[Phpmyadmin-devel] Is PMA_STR_binarySearchInArr needed?

[Marc Delisle]

Rouslan Placella a écrit :
> On Tue, 2011-06-07 at 12:25 -0400, Marc Delisle wrote:
>> Marc Delisle a écrit :
>>> Piotr Przybylski a écrit :
>>>> Hi,
>>>>
>>>> For some time I was curious whether PMA_STR_binarySearchInArr is
>>>> needed at all, and my test showed that there are faster (sometimes
>>>> much faster) alternatives. Test for 100 000 iterations on PHP 5.3.4
>>>> (Windows, i5 2,53 GHz core):
>>>>
>>>> PMA_STR_binarySearchInArr:    2.6606s
>>>> array_search:     1.8936s
>>>> isset:            0.0102s
>>>> array_key_exists: 0.0934s
>>>>
>>>> Isset and array_key_exists require flipped array, but array_search is
>>>> a drop-in replacement that works faster, even though it does a linear
>>>> search. Code used to perform this test is at [1].
>>>>
>>>> [1] http://pastebin.com/cJmpmCPh
>>>>
>>> Piotr,
>>> I tested on a 64-bit Linux machine (running as a VM under ESX 4.1) under 
>>> PHP 5.3.6-RC3 and got different results (for current master):
>>>
>>> Binary search:    0.6088
>>> array_search:     2.0246
>>> isset:            0.0068
>>> array_key_exists: 0.0176
>>>
>>>
>>>
>> And on a similar VM running PHP 5.2.17:
>>
>> Binary search:    0.7197
>> array_search:     2.7731
>> isset:            0.0075
>> array_key_exists: 0.0178
>>
> 
> My results look a lot like Marc's, too:
> 
> PHP: 5.3.5
> PMA: Latest GIT
> OS:  Ubuntu Linux 11.04 - 64bit
> CPU: AMD Phenom II @ 3.95GHz
> RAM: DDR2 @ 1066MHz
> 
> Binary search:    0.4967
> array_search:     1.5545
> isset:            0.0041
> array_key_exists: 0.0162
> 
> Rouslan

isset() on a flipped array is the winner, but would require a logic 
verification everywhere to be sure we flip a minimum of times.

I also like the fact that we would no longer need to maintain a long 
list of keywords in proper alpha order.


-- 
Marc Delisle
http://infomarc.info