Re: [PATCH GSoC v20 00/13] cat-file: add remote-object-info to batch-command

On Tue Jul 21, 2026 at 10:12 PM CEST, Karthik Nayak wrote:

Pablo Sabater [off-list ref] writes:

[snip]

quoted

Changes in v20:
- Moved the prep patch that fixes hash_algo's type to be before
  write_fetch_command_and_capabilities() being moved to 'connect.c'
- Reverted git-cat-file.adoc documentation comments about CAVEATS
- Fixed style for EXPAND_DATA_INIT
- Added more context for comman line die()

[snip]

quoted

Range-diff versus v19:

 1:  6df5bcb3bc =  1:  31b02f10b5 transport-helper: fix memory leak of helper on disconnect
 2:  141d85a76f =  2:  7d62e0586f cat-file: declare loop counter inside for()
 3:  87457a1fe3 =  3:  082d593fb7 t1006: extract helper functions into new 'lib-cat-file.sh'
 4:  c26d378931 =  4:  8646b9d7cf fetch-pack: drop the static advertise_sid variable
 -:  ---------- >  5:  5531a3c399 fetch-pack: use unsigned int for hash_algo variable
 5:  ee16e17228 !  6:  92b4122642 fetch-pack: move write_fetch_command_and_capabilities() to connect.c
    @@ connect.c: int server_supports(const char *feature)
     +	}
     +
     +	if (server_feature_v2("object-format", &hash_name)) {
    -+		int hash_algo = hash_algo_by_name(hash_name);
    ++		const unsigned int hash_algo = hash_algo_by_name(hash_name);
     +		if (hash_algo_by_ptr(the_hash_algo) != hash_algo)
     +			die(_("mismatched algorithms: client %s; server %s"),
     +			    the_hash_algo->name, hash_name);
    @@ fetch-pack.c: static int add_haves(struct fetch_negotiator *negotiator,
     -	}
     -
     -	if (server_feature_v2("object-format", &hash_name)) {
    --		int hash_algo = hash_algo_by_name(hash_name);
    +-		const unsigned int hash_algo = hash_algo_by_name(hash_name);
     -		if (hash_algo_by_ptr(the_hash_algo) != hash_algo)
     -			die(_("mismatched algorithms: client %s; server %s"),
     -			    the_hash_algo->name, hash_name);
 6:  bb915f57ad <  -:  ---------- connect: use unsigned int for hash_algo_by_name() calls
 7:  b3b06b0cae =  7:  b954a5994a connect: make write_fetch_command_and_capabilities() more generic
 8:  79a87c7011 =  8:  627242a7a1 fetch-pack: move fetch initialization
 9:  37c3f93975 =  9:  0578594733 protocol-caps: check object existence regardless of the attributes requested
10:  c5062ecaf2 = 10:  816bfa9162 serve: advertise object-info feature
11:  22d72168bc = 11:  2323f45cb2 transport: add client support for object-info
12:  2cf3b24a35 ! 12:  a39975766b cat-file: add remote-object-info to batch-command
    @@ Documentation/git-cat-file.adoc: one per line, and print information based on th
      You can specify the information shown for each object by using a custom
      `<format>`. The `<format>` is copied literally to stdout for each
     @@ Documentation/git-cat-file.adoc: newline. The available atoms are:
    - 	reports).
    -
    - `objectsize:disk`::
    --	The size, in bytes, that the object takes up on disk. See the
    --	note about on-disk sizes in the `CAVEATS` section below.
    -+	The size, in bytes, that the object takes up on disk.
    -
      `deltabase`::
      	If the object is stored as a delta on-disk, this expands to the
      	full hex representation of the delta base object name.
     -	Otherwise, expands to the null OID (all zeroes). See `CAVEATS`
    --	below.
    -+	Otherwise, expands to the null OID (all zeroes).
    ++	Otherwise, expands to the null OID (all zeroes). See `CAVEATS` section
    + 	below.

