Re: [FR] Make notion of "modification time" configurable during publishing

[Ihor Radchenko <yantar92@posteo.net>]

Suhail Singh <suhailsingh247@gmail.com> writes:

> Ihor Radchenko writes:
>
>> I am a bit confused. What do you mean by "git author date" and "git
>> commit date"?
>
> In the output of `git log --pretty=fuller`, there is AuthorDate which is
> distinct from CommitDate. In case unfamiliar, an elaboration on the
> distinction: <https://stackoverflow.com/a/11857467>.

I see now.
But do you actually use one but not other in practice?

>> I think that we should use an alternative approach. Both "git time" and
>> "fs time" are only an approximation. The true decision to re-publish an
>> article should be triggered by article text being modified. So, we may
>> better decide based on the file text hash, not the modification times.
>
> For it to work, the "file text hash" would have to also take into
> account the "file text hash" of included files, or the decision to
> re-publish would have to be predicated on the hash of included files as
> well. I.e., the equivalent of this logic in
> org-publish-cache-file-needs-publishing :
>
> 	(let ((mtime (org-publish-cache-mtime-of-src filename)))
> 	  (or (time-less-p pstamp mtime)
> 	      (cl-some (lambda (ct) (time-less-p mtime ct))
> 		       included-files-mtime)))

And the code right above the quoted already looks into INCLUDEs. It
should not be too hard to add buffer hash calculation there.

> But assuming the existence of equivalent logic, yes something like a
> file hash would work. In fact, at least in the case of git, the VCS
> could even be queried for it (via git hash-object).

Probably an overkill. It will only work for files without includes and
force us to use exactly the same hash algorithm.

-- 
Ihor Radchenko // yantar92,
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