[PATCH] http-backend: remove a duplicated code branch

[PATCH] http-backend: remove a duplicated code branch

[Robin Dupret]

---

Hello,

This patch simply factorize two code paths into a single one.

Just wanted to say thanks for this piece of software and all
the work you are doing on it ; thank you very much !

I hope I properly followed the contributing guidelines ; if not,
sorry.

Have a nice day.

[PATCH] http-backend: remove a duplicated code branch

[Robin Dupret]

Signed-off-by: Robin Dupret <robin.dupret@hey.com>
---
 http-backend.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/http-backend.c b/http-backend.c
index e7c0eeab23..3d6e2ff17f 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -466,9 +466,7 @@ static void run_service(const char **argv, int buffer_input)
 	struct child_process cld = CHILD_PROCESS_INIT;
 	ssize_t req_len = get_content_length();
 
-	if (encoding && !strcmp(encoding, "gzip"))
-		gzipped_request = 1;
-	else if (encoding && !strcmp(encoding, "x-gzip"))
+	if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
 		gzipped_request = 1;
 
 	if (!user || !*user)
-- 
2.30.1 (Apple Git-130)

Re: [PATCH] http-backend: remove a duplicated code branch

[Jeff King]

On Mon, Oct 11, 2021 at 09:25:46PM +0200, Robin Dupret wrote:

> Signed-off-by: Robin Dupret <robin.dupret@hey.com>

You signed-off, which is good (and necessary for contributing a patch).
This is a good place to say "why". Even if it is "because it makes the
code more readable", it is good to say that rather than leave readers
guessing (though of course people won't necessarily agree ;) ).

> ---
>  http-backend.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/http-backend.c b/http-backend.c
> index e7c0eeab23..3d6e2ff17f 100644
> --- a/http-backend.c
> +++ b/http-backend.c
> @@ -466,9 +466,7 @@ static void run_service(const char **argv, int buffer_input)
>  	struct child_process cld = CHILD_PROCESS_INIT;
>  	ssize_t req_len = get_content_length();
>  
> -	if (encoding && !strcmp(encoding, "gzip"))
> -		gzipped_request = 1;
> -	else if (encoding && !strcmp(encoding, "x-gzip"))
> +	if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
>  		gzipped_request = 1;

I think this conversion is correct, and I do find the resulting slightly
easier to read. I wondered if the two conditions might have come
separately, but no, they were both there in the initial 556cfa3b6d
(Smart fetch and push over HTTP: server side, 2009-10-30).

We do frown a bit on making small style changes like this. This kind of
churn isn't dramatically improving the quality of the code, and it
carries the risk of regression (if there is something subtle that you or
the reviewers missed) and creates a maintenance burden (it may conflict
with other patches, though I doubt it in this case, and it creates work
for reviewers and the maintainer to apply).

So...I dunno. I don't mind it, but it is not a pattern we like to
encourage in general. Let's see what Junio thinks.

-Peff

Re: [PATCH] http-backend: remove a duplicated code branch

[Ævar Arnfjörð Bjarmason]

On Mon, Oct 11 2021, Jeff King wrote:

> On Mon, Oct 11, 2021 at 09:25:46PM +0200, Robin Dupret wrote:
>
>> Signed-off-by: Robin Dupret <robin.dupret@hey.com>
>
> You signed-off, which is good (and necessary for contributing a patch).
> This is a good place to say "why". Even if it is "because it makes the
> code more readable", it is good to say that rather than leave readers
> guessing (though of course people won't necessarily agree ;) ).
>
>> ---
>>  http-backend.c | 4 +---
>>  1 file changed, 1 insertion(+), 3 deletions(-)
>> 
>> diff --git a/http-backend.c b/http-backend.c
>> index e7c0eeab23..3d6e2ff17f 100644
>> --- a/http-backend.c
>> +++ b/http-backend.c
>> @@ -466,9 +466,7 @@ static void run_service(const char **argv, int buffer_input)
>>  	struct child_process cld = CHILD_PROCESS_INIT;
>>  	ssize_t req_len = get_content_length();
>>  
>> -	if (encoding && !strcmp(encoding, "gzip"))
>> -		gzipped_request = 1;
>> -	else if (encoding && !strcmp(encoding, "x-gzip"))
>> +	if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
>>  		gzipped_request = 1;
>
> I think this conversion is correct, and I do find the resulting slightly
> easier to read. I wondered if the two conditions might have come
> separately, but no, they were both there in the initial 556cfa3b6d
> (Smart fetch and push over HTTP: server side, 2009-10-30).
>
> We do frown a bit on making small style changes like this. This kind of
> churn isn't dramatically improving the quality of the code, and it
> carries the risk of regression (if there is something subtle that you or
> the reviewers missed) and creates a maintenance burden (it may conflict
> with other patches, though I doubt it in this case, and it creates work
> for reviewers and the maintainer to apply).
>
> So...I dunno. I don't mind it, but it is not a pattern we like to
> encourage in general. Let's see what Junio thinks.

