Re: [PATCH 1/6] fetch-pack: refactor packet writing

From: Karthik Nayak <karthik.188@gmail.com>
Date: Jul 4, 2024, 16:59 UTC
Message-ID: <CAOLa=ZSY1y4wz6M9mOLvTCPoeCmceD-HKqT5tomF+BzbL5yp4Q@mail.gmail.com>
In-Reply-To: <20240628190503.67389-2-eric.peijian@gmail.com>

Eric Ju <eric.peijian@gmail.com> writes:

> From: Calvin Wan <calvinwan@google.com>
>
> A subsequent patch need to write capabilities for another command.

s/need/needs

> Refactor write_fetch_command_and_capabilities() to be used by both
> fetch and future command.
>

Nit: mostly from my lack of understanding, but until I read the code, I
couldn't understand what 'command' meant in this para. Maybe some
preface would be nice here.

Show 50 quoted lines

> Signed-off-by: Calvin Wan <calvinwan@google.com>
> Signed-off-by: Eric Ju  <eric.peijian@gmail.com>
> Helped-by: Jonathan Tan <jonathantanmy@google.com>
> Helped-by: Christian Couder <chriscool@tuxfamily.org>
> ---
>  fetch-pack.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/fetch-pack.c b/fetch-pack.c
> index eba9e420ea..fc9fb66cd8 100644
> --- a/fetch-pack.c
> +++ b/fetch-pack.c
> @@ -1313,13 +1313,13 @@ static int add_haves(struct fetch_negotiator *negotiator,
>  	return haves_added;
>  }
>
> -static void write_fetch_command_and_capabilities(struct strbuf *req_buf,
> -						 const struct string_list *server_options)
> +static void write_command_and_capabilities(struct strbuf *req_buf,
> +						 const struct string_list *server_options, const char* command)
>  {
>  	const char *hash_name;
>
> -	ensure_server_supports_v2("fetch");
> -	packet_buf_write(req_buf, "command=fetch");
> +	ensure_server_supports_v2(command);
> +	packet_buf_write(req_buf, "command=%s", command);
>  	if (server_supports_v2("agent"))
>  		packet_buf_write(req_buf, "agent=%s", git_user_agent_sanitized());
>  	if (advertise_sid && server_supports_v2("session-id"))
> @@ -1355,7 +1355,7 @@ static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
>  	int done_sent = 0;
>  	struct strbuf req_buf = STRBUF_INIT;
>
> -	write_fetch_command_and_capabilities(&req_buf, args->server_options);
> +	write_command_and_capabilities(&req_buf, args->server_options, "fetch");
>
>  	if (args->use_thin_pack)
>  		packet_buf_write(&req_buf, "thin-pack");
> @@ -2163,7 +2163,7 @@ void negotiate_using_fetch(const struct oid_array *negotiation_tips,
>  					   the_repository, "%d",
>  					   negotiation_round);
>  		strbuf_reset(&req_buf);
> -		write_fetch_command_and_capabilities(&req_buf, server_options);
> +		write_command_and_capabilities(&req_buf, server_options, "fetch");
>
>  		packet_buf_write(&req_buf, "wait-for-done");
>
> --
> 2.45.2

Right, this commit in itself looks good. But I was curious why we need this, so I did a sneak peak into the following commits.

To summarize, we want to call:
   `write_command_and_capabilities(..., "object-info");`
in the upcoming patches to get the object-info details from the server.
But isn't this function too specific to the "fetch" command to be
generalized to be for "object-info" too?

Wouldn't it make sense to add a custom function for 'object-info' in 'connect.c'? Like how we currently have `get_remote_bundle_uri()` for 'bundle-uri' and `get_remote_refs` for 'ls-refs'?