RFR [9]: 8050142: Optimize java.util.Formatter

[Claes Redestad]

Hi again,

  updated webrev: http://cr.openjdk.java.net/~redestad/8050142/webrev.1

  changes:
  - specify capacity on line 2931 as suggested by Andrej Golovnin
  - exp.append("0") -> exp.append('0') on line 3781
  - merged append+justify into appendJustified as suggested by Peter Levart
  - replaced the reoccuring pattern of appending a number of zeros into 
a call to trailingZeros

  performance difference seemingly at noise levels in micros, but bonus 
to readability and Formatter*.class-files are now a total of 246 bytes 
smaller

/Claes

On 2014-07-14 13:29, Claes Redestad wrote:
> Hi Peter,
>
> On 2014-07-14 13:25, Peter Levart wrote:
>> On 07/14/2014 12:07 PM, Claes Redestad wrote:
>>> Hi,
>>>
>>>  please review this patch which optimizes away some allocations from 
>>> java.util.Formatter and achieve 1.1-1.3x speedups of micros 
>>> targetting String.format. See bug for more details.
>>>
>>>  webrev: http://cr.openjdk.java.net/~redestad/8050142/webrev.0
>>>  bug: https://bugs.openjdk.java.net/browse/JDK-8050142
>>>
>>>  Testing: JPRT, jtreg (java/lang/String, java/util/Formatter), 
>>> SPECjbb2013 and microbenchmarks
>>>
>>>  Thanks!
>>>
>>>  /Claes
>>
>> Hi Claes,
>>
>> Since justify() result is always appended to the resulting 
>> Appendable, you could merge the functionality and eliminate 
>> constructing intermediary StringBuilder altogether:
>>
>> http://cr.openjdk.java.net/~plevart/jdk9-dev/Formatter/webrev.01/
>>
> Looks good, especially eliminating the need for two different append 
> methods. I'll update based on this and other suggestions.
>
> /Claes
>> Regards, Peter
>