org.h2.mvstore.rtree
Class SpatialType

java.lang.Object
  org.h2.mvstore.rtree.SpatialType

All Implemented Interfaces:

DataType

public class SpatialType
extends java.lang.Object
implements DataType

A spatial data type. This class supports up to 255 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

SpatialType(int dimensions)

Method Summary

java.lang.String	asString() Get the stable string representation that is used to build this data type.
int	compare(java.lang.Object a, java.lang.Object b) Compare two keys.
boolean	contains(java.lang.Object objA, java.lang.Object objB) Check whether a contains b.
boolean	equals(java.lang.Object a, java.lang.Object b) Check whether two spatial values are equal.
static SpatialType	fromString(java.lang.String s) Read a value from a string.
float	getAreaIncrease(java.lang.Object objA, java.lang.Object objB) Get the area increase by extending a to contain b.
int[]	getExtremes(java.util.ArrayList<java.lang.Object> list) Get the most extreme pair (elements that are as far apart as possible).
int	getMaxLength(java.lang.Object obj) Get the maximum length in bytes used to store an object.
int	getMemory(java.lang.Object obj) Estimate the used memory in bytes.
void	increaseBounds(java.lang.Object bounds, java.lang.Object add) Increase the bounds in the given spatial object.
boolean	isInside(java.lang.Object objA, java.lang.Object objB) Check whether a is completely inside b and does not touch the given bound.
boolean	isOverlap(java.lang.Object objA, java.lang.Object objB) Check whether the two objects overlap.
java.lang.Object	read(java.nio.ByteBuffer buff) Read an object.
void	write(java.nio.ByteBuffer buff, java.lang.Object obj) Write the object.

Methods inherited from class java.lang.Object

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

Constructor Detail

SpatialType

public SpatialType(int dimensions)

Method Detail

fromString

public static SpatialType fromString(java.lang.String s)

Read a value from a string.

Parameters:

s - the string

Returns:

the value

compare

public int compare(java.lang.Object a,
                   java.lang.Object b)

Description copied from interface: DataType

Compare two keys.

Specified by:

compare in interface DataType

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(java.lang.Object a,
                      java.lang.Object b)

Check whether two spatial values are equal.

Parameters:

a - the first value

b - the second value

Returns:

true if they are equal

getMaxLength

public int getMaxLength(java.lang.Object obj)

Description copied from interface: DataType

Get the maximum length in bytes used to store an object. In many cases, this method can be faster than calculating the exact length.

Specified by:

getMaxLength in interface DataType

Parameters:

obj - the object

Returns:

the maximum length

getMemory

public int getMemory(java.lang.Object obj)

Description copied from interface: DataType

Estimate the used memory in bytes.

Specified by:

getMemory in interface DataType

Parameters:

obj - the object

Returns:

the used memory

write

public void write(java.nio.ByteBuffer buff,
                  java.lang.Object obj)

Description copied from interface: DataType

Write the object.

Specified by:

write in interface DataType

Parameters:

buff - the target buffer

obj - the value

read

public java.lang.Object read(java.nio.ByteBuffer buff)

Description copied from interface: DataType

Read an object.

Specified by:

read in interface DataType

Parameters:

buff - the source buffer

Returns:

the object

asString

public java.lang.String asString()

Description copied from interface: DataType

Get the stable string representation that is used to build this data type.

To avoid conflict with the default factory, the returned string should start with the package name of the type factory.

Specified by:

asString in interface DataType

Returns:

the string representation

isOverlap

public boolean isOverlap(java.lang.Object objA,
                         java.lang.Object objB)

Check whether the two objects overlap.

Parameters:

objA - the first object

objB - the second object

Returns:

true if they overlap

increaseBounds

public void increaseBounds(java.lang.Object bounds,
                           java.lang.Object add)

Increase the bounds in the given spatial object.

Parameters:

bounds - the bounds (may be modified)

add - the value

getAreaIncrease

public float getAreaIncrease(java.lang.Object objA,
                             java.lang.Object objB)

Get the area increase by extending a to contain b.

Parameters:

objA - the bounding box

objB - the object

Returns:

the area

contains

public boolean contains(java.lang.Object objA,
                        java.lang.Object objB)

Check whether a contains b.

Parameters:

objA - the bounding box

objB - the object

Returns:

the area

isInside

public boolean isInside(java.lang.Object objA,
                        java.lang.Object objB)

Check whether a is completely inside b and does not touch the given bound.

Parameters:

objA - the object to check

objB - the bounds

Returns:

true if a is completely inside b

getExtremes

public int[] getExtremes(java.util.ArrayList<java.lang.Object> 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