diff mbox series

[v2,4/6] transport: add client support for object-info

Message ID 20240720034337.57125-5-eric.peijian@gmail.com (mailing list archive)
State New, archived
Headers show
Series cat-file: add remote-object-info to batch-command | expand

Commit Message

Eric Ju July 20, 2024, 3:43 a.m. UTC
From: Calvin Wan <calvinwan@google.com>

Sometimes it is useful to get information about an object without having
to download it completely. The server logic has already been implemented
in “a2ba162cda (object-info: support for retrieving object info,
2021-04-20)”.

Add client functions to communicate with the server.

The client currently supports requesting a list of object ids with
feature 'size' from a v2 server. If a server does not
advertise the feature, then the client falls back
to making the request through 'fetch'.

Helped-by: Jonathan Tan <jonathantanmy@google.com>
Helped-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Eric Ju  <eric.peijian@gmail.com>
---
 fetch-pack.c       |  24 +++++++++
 fetch-pack.h       |  10 ++++
 transport-helper.c |   8 ++-
 transport.c        | 118 +++++++++++++++++++++++++++++++++++++++++++--
 transport.h        |  11 +++++
 5 files changed, 164 insertions(+), 7 deletions(-)

Comments

Christian Couder Sept. 24, 2024, 11:45 a.m. UTC | #1
On Sat, Jul 20, 2024 at 5:43 AM Eric Ju <eric.peijian@gmail.com> wrote:

[...]

>  fetch-pack.c       |  24 +++++++++
>  fetch-pack.h       |  10 ++++
>  transport-helper.c |   8 ++-
>  transport.c        | 118 +++++++++++++++++++++++++++++++++++++++++++--
>  transport.h        |  11 +++++
>  5 files changed, 164 insertions(+), 7 deletions(-)

Karthik suggested adding tests at this stage, but I see no tests here.
Maybe the tests are added later, but I agree with Karthik that it
would be nice to add them early if possible.

> diff --git a/transport-helper.c b/transport-helper.c
> index 09b3560ffd..841a32e80a 100644
> --- a/transport-helper.c
> +++ b/transport-helper.c
> @@ -699,13 +699,17 @@ static int fetch_refs(struct transport *transport,
>
>         /*
>          * If we reach here, then the server, the client, and/or the transport
> -        * helper does not support protocol v2. --negotiate-only requires
> -        * protocol v2.
> +        * helper does not support protocol v2. --negotiate-only and cat-file remote-object-info
> +        * require protocol v2.
>          */
>         if (data->transport_options.acked_commits) {
>                 warning(_("--negotiate-only requires protocol v2"));
>                 return -1;
>         }
> +       if (transport->smart_options->object_info) {
> +               // fail the command explicitly to avoid further commands input

We use "/* stuff */" for one line comments instead of "// stuff". Also
the comment could go before the if (...) above and the "{" and "}"
could be dropped.

> +               die(_("remote-object-info requires protocol v2"));
> +       }

[...]

> +static int fetch_object_info(struct transport *transport, struct object_info *object_info_data)
> +{
> +       int size_index = -1;
> +       struct git_transport_data *data = transport->data;
> +       struct object_info_args args = { 0 };
> +       struct packet_reader reader;
> +
> +       args.server_options = transport->server_options;
> +       args.object_info_options = transport->smart_options->object_info_options;
> +       args.oids = transport->smart_options->object_info_oids;
> +
> +       connect_setup(transport, 0);
> +       packet_reader_init(&reader, data->fd[0], NULL, 0,
> +                       PACKET_READ_CHOMP_NEWLINE |
> +                       PACKET_READ_GENTLE_ON_EOF |
> +                       PACKET_READ_DIE_ON_ERR_PACKET);
> +       data->version = discover_version(&reader);
> +
> +       transport->hash_algo = reader.hash_algo;
> +
> +       switch (data->version) {
> +       case protocol_v2:
> +               if (!server_supports_v2("object-info"))
> +                       return -1;
> +               if (unsorted_string_list_has_string(args.object_info_options, "size")
> +                               && !server_supports_feature("object-info", "size", 0)) {
> +                       return -1;
> +               }

The "{" and "}" can be dropped here too.

