Files
git/fetch-object-info.c
Pablo Sabater 56f3100adb cat-file: make remote-object-info allow-list dynamic
The static allow-list in expand_atom() is hardcoded to only allow
"objectname" and "objectsize" for remote queries. This works because
up to this point all servers will either support object-info with name
and size or they do not support them at all, but we cannot expect that
in a future different servers with different git versions to have the
same object-info capabilities. Therefore, the allow_list needs to be
dynamic depending on what does the server advertise.

The client will now:

1. Request the protocol option that the placeholder refers to (i.e.
   "size" when "%(objectsize)").

2. Filters the request in fetch_object_info() dropping any option that
   the server does not advertise.

3. After the fetching, the options that haven't been dropped are the ones
   fetched and supported by the server, these supported options are
   mapped and remote_allowed_atoms is populated with the placeholders.

4. expand_atom() checks remote_allowed_atoms with the same behaviour as
   the static allow_list had.

Move object_info_options out of get_remote_info so the caller which has
data can select what options will be requested instead of requesting
always size.
Move batch_object_write() out so there will always be an output even if
all the placeholders are not supported by the server (returns an empty
line).

Include "type" in the object_info_options so once the server supports
it, the clients know already how to request it.

Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-08 23:30:15 +09:00

94 lines
3.0 KiB
C

#include "git-compat-util.h"
#include "gettext.h"
#include "hex.h"
#include "pkt-line.h"
#include "connect.h"
#include "oid-array.h"
#include "odb.h"
#include "fetch-object-info.h"
#include "string-list.h"
/* Sends git-cat-file object-info command and its arguments into the request buffer. */
static void send_object_info_request(const int fd_out, struct object_info_args *args)
{
struct strbuf req_buf = STRBUF_INIT;
write_command_and_capabilities(&req_buf, "object-info", args->server_options);
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);
}
int fetch_object_info(const enum protocol_version version, struct object_info_args *args,
struct packet_reader *reader, struct object_info *object_info_data,
const int stateless_rpc, const int fd_out)
{
int size_index = -1;
switch (version) {
case protocol_v2:
if (!server_supports_v2("object-info"))
die(_("object-info capability is not enabled on the server"));
for (int i = args->object_info_options->nr - 1; i >= 0; i--)
if (!server_supports_feature("object-info",
args->object_info_options->items[i].string, 0))
unsorted_string_list_delete_item(args->object_info_options, i, 0);
send_object_info_request(fd_out, args);
break;
case protocol_v1:
case protocol_v0:
die(_("unsupported 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(stateless_rpc, reader, "stateless delimiter expected");
return -1;
}
if (!string_list_has_string(args->object_info_options, reader->line))
return -1;
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(*object_info_data[j].sizep));
}
}
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: server does not recognize object %s",
object_info_values.items[0].string);
if (strtoul_ul(object_info_values.items[1 + size_index].string, 10, object_info_data[i].sizep))
die("object-info: ref %s has invalid size %s",
object_info_values.items[0].string,
object_info_values.items[1 + size_index].string);
}
string_list_clear(&object_info_values, 0);
}
check_stateless_delimiter(stateless_rpc, reader, "stateless delimiter expected");
return 0;
}