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Date: Mon, 5 Jan 2015 20:42:23 -0800
Message-ID: <CAEZPtU4LP7hfjYNf1XaExPwu8yd4XH3jPOK5rbjG=qggjrfh=g@mail.gmail.com>
To: Xinchen Hui <laruence@php.net>
Cc: PHP Internals <internals@lists.php.net>, Dmitry Stogov <dmitry@zend.com>, 
	Nikita Popov <nikita.ppv@gmail.com>
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Subject: Re: [PHP-DEV] Faster zend sorting implementation
From: pierre.php@gmail.com (Pierre Joye)

hi :)

On Mon, Jan 5, 2015 at 9:08 AM, Xinchen Hui <laruence@php.net> wrote:
> Hey:
>
>      I was working on zend_qsort improvement. but I got a problem need
> to be disscussed with you fist..
>
>      as we know,  previously zend_qsort is not a stable sorting algo.
>
>      my draft patch (which already get 0.1% IRs reduce in wordpress)
> is kindof a stable sorting algo, you can find it here
> (https://github.com/laruence/php-src/compare/zend_sort)
>
>      so, there is a bc break, like for :
>
>      $array = array("o",  "O");
>      sort($array, SORT_STRING|SORT_FLAG_CASE);
>
>      var_dump($array);
>
>      previously implementation does the swap:
>
> array(2) {
>   [0]=>
>   string(1) "O"
>   [1]=>
>   string(1) "o"
> }
>
>      but new implementation doesn't not:
>
> array(2) {
>   [0]=>
>   string(1) "o"
>   [1]=>
>   string(1) "O"
> }
>
>     do you think such BC break is acceptable? or I still need a RFC? :<

I am not sure about that. Introducing a not easy to catch BC break for
0.1% gain on function (or even for the whole app) is not very
appealing.

However, there is nothing in the documentation actually describing how
it works and there are clear warnings about the unpredictable results.
That means we won't actually break it,per definition. I only wonder if
it is worth the effort for such little gain (yes, the ocean is made of
drops ;).

Cheers,
-- 
Pierre

@pierrejoye | http://www.libgd.org