Maybe the existence of this discussion is also why we frown on churn :)
But not being able to resist: FWIW I think if this were refactored the
below makes more sense (untested etc.):

Because the pattern in that function is to:

 1. Get params via getenv
 2. Provide defaults in case those are NULL
 3. Set resulting structs/variables, use them

The "encoding" and "gzipped_request" are the odd ones out there, this
makes them consistent with the rest.

It also has the effect of column-aligning the two strcmps, which along
with avoiding indentation is why I general is why I've sometimes used
this pattern of:

    if (a && b)
        ;
    else if (a && c)
        ;

Over the obvious simplification of:

    if (a && (b || c))
        ;

Although due to the "if" / "else if" in the pre-image that didn't apply
here...

diff --git a/http-backend.c b/http-backend.c
index e7c0eeab230..13bc421b4e8 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -462,19 +462,19 @@ static void run_service(const char **argv, int buffer_input)
 	const char *encoding = getenv("HTTP_CONTENT_ENCODING");
 	const char *user = getenv("REMOTE_USER");
 	const char *host = getenv("REMOTE_ADDR");
-	int gzipped_request = 0;
+	int gzipped_request;
 	struct child_process cld = CHILD_PROCESS_INIT;
 	ssize_t req_len = get_content_length();
 
-	if (encoding && !strcmp(encoding, "gzip"))
-		gzipped_request = 1;
-	else if (encoding && !strcmp(encoding, "x-gzip"))
-		gzipped_request = 1;
-
 	if (!user || !*user)
 		user = "anonymous";
 	if (!host || !*host)
 		host = "(none)";
+	if (!encoding)
+		encoding = "";
+
+	gzipped_request = (!strcmp(encoding, "gzip") ||
+			   !strcmp(encoding, "x-gzip"))
 
 	if (!getenv("GIT_COMMITTER_NAME"))
 		strvec_pushf(&cld.env_array, "GIT_COMMITTER_NAME=%s", user);

Re: [PATCH] http-backend: remove a duplicated code branch

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

>> diff --git a/http-backend.c b/http-backend.c
>> index e7c0eeab23..3d6e2ff17f 100644
>> --- a/http-backend.c
>> +++ b/http-backend.c
>> @@ -466,9 +466,7 @@ static void run_service(const char **argv, int buffer_input)
>>  	struct child_process cld = CHILD_PROCESS_INIT;
>>  	ssize_t req_len = get_content_length();
>>  
>> -	if (encoding && !strcmp(encoding, "gzip"))
>> -		gzipped_request = 1;
>> -	else if (encoding && !strcmp(encoding, "x-gzip"))
>> +	if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
>>  		gzipped_request = 1;
>
> I think this conversion is correct, and I do find the resulting slightly
> easier to read. I wondered if the two conditions might have come
> separately, but no, they were both there in the initial 556cfa3b6d
> (Smart fetch and push over HTTP: server side, 2009-10-30).
>
> We do frown a bit on making small style changes like this. This kind of
> churn isn't dramatically improving the quality of the code, and it
> carries the risk of regression (if there is something subtle that you or
> the reviewers missed) and creates a maintenance burden (it may conflict
> with other patches, though I doubt it in this case, and it creates work
> for reviewers and the maintainer to apply).
>
> So...I dunno. I don't mind it, but it is not a pattern we like to
> encourage in general. Let's see what Junio thinks.