> +               send_object_info_request(data->fd[1], &args);
> +               break;
> +       case protocol_v1:
> +       case protocol_v0:
> +               die(_("wrong protocol version. expected v2"));
> +       case protocol_unknown_version:
> +               BUG("unknown protocol version");
> +       }
> +
> +       for (size_t i = 0; i < args.object_info_options->nr; i++) {
> +               if (packet_reader_read(&reader) != PACKET_READ_NORMAL) {
> +                       check_stateless_delimiter(transport->stateless_rpc, &reader, "stateless delimiter expected");
> +                       return -1;
> +               }
> +               if (unsorted_string_list_has_string(args.object_info_options, reader.line)) {
> +                       if (!strcmp(reader.line, "size")) {
> +                               size_index = i;
> +                               for (size_t j = 0; j < args.oids->nr; j++) {
> +                                       object_info_data[j].sizep = xcalloc(1, sizeof(long));
> +                               }

The "{" and "}" can be dropped here too.

> +                       }
> +                       continue;
> +               }
> +               return -1;
> +       }
> +
> +       for (size_t i = 0; packet_reader_read(&reader) == PACKET_READ_NORMAL && i < args.oids->nr; i++){
> +               struct string_list object_info_values = STRING_LIST_INIT_DUP;
> +
> +               string_list_split(&object_info_values, reader.line, ' ', -1);
> +               if (0 <= size_index) {
> +                       if (!strcmp(object_info_values.items[1 + size_index].string, ""))
> +                               die("object-info: not our ref %s",
> +                                       object_info_values.items[0].string);
> +
> +                       *object_info_data[i].sizep = strtoul(object_info_values.items[1 + size_index].string, NULL, 10);
> +

This blank line can be removed.

> +               }
> +
> +               string_list_clear(&object_info_values, 0);
> +       }
> +       check_stateless_delimiter(transport->stateless_rpc, &reader, "stateless delimiter expected");
> +
> +       return 0;
> +}
> +
>  static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
>                                         struct transport_ls_refs_options *options)
>  {
> @@ -413,6 +487,7 @@ static int fetch_refs_via_pack(struct transport *transport,
>         struct ref *refs = NULL;
>         struct fetch_pack_args args;
>         struct ref *refs_tmp = NULL;
> +       struct ref *object_info_refs = NULL;
>
>         memset(&args, 0, sizeof(args));
>         args.uploadpack = data->options.uploadpack;
> @@ -439,11 +514,36 @@ static int fetch_refs_via_pack(struct transport *transport,
>         args.server_options = transport->server_options;
>         args.negotiation_tips = data->options.negotiation_tips;
>         args.reject_shallow_remote = transport->smart_options->reject_shallow;
> +       args.object_info = transport->smart_options->object_info;
> +
> +       if (transport->smart_options
> +               && transport->smart_options->object_info
> +               && transport->smart_options->object_info_oids->nr > 0) {
> +               struct ref *ref_itr = object_info_refs = alloc_ref("");
> +
> +               if (!fetch_object_info(transport, data->options.object_info_data))
> +                       goto cleanup;
> +
> +               args.object_info_data = data->options.object_info_data;
> +               args.quiet = 1;
> +               args.no_progress = 1;
> +               for (size_t i = 0; i < transport->smart_options->object_info_oids->nr; i++) {
> +                       ref_itr->old_oid = transport->smart_options->object_info_oids->oid[i];
> +                       ref_itr->exact_oid = 1;
> +                       if (i == transport->smart_options->object_info_oids->nr - 1)
> +                               /* last element, no need to allocat to next */

