org.locationtech.geowave.core.index.sfc.hilbert

Class HilbertSFC

java.lang.Object

org.locationtech.geowave.core.index.sfc.hilbert.HilbertSFC

All Implemented Interfaces:

Persistable, SpaceFillingCurve

public class HilbertSFC
extends Object
implements SpaceFillingCurve

Implementation of a Compact Hilbert space filling curve

Field Summary

Fields

Modifier and Type	Field and Description
protected com.google.uzaygezen.core.CompactHilbertCurve	compactHilbertCurve
protected HilbertSFCOperations	decomposeQueryOperations
protected SFCDimensionDefinition[]	dimensionDefinitions
protected HilbertSFCOperations	getIdOperations
protected int	totalPrecision

Constructor Summary

Constructors

Constructor and Description
HilbertSFC()
HilbertSFC(SFCDimensionDefinition[] dimensionDefs) Use the SFCFactory.createSpaceFillingCurve method - don't call this constructor directly

Method Summary

Modifier and Type	Method and Description
RangeDecomposition	decomposeRange(MultiDimensionalNumericData query, boolean overInclusiveOnEdge, int maxFilteredIndexedRanges) * Returns a collection of ranges on the 1-d space filling curve that correspond to the n-dimensional range described in the query parameter.
RangeDecomposition	decomposeRangeFully(MultiDimensionalNumericData query) * Returns a collection of ranges on the 1-d space filling curve that correspond to the n-dimensional range described in the query parameter.
boolean	equals(Object obj)
protected static byte[]	fitExpectedByteCount(int expectedByteCount, byte[] bytes)
void	fromBinary(byte[] bytes) Convert a stream of binary bytes to fields and data within an object.
long[]	getCoordinates(byte[] id) * Gets n-dimensional coordinates from a single dimension
BigInteger	getEstimatedIdCount(MultiDimensionalNumericData data) * Determines the estimated number of rows a multi-dimensional range will span within this space filling curve
byte[]	getId(Double[] values) * Maps a n-dimensional value to a single dimension, i.e.
double[]	getInsertionIdRangePerDimension() * Get the range/size of a single insertion ID for each dimension
MultiDimensionalNumericData	getRanges(byte[] id) * Gets n-dimensional ranges from a single dimension, i.e.
int	hashCode()
protected void	init(SFCDimensionDefinition[] dimensionDefs)
long[]	normalizeRange(double minValue, double maxValue, int dimension) * Determines the coordinates within this space filling curve for a dimension given a range
protected void	setOptimalOperations(int totalPrecision, List<Integer> bitsPerDimension, SFCDimensionDefinition[] dimensionDefs)
byte[]	toBinary() Convert fields and data within an object to binary form for transmission or storage.

Methods inherited from class java.lang.Object

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

Field Detail

compactHilbertCurve

protected com.google.uzaygezen.core.CompactHilbertCurve compactHilbertCurve

dimensionDefinitions

protected SFCDimensionDefinition[] dimensionDefinitions

totalPrecision

protected int totalPrecision

getIdOperations

protected HilbertSFCOperations getIdOperations

decomposeQueryOperations

protected HilbertSFCOperations decomposeQueryOperations

Constructor Detail

HilbertSFC

public HilbertSFC()

HilbertSFC

public HilbertSFC(SFCDimensionDefinition[] dimensionDefs)

Use the SFCFactory.createSpaceFillingCurve method - don't call this constructor directly

Method Detail

init

protected void init(SFCDimensionDefinition[] dimensionDefs)

setOptimalOperations

protected void setOptimalOperations(int totalPrecision,
                                    List<Integer> bitsPerDimension,
                                    SFCDimensionDefinition[] dimensionDefs)

getId

public byte[] getId(Double[] values)

* Maps a n-dimensional value to a single dimension, i.e. [12,33] -> 0033423

Specified by:

getId in interface SpaceFillingCurve

Parameters:

values - n-dimensional value to be encoded in the SFC. The size of value corresponds to the number of dimensions

Returns:

value derived from the the SFC transform. The value is left padded based on the number if bits in the SFC dimension

decomposeRangeFully

public RangeDecomposition decomposeRangeFully(MultiDimensionalNumericData query)

* Returns a collection of ranges on the 1-d space filling curve that correspond to the n-dimensional range described in the query parameter.