This particular conversion is mostly "Meh", although if it were done
in this way:

	if (encoding) {
		if (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip"))
			gzipped_request = 1;
	}

the result may be a bit less "meh" by making it easier to adjust the
code for other kinds of encoding in the future.

My usual rule of thumb for such a single-hunk clean-up patch that is
"obviously not incorrect" is to take it only once or twice per new
contributor.  At some point, new contributors gain enough experience
to know better, at which point I'd start frowning at them.

Thanks.

Re: [PATCH] http-backend: remove a duplicated code branch

[Junio C Hamano]

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

> diff --git a/http-backend.c b/http-backend.c
> index e7c0eeab230..13bc421b4e8 100644
> --- a/http-backend.c
> +++ b/http-backend.c
> @@ -462,19 +462,19 @@ static void run_service(const char **argv, int buffer_input)
>  	const char *encoding = getenv("HTTP_CONTENT_ENCODING");
>  	const char *user = getenv("REMOTE_USER");
>  	const char *host = getenv("REMOTE_ADDR");
> -	int gzipped_request = 0;
> +	int gzipped_request;
>  	struct child_process cld = CHILD_PROCESS_INIT;
>  	ssize_t req_len = get_content_length();
>  
> -	if (encoding && !strcmp(encoding, "gzip"))
> -		gzipped_request = 1;
> -	else if (encoding && !strcmp(encoding, "x-gzip"))
> -		gzipped_request = 1;
> -
>  	if (!user || !*user)
>  		user = "anonymous";
>  	if (!host || !*host)
>  		host = "(none)";
> +	if (!encoding)
> +		encoding = "";
> +
> +	gzipped_request = (!strcmp(encoding, "gzip") ||
> +			   !strcmp(encoding, "x-gzip"))

In general, I'd frown upon such a conversion.  In the the current
code, "encoding" might go dead after this point, but we are losing
information for no good reason by making !encoding and !*encoding
indistinguisable after this point.  Compared to that, the rewrite in
the patch that started this discussion would be more preferrable.

Thanks.

[PATCH] http-backend: remove a duplicated code branch

[Robin Dupret]

Try to make reading the computation of the gzipped flag a bit more
natural.

Signed-off-by: Robin Dupret <robin.dupret@hey.com>
---
 http-backend.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/http-backend.c b/http-backend.c
index e7c0eeab23..3d6e2ff17f 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -466,9 +466,7 @@ static void run_service(const char **argv, int buffer_input)
 	struct child_process cld = CHILD_PROCESS_INIT;
 	ssize_t req_len = get_content_length();
 
-	if (encoding && !strcmp(encoding, "gzip"))
-		gzipped_request = 1;
-	else if (encoding && !strcmp(encoding, "x-gzip"))
+	if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
 		gzipped_request = 1;
 
 	if (!user || !*user)
-- 
2.30.1 (Apple Git-130)

Re: [PATCH] http-backend: remove a duplicated code branch

[Robin Dupret]

In-Reply-To: xmqqbl3u5fhy.fsf@gitster.g
Cc: Jeff King <peff@peff.net>, Robin Dupret <robin.dupret@gmail.com>, git@vger.kernel.org, Robin Dupret <robin.dupret@hey.com>, junio@pobox.com

Hello,

Sorry for the late reply, I'm not really familiar with mailing lists.
I resent the patch with an ammended commit message.

Actually, the goal is not to add any maintainance burden. I just thought
the original prose was not really intentional. Feel free to discard this
patch if you doubt it brings any improvement to the code.

I'd be happy to send a more substantial patch later if the opportunity
arrises. :-)

(Thanks for your comments and again for all your work on this great
tool !)

Re: [PATCH] http-backend: remove a duplicated code branch

[Robin Dupret]

Hello,

Sorry for the late reply, I'm not really familiar with mailing lists.
I resent the patch with an ammended commit message.

Actually, the goal is not to add any maintainance burden. I just thought
the original prose was not really intentional. Feel free to discard this
patch if you doubt it brings any improvement to the code.