s/allocat/allocate/

> +                               ref_itr -> next = NULL;
> +                       else
> +                               ref_itr->next = alloc_ref("");
>
> -       if (!data->finished_handshake) {
> -               int i;
> +                       ref_itr = ref_itr->next;
> +               }
> +
> +               transport->remote_refs = object_info_refs;
> +
> +       } else if (!data->finished_handshake) {
>                 int must_list_refs = 0;
> -               for (i = 0; i < nr_heads; i++) {
> +               for (int i = 0; i < nr_heads; i++) {
>                         if (!to_fetch[i]->exact_oid) {
>                                 must_list_refs = 1;
>                                 break;
> @@ -481,23 +581,31 @@ static int fetch_refs_via_pack(struct transport *transport,
>                           &transport->pack_lockfiles, data->version);
>
>         data->finished_handshake = 0;
> +       if (args.object_info) {
> +               struct ref *ref_cpy_reader = object_info_refs;
> +               for (int i = 0; ref_cpy_reader; i++) {
> +                       oid_object_info_extended(the_repository, &ref_cpy_reader->old_oid, &args.object_info_data[i], OBJECT_INFO_LOOKUP_REPLACE);

This line might want to be folded.


> +                       ref_cpy_reader = ref_cpy_reader->next;
> +               }
> +       }
> +
Junio C Hamano Sept. 24, 2024, 5:29 p.m. UTC | #2
Christian Couder <christian.couder@gmail.com> writes:

> On Sat, Jul 20, 2024 at 5:43 AM Eric Ju <eric.peijian@gmail.com> wrote:
>
> [...]
>
>>  fetch-pack.c       |  24 +++++++++
>>  fetch-pack.h       |  10 ++++
>>  transport-helper.c |   8 ++-
>>  transport.c        | 118 +++++++++++++++++++++++++++++++++++++++++++--
>>  transport.h        |  11 +++++
>>  5 files changed, 164 insertions(+), 7 deletions(-)
>
> Karthik suggested adding tests at this stage, but I see no tests here.
> Maybe the tests are added later, but I agree with Karthik that it
> would be nice to add them early if possible.
> ...
>> +       if (args.object_info) {
>> +               struct ref *ref_cpy_reader = object_info_refs;
>> +               for (int i = 0; ref_cpy_reader; i++) {
>> +                       oid_object_info_extended(the_repository, &ref_cpy_reader->old_oid, &args.object_info_data[i], OBJECT_INFO_LOOKUP_REPLACE);
>
> This line might want to be folded.

Thanks for a review on this long patch.
Eric Ju Sept. 25, 2024, 6:29 p.m. UTC | #3
On Tue, Sep 24, 2024 at 7:45 AM Christian Couder
<christian.couder@gmail.com> wrote:
>
> On Sat, Jul 20, 2024 at 5:43 AM Eric Ju <eric.peijian@gmail.com> wrote:
>
> [...]
>
> >  fetch-pack.c       |  24 +++++++++
> >  fetch-pack.h       |  10 ++++
> >  transport-helper.c |   8 ++-
> >  transport.c        | 118 +++++++++++++++++++++++++++++++++++++++++++--
> >  transport.h        |  11 +++++
> >  5 files changed, 164 insertions(+), 7 deletions(-)
>
> Karthik suggested adding tests at this stage, but I see no tests here.
> Maybe the tests are added later, but I agree with Karthik that it
> would be nice to add them early if possible.
>

Thank you. I’m not sure if there’s an easy way to directly add unit
tests for the changes in fetch-pack.c, transport-helper.c, and
transport.c, as the relevant functions are deeply nested within the
client’s call stack. Therefore, I’m attempting to test them indirectly
through git cat-file in t/t1017-cat-file-remote-object-info.sh in the
next commit.

Specifically, in t/t1017-cat-file-remote-object-info.sh:

- The code in transport-helper.c is tested in the cases
“remote-object-info fails on server with legacy protocol” and
“remote-object-info fails on server with legacy protocol fallback”.

