Character decoding could be 3 times faster !

Xueming Shen Xueming.Shen at Sun.COM
Wed May 21 17:33:05 UTC 2008

It is a surprise to see that the String.charAt is way faster than the 
char[] index access...I had
the assumption that the array access is faster when considering to move 
the mappable table
from the String storage to a simple 256 length char[] for both 
singlebyte and doublebyte charsets.
Ulf, Martin and I were (will continue to, hopely) working on a project 
to improve the performance
of the charset implementation, your contribution will definitely 


Ulf Zibis wrote:
> Am 19.05.2008 13:16, Alan Bateman schrieb:
>> One other thing - it looks like you are using the jdk6 sources with 
>> the JRL license rather than OpenJDK sources. If you do improve the 
>> performance of the decode loop for this class of decoder then it 
>> would be best to post a patch against the OpenJDK sources.
>> -Alan.
> Yes, this might be. I'm afraid, this would become a BIG THING for me, 
> as I'm not familiar with the JDK7 contribution process, Mercurial, and 
> how to create a suitable NetBeans project to serve this.
> I hesitate to install JDK7 on my system, as it is less than Beta.
> Also my goal is, to provide a jar, which users could use with JDK6 by 
> -Xbootclasspath/p.
> Is there any sample NetBeans project regarding hacking the JDK7?
> How can I commit my steps of work against your Mercurial server? (At 
> I only have Subversion)
> What you think:
> - Can I simply use the the JDK7 sources of sun.nio.cs package, compile 
> them against JDK6 for my development and test runs, and then create 
> the patch from there?
> -Ulf

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