RFR: 8170467: (reflect) Optimize SignatureParser's use of StringBuilders

[Peter Levart]

Hi,

What about not using StringBuilder at all?

http://cr.openjdk.java.net/~plevart/jdk9-dev/8170467_SignatureParser/webrev.01/

There's also some mockery in getNext()/current()/advance() that uses 
exceptions for control flow which can be fixed while changing this part 
of code. The asserts in getNext()/current()/advance() could even fail if 
getNext()/advance() was called after already returning EOI (== character 
':')...

Regards, Peter


On 11/29/2016 03:03 PM, Claes Redestad wrote:
> Hi Andrej,
>
> On 2016-11-29 14:39, Andrej Golovnin wrote:
>> Hi Claes,
>>
>> 76     public static final int CLASS_NAME_SB_SIZE = 48;
>>
>> Why is this constant public?
>
> Good catch, made it private.
>
>> Btw. for our product this value is too small. We have packages with
>> longer names. I would use 64. :-)
>
> There's no one size fits all: something around 48 is likely to
> help most common cases, while not noticeably penalizing
> shorter names. I'd consider it a bad move to regress apps
> with short-to-normal names to get a small gain on apps with
> very long names
>
> Thanks!
>
> /Claes
>
>>
>> Best regards,
>> Andrej Golovnin
>>
>> On Tue, Nov 29, 2016 at 2:18 PM, Claes Redestad
>> <claes.redestad at oracle.com> wrote:
>>> Hi,
>>>
>>> please review this patch provided by Max Kanat-Alexander[1] to improve
>>> performance of sun.reflect.generics.parser.SignatureParser by reducing
>>> number of StringBuilders created and the rate at which they are resized
>>> during typical usage.
>>>
>>> Webrev: http://cr.openjdk.java.net/~redestad/8170467/webrev.01/
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8170467
>>>
>>> Thanks!
>>>
>>> /Claes
>>>
>>> [1]
>>> http://mail.openjdk.java.net/pipermail/core-libs-dev/2016-November/045046.html 
>>>
>