diff mbox series

[v3,4/4] pack-objects.c: make use of REV_INFO_STDIN_LINE_PROCESS

Message ID patch-4.4-34750ab81cf-20210621T150651Z-avarab@gmail.com (mailing list archive)
State New, archived
Headers show
Series pack-objects: use revision.c's --stdin parsing | expand

Commit Message

Ævar Arnfjörð Bjarmason June 21, 2021, 3:10 p.m. UTC
Continue the work started in the preceding commit of porting
pack-objects.c over to the new handle_stdin_line callback pattern. The
common case for the users of this API is to do some of their own
parsing or munging, and then have handle_revision_arg() handle the
rest.

The existing users of the --stdin parsing always wanted a flag of "0"
to be passed to handle_revision_arg(), but pack-objects.c wants to set
custom flags. Let's support this common case by having a
"revarg_flags" member in the "rev_info" struct.

This allows us to return REV_INFO_STDIN_LINE_PROCESS in the new
get_object_list_handle_stdin_line() instead of
REV_INFO_STDIN_LINE_CONTINUE, as read_revisions_from_stdin() will now
pass down the right flag for us.

I considered making the "--not" parsing be another flag handled by the
revision.c API itself, but since there's only one caller who wants
this, and the "write_bitmap_index = 0" case is more specific than
marking things UNINTERESTING I think it's better to handle it with a
more general mechanism.

These changes means that we can make the handle_revision_arg()
function static. Now that the only external user of the API has been
migrated over to the callback mechanism nothing external to revision.c
needs to call handle_revision_arg() anymore.

That handle_revision_arg() function was made public in a combination
of 5d6f0935e6d (revision.c: allow injecting revision parameters after
setup_revisions()., 2006-09-05) and b5d97e6b0a0 (pack-objects: run
rev-list equivalent internally., 2006-09-04).

This change leaves the briefly-used in preceding commits
"void *stdin_line_priv" without any in-tree user, as
builtin/pack-objects.c could be ported over to our new "revarg_flags"
common case.

I'm leaving that "void *stdin_line_priv" in place anyway for two
reasons:

 1. It's a common pattern to allow such a "void *" to be used for
    callback data, so we might as well follow that pattern here in
    anticipation of a future in-tree user.

 2. I have patches for such an in-tree user already in a series
    that'll be submitted after this one.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 builtin/pack-objects.c | 35 +++++++++++++++--------------------
 revision.c             |  4 ++--
 revision.h             |  6 ++++--
 3 files changed, 21 insertions(+), 24 deletions(-)

Comments

Junio C Hamano July 8, 2021, 10:21 p.m. UTC | #1
Ævar Arnfjörð Bjarmason  <avarab@gmail.com> writes:

> @@ -3758,28 +3758,25 @@ static void mark_bitmap_preferred_tips(void)
>  static enum rev_info_stdin_line get_object_list_handle_stdin_line(
>  	struct rev_info *revs, struct strbuf *line_sb, void *stdin_line_priv)
>  {
> -	int *flags = stdin_line_priv;
>  	char *line = line_sb->buf;
>  
> -	if (*line == '-') {
> -		if (!strcmp(line, "--not")) {
> -			*flags ^= UNINTERESTING;
> -			write_bitmap_index = 0;
> -			return REV_INFO_STDIN_LINE_CONTINUE;
> -		}
> -		if (starts_with(line, "--shallow ")) {
> -			struct object_id oid;
> -			if (get_oid_hex(line + 10, &oid))
> -				die("not an object name '%s'", line + 10);
> -			register_shallow(the_repository, &oid);
> -			use_bitmap_index = 0;
> -			return REV_INFO_STDIN_LINE_CONTINUE;
> -		}
> +	if (*line != '-')
> +		return REV_INFO_STDIN_LINE_PROCESS;
> +
> +	if (!strcmp(line, "--not")) {
> +		revs->revarg_flags ^= UNINTERESTING;
> +		write_bitmap_index = 0;
> +		return REV_INFO_STDIN_LINE_CONTINUE;
> +	} else if (starts_with(line, "--shallow ")) {
> +		struct object_id oid;
> +		if (get_oid_hex(line + 10, &oid))
> +			die("not an object name '%s'", line + 10);
> +		register_shallow(the_repository, &oid);
> +		use_bitmap_index = 0;
> +		return REV_INFO_STDIN_LINE_CONTINUE;
> +	} else {
>  		die(_("not a rev '%s'"), line);
>  	}
> -	if (handle_revision_arg(line, revs, *flags, REVARG_CANNOT_BE_FILENAME))
> -			die(_("bad revision '%s'"), line);
> -	return REV_INFO_STDIN_LINE_CONTINUE;
>  }

Now, this does make things slightly more modular (specifically, it
no longer is necessary for handle_revision_arg() to be visible
outside revision.c).

Having said that, it is not immediately obvious if the amount of
code churn by 3/4 and 4/4 is justified.  This still looks more like
"we can add a new API, so we added it" than "we needed a new API for
such and such reasons---now we can do this more easily then before".

