[PATCH v3] commit.c: Replace starts_with() with skip_prefix()

[PATCH v3] commit.c: Replace starts_with() with skip_prefix()

[Karthik Nayak]

Replace all instances of starts_with() by skip_prefix(),
which can not only be used to check presence of a prefix,
but also used further on as it returns the string after the prefix,
if the prefix is present. And also manages to do, what the current
code does in two steps.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
---
Hello Eric,
In this patch, I have:
1. Fixed the improper placement of buf_date , initialised to a NULL string.
2. Fixed whitespace.
3. Better naming as per your suggestion.
4. Fixed the initilisation before the if statement.
Thanks for your suggestion.
---
 commit.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/commit.c b/commit.c
index 6bf4fe0..4144e00 100644
--- a/commit.c
+++ b/commit.c
@@ -553,6 +553,7 @@ static void record_author_date(struct author_date_slab *author_date,
 	struct ident_split ident;
 	char *date_end;
 	unsigned long date;
+	const char *buf_date;
 
 	if (!commit->buffer) {
 		unsigned long size;
@@ -565,15 +566,15 @@ static void record_author_date(struct author_date_slab *author_date,
 	for (buf = commit->buffer ? commit->buffer : buffer;
 	     buf;
 	     buf = line_end + 1) {
+		buf_date = skip_prefix(buf, "author ");
 		line_end = strchrnul(buf, '\n');
-		if (!starts_with(buf, "author ")) {
+		if (!buf_date) {
 			if (!line_end[0] || line_end[1] == '\n')
 				return; /* end of header */
 			continue;
 		}
-		if (split_ident_line(&ident,
-				     buf + strlen("author "),
-				     line_end - (buf + strlen("author "))) ||
+		if (split_ident_line(&ident, buf_date,
+				     line_end - buf_date) ||
 		    !ident.date_begin || !ident.date_end)
 			goto fail_exit; /* malformed "author" line */
 		break;
@@ -1098,6 +1099,7 @@ int parse_signed_commit(const unsigned char *sha1,
 	char *buffer = read_sha1_file(sha1, &type, &size);
 	int in_signature, saw_signature = -1;
 	char *line, *tail;
+	const char *gpg_sig;
 
 	if (!buffer || type != OBJ_COMMIT)
 		goto cleanup;
@@ -1113,9 +1115,9 @@ int parse_signed_commit(const unsigned char *sha1,
 		next = next ? next + 1 : tail;
 		if (in_signature && line[0] == ' ')
 			sig = line + 1;
-		else if (starts_with(line, gpg_sig_header) &&
-			 line[gpg_sig_header_len] == ' ')
-			sig = line + gpg_sig_header_len + 1;
+		else if ((gpg_sig = skip_prefix(line, gpg_sig_header))
+			  && gpg_sig[0] == ' ')
+			sig = gpg_sig + 1;
 		if (sig) {
 			strbuf_add(signature, sig, next - sig);
 			saw_signature = 1;
@@ -1193,10 +1195,8 @@ 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)) {
-			/* At the very beginning of the buffer */
-			found = buf + strlen(sigcheck_gpg_status[i].check + 1);
-		} else {
+		found = skip_prefix(buf, sigcheck_gpg_status[i].check + 1);
+		if (!found) {
 			found = strstr(buf, sigcheck_gpg_status[i].check);
 			if (!found)
 				continue;
-- 
1.9.0.138.g2de3478

Re: [PATCH v3] commit.c: Replace starts_with() with skip_prefix()

[Junio C Hamano]

We already have 147972b1 (commit.c: use skip_prefix() instead of
starts_with(), 2014-03-04) that covers the record_author_date() and
parse_gpg_output(), don't we?

Re: [PATCH v3] commit.c: Replace starts_with() with skip_prefix()

[Junio C Hamano]

Karthik Nayak <karthik.188@gmail.com> writes:

> @@ -1098,6 +1099,7 @@ int parse_signed_commit(const unsigned char *sha1,
>  	char *buffer = read_sha1_file(sha1, &type, &size);
>  	int in_signature, saw_signature = -1;
>  	char *line, *tail;
> +	const char *gpg_sig;
>  
>  	if (!buffer || type != OBJ_COMMIT)
>  		goto cleanup;
> @@ -1113,9 +1115,9 @@ int parse_signed_commit(const unsigned char *sha1,
>  		next = next ? next + 1 : tail;
>  		if (in_signature && line[0] == ' ')
>  			sig = line + 1;
> -		else if (starts_with(line, gpg_sig_header) &&
> -			 line[gpg_sig_header_len] == ' ')
> -			sig = line + gpg_sig_header_len + 1;
> +		else if ((gpg_sig = skip_prefix(line, gpg_sig_header))
> +			  && gpg_sig[0] == ' ')
> +			sig = gpg_sig + 1;

I am not sure if this hunk is a great improvement, as we know the
length of what we are skipping in the gpg_sig_header_len constant
that is used throughout this file.

