From: Junio C Hamano <gitster@pobox•com>
To: Tanay Abhra <tanayabh@gmail•com>
Cc: git@vger•kernel.org
Subject: Re: [PATCH V2] commit.c: Use skip_prefix() instead of starts_with()
Date: Mon, 03 Mar 2014 11:43:35 -0800 [thread overview]
Message-ID: <xmqqiorvoyoo.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <1393862398-2989-1-git-send-email-tanayabh@gmail.com> (Tanay Abhra's message of "Mon, 3 Mar 2014 07:59:58 -0800")
Tanay Abhra <tanayabh@gmail•com> writes:
> In record_author_date() & parse_gpg_output() ,using skip_prefix() instead of
> starts_with() is more elegant and abstracts away the details.
Avoid subjective judgement like "more elegant" when justifying your
change; you are not your own judge.
The caller of starts_with() actually can use the string that follows
the expected prefix and that is the reason why using skip_prefix()
in these places is a good idea. There is no need to be subjective
to justify that change.
I do not think there is any more abstracting away of the details in
this change. The updated uses a different and more suitable
abstraction than the original.
> diff --git a/commit.c b/commit.c
> index 6bf4fe0..668c703 100644
> --- a/commit.c
> +++ b/commit.c
> @@ -548,7 +548,7 @@ define_commit_slab(author_date_slab, unsigned long);
> static void record_author_date(struct author_date_slab *author_date,
> struct commit *commit)
> {
> - const char *buf, *line_end;
> + const char *buf, *line_end, *skip;
> char *buffer = NULL;
> struct ident_split ident;
> char *date_end;
> @@ -566,14 +566,15 @@ static void record_author_date(struct author_date_slab *author_date,
> buf;
> buf = line_end + 1) {
> line_end = strchrnul(buf, '\n');
> - if (!starts_with(buf, "author ")) {
> + if (!(skip = skip_prefix(buf, "author "))) {
We tend to avoid assignments in conditionals.
> if (!line_end[0] || line_end[1] == '\n')
> return; /* end of header */
> continue;
> }
> + buf = skip;
> if (split_ident_line(&ident,
> - buf + strlen("author "),
> - line_end - (buf + strlen("author "))) ||
> + buf,
> + line_end - buf) ||
> !ident.date_begin || !ident.date_end)
> goto fail_exit; /* malformed "author" line */
> break;
If you give a sensible name to what 'buf + strlen("author ")' is,
then the result becomes a lot more readable compared to the
original, and I think that is what this change is about.
And "skip" is not a good name for that. 'but + strlen("author ")'
is what split_ident_line() expects its input to be split; let's
tentatively call it "ident_line" and see what the call looks like:
split_ident_line(&ident, ident_line, line_end - ident_line))
And that is what we want to see here. It is a bit more clear than
the original that we are splitting the ident information on the line,
ident_line (you could call it ident_begin) points at the beginning
and line_end points at the end of that ident information.
Use of skip_prefix(), which I am sure you took the name of the new
variable "skip" from, is merely an implementation detail of finding
where the ident begins. A good rule of thumb to remember is to name
things after what they are, not how you obtain them, how they are
used or what they are used for/as.
> @@ -1193,9 +1194,9 @@ static void parse_gpg_output(struct signature_check *sigc)
> for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
> const char *found, *next;
>
> - if (starts_with(buf, sigcheck_gpg_status[i].check + 1)) {
> + if (found = skip_prefix(buf, sigcheck_gpg_status[i].check + 1)) {
> /* At the very beginning of the buffer */
> - found = buf + strlen(sigcheck_gpg_status[i].check + 1);
> + ;
> } else {
> found = strstr(buf, sigcheck_gpg_status[i].check);
> if (!found)
This hunk looks good. It can be a separate patch but they are both
minor changes so it is OK to have it in a single patch.
next prev parent reply other threads:[~2014-03-03 19:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-03 15:59 [PATCH V2] commit.c: Use skip_prefix() instead of starts_with() Tanay Abhra
2014-03-03 19:43 ` Junio C Hamano [this message]
2014-03-03 22:59 ` Max Horn
2014-03-03 23:45 ` Junio C Hamano
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