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From Regis <xu.re...@gmail.com>
Subject Re: [classlib][util]java6 TreeMap improvement
Date Tue, 26 Aug 2008 11:53:22 GMT
Hi Jimmy,

That's great! But what I'm thinking is if we should create a JIRA to 
track this merge. As you
said, there are lots of work, include bugs fixing, refactors, adding 
tests, it's better to be
tracked by JIRA, so we can see all the progress. And I'm volunteer to 
join Jimmy, if there
are anything I can do.

Best Regards,
Regis.

Jimmy,Jing Lv wrote:
> Hi All,
> 
>     As we discussed before, I plan to merge TreeMap performance
> improvement into Harmony java6 level, which have many API enhancement,
> and the structure of code refactors a lot due to the API changes.
> Currently I am close to finish.
>     Mainly Java6 TreeMap has a new interface "NavigableMap"  which
> requires a lot more operations on TreeMap as ascending/descending the
> map, define submaps and entries more precisely. That's the reason we
> have many different inner classes for TreeMap. And in Harmony5 TreeMap
> performance improvement,  the basic Node/Entry of the TreeMap is
> changed so it requires a big change in the whole TreeMap class and its
> variety of child classes.
>     I've tried best to avoid performance downgrading with API changes
> in java6. The main solution is that I try to keep simple operations as
> it is in java5,  that is, if some methods are changed due to Java6
> inner classes changes at the begining, I may try to keep a java5 inner
> class and operate it. That's why the size of java6 TreeMap has
> increased a bit.   However with some benchmark it shows the
> performance was at least no worse than harmony java5 TreeMap. And I've
> add a few more test cases to ensure the correctiveness of the
> refactor, and also fix some bugs that remains in the original java6
> TreeMap.
> 
>     I'll soon commit the fix.  I believe there's still a lot to be
> improved here, e.g, reduce the class size, refactor/merge some inner
> classes, and improve some methods that are not optimized yet.
> 
> 
> ------------
> Best Regards!
> 
> Jimmy, Jing Lv
> China Software Development Lab, IBM
> 

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