[FFmpeg-devel] [PATCH 3/8] avutil/mem: Add av_fast_realloc_array()

[Tomas Härdin]

mån 2022-09-26 klockan 16:24 +0200 skrev Tomas Härdin:
> mån 2022-09-26 klockan 14:25 +0200 skrev Andreas Rheinhardt:
> > Anton Khirnov:
> > > Quoting Andreas Rheinhardt (2022-07-14 14:51:07)
> > > > Anton Khirnov:
> > > > > Quoting Andreas Rheinhardt (2022-07-12 16:12:16)
> > > > > > Anton really dislikes the av_fast_* naming and instead
> > > > > > wants
> > > > > > this to be
> > > > > > called av_realloc_array_reuse(). I don't care either way.
> > > > > > Any
> > > > > > more
> > > > > > opinions on this (or on the patch itself)?
> > > > > 
> > > > > If people dislike _reuse(), I am open to other reasonable
> > > > > suggestions.
> > > > > This 'fast' naming sucks because
> > > > > - it tells you nothing about how this function is "fast"
> > > > > - it is added at the beginning rather than the end, which is
> > > > >   against standard namespacing conventions
> > > > > 
> > > > 
> > > > Isn't reusing the basic modus operandi for a reallocation
> > > > function? So
> > > > your suggested name doesn't seem to fit either.
> > > 
> > > Ordinary realloc just keeps the data, I wouldn't call that
> > > "reuse"
> > > since
> > > it will often be a copy. This "fast" realloc OTOH reuses the
> > > actual
> > > buffer, same as all the other "fast" mem.h functions.
> > > 
> > > But feel free to suggest another naming pattern if you can think
> > > of
> > > one.
> > > 
> > 
> > I see two differences between this function and ordinary realloc:
> > It
> > never shrinks the buffer and it overallocates. These two properties
> > make
> > it more likely that these functions can avoid copies more often
> > than
> > plain realloc (but in contrast to realloc, we can not grow the
> > buffer
> > in
> > case there is free space after it), but it is nevertheless the same
> > as
> > realloc.
> > 
> > But I don't really care that much about the name and will therefore
> > use
> > your name as I can't come up with anything better.
> > (Of course, I am still open to alternative suggestions.)
> > 
> > - Andreas
> 
> So this means av_realloc_array_reuse()? Eh, it works. I will add a
> function that also zeroes the newly allocated space, what should we
> call that? av_realloc_array_reusez()?
> av_realloc_array_reuse_zerofill()?

Here's a draft patch that calls it av_reallocz_array_reuse(). Needs a
minor version bump of course

/Tomas
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