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* [PATCH v3 0/2] GSoC micro project, rewrite fsck_commit() to use skip_prefix()
@ 2014-03-13  4:45 Yuxuan Shui
  2014-03-13  4:45 ` [PATCH v3 1/2] fsck.c: Change the type of fsck_ident()'s first argument Yuxuan Shui
  2014-03-13  4:45 ` [PATCH v3 2/2] fsck.c: Rewrite fsck_commit() to use skip_prefix() Yuxuan Shui
  0 siblings, 2 replies; 6+ messages in thread
From: Yuxuan Shui @ 2014-03-13  4:45 UTC (permalink / raw)
  To: git; +Cc: Yuxuan Shui

Improved commit message, and added a missing hunk to the second commit.

Yuxuan Shui (2):
  fsck.c: Change the type of fsck_ident()'s first argument
  fsck.c: Rewrite fsck_commit() to use skip_prefix()

 fsck.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

-- 
1.9.0

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v3 1/2] fsck.c: Change the type of fsck_ident()'s first argument
  2014-03-13  4:45 [PATCH v3 0/2] GSoC micro project, rewrite fsck_commit() to use skip_prefix() Yuxuan Shui
@ 2014-03-13  4:45 ` Yuxuan Shui
  2014-03-13 19:11   ` Junio C Hamano
  2014-03-13  4:45 ` [PATCH v3 2/2] fsck.c: Rewrite fsck_commit() to use skip_prefix() Yuxuan Shui
  1 sibling, 1 reply; 6+ messages in thread
From: Yuxuan Shui @ 2014-03-13  4:45 UTC (permalink / raw)
  To: git; +Cc: Yuxuan Shui

Since fsck_ident doesn't change the content of **ident, the type of
ident could be const char **.

This change is required to rewrite fsck_commit() to use skip_prefix().

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
---
 fsck.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fsck.c b/fsck.c
index 99c0497..7776660 100644
--- a/fsck.c
+++ b/fsck.c
@@ -243,7 +243,7 @@ static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
 	return retval;
 }
 
-static int fsck_ident(char **ident, struct object *obj, fsck_error error_func)
+static int fsck_ident(const char **ident, struct object *obj, fsck_error error_func)
 {
 	if (**ident == '<')
 		return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email");
@@ -281,7 +281,7 @@ static int fsck_ident(char **ident, struct object *obj, fsck_error error_func)
 
 static int fsck_commit(struct commit *commit, fsck_error error_func)
 {
-	char *buffer = commit->buffer;
+	const char *buffer = commit->buffer;
 	unsigned char tree_sha1[20], sha1[20];
 	struct commit_graft *graft;
 	int parents = 0;
-- 
1.9.0

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v3 2/2] fsck.c: Rewrite fsck_commit() to use skip_prefix()
  2014-03-13  4:45 [PATCH v3 0/2] GSoC micro project, rewrite fsck_commit() to use skip_prefix() Yuxuan Shui
  2014-03-13  4:45 ` [PATCH v3 1/2] fsck.c: Change the type of fsck_ident()'s first argument Yuxuan Shui
@ 2014-03-13  4:45 ` Yuxuan Shui
  2014-03-13 19:14   ` Junio C Hamano
  1 sibling, 1 reply; 6+ messages in thread
From: Yuxuan Shui @ 2014-03-13  4:45 UTC (permalink / raw)
  To: git; +Cc: Yuxuan Shui

