Re: [PATCH v2] fetch-pack: do not reset in_vain on non-novel acks

[Junio C Hamano <gitster@pobox.com>]

Jonathan Tan <jonathantanmy@google.com> writes:

> I tried looking at creating a helper function to reduce both the size
> and the nesting level of the loop, but it seems to me that a helper
> function can't be extracted so easily because the logic is quite
> intertwined with the rest of the function. For example, the "if
> (args->stateless_rpc..." block uses 6 variables from the outer scope:
> args, ack, commit, result_sha1, req_buf, and state_len (and in_vain, but
> this can be the return value of the function). Expanding it wider would
> allow us to make some of those 6 local, but also introduce new ones from
> the outer scope.

Yup, I suspected that much when I wrote the message you are
responding to, but was sort-of hoping that you might come up with a
more clever way to restructure the code.  It is OK to leave it
as-is, and let others try making it cleaner ;-).

Thanks.

>
>  fetch-pack.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/fetch-pack.c b/fetch-pack.c
> index 85e77af..413937e 100644
> --- a/fetch-pack.c
> +++ b/fetch-pack.c
> @@ -428,10 +428,17 @@ static int find_common(struct fetch_pack_args *args,
>  						const char *hex = sha1_to_hex(result_sha1);
>  						packet_buf_write(&req_buf, "have %s\n", hex);
>  						state_len = req_buf.len;
> -					}
> +						/*
> +						 * Reset in_vain because an ack
> +						 * for this commit has not been
> +						 * seen.
> +						 */
> +						in_vain = 0;
> +					} else if (!args->stateless_rpc
> +						   || ack != ACK_common)
> +						in_vain = 0;
>  					mark_common(commit, 0, 1);
>  					retval = 0;
> -					in_vain = 0;
>  					got_continue = 1;
>  					if (ack == ACK_ready) {
>  						clear_prio_queue(&rev_list);