Re: [PATCH v3] commit.c: Replace starts_with() with skip_prefix()

[Eric Sunshine]

On Thu, Mar 6, 2014 at 12:05 PM, Karthik Nayak <karthik.188@gmail.com> wrote:
> Replace all instances of starts_with() by skip_prefix(),
> which can not only be used to check presence of a prefix,
> but also used further on as it returns the string after the prefix,
> if the prefix is present. And also manages to do, what the current
> code does in two steps.

Better. Thanks.

> Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
> ---
> Hello Eric,
> In this patch, I have:
> 1. Fixed the improper placement of buf_date , initialised to a NULL string.
> 2. Fixed whitespace.
> 3. Better naming as per your suggestion.
> 4. Fixed the initilisation before the if statement.
> Thanks for your suggestion.
> ---
>  commit.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/commit.c b/commit.c
> index 6bf4fe0..4144e00 100644
> --- a/commit.c
> +++ b/commit.c
> @@ -553,6 +553,7 @@ static void record_author_date(struct author_date_slab *author_date,
>         struct ident_split ident;
>         char *date_end;
>         unsigned long date;
> +       const char *buf_date;
>
>         if (!commit->buffer) {
>                 unsigned long size;
> @@ -565,15 +566,15 @@ static void record_author_date(struct author_date_slab *author_date,
>         for (buf = commit->buffer ? commit->buffer : buffer;
>              buf;
>              buf = line_end + 1) {
> +               buf_date = skip_prefix(buf, "author ");

The data after "author " is identification information (name, email),
not date. In fact, this information gets passed to the function
split_ident_line(), so a better name for this variable is 'ident_line'
(but not the misspelling 'indent_line' from one of your earlier
attempts).

>                 line_end = strchrnul(buf, '\n');
> -               if (!starts_with(buf, "author ")) {
> +               if (!buf_date) {
>                         if (!line_end[0] || line_end[1] == '\n')
>                                 return; /* end of header */
>                         continue;
>                 }
> -               if (split_ident_line(&ident,
> -                                    buf + strlen("author "),
> -                                    line_end - (buf + strlen("author "))) ||
> +               if (split_ident_line(&ident, buf_date,
> +                                    line_end - buf_date) ||
>                     !ident.date_begin || !ident.date_end)
>                         goto fail_exit; /* malformed "author" line */
>                 break;
> @@ -1098,6 +1099,7 @@ int parse_signed_commit(const unsigned char *sha1,
>         char *buffer = read_sha1_file(sha1, &type, &size);
>         int in_signature, saw_signature = -1;
>         char *line, *tail;
> +       const char *gpg_sig;
>
>         if (!buffer || type != OBJ_COMMIT)
>                 goto cleanup;
> @@ -1113,9 +1115,9 @@ int parse_signed_commit(const unsigned char *sha1,
>                 next = next ? next + 1 : tail;
>                 if (in_signature && line[0] == ' ')
>                         sig = line + 1;
> -               else if (starts_with(line, gpg_sig_header) &&
> -                        line[gpg_sig_header_len] == ' ')
> -                       sig = line + gpg_sig_header_len + 1;
> +               else if ((gpg_sig = skip_prefix(line, gpg_sig_header))
> +                         && gpg_sig[0] == ' ')
> +                       sig = gpg_sig + 1;

Other than the poor variable name 'buf_date' and the review comments
by Junio and Tanay that this particular change is of questionable
value and perhaps should be dropped, this version of the patch looks
reasonable.

Thanks.

