Class AbstractSTRtree

  • All Implemented Interfaces:
    Serializable
    Direct Known Subclasses:
    SIRtree, STRtree

    public abstract class AbstractSTRtree
    extends Object
    implements Serializable
    Base class for STRtree and SIRtree. STR-packed R-trees are described in: P. Rigaux, Michel Scholl and Agnes Voisard. Spatial Databases With Application To GIS. Morgan Kaufmann, San Francisco, 2002.

    This implementation is based on Boundables rather than AbstractNodes, because the STR algorithm operates on both nodes and data, both of which are treated as Boundables.

    This class is thread-safe. Building the tree is synchronized, and querying is stateless.

    Version:
    1.7
    See Also:
    STRtree, SIRtree, Serialized Form
    • Constructor Detail

      • AbstractSTRtree

        public AbstractSTRtree()
        Constructs an AbstractSTRtree with the default node capacity.
      • AbstractSTRtree

        public AbstractSTRtree​(int nodeCapacity)
        Constructs an AbstractSTRtree with the specified maximum number of child nodes that a node may have
        Parameters:
        nodeCapacity - the maximum number of child nodes in a node
      • AbstractSTRtree

        public AbstractSTRtree​(int nodeCapacity,
                               AbstractNode root)
        Constructs an AbstractSTRtree with the specified maximum number of child nodes that a node may have, and the root node
        Parameters:
        nodeCapacity - the maximum number of child nodes in a node
        root - the root node that links to all other nodes in the tree
      • AbstractSTRtree

        public AbstractSTRtree​(int nodeCapacity,
                               ArrayList itemBoundables)
        Constructs an AbstractSTRtree with the specified maximum number of child nodes that a node may have, and all leaf nodes in the tree
        Parameters:
        nodeCapacity - the maximum number of child nodes in a node
        itemBoundables - the list of leaf nodes in the tree
    • Method Detail

      • build

        public void build()
        Creates parent nodes, grandparent nodes, and so forth up to the root node, for the data that has been inserted into the tree. Can only be called once, and thus can be called only after all of the data has been inserted into the tree.
      • createNode

        protected abstract AbstractNode createNode​(int level)
      • createParentBoundables

        protected List createParentBoundables​(List childBoundables,
                                              int newLevel)
        Sorts the childBoundables then divides them into groups of size M, where M is the node capacity.
      • compareDoubles

        protected static int compareDoubles​(double a,
                                            double b)
      • getRoot

        public AbstractNode getRoot()
        Gets the root node of the tree.
        Returns:
        the root node
      • getNodeCapacity

        public int getNodeCapacity()
        Returns the maximum number of child nodes that a node may have.
        Returns:
        the node capacity
      • isEmpty

        public boolean isEmpty()
        Tests whether the index contains any items. This method does not build the index, so items can still be inserted after it has been called.
        Returns:
        true if the index does not contain any items
      • size

        protected int size()
      • depth

        protected int depth()
      • insert

        protected void insert​(Object bounds,
                              Object item)
      • query

        protected List query​(Object searchBounds)
        Also builds the tree, if necessary.
      • query

        protected void query​(Object searchBounds,
                             ItemVisitor visitor)
        Also builds the tree, if necessary.
      • itemsTree

        public List itemsTree()
        Gets a tree structure (as a nested list) corresponding to the structure of the items and nodes in this tree.

        The returned Lists contain either Object items, or Lists which correspond to subtrees of the tree Subtrees which do not contain any items are not included.

        Builds the tree if necessary.

        Returns:
        a List of items and/or Lists
      • remove

        protected boolean remove​(Object searchBounds,
                                 Object item)
        Removes an item from the tree. (Builds the tree, if necessary.)
      • boundablesAtLevel

        protected List boundablesAtLevel​(int level)
      • getComparator

        protected abstract Comparator getComparator()