Currently we use memcmp() in fsck_commit() to check if buffer start
with a certain prefix, and skip the prefix if it does. This is exactly
what skip_prefix() does. And since skip_prefix() has a self-explaintory
name, this could make the code more readable.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
---
 fsck.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/fsck.c b/fsck.c
index 7776660..7e6b829 100644
--- a/fsck.c
+++ b/fsck.c
@@ -281,7 +281,7 @@ static int fsck_ident(const char **ident, struct object *obj, fsck_error error_f
 
 static int fsck_commit(struct commit *commit, fsck_error error_func)
 {
-	const char *buffer = commit->buffer;
+	const char *buffer = commit->buffer, *tmp;
 	unsigned char tree_sha1[20], sha1[20];
 	struct commit_graft *graft;
 	int parents = 0;
@@ -290,15 +290,17 @@ static int fsck_commit(struct commit *commit, fsck_error error_func)
 	if (commit->date == ULONG_MAX)
 		return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
 
-	if (memcmp(buffer, "tree ", 5))
+	buffer = skip_prefix(buffer, "tree ");
+	if (buffer == NULL)
 		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
-	if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
+	if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n')
 		return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
-	buffer += 46;
-	while (!memcmp(buffer, "parent ", 7)) {
-		if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
+	buffer += 41;
+	while ((tmp = skip_prefix(buffer, "parent "))) {
+		buffer = tmp;
+		if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n')
 			return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
-		buffer += 48;
+		buffer += 41;
 		parents++;
 	}
 	graft = lookup_commit_graft(commit->object.sha1);
@@ -322,15 +324,15 @@ static int fsck_commit(struct commit *commit, fsck_error error_func)
 		if (p || parents)
 			return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
 	}
-	if (memcmp(buffer, "author ", 7))
+	buffer = skip_prefix(buffer, "author ");
+	if (buffer == NULL)
 		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
-	buffer += 7;
 	err = fsck_ident(&buffer, &commit->object, error_func);
 	if (err)
 		return err;
-	if (memcmp(buffer, "committer ", strlen("committer ")))
+	buffer = skip_prefix(buffer, "committer ");
+	if (buffer == NULL)
 		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'committer' line");
-	buffer += strlen("committer ");
 	err = fsck_ident(&buffer, &commit->object, error_func);
 	if (err)
 		return err;
-- 
1.9.0

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 1/2] fsck.c: Change the type of fsck_ident()'s first argument
  2014-03-13  4:45 ` [PATCH v3 1/2] fsck.c: Change the type of fsck_ident()'s first argument Yuxuan Shui
@ 2014-03-13 19:11   ` Junio C Hamano
  0 siblings, 0 replies; 6+ messages in thread
From: Junio C Hamano @ 2014-03-13 19:11 UTC (permalink / raw)
  To: Yuxuan Shui; +Cc: git

Yuxuan Shui <yshuiv7@gmail.com> writes:

> Since fsck_ident doesn't change the content of **ident, the type of
> ident could be const char **.
>
> This change is required to rewrite fsck_commit() to use skip_prefix().
>
> Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
> ---

It may not be a bad idea to read and understand reviews other people
are receiving for their microprojects, e.g. $gmane/243852.

"Change the type" is not technically incorrect per-se, but when
viewed in "git shortlog" output, it wastes more bytes than it
conveys information about this change if stated differently.  Any
patch that touch existing code is a "change" by definition.

Perhaps

	fsck.c:fsck_ident(): ident argument points at a const string

or something?

I see that the body of the patch follows the review by Peff on the
previous round of this series, so I'll forge a Helped-by: or
something into the log message when I queue this patch.

Thanks.

>  fsck.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fsck.c b/fsck.c
> index 99c0497..7776660 100644
> --- a/fsck.c
> +++ b/fsck.c
> @@ -243,7 +243,7 @@ static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
>  	return retval;
>  }
>  
> -static int fsck_ident(char **ident, struct object *obj, fsck_error error_func)
> +static int fsck_ident(const char **ident, struct object *obj, fsck_error error_func)
>  {
>  	if (**ident == '<')
>  		return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email");
> @@ -281,7 +281,7 @@ static int fsck_ident(char **ident, struct object *obj, fsck_error error_func)
>  
>  static int fsck_commit(struct commit *commit, fsck_error error_func)
>  {
> -	char *buffer = commit->buffer;
> +	const char *buffer = commit->buffer;
>  	unsigned char tree_sha1[20], sha1[20];
>  	struct commit_graft *graft;
>  	int parents = 0;

