Skip to content

Commit

Permalink
Fixed performance bug with not filtering out tiels early
Browse files Browse the repository at this point in the history
  • Loading branch information
@craigtaverner @Lojjs
craigtaverner authored and Lojjs committed Feb 15, 2018
1 parent 4ed4243 commit 74bcf34
Show file tree
Hide file tree
Showing 2 changed files with 149 additions and 15 deletions.
133 changes: 121 additions & 12 deletions ...ity/spatial-index/src/main/java/org/neo4j/gis/spatial/index/curves/SpaceFillingCurve.java
View file
Expand Up @@ -256,15 +256,38 @@ long[] normalizedCoordinateFor( long derivedValue, int level )
* Given an envelope, find a collection of LongRange of tiles intersecting it on maxLevel and merge adjacent ones
*/
public List<LongRange> getTilesIntersectingEnvelope( Envelope referenceEnvelope )
{
return getTilesIntersectingEnvelope( referenceEnvelope, new RecursionStats( this.maxLevel ) );
}

/**
* Given an envelope, find a collection of LongRange of tiles intersecting it on maxLevel and merge adjacent ones
*/
List<LongRange> getTilesIntersectingEnvelope( Envelope referenceEnvelope, RecursionStats stats )
{
SearchEnvelope search = new SearchEnvelope( referenceEnvelope );
ArrayList<LongRange> results = new ArrayList<>();
ArrayList<LongRange> results = new ArrayList<>(1000);

addTilesIntersectingEnvelopeAt( search, new SearchEnvelope( 0, this.getWidth(), nbrDim ), rootCurve(), 0, this.getValueWidth(), results );
addTilesIntersectingEnvelopeAt( stats, 0, search, new SearchEnvelope( 0, this.getWidth(), nbrDim ), rootCurve(), 0, this.getValueWidth(), results );
return results;
}

private void addTilesIntersectingEnvelopeAt( SearchEnvelope search, SearchEnvelope currentExtent, CurveRule curve, long left, long right,
public static class RecursionStats
{
int maxDepth=0;
int[] counts;
RecursionStats(int maxLevel)
{
this.counts = new int[maxLevel + 1];
}
void mark(int depth)
{
maxDepth = Math.max( maxDepth, depth );
counts[depth] ++;
}
}

private void addTilesIntersectingEnvelopeAt( RecursionStats stats, int depth, SearchEnvelope search, SearchEnvelope currentExtent, CurveRule curve, long left, long right,
ArrayList<LongRange> results )
{
if ( right - left == 1 )
Expand All @@ -283,16 +306,36 @@ private void addTilesIntersectingEnvelopeAt( SearchEnvelope search, SearchEnvelo
results.add( current );
}
}
stats.mark( depth );
}
else if ( search.intersects( currentExtent ) )
{
long width = (right - left) / quadFactor;
for ( int i = 0; i < quadFactor; i++ )
double overlap = search.fractionOf( currentExtent );
if ( overlap >= 0.50 )
{
// Note that LongRange upper bound is inclusive, hence the '-1' in several places
LongRange current = (results.size() > 0) ? results.get( results.size() - 1 ) : null;
if ( current != null && current.max == left - 1 )
{
current.expandToMax( right - 1 );
}
else
{
current = new LongRange( left, right - 1 );
results.add( current );
}
stats.mark( depth );
}
else
{
int npoint = curve.npointForIndex( i );
long width = (right - left) / quadFactor;
for ( int i = 0; i < quadFactor; i++ )
{
int npoint = curve.npointForIndex( i );

SearchEnvelope quadrant = currentExtent.quadrant( bitValues( npoint ) );
addTilesIntersectingEnvelopeAt( search, quadrant, curve.childAt( i ), left + i * width, left + (i + 1) * width, results );
SearchEnvelope quadrant = currentExtent.quadrant( bitValues( npoint ) );
addTilesIntersectingEnvelopeAt( stats, depth + 1, search, quadrant, curve.childAt( i ), left + i * width, left + (i + 1) * width, results );
}
}
}
}
Expand Down Expand Up @@ -426,15 +469,19 @@ public String toString()
*/
private class SearchEnvelope
{
long[] min;
long[] max;
long[] min; // inclusive lower bounds
long[] max; // exclusive upper bounds
int nbrDim;

private SearchEnvelope( Envelope referenceEnvelope )
{
this.min = getNormalizedCoord( referenceEnvelope.getMin() );
this.max = getNormalizedCoord( referenceEnvelope.getMax() );
this.nbrDim = referenceEnvelope.getDimension();
for ( int i = 0; i < nbrDim; i++ )
{
this.max[i] += 1;
}
}

private SearchEnvelope( long[] min, long[] max )
Expand Down Expand Up @@ -475,7 +522,7 @@ private boolean contains( long[] coord )
{
for ( int dim = 0; dim < nbrDim; dim++ )
{
if ( coord[dim] < min[dim] || coord[dim] > max[dim] )
if ( coord[dim] < min[dim] || coord[dim] >= max[dim] )
{
return false;
}
Expand All @@ -487,12 +534,74 @@ private boolean intersects( SearchEnvelope other )
{
for ( int dim = 0; dim < nbrDim; dim++ )
{
if ( max[dim] < other.min[dim] || other.max[dim] < min[dim] )
if ( this.max[dim] <= other.min[dim] || other.max[dim] <= this.min[dim] )
{
return false;
}
}
return true;
}

