geos::index::strtree::STRtree Class Reference

A query-only R-tree created using the Sort-Tile-Recursive (STR) algorithm. For two-dimensional spatial data. More...

#include <STRtree.h>

Inheritance diagram for geos::index::strtree::STRtree:

Public Member Functions
	STRtree (std::size_t nodeCapacity=10)
void	insert (const geom::Envelope *itemEnv, void *item) override
	Adds a spatial item with an extent specified by the given Envelope to the index.
void	query (const geom::Envelope *searchEnv, std::vector< void * > &matches) override
	Queries the index for all items whose extents intersect the given search Envelope.
void	query (const geom::Envelope *searchEnv, ItemVisitor &visitor) override
	Queries the index for all items whose extents intersect the given search Envelope and applies an ItemVisitor to them.
std::pair< const void *, const void * >	nearestNeighbour (ItemDistance *itemDist)
const void *	nearestNeighbour (const geom::Envelope *env, const void *item, ItemDistance *itemDist)
std::pair< const void *, const void * >	nearestNeighbour (STRtree *tree, ItemDistance *itemDist)
std::pair< const void *, const void * >	nearestNeighbour (BoundablePair *initBndPair)
std::pair< const void *, const void * >	nearestNeighbour (BoundablePair *initBndPair, double maxDistance)
bool	remove (const geom::Envelope *itemEnv, void *item) override
	Removes a single item from the tree.
bool	isWithinDistance (STRtree *tree, ItemDistance *itemDist, double maxDistance)
Public Member Functions inherited from geos::index::strtree::AbstractSTRtree
	AbstractSTRtree (std::size_t newNodeCapacity)
	Constructs an AbstractSTRtree with the specified maximum number of child nodes that a node may have.
virtual 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.
virtual std::size_t	getNodeCapacity ()
	Returns the maximum number of child nodes that a node may have.
void	iterate (ItemVisitor &visitor)
virtual void	boundablesAtLevel (int level, AbstractNode *top, BoundableList *boundables)
ItemsList *	itemsTree ()
	Gets a tree structure (as a nested list) corresponding to the structure of the items and nodes in this tree.

Static Public Member Functions
static double	avg (double a, double b)
static double	centreY (const geom::Envelope *e)

Protected Member Functions
AbstractNode *	createNode (int level) override
IntersectsOp *	getIntersectsOp () override
Protected Member Functions inherited from geos::index::strtree::AbstractSTRtree
virtual AbstractNode *	lastNode (BoundableList *nodeList)
virtual AbstractNode *	getRoot ()
void	query (const void *searchBounds, std::vector< void * > &foundItems)
	Also builds the tree, if necessary.
void	query (const void *searchBounds, ItemVisitor &visitor)
	Also builds the tree, if necessary.
void	query (const void *searchBounds, const AbstractNode &node, ItemVisitor &visitor)
bool	remove (const void *itemEnv, void *item)
	Also builds the tree, if necessary.
std::unique_ptr< BoundableList >	boundablesAtLevel (int level)

Additional Inherited Members
Protected Attributes inherited from geos::index::strtree::AbstractSTRtree
AbstractNode *	root
std::vector< AbstractNode * > *	nodes
std::size_t	nodeCapacity

Detailed Description

A query-only R-tree created using the Sort-Tile-Recursive (STR) algorithm. For two-dimensional spatial data.

The STR packed R-tree is simple to implement and maximizes space utilization; that is, as many leaves as possible are filled to capacity. Overlap between nodes is far less than in a basic R-tree. However, once the tree has been built (explicitly or on the first call to query), items may not be added or removed.

Described in: P. Rigaux, Michel Scholl and Agnes Voisard. Spatial Databases With Application To GIS. Morgan Kaufmann, San Francisco, 2002.

Constructor & Destructor Documentation

STRtree()

geos::index::strtree::STRtree::STRtree

(

std::size_t

nodeCapacity = 10

)

Constructs an STRtree with the given maximum number of child nodes that a node may have

Member Function Documentation

createNode()

AbstractNode * geos::index::strtree::STRtree::createNode ( int  level )

overrideprotectedvirtual

Implements geos::index::strtree::AbstractSTRtree.

getIntersectsOp()

IntersectsOp * geos::index::strtree::STRtree::getIntersectsOp ( )

inlineoverrideprotectedvirtual

Returns

a test for intersection between two bounds, necessary because subclasses of AbstractSTRtree have different implementations of bounds.

See also

IntersectsOp

Implements geos::index::strtree::AbstractSTRtree.

insert()

void geos::index::strtree::STRtree::insert ( const geom::Envelope *  itemEnv, void *  item  )

overridevirtual

Adds a spatial item with an extent specified by the given Envelope to the index.

Parameters

itemEnv	Envelope of the item, ownership left to caller. TODO: Reference hold by this class ?
item	Opaque item, ownership left to caller. Reference hold by this class.

Implements geos::index::SpatialIndex.

query() [1/2]

void geos::index::strtree::STRtree::query ( const geom::Envelope *  searchEnv, ItemVisitor &  visitor  )

inlineoverridevirtual

Queries the index for all items whose extents intersect the given search Envelope and applies an ItemVisitor to them.

Note that some kinds of indexes may also return objects which do not in fact intersect the query envelope.

Parameters

searchEnv	the envelope to query for
visitor	a visitor object to apply to the items found

Implements geos::index::SpatialIndex.

query() [2/2]

void geos::index::strtree::STRtree::query ( const geom::Envelope *  searchEnv, std::vector< void * > &    )

inlineoverridevirtual

Queries the index for all items whose extents intersect the given search Envelope.

Note that some kinds of indexes may also return objects which do not in fact intersect the query envelope.

Parameters

searchEnv

the envelope to query for

Implements geos::index::SpatialIndex.

remove()

bool geos::index::strtree::STRtree::remove ( const geom::Envelope *  itemEnv, void *  item  )

inlineoverridevirtual

Removes a single item from the tree.

Parameters

itemEnv	the Envelope of the item to remove
item	the item to remove

Returns

true if the item was found

Implements geos::index::SpatialIndex.

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The documentation for this class was generated from the following file:

• STRtree.h