I ran FindBugs code analyzer (http://findbugs.sourceforge.net/) on JTS 1.9. It
revealed several potential problems.
*) fall through switch statement in DefaultCoordinateSequence
method: "setOrdinate" should have "break" after case
this class is deprecated so no fix is necessary
*) unused package local variables in EdgeSetIntersector
List edges0
List edges1
are never used
*) 7 inner classes that can be made static
- it improves speed and lowers memory consumption
*) and others
---- PERFORMANCE
*) replace new Integer(<value>) with Integer.valueOf(<value>)
- all values from range -128...+127 are cached (no new allocations) - it's
faster
PLACES:
PrecisionModel.compareTo
MonotoneChainIndexer.getChainStartIndices
MonotoneChainBuilder.getChainStartIndices
SegmentNodeList.findCollapsesFromExistingVertices
SegmentNodeList.findCollapsesFromInsertedNodes
*) replace Math.sqrt(2.0) with constant in OctogonalEnvelope.expandBy
Math.sqrt(2.0) is expensive to compute and Java hasn't constant methods as
C++ so the compilers preprocessor can't replace invakestatic Math.sqrt with
constant value. I think that Math.sqrt is directed to StrictMath.sqrt that
should correctly deal with NaN and Infinity values according to IEEE 754.
*) I suggest improve HCoordinate.intersection. There is allocated ~24MB for
HCoordinate in memory (original JTS-1.9). After suggested change only ~8MB is
allocated. There is no visible impact because all allocations are made fast in
young generation and immediately discarded without moving to old generation.
But still it is less work for GC.
public static Coordinate intersection(
Coordinate p1, Coordinate p2,
Coordinate q1, Coordinate q2)
throws NotRepresentableException
{
HCoordinate l1 = new HCoordinate(p1, p2); // removed creation of
HCoordinate from Coordinate
HCoordinate l2 = new HCoordinate(q1, q2); // removed creation of
HCoordinate from Coordinate
HCoordinate intHCoord = new HCoordinate(l1, l2);
Coordinate intPt = intHCoord.getCoordinate();
return intPt;
}
// NEW constructor for HCoordinate that accepts two Coordinate values instead
of two HCoordinate
// it is simplified due to HCoordinate.w = 1.0 when created from Coordinate
public HCoordinate(Coordinate p1, Coordinate p2) {
x = p1.y - p2.y;
y = p2.x - p1.x;
w = p1.x * p2.y - p2.x * p1.y;
}
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