/**
* The smallest possible envelope has unit area 1
*/
public double getArea()
{
double area = 1.0;
for ( int i = 0; i < min.length; i++ )
{
area *= max[i] - min[i];
}
return area;
}

public double fractionOf( SearchEnvelope other )
{
SearchEnvelope intersection = this.intersection(other);
return intersection == null ? 0.0 : intersection.getArea() / other.getArea();
}

/**
* Returns true for the smallest possible envelope, of area 1
*/
public boolean isUnit()
{
for ( int i = 0; i < min.length; i++ )
{
if ( max[i] - min[i] > 1 )
{
return false;
}
}
return true;
}

public SearchEnvelope intersection( SearchEnvelope other )
{
if ( nbrDim == other.nbrDim )
{
long[] i_min = new long[this.min.length];
long[] i_max = new long[this.min.length];
boolean result = true;
for ( int i = 0; i < min.length; i++ )
{
if ( other.min[i] < this.max[i] && this.min[i] < other.max[i] )
{
i_min[i] = Math.max(this.min[i], other.min[i]);
i_max[i] = Math.min(this.max[i], other.max[i]);
}
else
{
result = false;
}
}
return result ? new SearchEnvelope( i_min, i_max ) : null;
}
else
{
throw new IllegalArgumentException(
"Cannot calculate intersection of Envelopes with different dimensions: " + this.nbrDim + " != " + other.nbrDim );
}
}
}
}
31 changes: 28 additions & 3 deletions ...spatial-index/src/test/java/org/neo4j/gis/spatial/index/curves/SpaceFillingCurveTest.java
View file
Expand Up @@ -334,11 +334,11 @@ public void shouldGet2DHilbertSearchTilesForManyLevels()
@Test
public void shouldGet2DHilbertSearchTilesForWideRangeAtManyLevels()
{
boolean verbose = false;
Envelope envelope = new Envelope( -180, 180, -90, 90 );
for ( int level = 1; level <= 11; level++ ) // 12 takes 6s, 13 takes 25s, 14 takes 100s, 15 takes over 400s
for ( int level = 1; level <= HilbertSpaceFillingCurve2D.MAX_LEVEL; level++ ) // 12 takes 6s, 13 takes 25s, 14 takes 100s, 15 takes over 400s
{
HilbertSpaceFillingCurve2D curve = new HilbertSpaceFillingCurve2D( envelope, level );
System.out.print( "Testing hilbert query at level " + level );
double halfTile = curve.getTileWidth( 0, level ) / 2.0;
long start = System.currentTimeMillis();
// Bottom left should give 1/4 of all tiles started at index 0
Expand All @@ -353,7 +353,32 @@ public void shouldGet2DHilbertSearchTilesForWideRangeAtManyLevels()
// Bottom right should give 1/4 of all tiles started at index 3/4
assertTiles( curve.getTilesIntersectingEnvelope( new Envelope( 0, envelope.getMax( 0 ), envelope.getMin( 1 ), 0 - halfTile ) ),
new SpaceFillingCurve.LongRange( 3 * curve.getValueWidth() / 4, curve.getValueWidth() - 1 ) );
System.out.println( ", took " + (System.currentTimeMillis() - start) + "ms" );

// Now use a sliding window of moderate size (1/8 width and 1/8 height) to test many non-aligned positions
double eighthWidth = envelope.getWidth( 0 ) / 8.0;
double eighthHeight = envelope.getWidth( 1 ) / 8.0;
double left = envelope.getMin( 0 );
double bottom = envelope.getMin( 1 );
while ( left < envelope.getMax( 0 ) - eighthWidth )
{
Envelope eighth = new Envelope( left, left + eighthWidth, bottom, bottom + eighthHeight );
SpaceFillingCurve.RecursionStats stats = new SpaceFillingCurve.RecursionStats( curve.getMaxLevel() );
curve.getTilesIntersectingEnvelope( eighth, stats );
int expectedMaxDepth = Math.max( 10, level / 1 );
assertThat( "Expected to not recurse deeper than " + expectedMaxDepth + " for level " + level, stats.maxDepth,
lessThanOrEqualTo( expectedMaxDepth ) );
if ( verbose )
{
System.out.println( "Recursed to max-depth: " + stats.maxDepth );
for ( int i = 0; i <= stats.maxDepth; i++ )
{
System.out.println( "\t" + i + "\t" + stats.counts[i] );
}
}
left += eighthWidth / 5.12;
bottom += eighthHeight / 5.12;
}
System.out.println( "Tested hilbert query at level " + level + ", took " + (System.currentTimeMillis() - start) + "ms" );
}
}

Expand Down

0 comments on commit 74bcf34

Please sign in to comment.