This chagne is still unnecessary, no?

I guess it is unnecessary. I added it because on top, at objectsize:disk
it says "`CAVEATS` section". So I tried to have it consistently.

Is it worth a reroll?

quoted

      `rest`::
    - 	If this atom is used in the output string, input lines are split
     @@ Documentation/git-cat-file.adoc: newline. The available atoms are:
      	after that first run of whitespace (i.e., the "rest" of the
      	line) are output in place of the `%(rest)` atom.
    @@ builtin/cat-file.c: struct expand_data {
     +	 */
     +	unsigned is_remote:1;
     +};
    ++
     +#define EXPAND_DATA_INIT  { .mode = S_IFINVALID, .type = OBJ_BAD }
     +
     +static const char *remote_object_info_atoms[] = {
    @@ builtin/cat-file.c: static void parse_cmd_mailmap(struct batch_options *opt UNUS
     +	line_to_split = xstrdup(line);
     +	count = split_cmdline(line_to_split, &argv);
     +	if (count < 0)
    -+		die(_("remote-object-info: %s"), split_cmdline_strerror(count));
    ++		die(_("remote-object-info: failed to parse command line: %s"),
    ++		    split_cmdline_strerror(count));
     +	if (count - 1 > MAX_ALLOWED_OBJ_LIMIT)
     +		die(_("remote-object-info supports at most %d objects"),
     +		    MAX_ALLOWED_OBJ_LIMIT);
13:  ebdfc22fb7 ! 13:  70a11d2aea cat-file: make remote-object-info allow-list adapt to the server
    @@ builtin/cat-file.c: struct expand_data {
      	 */
      	unsigned is_remote:1;
     -};
    +-
     -#define EXPAND_DATA_INIT  { .mode = S_IFINVALID, .type = OBJ_BAD }

     -static const char *remote_object_info_atoms[] = {
     -	"objectname",
     -	"objectsize",
    ++	/*
    ++	 * List of atoms (i.e. "objectsize") that the server supports. Built
    ++	 * from the server's object-info advertised capabilities.
    ++	 */
     +	struct string_list remote_allowed_atoms;
      };
    -+#define EXPAND_DATA_INIT  { .mode = S_IFINVALID, .type = OBJ_BAD, \
    -+			    .remote_allowed_atoms = STRING_LIST_INIT_NODUP }

    ++#define EXPAND_DATA_INIT  { .mode = S_IFINVALID, \
    ++			    .type = OBJ_BAD, \
    ++			    .remote_allowed_atoms = STRING_LIST_INIT_NODUP }
    ++

I guess this is output of running the style check script (which I did
recommend, but I should've mentioned that you should take it with a
pinch of salt, it doesn't always provide the best solutions.)

It comes in part from Junio's suggestion [1]. Although I don't think that
it will receive a lot of new fields, I thought that it would leave the
macro clean for that.

quoted

      static int is_atom(const char *atom, const char *s, int slen)
      {
    + 	int alen = strlen(atom);
     @@ builtin/cat-file.c: static int expand_atom(struct strbuf *sb, const char *atom, int len,
      		       struct expand_data *data)
      {
    @@ builtin/cat-file.c: static int expand_atom(struct strbuf *sb, const char *atom,
     -			if (is_atom(remote_object_info_atoms[i], atom, len))
     +		size_t i;
     +		for (i = 0; i < data->remote_allowed_atoms.nr; i++)
    -+			if (is_atom(data->remote_allowed_atoms.items[i].string, atom, len))
    ++			if (is_atom(data->remote_allowed_atoms.items[i].string,
    ++				    atom, len))
      				break;
     -
     -		/*

---
base-commit: 44de1520f08d1dfebc3ab2d9f644208eaa5ac925

I reviewed v18 last, but the diff here looks good to me. Thanks!

[1]: https://lore.kernel.org/git/xmqqcxwonnkx.fsf@gitster.g/ (local)

Thanks,
Pablo