- The code in transport.c and fetch-pack.c is tested in the cases
where transfer.advertiseobjectinfo is set to true, such as in
“batch-command remote-object-info http://”, “batch-command
remote-object-info file://”, and “batch-command remote-object-info
git://”. In these tests, we verify that remote-object-info
successfully retrieves the size from the remote without downloading
the objects locally.


> > diff --git a/transport-helper.c b/transport-helper.c
> > index 09b3560ffd..841a32e80a 100644
> > --- a/transport-helper.c
> > +++ b/transport-helper.c
> > @@ -699,13 +699,17 @@ static int fetch_refs(struct transport *transport,
> >
> >         /*
> >          * If we reach here, then the server, the client, and/or the transport
> > -        * helper does not support protocol v2. --negotiate-only requires
> > -        * protocol v2.
> > +        * helper does not support protocol v2. --negotiate-only and cat-file remote-object-info
> > +        * require protocol v2.
> >          */
> >         if (data->transport_options.acked_commits) {
> >                 warning(_("--negotiate-only requires protocol v2"));
> >                 return -1;
> >         }
> > +       if (transport->smart_options->object_info) {
> > +               // fail the command explicitly to avoid further commands input
>
> We use "/* stuff */" for one line comments instead of "// stuff". Also
> the comment could go before the if (...) above and the "{" and "}"
> could be dropped.
>

Thank you. Revised in V3.

> > +               die(_("remote-object-info requires protocol v2"));
> > +       }
>
> [...]
>
> > +static int fetch_object_info(struct transport *transport, struct object_info *object_info_data)
> > +{
> > +       int size_index = -1;
> > +       struct git_transport_data *data = transport->data;
> > +       struct object_info_args args = { 0 };
> > +       struct packet_reader reader;
> > +
> > +       args.server_options = transport->server_options;
> > +       args.object_info_options = transport->smart_options->object_info_options;
> > +       args.oids = transport->smart_options->object_info_oids;
> > +
> > +       connect_setup(transport, 0);
> > +       packet_reader_init(&reader, data->fd[0], NULL, 0,
> > +                       PACKET_READ_CHOMP_NEWLINE |
> > +                       PACKET_READ_GENTLE_ON_EOF |
> > +                       PACKET_READ_DIE_ON_ERR_PACKET);
> > +       data->version = discover_version(&reader);
> > +
> > +       transport->hash_algo = reader.hash_algo;
> > +
> > +       switch (data->version) {
> > +       case protocol_v2:
> > +               if (!server_supports_v2("object-info"))
> > +                       return -1;
> > +               if (unsorted_string_list_has_string(args.object_info_options, "size")
> > +                               && !server_supports_feature("object-info", "size", 0)) {
> > +                       return -1;
> > +               }
>
> The "{" and "}" can be dropped here too.
>

Thank you. Fixed in V3.

> > +               send_object_info_request(data->fd[1], &args);
> > +               break;
> > +       case protocol_v1:
> > +       case protocol_v0:
> > +               die(_("wrong protocol version. expected v2"));
> > +       case protocol_unknown_version:
> > +               BUG("unknown protocol version");
> > +       }
> > +
> > +       for (size_t i = 0; i < args.object_info_options->nr; i++) {
> > +               if (packet_reader_read(&reader) != PACKET_READ_NORMAL) {
> > +                       check_stateless_delimiter(transport->stateless_rpc, &reader, "stateless delimiter expected");
> > +                       return -1;
> > +               }
> > +               if (unsorted_string_list_has_string(args.object_info_options, reader.line)) {
> > +                       if (!strcmp(reader.line, "size")) {
> > +                               size_index = i;
> > +                               for (size_t j = 0; j < args.oids->nr; j++) {
> > +                                       object_info_data[j].sizep = xcalloc(1, sizeof(long));
> > +                               }
>
> The "{" and "}" can be dropped here too.
>

Thank you. Fixed in V3.

