Performance issue in TastyUtil::hasTastyFile when using Java classes

Hey, after I upgraded to a newer jackson version, I saw a lot of weird timeouts in our unit tests which should finish immediately.

After inspection I found this

It seems like it checks if the class has a tasty file by operating on the the jar files which is a very costly operation if we assume that this is a cpu bound operation.

https://github.com/FasterXML/jackson-module-scala/blob/2.14/src/main/scala/com/fasterxml/jackson/module/scala/util/Classes.scala#L10-L12

It seems like this code path will always hit for classes defined in java(not scala classes), because the first two checks will always be false.

The tests succeeds if I add a retry, so I assume the result of this operation is cached? Maybe it is possible to do val extendsScalaClass ?

[pjfanning]

I did some testing and for non-Scala classes, there is no caching of the introspection results - meaning the work is duplicated on subsequent calls - I have added https://github.com/FasterXML/jackson-module-scala/pull/578 and it will be released when v2.14.0 is released

[wix-andriusb]

Thanks for clarifying, you guys are fast 😃