Area#add(Area) Optimization

[Jeremy Wood]

OK, thanks for the feedback.

Regards,
  - Jeremy

------ Original Message ------
From: "Philip Race" <philip.race at oracle.com>
To: "Jeremy Wood" <mickleness at gmail.com>; 
client-libs-dev at openjdk.java.net
Sent: 2/12/2022 5:26:37 PM
Subject: Re: Area#add(Area) Optimization

>I suppose this could be added but it is something an application also can easily do for itself.
>
> >     curves = rhs.curves;
>
>The straight reference, rather than a copy surprised me, but I suppose (I am not familiar
>with the working of the Area class) that all mutations must create a new Vector ...
>
>-phil.
>
>
>On 2/11/22 3:51 PM, Jeremy Wood wrote:
>>I’m working a lot with the Area class lately. Is there any interest in the following optimization?
>>
>>Area#add(Area) currently resembles:
>>
>>public void add(Area rhs) {
>>   curves = new AreaOp.AddOp().calculate(this.curves, rhs.curves);
>>   invalidateBounds();
>>}
>>
>>I propose replacing it with:
>>
>>public void add(Area rhs) {
>>   if (isEmpty()) {
>>     curves = rhs.curves;
>>   } else if (rhs.isEmpty()) {
>>     return;
>>   } else {
>>     curves = new AreaOp.AddOp().calculate(this.curves, rhs.curves);
>>   }
>>   invalidateBounds();
>>}
>>
>>If either operand is empty then this is effectively a null op. But the current implementation may still take several seconds to return depending on the complexity of the non-empty operand.
>>
>>For example the following two snippets of code may have significantly different execution times:
>>
>>Area sum = new Area();
>>for(Shape shape : incomingShapes) {
>>   sum.add(new Area(shape));
>>}
>>
>>vs
>>
>>Area sum = new Area(shapes.get(0));
>>for(int a = 1; a < incomingShapes.size(); a++) {
>>   Shape shape = incomingShapes.get(a);
>>   sum.add(new Area(shape));
>>}
>>
>>And similarly we could review the other operations (subtract/intersect/exclusiveOr/transform) for obvious potential null ops.
>>
>>If I understand openjdk rules correctly: I'm not authorized to submit an openJDK ticket. Does this interest anyone else on this list enough to submit this as an openJDK ticket? (I'm happy to work on it if I can help.)
>>
>>Regards,
>>  - Jeremy
>