> > +                       }
> > +                       continue;
> > +               }
> > +               return -1;
> > +       }
> > +
> > +       for (size_t i = 0; packet_reader_read(&reader) == PACKET_READ_NORMAL && i < args.oids->nr; i++){
> > +               struct string_list object_info_values = STRING_LIST_INIT_DUP;
> > +
> > +               string_list_split(&object_info_values, reader.line, ' ', -1);
> > +               if (0 <= size_index) {
> > +                       if (!strcmp(object_info_values.items[1 + size_index].string, ""))
> > +                               die("object-info: not our ref %s",
> > +                                       object_info_values.items[0].string);
> > +
> > +                       *object_info_data[i].sizep = strtoul(object_info_values.items[1 + size_index].string, NULL, 10);
> > +
>
> This blank line can be removed.
>

Thank you. Fixed in V3.

> > +               }
> > +
> > +               string_list_clear(&object_info_values, 0);
> > +       }
> > +       check_stateless_delimiter(transport->stateless_rpc, &reader, "stateless delimiter expected");
> > +
> > +       return 0;
> > +}
> > +
> >  static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
> >                                         struct transport_ls_refs_options *options)
> >  {
> > @@ -413,6 +487,7 @@ static int fetch_refs_via_pack(struct transport *transport,
> >         struct ref *refs = NULL;
> >         struct fetch_pack_args args;
> >         struct ref *refs_tmp = NULL;
> > +       struct ref *object_info_refs = NULL;
> >
> >         memset(&args, 0, sizeof(args));
> >         args.uploadpack = data->options.uploadpack;
> > @@ -439,11 +514,36 @@ static int fetch_refs_via_pack(struct transport *transport,
> >         args.server_options = transport->server_options;
> >         args.negotiation_tips = data->options.negotiation_tips;
> >         args.reject_shallow_remote = transport->smart_options->reject_shallow;
> > +       args.object_info = transport->smart_options->object_info;
> > +
> > +       if (transport->smart_options
> > +               && transport->smart_options->object_info
> > +               && transport->smart_options->object_info_oids->nr > 0) {
> > +               struct ref *ref_itr = object_info_refs = alloc_ref("");
> > +
> > +               if (!fetch_object_info(transport, data->options.object_info_data))
> > +                       goto cleanup;
> > +
> > +               args.object_info_data = data->options.object_info_data;
> > +               args.quiet = 1;
> > +               args.no_progress = 1;
> > +               for (size_t i = 0; i < transport->smart_options->object_info_oids->nr; i++) {
> > +                       ref_itr->old_oid = transport->smart_options->object_info_oids->oid[i];
> > +                       ref_itr->exact_oid = 1;
> > +                       if (i == transport->smart_options->object_info_oids->nr - 1)
> > +                               /* last element, no need to allocat to next */
>
> s/allocat/allocate/
>

Thank you. Fixed in V3.

> > +                               ref_itr -> next = NULL;
> > +                       else
> > +                               ref_itr->next = alloc_ref("");
> >
> > -       if (!data->finished_handshake) {
> > -               int i;
> > +                       ref_itr = ref_itr->next;
> > +               }
> > +
> > +               transport->remote_refs = object_info_refs;
> > +
> > +       } else if (!data->finished_handshake) {
> >                 int must_list_refs = 0;
> > -               for (i = 0; i < nr_heads; i++) {
> > +               for (int i = 0; i < nr_heads; i++) {
> >                         if (!to_fetch[i]->exact_oid) {
> >                                 must_list_refs = 1;
> >                                 break;
> > @@ -481,23 +581,31 @@ static int fetch_refs_via_pack(struct transport *transport,
> >                           &transport->pack_lockfiles, data->version);
> >
> >         data->finished_handshake = 0;
> > +       if (args.object_info) {
> > +               struct ref *ref_cpy_reader = object_info_refs;
> > +               for (int i = 0; ref_cpy_reader; i++) {
> > +                       oid_object_info_extended(the_repository, &ref_cpy_reader->old_oid, &args.object_info_data[i], OBJECT_INFO_LOOKUP_REPLACE);
>
> This line might want to be folded.
>

Thank you. Fixed in V3.



