Re: [Libguestfs] [PATCH libnbd v3 2/3] copy: Use preferred block size for copying
On Thu, Jun 30, 2022 at 05:38:14PM +0200, Laszlo Ersek wrote:
> +static bool
> +only_zeroes (const extent_list exts, size_t *i,
[...]
> +
> + if (start >= offset + len)
> + break;
> +
(13) I think we can insert a micro-optimization here:
*i = j;
[...]
The loop at the start of the function is correct, but here we can
save
some work for its next execution (in the next invocation of this function).
Just a note that I didn't do this optimization.
The reason is that it breaks the ability (which we don't use) of
calling only_zeroes twice on the same offset. I just feel that it
might cause unexpected results if someone hoisted out the only_zeroes
call into a debug printf or similar.
I made the rest of the suggested changes, except for splitting out the
test into another commit - we surely want to keep the test with the
change that is being tested.
Rich.
--
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