It's not wrong per-se, but I am not all that impressed.  Sorry.
diff mbox series

Patch

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index f8cae6c305a..50f703e1795 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -3758,28 +3758,25 @@  static void mark_bitmap_preferred_tips(void)
 static enum rev_info_stdin_line get_object_list_handle_stdin_line(
 	struct rev_info *revs, struct strbuf *line_sb, void *stdin_line_priv)
 {
-	int *flags = stdin_line_priv;
 	char *line = line_sb->buf;
 
-	if (*line == '-') {
-		if (!strcmp(line, "--not")) {
-			*flags ^= UNINTERESTING;
-			write_bitmap_index = 0;
-			return REV_INFO_STDIN_LINE_CONTINUE;
-		}
-		if (starts_with(line, "--shallow ")) {
-			struct object_id oid;
-			if (get_oid_hex(line + 10, &oid))
-				die("not an object name '%s'", line + 10);
-			register_shallow(the_repository, &oid);
-			use_bitmap_index = 0;
-			return REV_INFO_STDIN_LINE_CONTINUE;
-		}
+	if (*line != '-')
+		return REV_INFO_STDIN_LINE_PROCESS;
+
+	if (!strcmp(line, "--not")) {
+		revs->revarg_flags ^= UNINTERESTING;
+		write_bitmap_index = 0;
+		return REV_INFO_STDIN_LINE_CONTINUE;
+	} else if (starts_with(line, "--shallow ")) {
+		struct object_id oid;
+		if (get_oid_hex(line + 10, &oid))
+			die("not an object name '%s'", line + 10);
+		register_shallow(the_repository, &oid);
+		use_bitmap_index = 0;
+		return REV_INFO_STDIN_LINE_CONTINUE;
+	} else {
 		die(_("not a rev '%s'"), line);
 	}
-	if (handle_revision_arg(line, revs, *flags, REVARG_CANNOT_BE_FILENAME))
-			die(_("bad revision '%s'"), line);
-	return REV_INFO_STDIN_LINE_CONTINUE;
 }
 
 static void get_object_list(int ac, const char **av)
@@ -3788,7 +3785,6 @@  static void get_object_list(int ac, const char **av)
 	struct setup_revision_opt s_r_opt = {
 		.allow_exclude_promisor_objects = 1,
 	};
-	int flags = 0;
 
 	repo_init_revisions(the_repository, &revs, NULL);
 	save_commit_buffer = 0;
@@ -3798,7 +3794,6 @@  static void get_object_list(int ac, const char **av)
 
 	revs.stdin_handling = REV_INFO_STDIN_ALWAYS_READ;
 	revs.handle_stdin_line = get_object_list_handle_stdin_line;
-	revs.stdin_line_priv = &flags;
 	setup_revisions(ac, av, &revs, &s_r_opt);
 
 	if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
diff --git a/revision.c b/revision.c
index f55b3a1caf4..17121f40c0b 100644
--- a/revision.c
+++ b/revision.c
@@ -2089,7 +2089,7 @@  static int handle_revision_arg_1(const char *arg_, struct rev_info *revs, int fl
 	return 0;
 }
 
-int handle_revision_arg(const char *arg, struct rev_info *revs, int flags, unsigned revarg_opt)
+static int handle_revision_arg(const char *arg, struct rev_info *revs, int flags, unsigned revarg_opt)
 {
 	int ret = handle_revision_arg_1(arg, revs, flags, revarg_opt);
 	if (!ret)
@@ -2139,7 +2139,7 @@  static void read_revisions_from_stdin(struct rev_info *revs,
 			}
 			die("options not supported in --stdin mode");
 		}
-		if (handle_revision_arg(sb.buf, revs, 0,
+		if (handle_revision_arg(sb.buf, revs, revs->revarg_flags,
 					REVARG_CANNOT_BE_FILENAME))
 			die("bad revision '%s'", sb.buf);
 	}
diff --git a/revision.h b/revision.h
index ff7994bb13d..2b96c05ced8 100644
--- a/revision.h
+++ b/revision.h
@@ -156,6 +156,9 @@  struct rev_info {
 	 *   revision.c's normal processing of the line (after
 	 *   possibly munging the provided strbuf).
 	 *
+	 *   Change "revarg_flags" to affect the subsequent handling
+	 *   in handle_revision_arg()
+	 *
 	 * - Return REV_INFO_STDIN_LINE_CONTINUE to indicate that the
 	 *   line is fully processed, moving onto the next line (if
 	 *   any)
@@ -164,6 +167,7 @@  struct rev_info {
 	 * around.
 	 */
 	rev_info_stdin_line_func handle_stdin_line;
+	int revarg_flags;
 	void *stdin_line_priv;
 
 	/* topo-sort */
@@ -421,8 +425,6 @@  void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
 			const char * const usagestr[]);
 #define REVARG_CANNOT_BE_FILENAME 01
 #define REVARG_COMMITTISH 02
-int handle_revision_arg(const char *arg, struct rev_info *revs,
-			int flags, unsigned revarg_opt);
 
 /**
  * Reset the flags used by the revision walking api. You can use this to do