>
> > +                       ref_cpy_reader = ref_cpy_reader->next;
> > +               }
> > +       }
> > +
diff mbox series

Patch

diff --git a/fetch-pack.c b/fetch-pack.c
index a605b9a499..419450c8dd 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1344,6 +1344,27 @@  static void write_command_and_capabilities(struct strbuf *req_buf,
 	packet_buf_delim(req_buf);
 }
 
+void send_object_info_request(int fd_out, struct object_info_args *args)
+{
+	struct strbuf req_buf = STRBUF_INIT;
+
+	write_command_and_capabilities(&req_buf, args->server_options, "object-info");
+
+	if (unsorted_string_list_has_string(args->object_info_options, "size"))
+		packet_buf_write(&req_buf, "size");
+
+	if (args->oids) {
+		for (size_t i = 0; i < args->oids->nr; i++)
+			packet_buf_write(&req_buf, "oid %s", oid_to_hex(&args->oids->oid[i]));
+	}
+
+	packet_buf_flush(&req_buf);
+	if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
+		die_errno(_("unable to write request to remote"));
+
+	strbuf_release(&req_buf);
+}
+
 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
 			      struct fetch_pack_args *args,
 			      const struct ref *wants, struct oidset *common,
@@ -1681,6 +1702,9 @@  static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 	if (args->depth > 0 || args->deepen_since || args->deepen_not)
 		args->deepen = 1;
 
+	if (args->object_info)
+		state = FETCH_SEND_REQUEST;
+
 	while (state != FETCH_DONE) {
 		switch (state) {
 		case FETCH_CHECK_LOCAL:
diff --git a/fetch-pack.h b/fetch-pack.h
index b5c579cdae..5a5211e355 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -16,6 +16,7 @@  struct fetch_pack_args {
 	const struct string_list *deepen_not;
 	struct list_objects_filter_options filter_options;
 	const struct string_list *server_options;
+	struct object_info *object_info_data;
 
 	/*
 	 * If not NULL, during packfile negotiation, fetch-pack will send "have"
@@ -42,6 +43,7 @@  struct fetch_pack_args {
 	unsigned reject_shallow_remote:1;
 	unsigned deepen:1;
 	unsigned refetch:1;
+	unsigned object_info:1;
 
 	/*
 	 * Indicate that the remote of this request is a promisor remote. The
@@ -68,6 +70,12 @@  struct fetch_pack_args {
 	unsigned connectivity_checked:1;
 };
 
+struct object_info_args {
+	struct string_list *object_info_options;
+	const struct string_list *server_options;
+	struct oid_array *oids;
+};
+
 /*
  * sought represents remote references that should be updated from.
  * On return, the names that were found on the remote will have been
@@ -106,4 +114,6 @@  int report_unmatched_refs(struct ref **sought, int nr_sought);
  */
 int fetch_pack_fsck_objects(void);
 
+void send_object_info_request(int fd_out, struct object_info_args *args);
+
 #endif
diff --git a/transport-helper.c b/transport-helper.c
index 09b3560ffd..841a32e80a 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -699,13 +699,17 @@  static int fetch_refs(struct transport *transport,
 
 	/*
 	 * If we reach here, then the server, the client, and/or the transport
-	 * helper does not support protocol v2. --negotiate-only requires
-	 * protocol v2.
+	 * helper does not support protocol v2. --negotiate-only and cat-file remote-object-info
+	 * require protocol v2.
 	 */
 	if (data->transport_options.acked_commits) {
 		warning(_("--negotiate-only requires protocol v2"));
 		return -1;
 	}
+	if (transport->smart_options->object_info) {
+		// fail the command explicitly to avoid further commands input
+		die(_("remote-object-info requires protocol v2"));
+	}
 
 	if (!data->get_refs_list_called)
 		get_refs_list_using_list(transport, 0);
diff --git a/transport.c b/transport.c
index 12cc5b4d96..8f990fcba6 100644
--- a/transport.c
+++ b/transport.c
@@ -366,6 +366,80 @@  static struct ref *handshake(struct transport *transport, int for_push,
 	return refs;
 }
 
