Module org.elasticsearch.geo

Package org.elasticsearch.geometry.simplify

Class StreamingGeometrySimplifier<T extends Geometry>

java.lang.Object

org.elasticsearch.geometry.simplify.StreamingGeometrySimplifier<T>

Direct Known Subclasses:

StreamingGeometrySimplifier.LinearRingSimplifier, StreamingGeometrySimplifier.LineSimplifier, StreamingGeometrySimplifier.PolygonSimplifier

public abstract class StreamingGeometrySimplifier<T extends Geometry>
extends Object

The streaming geometry simplifier can only simplify geometries composed on a single list of Points provided on a stream. This includes Line, LinearRing and Polygon (with no holes). To produce such a geometry from a stream, perform the following steps:

• Construct the simplifier with the maximum number of points allowed, or call reset() on a previously used simplifier
• Call consume(x, y) for each incoming point on the stream
• Call produce() to generate the final simplified geometry of the desired type

Regardless of the number of times consume(x, y) is called, the internal state will never contain more than the stated maximum number of points (plus one for sorting), and the final geometry will be that size, or smaller (if fewer points were consumed).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	StreamingGeometrySimplifier.LinearRingSimplifier	This behaves the same as the LineSimplifier except that it assumes the first and last point are the same point.
static class	StreamingGeometrySimplifier.LineSimplifier	Simplifies a Line geometry to the specified maximum number of points.
static interface	StreamingGeometrySimplifier.Monitor	Implementation of this interface will receive calls with internal data at each step of the simplification algorithm.
static interface	StreamingGeometrySimplifier.PointConstructor	Override this method to use alternative objects within the algorithm.
static class	StreamingGeometrySimplifier.PointError	Each point on the geometry has an error estimate, which is a measure of how much error would be introduced to the geometry should this point be removed from the geometry.
static interface	StreamingGeometrySimplifier.PointResetter	Override this method to use alternative objects within the algorithm.
static class	StreamingGeometrySimplifier.PolygonSimplifier	As with the LinearRingSimplifier, this works similarly to the LineSimplifier except that it assumes the and requires that first and last point are the same point.

Field Summary

Fields

Modifier and Type	Field	Description
protected final SimplificationErrorCalculator	calculator
protected String	description
protected StreamingGeometrySimplifier.PointError	lastRemoved
protected int	length
protected final int	maxPoints
protected final StreamingGeometrySimplifier.Monitor	monitor
protected int	objCount
protected StreamingGeometrySimplifier.PointConstructor	pointConstructor
protected StreamingGeometrySimplifier.PointResetter	pointResetter
protected final StreamingGeometrySimplifier.PointError[]	points
protected final PriorityQueue<StreamingGeometrySimplifier.PointError>	queue

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	StreamingGeometrySimplifier(String description, int maxPoints, SimplificationErrorCalculator calculator, StreamingGeometrySimplifier.Monitor monitor)

Method Summary

Modifier and Type	Method	Description
void	consume(double x, double y)	Consume a single point on the stream of points to be simplified.
void	consume(StreamingGeometrySimplifier.PointError pointError)	Consume a single point on the stream of points to be simplified.
protected void	notifyMonitorPointAdded()
protected void	notifyMonitorPointRemoved(StreamingGeometrySimplifier.PointError removed)
abstract T	produce()	Produce the simplified geometry from the consumed points
void	reset()	Initialize for simplifying using a stream of points.

Methods inherited from class java.lang.Object

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

Field Details

maxPoints

protected final int maxPoints

calculator

protected final SimplificationErrorCalculator calculator

points

protected final StreamingGeometrySimplifier.PointError[] points

lastRemoved

protected StreamingGeometrySimplifier.PointError lastRemoved

monitor

protected final StreamingGeometrySimplifier.Monitor monitor

length

protected int length

objCount

protected int objCount

description

protected String description

pointConstructor

protected StreamingGeometrySimplifier.PointConstructor pointConstructor

pointResetter

protected StreamingGeometrySimplifier.PointResetter pointResetter

queue

protected final PriorityQueue<StreamingGeometrySimplifier.PointError> queue

Constructor Details

StreamingGeometrySimplifier

protected StreamingGeometrySimplifier(String description,
 int maxPoints,
 SimplificationErrorCalculator calculator,
 StreamingGeometrySimplifier.Monitor monitor)

Method Details

reset

public void reset()

Initialize for simplifying using a stream of points. To save on memory it is useful to re-use the same simplifier instance for multiple geometries. Make sure to call reset before each to mark a separation.

consume

public void consume(double x,
 double y)

Consume a single point on the stream of points to be simplified. The internal PointError objects will be re-used from a pool of at most maxPoints + 1 objects.

consume

public void consume(StreamingGeometrySimplifier.PointError pointError)

Consume a single point on the stream of points to be simplified. No memory management of the points passed in is done, so only use this call if you manage these objects from calling code.

produce

public abstract T produce()

Produce the simplified geometry from the consumed points

notifyMonitorPointRemoved

protected void notifyMonitorPointRemoved(StreamingGeometrySimplifier.PointError removed)

notifyMonitorPointAdded

protected void notifyMonitorPointAdded()