Subject: Re: bug#73484: 31.0.50; Abolishing etags-regen-file-extensions

From: Dmitry Gutov <[email-masked]>
Date: Mon, 7 Oct 2024 10:11:08 +0300

On 07/10/2024 05:33, Eli Zaretskii wrote:
>> Sorry, I have to add a correction: it's about 15 min either way. Seems
>> like the first time I either messed up the start time, or the directory
>> was in "cold" cache, or the used etags some much older version.
>>
>> So to reiterate: the current etags-regen scans in around 30s, and the
>> simple switch scans the directory in 15 minutes. Retesting the change
>> from previous email, it doesn't really help.
> Can you please show the etags command line in each of these two cases
> that you are comparing?

Both commands end with a '-' (scanning the list of files passed from stdin).

>>> And if they don't have extensions, the code you
>>> removed would have caused etags to scan these files anyway, looking
>>> for Fortran or C tags.  So how come the change slowed down etags so
>>> much?  What am I missing?
>> I think it would also concern "unknown" extensions, right? Like .txt,
>> .png and so on.
> I have difficulty reasoning about this without knowing the command
> lines you used.  E.g., I don't understand why in one case it would
> scan files with unknown extensions that were not scanned in the other.

In one case the list is pre-filtered with etags-regen-file-extensions 
(see 'etags-regen--all-files'), in the other - it is not, and all files 
in project are passed.