Re: [PATCH 0/3] t: add "test-tool genbytes" to avoid slow tr(1) on macOS

[Junio C Hamano <gitster@pobox.com>]

"Kristofer Karlsson via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> Open question: is patch 3 wanted? It folds "genzeros" into "genbytes",
> spelling the NUL byte as "NUL", so that there is a single command.

I would suggest genbytes to take the value of the byte in decimal or
hex, instead of av[1][0], so that you do not have to treat NUL any
specially.  I would actually think it is even better to limit the
input format only to [0-9a-f][0-9a-f], i.e., two hexadecimal digits
that does not allow uppercase to represent values 0-255 (inclusive),
without support for any other input format like decimal.

After all, this is just a test helper, so ergonomics or flexibility
do not matter as much as simplicity.

> Some other decisions that may be worth pointing out:
>
>  * The buffer is no longer static: it used to be static so that it was
>    zero-initialized for free, but now that it is filled with the requested
>    byte on every call, a local buffer avoids shared state. It keeps its size
>    of 256KB. Smaller buffers made no measurable difference in my tests, but
>    there was no reason to change it.

Shouldn't matter.

>  * Invalid counts are still silently treated as 0, as before. That could be
>    tightened, but it is unrelated to this series.

Shouldn't matter.  That's ergonomics and flexibility that we do not
value as much as in a normal program.

Thanks.