>                 if (sig) {
>                         strbuf_add(signature, sig, next - sig);
>                         saw_signature = 1;
> @@ -1193,10 +1195,8 @@ 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)) {
> -                       /* At the very beginning of the buffer */
> -                       found = buf + strlen(sigcheck_gpg_status[i].check + 1);
> -               } else {
> +               found = skip_prefix(buf, sigcheck_gpg_status[i].check + 1);
> +               if (!found) {
>                         found = strstr(buf, sigcheck_gpg_status[i].check);
>                         if (!found)
>                                 continue;
> --
> 1.9.0.138.g2de3478
>

Re: [PATCH v3] commit.c: Replace starts_with() with skip_prefix()

[karthik nayak]

Hello Eric,
Thanks for your reply, and for that information.  should i patch again
or this should do?
And what next? Talk to the mentor?
Thanks

Re: [PATCH v3] commit.c: Replace starts_with() with skip_prefix()

[Eric Sunshine]

On Fri, Mar 7, 2014 at 5:49 AM, karthik nayak <karthik.188@gmail.com> wrote:
> Hello Eric,
> Thanks for your reply, and for that information.  should i patch again or
> this should do?
> And what next? Talk to the mentor?

The ultimate authority deciding if a patch is ready is Junio, as it
would have to be accepted into his tree. Since he already accepted a
similar patch from a different potential GSoC applicant, it may not
make sense to refine this one further. What is important is that you
are now familiar with the review process on this project, and the
mentors (hopefully) have gained insight into your abilities and how
you interact with reviewers (which was the goal of these
microprojects).

Probably best at this point is to consider a proposed project [1] or
choose your own, and start the task of applying for a GSoC position
(by whatever means that is done).

[1]: https://github.com/git/git.github.io/blob/master/SoC-2014-Ideas.md

> On Fri, Mar 7, 2014 at 3:04 PM, Eric Sunshine <sunshine@sunshineco.com>
> wrote:
>>
>> On Thu, Mar 6, 2014 at 12:05 PM, Karthik Nayak <karthik.188@gmail.com>
>> wrote:
>> > Replace all instances of starts_with() by skip_prefix(),
>> > which can not only be used to check presence of a prefix,
>> > but also used further on as it returns the string after the prefix,
>> > if the prefix is present. And also manages to do, what the current
>> > code does in two steps.
>>
>> Better. Thanks.
>>
>> > Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
>> > ---
>> > Hello Eric,
>> > In this patch, I have:
>> > 1. Fixed the improper placement of buf_date , initialised to a NULL
>> > string.
>> > 2. Fixed whitespace.
>> > 3. Better naming as per your suggestion.
>> > 4. Fixed the initilisation before the if statement.
>> > Thanks for your suggestion.
>> > ---
>> >  commit.c | 22 +++++++++++-----------
>> >  1 file changed, 11 insertions(+), 11 deletions(-)
>> >
>> > diff --git a/commit.c b/commit.c
>> > index 6bf4fe0..4144e00 100644
>> > --- a/commit.c
>> > +++ b/commit.c
>> > @@ -553,6 +553,7 @@ static void record_author_date(struct
>> > author_date_slab *author_date,
>> >         struct ident_split ident;
>> >         char *date_end;
>> >         unsigned long date;
>> > +       const char *buf_date;
>> >
>> >         if (!commit->buffer) {
>> >                 unsigned long size;
