Re: [PATCH] [GSOC] ref-filter: add %(notes) format atom

From: René Scharfe <l.s.r@web.de>
Date: May 1, 2021, 19:21 UTC
Message-ID: <38083c1b-f92b-7624-67b7-3a5dcf213d79@web.de>
In-Reply-To: <pull.944.git.1619691880696.gitgitgadget@gmail.com>

Am 29.04.21 um 12:24 schrieb ZheNing Hu via GitGitGadget:

Show 7 quoted lines

> From: ZheNing Hu <adlternative@gmail.com>
>
> Note that `--pretty="%N"` can view notes related
> to the commit. So add `%(notes)` to ref-filter
> seem is a good choice. This atom `%(notes)` view
> the notes associated with the ref, and support
> dereference.

I can't judge the usefulness of this feature because I don't use notes.

Show 7 quoted lines

> Signed-off-by: ZheNing Hu <adlternative@gmail.com>
> ---
>     [GSOC] ref-filter: add %(notes) format atom
>
>     An important step in the GSOC project Use ref-filter formats in git
>     cat-file is to integrate different format atoms into the ref-filter.
>     Olga and Hariom have also made a lot of efforts in this area.

This is done to replace the custom format parser in git cat-file with ref-filter in order to reduce code duplication, right?

>     Currently, I noticed that there may be some format atoms in "pretty.c"
>     that have not been migrated to ref-filter, such as --pretty="%N",
>     --pretty="%(describe)".

git cat-file doesn't support pretty format atoms, so I'm not sure I see the connection here.

Show 71 quoted lines

>     So in this patch, I tried to migrate --pretty=%N to --format=%(notes).
>
>     Hope this will be hopeful !!!
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-944%2Fadlternative%2Fformat-notes-atom-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-944/adlternative/format-notes-atom-v1
> Pull-Request: https://github.com/gitgitgadget/git/pull/944
>
>  Documentation/git-for-each-ref.txt |  4 ++++
>  ref-filter.c                       | 31 ++++++++++++++++++++++++++++--
>  t/t6300-for-each-ref.sh            | 10 ++++++++++
>  3 files changed, 43 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
> index 2ae2478de706..07f037a16e13 100644
> --- a/Documentation/git-for-each-ref.txt
> +++ b/Documentation/git-for-each-ref.txt
> @@ -139,6 +139,9 @@ deltabase::
>  	given object, if it is stored as a delta.  Otherwise it
>  	expands to the null object name (all zeroes).
>
> +notes::
> +	The notes associated with the ref.
> +
>  upstream::
>  	The name of a local ref which can be considered ``upstream''
>  	from the displayed ref. Respects `:short`, `:lstrip` and
> @@ -302,6 +305,7 @@ git for-each-ref --count=3 --sort='-*authordate' \
>  Subject: %(*subject)
>  Date: %(*authordate)
>  Ref: %(*refname)
> +Notes: %(*notes)
>
>  %(*body)
>  ' 'refs/tags'
> diff --git a/ref-filter.c b/ref-filter.c
> index a0adb4551d87..42a5608a3056 100644
> --- a/ref-filter.c
> +++ b/ref-filter.c
> @@ -23,6 +23,7 @@
>  #include "worktree.h"
>  #include "hashmap.h"
>  #include "strvec.h"
> +#include "run-command.h"
>
>  static struct ref_msg {
>  	const char *gone;
> @@ -506,6 +507,7 @@ static struct {
>  	{ "objectsize", SOURCE_OTHER, FIELD_ULONG, objectsize_atom_parser },
>  	{ "objectname", SOURCE_OTHER, FIELD_STR, oid_atom_parser },
>  	{ "deltabase", SOURCE_OTHER, FIELD_STR, deltabase_atom_parser },
> +	{ "notes", SOURCE_OTHER, FIELD_STR },
>  	{ "tree", SOURCE_OBJ, FIELD_STR, oid_atom_parser },
>  	{ "parent", SOURCE_OBJ, FIELD_STR, oid_atom_parser },
>  	{ "numparent", SOURCE_OBJ, FIELD_ULONG },
> @@ -953,6 +955,24 @@ static int grab_oid(const char *name, const char *field, const struct object_id
>  	return 0;
>  }
>
> +static int grab_notes(const struct object_id *oid, struct atom_value *v)
> +{
> +	struct child_process cmd = CHILD_PROCESS_INIT;
> +	struct strbuf out = STRBUF_INIT;
> +	struct strbuf err = STRBUF_INIT;
> +	const char *args[] = { "notes", "show", NULL };
> +	int ret;
> +
> +	cmd.git_cmd = 1;
> +	strvec_pushv(&cmd.args, args);
> +	strvec_push(&cmd.args, oid_to_hex(oid));
> +	ret = pipe_command(&cmd, NULL, 0, &out, 0, &err, 0);

Nice prototype. Is it possible to avoid the overhead of calling git notes as an external process by calling load_display_notes() once at parse time and format_display_notes() for each item? Would it cause conflicts for code that uses ref-filter and handles notes already?

Show 34 quoted lines

> +	strbuf_trim_trailing_newline(&out);
> +	v->s = strbuf_detach(&out, NULL);
> +	strbuf_release(&err);
> +	return ret;
> +}
> +
>  /* See grab_values */
>  static void grab_common_values(struct atom_value *val, int deref, struct expand_data *oi)
>  {
> @@ -975,8 +995,12 @@ static void grab_common_values(struct atom_value *val, int deref, struct expand_
>  			v->s = xstrfmt("%"PRIuMAX , (uintmax_t)oi->size);
>  		} else if (!strcmp(name, "deltabase"))
>  			v->s = xstrdup(oid_to_hex(&oi->delta_base_oid));
> -		else if (deref)
> -			grab_oid(name, "objectname", &oi->oid, v, &used_atom[i]);
> +		else if (deref) {
> +			if (!strcmp(name, "notes"))
> +				grab_notes(&oi->oid, v);
> +			else
> +				grab_oid(name, "objectname", &oi->oid, v, &used_atom[i]);
> +		}
>  	}
>  }
>
> @@ -1767,6 +1791,9 @@ static int populate_value(struct ref_array_item *ref, struct strbuf *err)
>  			continue;
>  		} else if (!deref && grab_oid(name, "objectname", &ref->objectname, v, atom)) {
>  			continue;
> +		} else if (!deref && !strcmp(name, "notes")) {
> +			grab_notes(&ref->objectname, v);
> +			continue;
>  		} else if (!strcmp(name, "HEAD")) {
>  			if (atom->u.head && !strcmp(ref->refname, atom->u.head))
>  				v->s = xstrdup("*");