I'd be happy to send a more substantial patch later if the opportunity
arrises. :-)

(Thanks for your comments and again for all your work on this great
tool !)


Le dim. 24 oct. 2021 à 19:25, Robin Dupret <robin.dupret@gmail.com> a écrit :
>
> In-Reply-To: xmqqbl3u5fhy.fsf@gitster.g
> Cc: Jeff King <peff@peff.net>, Robin Dupret <robin.dupret@gmail.com>, git@vger.kernel.org, Robin Dupret <robin.dupret@hey.com>, junio@pobox.com
>
> Hello,
>
> Sorry for the late reply, I'm not really familiar with mailing lists.
> I resent the patch with an ammended commit message.
>
> Actually, the goal is not to add any maintainance burden. I just thought
> the original prose was not really intentional. Feel free to discard this
> patch if you doubt it brings any improvement to the code.
>
> I'd be happy to send a more substantial patch later if the opportunity
> arrises. :-)
>
> (Thanks for your comments and again for all your work on this great
> tool !)

Re: [PATCH] http-backend: remove a duplicated code branch

[Junio C Hamano]

Robin Dupret <robin.dupret@gmail.com> writes:

> Try to make reading the computation of the gzipped flag a bit more
> natural.

... and did you succeed? ;-)

We are all imperfect human and anything we do is merely "trying to",
so let's not say "try to", unless the change is so involved that it
is hard to judge if the result has succeeded in trying.

Did you mean to send the same patch text (but with an updated log
message)?  Just making sure.

Thanks; will queue.

> Signed-off-by: Robin Dupret <robin.dupret@hey.com>
> ---
>  http-backend.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/http-backend.c b/http-backend.c
> index e7c0eeab23..3d6e2ff17f 100644
> --- a/http-backend.c
> +++ b/http-backend.c
> @@ -466,9 +466,7 @@ static void run_service(const char **argv, int buffer_input)
>  	struct child_process cld = CHILD_PROCESS_INIT;
>  	ssize_t req_len = get_content_length();
>  
> -	if (encoding && !strcmp(encoding, "gzip"))
> -		gzipped_request = 1;
> -	else if (encoding && !strcmp(encoding, "x-gzip"))
> +	if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
>  		gzipped_request = 1;
>  
>  	if (!user || !*user)

Re: [PATCH] http-backend: remove a duplicated code branch

[Robin Dupret]

> Did you mean to send the same patch text (but with an updated log
> message)?  Just making sure.

Yes, exactly.

> We are all imperfect human and anything we do is merely "trying to"

Fair point. :-) Do you want me to resend the patch without this part
or is it ok ?

Thank you !

Le lun. 25 oct. 2021 à 17:55, Junio C Hamano <gitster@pobox.com> a écrit :
>
> Robin Dupret <robin.dupret@gmail.com> writes:
>
> > Try to make reading the computation of the gzipped flag a bit more
> > natural.
>
> ... and did you succeed? ;-)
>
> We are all imperfect human and anything we do is merely "trying to",
> so let's not say "try to", unless the change is so involved that it
> is hard to judge if the result has succeeded in trying.
>
> Did you mean to send the same patch text (but with an updated log
> message)?  Just making sure.
>
> Thanks; will queue.
>
> > Signed-off-by: Robin Dupret <robin.dupret@hey.com>
> > ---
> >  http-backend.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/http-backend.c b/http-backend.c
> > index e7c0eeab23..3d6e2ff17f 100644
> > --- a/http-backend.c
> > +++ b/http-backend.c
> > @@ -466,9 +466,7 @@ static void run_service(const char **argv, int buffer_input)
> >       struct child_process cld = CHILD_PROCESS_INIT;
> >       ssize_t req_len = get_content_length();
> >
> > -     if (encoding && !strcmp(encoding, "gzip"))
> > -             gzipped_request = 1;
> > -     else if (encoding && !strcmp(encoding, "x-gzip"))
> > +     if (encoding && (!strcmp(encoding, "gzip") || !strcmp(encoding, "x-gzip")))
> >               gzipped_request = 1;
> >
> >       if (!user || !*user)