>> > @@ -565,15 +566,15 @@ static void record_author_date(struct
>> > author_date_slab *author_date,
>> >         for (buf = commit->buffer ? commit->buffer : buffer;
>> >              buf;
>> >              buf = line_end + 1) {
>> > +               buf_date = skip_prefix(buf, "author ");
>>
>> The data after "author " is identification information (name, email),
>> not date. In fact, this information gets passed to the function
>> split_ident_line(), so a better name for this variable is 'ident_line'
>> (but not the misspelling 'indent_line' from one of your earlier
>> attempts).
>>
>> >                 line_end = strchrnul(buf, '\n');
>> > -               if (!starts_with(buf, "author ")) {
>> > +               if (!buf_date) {
>> >                         if (!line_end[0] || line_end[1] == '\n')
>> >                                 return; /* end of header */
>> >                         continue;
>> >                 }
>> > -               if (split_ident_line(&ident,
>> > -                                    buf + strlen("author "),
>> > -                                    line_end - (buf + strlen("author
>> > "))) ||
>> > +               if (split_ident_line(&ident, buf_date,
>> > +                                    line_end - buf_date) ||
>> >                     !ident.date_begin || !ident.date_end)
>> >                         goto fail_exit; /* malformed "author" line */
>> >                 break;
>> > @@ -1098,6 +1099,7 @@ int parse_signed_commit(const unsigned char *sha1,
>> >         char *buffer = read_sha1_file(sha1, &type, &size);
>> >         int in_signature, saw_signature = -1;
>> >         char *line, *tail;
>> > +       const char *gpg_sig;
>> >
>> >         if (!buffer || type != OBJ_COMMIT)
>> >                 goto cleanup;
>> > @@ -1113,9 +1115,9 @@ int parse_signed_commit(const unsigned char *sha1,
>> >                 next = next ? next + 1 : tail;
>> >                 if (in_signature && line[0] == ' ')
>> >                         sig = line + 1;
>> > -               else if (starts_with(line, gpg_sig_header) &&
>> > -                        line[gpg_sig_header_len] == ' ')
>> > -                       sig = line + gpg_sig_header_len + 1;
>> > +               else if ((gpg_sig = skip_prefix(line, gpg_sig_header))
>> > +                         && gpg_sig[0] == ' ')
>> > +                       sig = gpg_sig + 1;
>>
>> Other than the poor variable name 'buf_date' and the review comments
>> by Junio and Tanay that this particular change is of questionable
>> value and perhaps should be dropped, this version of the patch looks
>> reasonable.
>>
>> Thanks.
>>
>> >                 if (sig) {
>> >                         strbuf_add(signature, sig, next - sig);
>> >                         saw_signature = 1;
>> > @@ -1193,10 +1195,8 @@ 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))
>> > {
>> > -                       /* At the very beginning of the buffer */
>> > -                       found = buf +
>> > strlen(sigcheck_gpg_status[i].check + 1);
>> > -               } else {
>> > +               found = skip_prefix(buf, sigcheck_gpg_status[i].check +
>> > 1);
>> > +               if (!found) {
>> >                         found = strstr(buf,
>> > sigcheck_gpg_status[i].check);
>> >                         if (!found)
>> >                                 continue;
>> > --
>> > 1.9.0.138.g2de3478
>> >
>
>

