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From "Jimmy,Jing Lv" <firep...@gmail.com>
Subject Re: [classlib][util]java6 TreeMap improvement
Date Wed, 27 Aug 2008 05:43:41 GMT

     Sounds reasonable, thanks a lot and welcome Regis! :)
     And please check https://issues.apache.org/jira/browse/HARMONY-5959

2008/8/26 Regis <xu.regis@gmail.com>:
> 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


Best Regards!

Jimmy, Jing Lv
China Software Development Lab, IBM

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