Package org.h2.mvstore.rtree

Class SpatialDataType

java.lang.Object

org.h2.mvstore.type.BasicDataType<Spatial>

org.h2.mvstore.rtree.SpatialDataType

All Implemented Interfaces:

java.util.Comparator<Spatial>, DataType<Spatial>

public class SpatialDataType
extends BasicDataType<Spatial>

A spatial data type. This class supports up to 31 dimensions. Each dimension can have a minimum and a maximum value of type float. For each dimension, the maximum value is only stored when it is not the same as the minimum.

Constructor Summary

Constructors

Constructor	Description
SpatialDataType(int dimensions)

Method Summary

Modifier and Type	Method	Description
int	compare(Spatial a, Spatial b)	Compare two keys.
boolean	contains(Spatial bounds, Spatial object)	Check whether bounds contains object.
protected Spatial	create(long id, float... minMax)	Creates spatial object with specified parameters.
Spatial[]	createStorage(int size)	Create storage object of array type to hold values
boolean	equals(Spatial a, Spatial b)	Check whether two spatial values are equal.
float	getAreaIncrease(Spatial bounds, Spatial add)	Get the area increase by extending a to contain b.
int[]	getExtremes(java.util.ArrayList<Spatial> list)	Get the most extreme pair (elements that are as far apart as possible).
int	getMemory(Spatial obj)	Calculates the amount of used memory in bytes.
void	increaseBounds(Spatial bounds, Spatial add)	Increase the bounds in the given spatial object.
boolean	isInside(Spatial object, Spatial bounds)	Check whether object is completely inside bounds and does not touch them.
boolean	isOverlap(Spatial a, Spatial b)	Check whether the two objects overlap.
Spatial	read(java.nio.ByteBuffer buff)	Read an object.
void	write(WriteBuffer buff, Spatial k)	Write an object.

Methods inherited from class org.h2.mvstore.type.BasicDataType

binarySearch, cast, equals, hashCode, isMemoryEstimationAllowed, read, write

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

SpatialDataType

public SpatialDataType(int dimensions)

Method Detail

create

protected Spatial create(long id,
                         float... minMax)

Creates spatial object with specified parameters.

Parameters:

id - the ID

minMax - min x, max x, min y, max y, and so on

Returns:

the spatial object

createStorage

public Spatial[] createStorage(int size)

Description copied from interface: DataType

Create storage object of array type to hold values

Parameters:

size - number of values to hold

Returns:

storage object

compare

public int compare(Spatial a,
                   Spatial b)

Description copied from interface: DataType

Compare two keys.

Specified by:

compare in interface java.util.Comparator<Spatial>

Specified by:

compare in interface DataType<Spatial>

Overrides:

compare in class BasicDataType<Spatial>

Parameters:

a - the first key

b - the second key

Returns:

-1 if the first key is smaller, 1 if larger, and 0 if equal

equals

public boolean equals(Spatial a,
                      Spatial b)

Check whether two spatial values are equal.

Parameters:

a - the first value

b - the second value

Returns:

true if they are equal

getMemory

public int getMemory(Spatial obj)

Description copied from interface: DataType

Calculates the amount of used memory in bytes.

Specified by:

getMemory in interface DataType<Spatial>

Specified by:

getMemory in class BasicDataType<Spatial>

Parameters:

obj - the object

Returns:

the used memory

write

public void write(WriteBuffer buff,
                  Spatial k)

Description copied from interface: DataType

Write an object.

Specified by:

write in interface DataType<Spatial>

Specified by:

write in class BasicDataType<Spatial>

Parameters:

buff - the target buffer

k - the value

read

public Spatial read(java.nio.ByteBuffer buff)

Description copied from interface: DataType

Read an object.

Specified by:

read in interface DataType<Spatial>

Specified by:

read in class BasicDataType<Spatial>

Parameters:

buff - the source buffer

Returns:

the object

isOverlap

public boolean isOverlap(Spatial a,
                         Spatial b)

Check whether the two objects overlap.

Parameters:

a - the first object

b - the second object

Returns:

true if they overlap

increaseBounds

public void increaseBounds(Spatial bounds,
                           Spatial add)

Increase the bounds in the given spatial object.

Parameters:

bounds - the bounds (may be modified)

add - the value

getAreaIncrease

public float getAreaIncrease(Spatial bounds,
                             Spatial add)

Get the area increase by extending a to contain b.

Parameters:

bounds - the bounding box

add - the object

Returns:

the area

contains

public boolean contains(Spatial bounds,
                        Spatial object)

Check whether bounds contains object.

Parameters:

bounds - the bounding box

object - the object

Returns:

the area

isInside

public boolean isInside(Spatial object,
                        Spatial bounds)

Check whether object is completely inside bounds and does not touch them.

Parameters:

object - the object to check

bounds - the bounds

Returns:

true if a is completely inside b

getExtremes

public int[] getExtremes(java.util.ArrayList<Spatial> list)

Get the most extreme pair (elements that are as far apart as possible). This method is used to split a page (linear split). If no extreme objects could be found, this method returns null.

Parameters:

list - the objects

Returns:

the indexes of the extremes