RFR: JDK-8184947:,ZipCoder performance improvements

[Claes Redestad]

Hi Sherman,

On 2017-12-11 05:08, Xueming Shen wrote:
> http://cr.openjdk.java.net/~sherman/8184947/webrev

thanks for incorporating my suggestion!

It looks pretty good to me.  While many parts is just code that has been 
moved, this is
still a pretty big change, so I hope we can get at least another pair of 
eyes on it.

StringCoding.java:

private static void throwMalformed(int nb) {
     throw new IllegalArgumentException("malformed input length : " + nb);
}

nb is the number of bytes of the *first* offending chunk of bytes(?); is 
this information
generally useful? I think the error message can be improved as input 
length is
ambiguous in this context, but I wouldn't mind if the nb parameter was 
dropped along
with a simplification of the error message.

Indentation errors at lines 321, 324, 728, 746, 913

TestStringCoding.java:

Are the added System.out.println's intentional? Indentation.

>
> Yes, understood the threadlocal might not be the best choice here. But 
> just feel
> something need to be done for the temporary Result object after 
> observed its
> usage with the jfr in #8184947. It is taking as many spaces as the 
> overall String
> objects do. Sure, it's in young-gen, should be wiped with quickly. But 
> my take is
> it might be worth the tradeoff of having each/every new String/cs) get 
> a little slower
> instead of having the "global" vm has to do some extra clean up for 
> this extra
> Result object, for now.

Right, as this can be cause for significant GC pressure then I see how a 
bit of
ThreadLocal overhead is fine until we come up with something better.

Thanks!

/Claes

>
> thanks,
> sherman
>
>