Thanks for picking up this series btw!
On Mon, Dec 23, 2024 at 3:25 PM Eric Ju <eric.peijian@xxxxxxxxx> wrote:
>
> From: Calvin Wan <calvinwan@xxxxxxxxxx>
>
> Sometimes, it is beneficial to retrieve information about an object
> without downloading it entirely. The server-side logic for this
> functionality was implemented in commit "a2ba162cda (object-info:
> support for retrieving object info, 2021-04-20)."
>
> This commit introduces client functions to interact with the server.
>
> Currently, the client supports requesting a list of object IDs with
> the ‘size’ feature from a v2 server. If the server does not advertise
> this feature (i.e., transfer.advertiseobjectinfo is set to false),
> the client will return an error and exit.
>
> Helped-by: Jonathan Tan <jonathantanmy@xxxxxxxxxx>
> Helped-by: Christian Couder <chriscool@xxxxxxxxxxxxx>
> Signed-off-by: Calvin Wan <calvinwan@xxxxxxxxxx>
> Signed-off-by: Eric Ju <eric.peijian@xxxxxxxxx>
> ---
> Makefile | 1 +
> fetch-object-info.c | 92 +++++++++++++++++++++++++++++++++++++++++++++
> fetch-object-info.h | 18 +++++++++
> fetch-pack.c | 3 ++
> fetch-pack.h | 2 +
> transport-helper.c | 11 +++++-
> transport.c | 28 +++++++++++++-
> transport.h | 11 ++++++
> 8 files changed, 163 insertions(+), 3 deletions(-)
> create mode 100644 fetch-object-info.c
> create mode 100644 fetch-object-info.h
>
> diff --git a/Makefile b/Makefile
> index 3fa4bf0d06..70e9ec0464 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1020,6 +1020,7 @@ LIB_OBJS += ewah/ewah_rlw.o
> LIB_OBJS += exec-cmd.o
> LIB_OBJS += fetch-negotiator.o
> LIB_OBJS += fetch-pack.o
> +LIB_OBJS += fetch-object-info.o
> LIB_OBJS += fmt-merge-msg.o
> LIB_OBJS += fsck.o
> LIB_OBJS += fsmonitor.o
> diff --git a/fetch-object-info.c b/fetch-object-info.c
> new file mode 100644
> index 0000000000..2aa9f2b70d
> --- /dev/null
> +++ b/fetch-object-info.c
> @@ -0,0 +1,92 @@
> +#include "git-compat-util.h"
> +#include "gettext.h"
> +#include "hex.h"
> +#include "pkt-line.h"
> +#include "connect.h"
> +#include "oid-array.h"
> +#include "object-store-ll.h"
> +#include "fetch-object-info.h"
> +#include "string-list.h"
> +
> +/**
> + * send_object_info_request 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);
> +}
> +
> +/**
> + * fetch_object_info sends git-cat-file object-info command into the request buf
> + * and read the results from packets.
> + */
> +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"));
> + send_object_info_request(fd_out, args);
> + break;
> + case protocol_v1:
> + case protocol_v0:
> + die(_("wrong protocol version. expected v2"));
s/wrong/unsupported
> + 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 (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;
> + }
I think we can flatten this logic a bit more here to make it more intuitive.
if (!unsorted_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(long));
}