This method will decompose the range all the way down to the unit interval of 1.

Specified by:

decomposeRangeFully in interface SpaceFillingCurve

Parameters:

query - describes the n-dimensional query window that will be decomposed

Returns:

an object containing the ranges on the SFC that overlap the parameters supplied in the query object

decomposeRange

public RangeDecomposition decomposeRange(MultiDimensionalNumericData query,
                                         boolean overInclusiveOnEdge,
                                         int maxFilteredIndexedRanges)

* Returns a collection of ranges on the 1-d space filling curve that correspond to the n-dimensional range described in the query parameter.

This method will roll up the ranges based on the maxRanges parameter. Ranges will be "connected" based on the minimization of distance between the end of one range and the start of the next.

Specified by:

decomposeRange in interface SpaceFillingCurve

Parameters:

query - describes the n-dimensional query window that will be decomposed

Returns:

an object containing the ranges on the SFC that overlap the parameters supplied in the query object

fitExpectedByteCount

protected static byte[] fitExpectedByteCount(int expectedByteCount,
                                             byte[] bytes)

toBinary

public byte[] toBinary()

Description copied from interface: Persistable

Convert fields and data within an object to binary form for transmission or storage.

Specified by:

toBinary in interface Persistable

Returns:

an array of bytes representing a binary stream representation of the object.

fromBinary

public void fromBinary(byte[] bytes)

Description copied from interface: Persistable

Convert a stream of binary bytes to fields and data within an object.

Specified by:

fromBinary in interface Persistable

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

getEstimatedIdCount

public BigInteger getEstimatedIdCount(MultiDimensionalNumericData data)

Description copied from interface: SpaceFillingCurve

* Determines the estimated number of rows a multi-dimensional range will span within this space filling curve

Specified by:

getEstimatedIdCount in interface SpaceFillingCurve

Parameters:

data - describes the n-dimensional range to estimate the row count for

Returns:

an estimate of the row count for the ranges given within this space filling curve

getRanges

public MultiDimensionalNumericData getRanges(byte[] id)

Description copied from interface: SpaceFillingCurve

* Gets n-dimensional ranges from a single dimension, i.e. 0033423 -> [12,33]

Specified by:

getRanges in interface SpaceFillingCurve

Parameters:

id - the SFC ID to calculate the ranges of values represented.

Returns:

the valid ranges per dimension of a single SFC ID derived from the the SFC transform.

normalizeRange

public long[] normalizeRange(double minValue,
                             double maxValue,
                             int dimension)

Description copied from interface: SpaceFillingCurve

* Determines the coordinates within this space filling curve for a dimension given a range

Specified by:

normalizeRange in interface SpaceFillingCurve

Parameters:

minValue - describes the minimum of a range in a single dimension used to determine the SFC coordinate range

maxValue - describes the maximum of a range in a single dimension used to determine the SFC coordinate range

dimension - the dimension

Returns:

the range of coordinates as an array where the first element is the min and the second element is the max

getCoordinates

public long[] getCoordinates(byte[] id)

Description copied from interface: SpaceFillingCurve

* Gets n-dimensional coordinates from a single dimension

Specified by:

getCoordinates in interface SpaceFillingCurve

Parameters:

id - the SFC ID to calculate the coordinates for each dimension.

Returns:

the coordinate in each dimension for the given ID

getInsertionIdRangePerDimension

public double[] getInsertionIdRangePerDimension()

Description copied from interface: SpaceFillingCurve

* Get the range/size of a single insertion ID for each dimension

Specified by:

getInsertionIdRangePerDimension in interface SpaceFillingCurve

Returns:

the range of a single insertion ID for each dimension