Re: [PATCH v3] commit.c: Replace starts_with() with skip_prefix()

[karthik nayak]

Hey Eric,

Its been nice learning from you about how to submit patches to git.
was a nice learning curve, now I'm looking into the ideas and will contact the
appropriate mentor soon with a plan.

Thanks
- Karthik

On Sun, Mar 9, 2014 at 1:19 PM, Eric Sunshine <sunshine@sunshineco.com> wrote:
> On Fri, Mar 7, 2014 at 5:49 AM, karthik nayak <karthik.188@gmail.com> wrote:
>> Hello Eric,
>> Thanks for your reply, and for that information.  should i patch again or
>> this should do?
>> And what next? Talk to the mentor?
>
> The ultimate authority deciding if a patch is ready is Junio, as it
> would have to be accepted into his tree. Since he already accepted a
> similar patch from a different potential GSoC applicant, it may not
> make sense to refine this one further. What is important is that you
> are now familiar with the review process on this project, and the
> mentors (hopefully) have gained insight into your abilities and how
> you interact with reviewers (which was the goal of these
> microprojects).
>
> Probably best at this point is to consider a proposed project [1] or
> choose your own, and start the task of applying for a GSoC position
> (by whatever means that is done).
>
> [1]: https://github.com/git/git.github.io/blob/master/SoC-2014-Ideas.md
>
>> On Fri, Mar 7, 2014 at 3:04 PM, Eric Sunshine <sunshine@sunshineco.com>
>> wrote:
>>>
>>> On Thu, Mar 6, 2014 at 12:05 PM, Karthik Nayak <karthik.188@gmail.com>
>>> wrote:
>>> > Replace all instances of starts_with() by skip_prefix(),
>>> > which can not only be used to check presence of a prefix,
>>> > but also used further on as it returns the string after the prefix,
>>> > if the prefix is present. And also manages to do, what the current
>>> > code does in two steps.
>>>
>>> Better. Thanks.
>>>
>>> > Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
>>> > ---
>>> > Hello Eric,
>>> > In this patch, I have:
>>> > 1. Fixed the improper placement of buf_date , initialised to a NULL
>>> > string.
>>> > 2. Fixed whitespace.
>>> > 3. Better naming as per your suggestion.
>>> > 4. Fixed the initilisation before the if statement.
>>> > Thanks for your suggestion.
>>> > ---
>>> >  commit.c | 22 +++++++++++-----------
>>> >  1 file changed, 11 insertions(+), 11 deletions(-)
>>> >
>>> > diff --git a/commit.c b/commit.c
>>> > index 6bf4fe0..4144e00 100644
>>> > --- a/commit.c
>>> > +++ b/commit.c
>>> > @@ -553,6 +553,7 @@ static void record_author_date(struct
>>> > author_date_slab *author_date,
>>> >         struct ident_split ident;
>>> >         char *date_end;
>>> >         unsigned long date;
>>> > +       const char *buf_date;
>>> >
>>> >         if (!commit->buffer) {
>>> >                 unsigned long size;
>>> > @@ -565,15 +566,15 @@ static void record_author_date(struct
>>> > author_date_slab *author_date,
>>> >         for (buf = commit->buffer ? commit->buffer : buffer;
>>> >              buf;
>>> >              buf = line_end + 1) {
>>> > +               buf_date = skip_prefix(buf, "author ");
>>>
>>> The data after "author " is identification information (name, email),
>>> not date. In fact, this information gets passed to the function
>>> split_ident_line(), so a better name for this variable is 'ident_line'
>>> (but not the misspelling 'indent_line' from one of your earlier
>>> attempts).
>>>
>>> >                 line_end = strchrnul(buf, '\n');
>>> > -               if (!starts_with(buf, "author ")) {
>>> > +               if (!buf_date) {
>>> >                         if (!line_end[0] || line_end[1] == '\n')
>>> >                                 return; /* end of header */
>>> >                         continue;
>>> >                 }
>>> > -               if (split_ident_line(&ident,
>>> > -                                    buf + strlen("author "),
>>> > -                                    line_end - (buf + strlen("author
>>> > "))) ||
>>> > +               if (split_ident_line(&ident, buf_date,
>>> > +                                    line_end - buf_date) ||
>>> >                     !ident.date_begin || !ident.date_end)
>>> >                         goto fail_exit; /* malformed "author" line */
>>> >                 break;
>>> > @@ -1098,6 +1099,7 @@ int parse_signed_commit(const unsigned char *sha1,
>>> >         char *buffer = read_sha1_file(sha1, &type, &size);
>>> >         int in_signature, saw_signature = -1;
>>> >         char *line, *tail;
>>> > +       const char *gpg_sig;
>>> >
>>> >         if (!buffer || type != OBJ_COMMIT)
>>> >                 goto cleanup;
>>> > @@ -1113,9 +1115,9 @@ int parse_signed_commit(const unsigned char *sha1,
>>> >                 next = next ? next + 1 : tail;
>>> >                 if (in_signature && line[0] == ' ')
>>> >                         sig = line + 1;
>>> > -               else if (starts_with(line, gpg_sig_header) &&
>>> > -                        line[gpg_sig_header_len] == ' ')
>>> > -                       sig = line + gpg_sig_header_len + 1;
>>> > +               else if ((gpg_sig = skip_prefix(line, gpg_sig_header))
>>> > +                         && gpg_sig[0] == ' ')
>>> > +                       sig = gpg_sig + 1;
>>>
>>> Other than the poor variable name 'buf_date' and the review comments
>>> by Junio and Tanay that this particular change is of questionable
>>> value and perhaps should be dropped, this version of the patch looks
>>> reasonable.
>>>
>>> Thanks.
>>>
>>> >                 if (sig) {
>>> >                         strbuf_add(signature, sig, next - sig);
>>> >                         saw_signature = 1;
>>> > @@ -1193,10 +1195,8 @@ 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))
>>> > {
>>> > -                       /* At the very beginning of the buffer */
>>> > -                       found = buf +
>>> > strlen(sigcheck_gpg_status[i].check + 1);
>>> > -               } else {
>>> > +               found = skip_prefix(buf, sigcheck_gpg_status[i].check +
>>> > 1);
>>> > +               if (!found) {
>>> >                         found = strstr(buf,
>>> > sigcheck_gpg_status[i].check);
>>> >                         if (!found)
>>> >                                 continue;
>>> > --
>>> > 1.9.0.138.g2de3478
>>> >
>>
>>