mbeckerle commented on a change in pull request #316: Assortment of changes to
improve performance
URL: https://github.com/apache/incubator-daffodil/pull/316#discussion_r370629373
##########
File path:
daffodil-runtime1/src/main/scala/org/apache/daffodil/processors/Evaluatable.scala
##########
@@ -285,7 +285,17 @@ abstract class Evaluatable[+T <: AnyRef](protected val
ci: DPathCompileInfo, qNa
/**
* Preferred for use in the runtime.
*/
- @inline final def maybeConstant = constValue_.asInstanceOf[Maybe[T]]
+ @inline final def maybeConstant = {
+ // We could just do constValue_.asInstanceOf[Maybe[T]], but the compiled
+ // bytecode ends up allocating a Maybe. Since constant values are accessed
+ // very often, we really want to avoid that overhead. The following gets
+ // rid of those unnecessary allocations.
+ if (constValue_.isDefined) {
+ Maybe[T](constValue_.get.asInstanceOf[T])
Review comment:
I'm not exactly sure how to do this, so adding a note to this effect to the
wiki page about performance coding is worth doing in a section (probably
already is one) about avoiding excess boxing and unnecessary allocations.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
With regards,
Apache Git Services
