[Geany-devel] About disabling GTK+/GLib deprecated symbols

Colomban Wendling ban-ubuntu at xxxxx
Mon Oct 27 23:06:48 UTC 2008


Enrico Tröger a écrit :
> On Thu, 23 Oct 2008 18:57:09 +0200, Enrico Tröger
> <enrico.troeger at uvena.de> wrote:
>
>
>   
>>> About the g_strcasecmp() problem:
>>> I don't think the right solution is to copy the old, broken code from
>>> GLib into Geany. As the docs mention, there is a reason why this
>>> function is deprecated and should not used.
>>> IMO we should rewrite the code which uses this function with the
>>> alternative functions mentioned in the docs.
>>>       
>> Update:
>> Yesterday, I did some work on this and wrote utils_str_casecmp() which
>> uses g_utf8_casefold() and g_utf8_collate() as suggested in the GLib
>> API docs. It seems to work, for simple examples actually better than
>> g_strcasecmp().
>> But the new code is noticeably slower, about factor 100 (!).
>>
>> When starting Geany with a fresh configuration and opening about 30
>> files with different filetypes, we almost have 1000 calls to this
>> function (by only counting calls which actually pass g_utf8_collate()).
>> (we could eliminate many of these calls by changing utils_atob() to be
>> case-sensitive or something smarter, this is used when reading the
>> filetype definition files to evaluate false/true strings into
>> booleans, maybe it's enough to check for true and TRUE, and treat
>> anything else as false.)
>>
>> I've attached a testcase with some simple test strings to test the
>> correctness of both implementations. These show the new code works
>> better but please note that the code uses only simple example strings,
>> without more complex unicode characters).
>>
>> The testcase additionally does some speed comparisons of both
>> functions, so you can easily see the big difference in execution time.
>> Simply change the value of the CALLS macro to change the amount of
>> calls of both functions.
>> Note: the gap in execution time of both implementations might be even
>> bigger if the test strings are not encoded in UTF-8 but any other
>> encoding and so have to be passed through g_locale_to_utf8().
>>
>> Conclusion:
>> I'm not sure anymore if it's worth to use this code because of the
>> execution time. Assuming (read: hoping) that most users will use
>> Ascii-only characters in filenames (for which the code is mostly used)
>> it maybe isn't worth.
>> OTOH utils_str_casecmp() can surely be still improved to get it run
>> faster.
>>     
>
> There is another possibility :
>
> see the attached testcase, an updated version of the first one. It has
> an additional variant of the code, utils_str_casecmp_easy() which
> simply converts the strings to compare into lowercase using
> g_utf8_strdown() and then compare them with strcmp().
> This is to some extend also 'broken' because it doesn't take different
> locale-specific case sorting rules into account. But therefore it is
> noticeable faster than the full variant. It's only about ten times
> slower than g_strcasecmp() which is IMO not that bad and so I'm
> thinking this could go in.
>
>
> Regards,
> Enrico
>   
Hi,

I think this is a good compromise, and I think most people using Geany
will not be annoyed by the approximation since most programmers just use
full ASCII filenames. And even with non-ASCII filenames, the
approximation is IMO very acceptable.

Regards,
Colomban



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