Re: [GSoC] Git Blog 5

On Sun, Jun 20, 2021 at 6:53 PM ZheNing Hu [off-list ref] wrote:

My fifth week blog finished:
The web version is here:
https://adlternative.github.io/GSOC-Git-Blog-5/

Great, thanks!

## Week5: Tempting apple

This week, I spent a lot of time working on the digital circuit
course design of the school. So this week's patches for git
was completed in a hurry. This week `Ævar Arnfjörð Bjarmason`

s/was/were/

gave a lot of useful suggestions for the patch I wrote earlier.

Maybe a link could help.

Some are related to code style improvements, and some are
better design ideas.

[...]

But something like `fill_remote_ref_details()`, things gradually
become complicated and difficult. `fill_remote_ref_details()`.

I think you can remove the above `fill_remote_ref_details()` as you
are talking about it later.

Just consider the `show_ref()` called in `fill_remote_ref_details()`,
`show_ref()` may call `shorten_unambiguous_ref()` internally, and
then another function is called internally in `shorten_unambiguous_ref()`...

Well, this is one of the reasons why I cannot move on.

On the other hand, look at the following piece of code, it appears
in `populate_value()`.

for (i = 0; i < used_atom_cnt; i++) {
struct atom_value *v = &ref->value[i];
if (v->s == NULL && used_atom[i].source == SOURCE_NONE)
return strbuf_addf_ret(err, -1, _("missing object %s for %s"),
oid_to_hex(&ref->objectname), ref->refname);
}

We need to determine whether `v->s` equals to `NULL`. We can use

s/equals to/equals/

c-style strings to easily distinguish between empty strings(`xstrdup("")`)
and `NULL`, but if we use strbuf, it is not easy to distinguish, because
an empty strbuf has the following characteristics: `s.buf == strbuf_slopbuf`
or `sb->buf[0] == '\0'`. It can be said that we shouldn’t even use `NULL`
to assign to `s.buf`.

So in the end, I rejected this seemingly very attractive solution, and use the
previous strategy: `<s, s_size>`, unless someone can think of a better
solution later `;-)`.

* FootNote:
1. Why is there no `strbuf_empty()` in `strbuf` API? I think this may be
a very important thing.

There is a 'size_t len' field in 'struct strbuf', so doing `buf->len
== 0` works.

2. Another thing worth mentioning is: I will have the school final exam
between July 7th and July 14th, I may be busy during this period.

Ok, thanks for telling us in advance.