Suberb !!!

Thanks a lot 
François 





Le 18 sept. 2015 à 21:48, Martijn Dashorst <[email protected]> a écrit 
:

> I'm working on a test case that can check for this, but it requires
> considerable memory due to the massive number of components added to
> make the test cases significant:
> 
> Adding      40000 components took   202ms
> Adding      10000 components took    10ms
> Adding      20000 components took    19ms
> Adding      40000 components took    34ms
> Adding      80000 components took    60ms
> Adding     160000 components took   119ms
> Adding     320000 components took   254ms
> Adding     640000 components took   602ms
> 
> These numbers were generated running JUnit with -Xmx4g and -Xms4g.
> Running with default settings (iirc -Xmx256m) will make the results
> unreliable due to the garbage collector kicking in (1g is also not
> safe).
> 
> Now we don't have too much control over our systems where the tests
> run, so the value might not be there. The algorithm's O(1) complexity
> after our changes is 'proven', so we can leave it at that.
> 
> What do you think?
> 
> Martijn
> 
> 
> On Fri, Sep 18, 2015 at 8:21 PM, Martijn Dashorst
> <[email protected]> wrote:
>> You can find the commit(s) here:
>> 
>> https://github.com/apache/wicket/compare/WICKET-5981
>> 
>> Martijn
>> 
>> 
>> On Fri, Sep 18, 2015 at 3:04 PM, Emond Papegaaij
>> <[email protected]> wrote:
>>> Hi all,
>>> 
>>> Martijn and I spent some more time measuring Wicket's performance, mostly in
>>> component tree construction. It turned out that code written bij Johan, back
>>> in the Wicket 1.2 time, causes O(n^2) complexity on the number children of a
>>> MarkupContainer. We've rewritten the entire children storage, using a
>>> LinkedHashMap when the number of children exceeds 24 (this number was found
>>> after some test trials). For smaller sizes, a simple ArrayList is used, 
>>> which
>>> is more memory efficient.
>>> 
>>> The new code now has almost O(1) on adding/removing/get-by-id but O(n) on 
>>> get
>>> by index. MarkupContainer.swap also is O(n).
>>> 
>>> Can someone take a look at the new code? MarkupContainer is a rather 
>>> important
>>> class and if we want to put this in 7.1, it'd better be bug-free :)
>>> 
>>> Best regards,
>>> Martijn and Emond
>> 
>> 
>> 
>> --
>> Become a Wicket expert, learn from the best: http://wicketinaction.com
> 
> 
> 
> -- 
> Become a Wicket expert, learn from the best: http://wicketinaction.com

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