From: Matthieu Moy <Matthieu.Moy@grenoble-inp•fr>
To: Tanay Abhra <tanayabh@gmail•com>
Cc: git@vger•kernel.org, Ramkumar Ramachandra <artagnon@gmail•com>
Subject: Re: [PATCH v4 2/5] notes.c: replace `git_config()` with `git_config_get_value_multi()`
Date: Wed, 30 Jul 2014 18:42:27 +0200 [thread overview]
Message-ID: <vpqsiliol1o.fsf@anie.imag.fr> (raw)
In-Reply-To: <53D903E0.4080209@gmail.com> (Tanay Abhra's message of "Wed, 30 Jul 2014 20:10:32 +0530")
Tanay Abhra <tanayabh@gmail•com> writes:
> On 7/30/2014 7:43 PM, Matthieu Moy wrote:
>> Tanay Abhra <tanayabh@gmail•com> writes:
>>
>>> - git_config(notes_display_config, &load_config_refs);
>>> + if (load_config_refs) {
>>> + values = git_config_get_value_multi("notes.displayref");
>>> + if (values) {
>>> + for (i = 0; i < values->nr; i++) {
>>> + if (!values->items[i].string)
>>> + config_error_nonbool("notes.displayref");
>>> + else
>>> + string_list_add_refs_by_glob(&display_notes_refs,
>>> + values->items[i].string);
>>> + }
>>> + }
>>> + }
>>
>> It seems to me that you're doing a lot here that should have been done
>> once in the config API:
>>
>> * if (values) {
>> for (i = 0; i < values->nr
>>
>> => We could avoid the "if" statement if git_config_get_value_multi was
>> always returning a string_list, possibly empty (values->nr == 0
>> instead of values == NULL).
>>
>
> or we can do something like,
>
> if (!git_config_get_value_multi("notes.displayref", &values)) {
> /* return 0 if there is a value_list for the key */
>
>> Not as obvious as it seems, because you normally return a pointer to
>> the string_list that is already in the hashmap, so you can't just
>> malloc() an empty one if you don't want to leak it.
>>
>> Another option would be to provide an iterator that would call a
>> function on each value of the list, and do nothing when there's no
>> list at all (back to the callback-style API, but you would iterate
>> only through the values for the right key).
>>
>
> This is also a good idea, but still we are back to the callback API,
> and what we are gaining is fewer loop iterations than git_config().
Regardless of performance, the code would also be a bit shorter, since
the callback just gets the values for the right key, so it doesn't need
to re-test that the key is the right one.
Here, the callback would basically be the body of the for loop above.
> Which way do you prefer, a reroll is easy but Junio might have been sick
> of replacing the patches in pu by now. :)
No need to replace anything, you can add new helpers on top of the
existing.
Do it the way you feel is better, I'm just giving ideas.
>> * if (!values->items[i].string)
>> config_error_nonbool(
>>
>> => This check could be done once and for all in a function, say
>> git_config_get_value_multi_nonbool, a trivial wrapper around
>> git_config_get_value_multi like
>>
>> const struct string_list *git_configset_get_value_multi_nonbool(struct config_set *cs, const char *key)
>> {
>> struct string_list l = git_configset_get_value_multi(cs, key);
>> // possibly if(l) depending on the point above.
>> for (i = 0; i < values->nr; i++) {
>> if (!values->items[i].string)
>> git_config_die(key);
>> }
>> return l;
>> }
>>
>
> Not worth it, most the multi value calls do not die on a nonbool.
Can you cite some multi-value variables that can be nonbool? I can't
find many multi-valued variables, and I can't find any which would allow
bool and nonbool.
>> const struct string_list *git_config_get_value_multi_nonbool(const char *key)
>> {
>> git_config_check_init();
>> return git_configset_get_value_multi_nonbool(&the_config_set, key);
>> }
>>
>>
>> (totally untested)
>>
>> BTW, is it intentional that you call config_error_nonbool() without
>> die-ing?
>>
>
> Yup, it's intentional, original code didn't die for empty values, and it seemed
> logical to me to emulate that over to the rewrite.
The old code was doing
if (*load_refs && !strcmp(k, "notes.displayref")) {
if (!v)
config_error_nonbool(k);
string_list_add_refs_by_glob(&display_notes_refs, v);
It seems that the intent of the programmer was
if (*load_refs && !strcmp(k, "notes.displayref")) {
if (!v)
return config_error_nonbool(k); // <---------------
string_list_add_refs_by_glob(&display_notes_refs, v);
At least, that would explain why the code uses v even after testing that
it is a NULL pointer.
You're already fixing a bug in your patch by not using NULL values, but
then I don't see any reason to keep the old weird behavior (display an
error but do not die).
--
Matthieu Moy
http://www-verimag.imag.fr/~moy/
next prev parent reply other threads:[~2014-07-30 16:42 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-30 13:39 [PATCH v4 0/5] git_config callers rewritten with the new config cache API Tanay Abhra
2014-07-30 13:39 ` [PATCH v4 1/5] pager.c: replace `git_config()` with `git_config_get_value()` Tanay Abhra
2014-07-30 13:39 ` [PATCH v4 2/5] notes.c: replace `git_config()` with `git_config_get_value_multi()` Tanay Abhra
2014-07-30 14:13 ` Matthieu Moy
2014-07-30 14:40 ` Tanay Abhra
2014-07-30 16:42 ` Matthieu Moy [this message]
2014-07-31 11:38 ` Matthieu Moy
2014-07-31 12:13 ` Tanay Abhra
2014-07-30 13:39 ` [PATCH v4 3/5] imap-send.c: replace `git_config()` with `git_config_get_*()` family Tanay Abhra
2014-07-30 13:39 ` [PATCH v4 4/5] branch.c: replace `git_config()` with `git_config_get_string() Tanay Abhra
2014-07-30 16:23 ` Matthieu Moy
2014-07-30 13:39 ` [PATCH v4 5/5] alias.c: replace `git_config()` with `git_config_get_string()` Tanay Abhra
2014-07-30 13:46 ` [PATCH v4 0/5] git_config callers rewritten with the new config cache API Matthieu Moy
2014-07-30 14:03 ` Tanay Abhra
2014-07-30 16:45 ` Matthieu Moy
2014-07-31 11:37 ` Ramsay Jones
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