+static int fetch_object_info(struct transport *transport, struct object_info *object_info_data)
+{
+	int size_index = -1;
+	struct git_transport_data *data = transport->data;
+	struct object_info_args args = { 0 };
+	struct packet_reader reader;
+
+	args.server_options = transport->server_options;
+	args.object_info_options = transport->smart_options->object_info_options;
+	args.oids = transport->smart_options->object_info_oids;
+
+	connect_setup(transport, 0);
+	packet_reader_init(&reader, data->fd[0], NULL, 0,
+			PACKET_READ_CHOMP_NEWLINE |
+			PACKET_READ_GENTLE_ON_EOF |
+			PACKET_READ_DIE_ON_ERR_PACKET);
+	data->version = discover_version(&reader);
+
+	transport->hash_algo = reader.hash_algo;
+
+	switch (data->version) {
+	case protocol_v2:
+		if (!server_supports_v2("object-info"))
+			return -1;
+		if (unsorted_string_list_has_string(args.object_info_options, "size")
+				&& !server_supports_feature("object-info", "size", 0)) {
+			return -1;
+		}
+		send_object_info_request(data->fd[1], &args);
+		break;
+	case protocol_v1:
+	case protocol_v0:
+		die(_("wrong protocol version. expected v2"));
+	case protocol_unknown_version:
+		BUG("unknown protocol version");
+	}
+
+	for (size_t i = 0; i < args.object_info_options->nr; i++) {
+		if (packet_reader_read(&reader) != PACKET_READ_NORMAL) {
+			check_stateless_delimiter(transport->stateless_rpc, &reader, "stateless delimiter expected");
+			return -1;
+		}
+		if (unsorted_string_list_has_string(args.object_info_options, reader.line)) {
+			if (!strcmp(reader.line, "size")) {
+				size_index = i;
+				for (size_t j = 0; j < args.oids->nr; j++) {
+					object_info_data[j].sizep = xcalloc(1, sizeof(long));
+				}
+			}
+			continue;
+		}
+		return -1;
+	}
+
+	for (size_t i = 0; packet_reader_read(&reader) == PACKET_READ_NORMAL && i < args.oids->nr; i++){
+		struct string_list object_info_values = STRING_LIST_INIT_DUP;
+
+		string_list_split(&object_info_values, reader.line, ' ', -1);
+		if (0 <= size_index) {
+			if (!strcmp(object_info_values.items[1 + size_index].string, ""))
+				die("object-info: not our ref %s",
+					object_info_values.items[0].string);
+
+			*object_info_data[i].sizep = strtoul(object_info_values.items[1 + size_index].string, NULL, 10);
+
+		}
+
+		string_list_clear(&object_info_values, 0);
+	}
+	check_stateless_delimiter(transport->stateless_rpc, &reader, "stateless delimiter expected");
+
+	return 0;
+}
+
 static struct ref *get_refs_via_connect(struct transport *transport, int for_push,
 					struct transport_ls_refs_options *options)
 {
@@ -413,6 +487,7 @@  static int fetch_refs_via_pack(struct transport *transport,
 	struct ref *refs = NULL;
 	struct fetch_pack_args args;
 	struct ref *refs_tmp = NULL;
+	struct ref *object_info_refs = NULL;
 