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 2/2] fsck.c: Rewrite fsck_commit() to use skip_prefix()
  2014-03-13  4:45 ` [PATCH v3 2/2] fsck.c: Rewrite fsck_commit() to use skip_prefix() Yuxuan Shui
@ 2014-03-13 19:14   ` Junio C Hamano
  2014-03-13 19:42     ` Junio C Hamano
  0 siblings, 1 reply; 6+ messages in thread
From: Junio C Hamano @ 2014-03-13 19:14 UTC (permalink / raw)
  To: Yuxuan Shui; +Cc: git

Yuxuan Shui <yshuiv7@gmail.com> writes:

> Currently we use memcmp() in fsck_commit() to check if buffer start
> with a certain prefix, and skip the prefix if it does. This is exactly
> what skip_prefix() does. And since skip_prefix() has a self-explaintory
> name, this could make the code more readable.
>
> Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
> ---
>  fsck.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/fsck.c b/fsck.c
> index 7776660..7e6b829 100644
> --- a/fsck.c
> +++ b/fsck.c
> @@ -281,7 +281,7 @@ static int fsck_ident(const char **ident, struct object *obj, fsck_error error_f
>  
>  static int fsck_commit(struct commit *commit, fsck_error error_func)
>  {
> -	const char *buffer = commit->buffer;
> +	const char *buffer = commit->buffer, *tmp;
>  	unsigned char tree_sha1[20], sha1[20];
>  	struct commit_graft *graft;
>  	int parents = 0;
> @@ -290,15 +290,17 @@ static int fsck_commit(struct commit *commit, fsck_error error_func)
>  	if (commit->date == ULONG_MAX)
>  		return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
>  
> -	if (memcmp(buffer, "tree ", 5))
> +	buffer = skip_prefix(buffer, "tree ");
> +	if (buffer == NULL)

We encourage people to write this as:

	if (!buffer)

The same comment applies to other new lines in this patch.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 2/2] fsck.c: Rewrite fsck_commit() to use skip_prefix()
  2014-03-13 19:14   ` Junio C Hamano
@ 2014-03-13 19:42     ` Junio C Hamano
  0 siblings, 0 replies; 6+ messages in thread
From: Junio C Hamano @ 2014-03-13 19:42 UTC (permalink / raw)
  To: git; +Cc: Yuxuan Shui

Junio C Hamano <gitster@pobox.com> writes:

>> -	if (memcmp(buffer, "tree ", 5))
>> +	buffer = skip_prefix(buffer, "tree ");
>> +	if (buffer == NULL)
>
> We encourage people to write this as:
>
> 	if (!buffer)
>
> The same comment applies to other new lines in this patch.

I also see a lot of repetitions in the code, before or after the
patch.  I wonder if a further refactoring along this line on top of
these two patches might be worth considering.

No, I am not proud of sneaking tree_sha1[] array pointers as a
seemingly boolean-looking must-match-header parameter into the
helper, but this is merely a "how about going in this direction"
weather-balloon patch, so....

 fsck.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 61 insertions(+), 22 deletions(-)

diff --git a/fsck.c b/fsck.c
index 6aab23b..a3eea7f 100644
--- a/fsck.c
+++ b/fsck.c
@@ -279,10 +279,55 @@ static int fsck_ident(const char **ident, struct object *obj, fsck_error error_f
 	return 0;
 }
 
