Subject: Re: [PATCH v2 1/3] fetch-pack: return enum from process_acks()

From: Jonathan Nieder <[email-masked]>
Date: Mon, 27 Apr 2020 17:53:33 -0700

Jonathan Tan wrote:

> process_acks() returns 0, 1, or 2, depending on whether "ready" was
> received and if not, whether at least one commit was found to be common.
> Replace these magic numbers with a documented enum.
>
> Signed-off-by: Jonathan Tan <[email-masked]>
> ---
>  fetch-pack.c | 35 ++++++++++++++++++++++++++++-------
>  1 file changed, 28 insertions(+), 7 deletions(-)

Yay!

> --- a/fetch-pack.c
> +++ b/fetch-pack.c
> @@ -1268,9 +1268,29 @@ static int process_section_header(struct packet_reader *reader,
>  	return ret;
>  }
>  
> -static int process_acks(struct fetch_negotiator *negotiator,
> -			struct packet_reader *reader,
> -			struct oidset *common)
> +enum common_found {
> +	/*
> +	 * No commit was found to be possessed by both the client and the
> +	 * server, and "ready" was not received.
> +	 */
> +	NO_COMMON_FOUND,
> +
> +	/*
> +	 * At least one commit was found to be possessed by both the client and
> +	 * the server, and "ready" was not received.
> +	 */
> +	COMMON_FOUND,
> +
> +	/*
> +	 * "ready" was received, indicating that the server is ready to send
> +	 * the packfile without any further negotiation.
> +	 */
> +	READY
> +};
> +
> +static enum common_found process_acks(struct fetch_negotiator *negotiator,
> +				      struct packet_reader *reader,
> +				      struct oidset *common)

Thanks for the clear comments.

>  {
>  	/* received */
>  	int received_ready = 0;
> @@ -1320,7 +1340,8 @@ static int process_acks(struct fetch_negotiator *negotiator,
>  		die(_("expected no other sections to be sent after no 'ready'"));
>  
>  	/* return 0 if no common, 1 if there are common, or 2 if ready */

This comment can be removed now, which is a nice bonus.

> -	return received_ready ? 2 : (received_ack ? 1 : 0);
> +	return received_ready ? READY :
> +		(received_ack ? COMMON_FOUND : NO_COMMON_FOUND);
>  }
>  
>  static void receive_shallow_info(struct fetch_pack_args *args,
> @@ -1508,13 +1529,13 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
>  		case FETCH_PROCESS_ACKS:
>  			/* Process ACKs/NAKs */
>  			switch (process_acks(negotiator, &reader, &common)) {
> -			case 2:
> +			case READY:
>  				state = FETCH_GET_PACK;
>  				break;
> -			case 1:
> +			case COMMON_FOUND:
>  				in_vain = 0;
>  				/* fallthrough */
> -			default:
> +			case NO_COMMON_FOUND:
>  				state = FETCH_SEND_REQUEST;
>  				break;
>  			}

With the extraneous comment removed,
Reviewed-by: Jonathan Nieder <[email-masked]>

Thanks.

diff --git i/fetch-pack.c w/fetch-pack.c
index 45547a621e6..7b0eef98db5 100644
--- i/fetch-pack.c
+++ w/fetch-pack.c
@@ -1339,7 +1339,6 @@ static enum common_found process_acks(struct fetch_negotiator *negotiator,
 	if (!received_ready && reader->status != PACKET_READ_FLUSH)
 		die(_("expected no other sections to be sent after no 'ready'"));
 
-	/* return 0 if no common, 1 if there are common, or 2 if ready */
 	return received_ready ? READY :
 		(received_ack ? COMMON_FOUND : NO_COMMON_FOUND);
 }