient here.

    • setShapeRel

      void setShapeRel(org.locationtech.spatial4j.shape.SpatialRelation rel)
      See getShapeRel().
      NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

    • isLeaf

      boolean isLeaf()
      Some cells are flagged as leaves, which are indexed as such. A leaf cell is either within some shape or it both intersects and the cell is at an accuracy threshold such that no smaller cells for the shape will be represented.

    • setLeaf

      void setLeaf()
      Set this cell to be a leaf. Warning: never call on a cell initialized to reference the same bytes from termsEnum, which should be treated as immutable. Note: not supported at level 0.
      NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

    • getTokenBytesWithLeaf

      BytesRef getTokenBytesWithLeaf(BytesRef result)
      Returns the bytes for this cell, with a leaf byte if this is a leaf cell. The result param is used to save object allocation, though its bytes aren't used.
      Parameters:
      result - where the result goes, or null to create new

    • getTokenBytesNoLeaf

      BytesRef getTokenBytesNoLeaf(BytesRef result)
      Returns the bytes for this cell, without a leaf set. The bytes should sort before getTokenBytesWithLeaf(org.apache.lucene.util.BytesRef). The result param is used to save object allocation, though its bytes aren't used.
      Parameters:
      result - where the result goes, or null to create new

    • getLevel

      int getLevel()
      Level 0 is the world (and has no parent), from then on a higher level means a smaller cell than the level before it.

    • getNextLevelCells

      CellIterator getNextLevelCells(org.locationtech.spatial4j.shape.Shape shapeFilter)
      Gets the cells at the next grid cell level underneath this one, optionally filtered by shapeFilter. The returned cells should have getShapeRel() set to their relation with shapeFilter. In addition, for non-points isLeaf() must be true when that relation is WITHIN.

      IMPORTANT: Cells returned from this iterator can be shared, as well as the bytes.

      Precondition: Never called when getLevel() == maxLevel.

      Parameters:
      shapeFilter - an optional filter for the returned cells.
      Returns:
      A set of cells (no dups), sorted. Not Modifiable.

    • getShape

      org.locationtech.spatial4j.shape.Shape getShape()
      Gets the shape for this cell; typically a Rectangle.

    • isPrefixOf

      boolean isPrefixOf(Cell c)
      Returns if the target term is within/underneath this cell; not necessarily a direct descendant.
      Parameters:
      c - the term

    • compareToNoLeaf

      int compareToNoLeaf(Cell fromCell)
      Equivalent to this.getTokenBytesNoLeaf(null).compareTo(fromCell.getTokenBytesNoLeaf(null)).