+static int fsck_object_line(struct commit *commit, fsck_error error_func,
+			    const char **buffer, const char *header,
+			    unsigned char must_match_header[])
+{
+	unsigned char sha1_buf[20];
+	unsigned char *sha1 = must_match_header ? must_match_header : sha1_buf;
+	const char *buf;
+
+	buf = skip_prefix(*buffer, header);
+	if (!buf) {
+		if (must_match_header)
+			return error_func(&commit->object, FSCK_ERROR,
+					  "invalid format - expected '%.*s' line",
+					  (int) strlen(header) - 1,
+					  header);
+		return 1;
+	}
+	if (get_sha1_hex(buf, sha1) || buf[40] != '\n')
+		return error_func(&commit->object, FSCK_ERROR,
+				  "invalid '%.*s' line format - bad sha1",
+				  (int) strlen(header) - 1,
+				  header);
+	*buffer = buf + 41;
+	return 0;
+}
+
+static int fsck_ident_line(struct commit *commit, fsck_error error_func,
+			   const char **buffer, const char *header)
+{
+	const char *buf;
+	int err;
+
+	buf = skip_prefix(*buffer, header);
+	if (!buf)
+		return error_func(&commit->object, FSCK_ERROR,
+				  "invalid format - expected '%.*s' line",
+				  (int) strlen(header) - 1,
+				  header);
+	err = fsck_ident(&buf, &commit->object, error_func);
+	if (err)
+		return err;
+	*buffer = buf;
+	return 0;
+}
+
 static int fsck_commit(struct commit *commit, fsck_error error_func)
 {
-	const char *buffer = commit->buffer, *tmp;
-	unsigned char tree_sha1[20], sha1[20];
+	const char *buffer = commit->buffer;
+	unsigned char tree_sha1[20];
 	struct commit_graft *graft;
 	int parents = 0;
 	int err;
@@ -290,18 +335,17 @@ static int fsck_commit(struct commit *commit, fsck_error error_func)
 	if (commit->date == ULONG_MAX)
 		return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
 
-	buffer = skip_prefix(buffer, "tree ");
-	if (!buffer)
-		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
-	if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n')
-		return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
-	buffer += 41;
-	while ((tmp = skip_prefix(buffer, "parent "))) {
-		buffer = tmp;
-		if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n')
-			return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
-		buffer += 41;
-		parents++;
+	err = fsck_object_line(commit, error_func, &buffer, "tree ", tree_sha1);
+	if (err)
+		return err;
+	while (1) {
+		err = fsck_object_line(commit, error_func, &buffer, "parent ", NULL);
+		if (err < 0)
+			return err;
+		else if (!err)
+			parents++;
+		else
+			break;
 	}
 	graft = lookup_commit_graft(commit->object.sha1);
 	if (graft) {
@@ -324,16 +368,11 @@ static int fsck_commit(struct commit *commit, fsck_error error_func)
 		if (p || parents)
 			return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
 	}
-	buffer = skip_prefix(buffer, "author ");
-	if (!buffer)
-		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
-	err = fsck_ident(&buffer, &commit->object, error_func);
+
+	err = fsck_ident_line(commit, error_func, &buffer, "author ");
 	if (err)
 		return err;
-	buffer = skip_prefix(buffer, "committer ");
-	if (!buffer)
-		return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'committer' line");
-	err = fsck_ident(&buffer, &commit->object, error_func);
+	err = fsck_ident_line(commit, error_func, &buffer, "committer ");
 	if (err)
 		return err;
 	if (!commit->tree)

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2014-03-13 19:42 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-03-13  4:45 [PATCH v3 0/2] GSoC micro project, rewrite fsck_commit() to use skip_prefix() Yuxuan Shui
2014-03-13  4:45 ` [PATCH v3 1/2] fsck.c: Change the type of fsck_ident()'s first argument Yuxuan Shui
2014-03-13 19:11   ` Junio C Hamano
2014-03-13  4:45 ` [PATCH v3 2/2] fsck.c: Rewrite fsck_commit() to use skip_prefix() Yuxuan Shui
2014-03-13 19:14   ` Junio C Hamano
2014-03-13 19:42     ` Junio C Hamano

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