 	memset(&args, 0, sizeof(args));
 	args.uploadpack = data->options.uploadpack;
@@ -439,11 +514,36 @@  static int fetch_refs_via_pack(struct transport *transport,
 	args.server_options = transport->server_options;
 	args.negotiation_tips = data->options.negotiation_tips;
 	args.reject_shallow_remote = transport->smart_options->reject_shallow;
+	args.object_info = transport->smart_options->object_info;
+
+	if (transport->smart_options
+		&& transport->smart_options->object_info
+		&& transport->smart_options->object_info_oids->nr > 0) {
+		struct ref *ref_itr = object_info_refs = alloc_ref("");
+
+		if (!fetch_object_info(transport, data->options.object_info_data))
+			goto cleanup;
+
+		args.object_info_data = data->options.object_info_data;
+		args.quiet = 1;
+		args.no_progress = 1;
+		for (size_t i = 0; i < transport->smart_options->object_info_oids->nr; i++) {
+			ref_itr->old_oid = transport->smart_options->object_info_oids->oid[i];
+			ref_itr->exact_oid = 1;
+			if (i == transport->smart_options->object_info_oids->nr - 1)
+				/* last element, no need to allocat to next */
+				ref_itr -> next = NULL;
+			else
+				ref_itr->next = alloc_ref("");
 
-	if (!data->finished_handshake) {
-		int i;
+			ref_itr = ref_itr->next;
+		}
+
+		transport->remote_refs = object_info_refs;
+
+	} else if (!data->finished_handshake) {
 		int must_list_refs = 0;
-		for (i = 0; i < nr_heads; i++) {
+		for (int i = 0; i < nr_heads; i++) {
 			if (!to_fetch[i]->exact_oid) {
 				must_list_refs = 1;
 				break;
@@ -481,23 +581,31 @@  static int fetch_refs_via_pack(struct transport *transport,
 			  &transport->pack_lockfiles, data->version);
 
 	data->finished_handshake = 0;
+	if (args.object_info) {
+		struct ref *ref_cpy_reader = object_info_refs;
+		for (int i = 0; ref_cpy_reader; i++) {
+			oid_object_info_extended(the_repository, &ref_cpy_reader->old_oid, &args.object_info_data[i], OBJECT_INFO_LOOKUP_REPLACE);
+			ref_cpy_reader = ref_cpy_reader->next;
+		}
+	}
+
 	data->options.self_contained_and_connected =
 		args.self_contained_and_connected;
 	data->options.connectivity_checked = args.connectivity_checked;
 
-	if (!refs)
+	if (!refs && !args.object_info)
 		ret = -1;
 	if (report_unmatched_refs(to_fetch, nr_heads))
 		ret = -1;
 
 cleanup:
+	free_refs(object_info_refs);
 	close(data->fd[0]);
 	if (data->fd[1] >= 0)
 		close(data->fd[1]);
 	if (finish_connect(data->conn))
 		ret = -1;
 	data->conn = NULL;
-
 	free_refs(refs_tmp);
 	free_refs(refs);
 	list_objects_filter_release(&args.filter_options);
diff --git a/transport.h b/transport.h
index 6393cd9823..50ea2b05cf 100644
--- a/transport.h
+++ b/transport.h
@@ -5,6 +5,7 @@ 
 #include "remote.h"
 #include "list-objects-filter-options.h"
 #include "string-list.h"
+#include "object-store.h"
 
 struct git_transport_options {
 	unsigned thin : 1;
@@ -30,6 +31,12 @@  struct git_transport_options {
 	 */
 	unsigned connectivity_checked:1;
 
+	/*
+	 * Transport will attempt to pull only object-info. Fallbacks
+	 * to pulling entire object if object-info is not supported.
+	 */
+	unsigned object_info : 1;
+
 	int depth;
 	const char *deepen_since;
 	const struct string_list *deepen_not;
@@ -53,6 +60,10 @@  struct git_transport_options {
 	 * common commits to this oidset instead of fetching any packfiles.
 	 */
 	struct oidset *acked_commits;
+
+	struct oid_array *object_info_oids;
+	struct object_info *object_info_data;
+	struct string_list *object_info_options;
 };
 
 enum transport_family {