Geometry.Distance() allocates unnecessary arrayList about jts

[AlexisDrogoul]

👍

[dr-jts]

Pull Request welcome! Otherwise will have to wait for time to do this.

[dr-jts]

Curious to know more about your use case. Are you seeing this as as hotspot? If you are doing a lot of distance computation, perhaps IndexedFacetDistance might be of use?

[dr-jts]

@cmhodgson Is the issue the ArrayList which is allocated by PolygonExtracter even if there are no polygons?

Perhaps a simple dimension check could be made beforehand, and if dimension < 2 this code can be skpped.

[cmhodgson]

IndexedFacetDistance is interesting but still uses distanceOp, which then still had the problem that you have now solved.

My use case was finding the closest street segment with a matching name to every address point in the province. There is already an index in place to narrow it down to all the segments with the matching name in the same locality so it isn't really worth the additional memory cost to index those groups spatially. The process only takes 5 mins but minimizing memory use is more important than speeding up the processing as it is a once a month process in production. The overhead of creating and collecting the extra arrays had essentially no effect on the performance time-wise but because of how sensitive Java is to the amount of garbage being collected, having these unused arrays lying around required an extra 1/2 GB of memory to be allocated to keep Java from throwing a "too much garbage collection" exception.

I think I had considered a fix as simple as what you have now done but then got lost in a bunch of other semantic issues that I thought needed "fixing" and forgot about the simple alternative.

[dr-jts]

Good to know this is working for you, Chris.

It seems it's more important to optimize Java memory use than performance (although often the two can be improved together). The recent issue #165 is another example of this.