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From: Eric Sunshine <sunshine@sunshineco.com>
To: Denton Liu <liu.denton@gmail.com>
Cc: Git Mailing List <git@vger.kernel.org>, Jeff King <peff@peff.net>
Subject: Re: [PATCH 3/6] transport: combine common cases with a fallthrough
Date: Wed, 13 May 2020 19:14:35 -0400
Message-ID: <CAPig+cQyCSMtSrdk54E6MVYL4prhNyWgBKkkBFHXo5hShqQ+=Q@mail.gmail.com> (raw)
In-Reply-To: <c89c1841008dfc2d111369fb682b946a0c33b7be.1589393036.git.liu.denton@gmail.com>

On Wed, May 13, 2020 at 2:07 PM Denton Liu <liu.denton@gmail.com> wrote:
> In the switch statement, the difference between the `protocol_v2` and
> `protocol_v{1,0}` arms is a prepatory call to die_if_server_options() in

What is "prepatory"?

More below...

> the latter. The fetch_pack() call is identical in both arms. However,
> since this fetch_pack() call has so many parameters, it is not
> immediately obvious that the call is identical in both cases.
>
> Rewrite the switch statement to fallthrough from the v{1,0} case to v2
> so that they share a common fetch_pack() call. This reduces duplication
> and makes the logic more clear for future readers.
>
> Signed-off-by: Denton Liu <liu.denton@gmail.com>
> ---
> diff --git a/transport.c b/transport.c
> @@ -370,15 +370,11 @@ static int fetch_refs_via_pack(struct transport *transport,
>         switch (data->version) {
> -       case protocol_v2:
> -               refs = fetch_pack(&args, data->fd,
> -                                 refs_tmp ? refs_tmp : transport->remote_refs,
> -                                 to_fetch, nr_heads, &data->shallow,
> -                                 &transport->pack_lockfile, data->version);
> -               break;
> -       case protocol_v1:
>         case protocol_v0:
> +       case protocol_v1:
>                 die_if_server_options(transport);
> +               /* fallthrough */
> +       case protocol_v2:
>                 refs = fetch_pack(&args, data->fd,
>                                   refs_tmp ? refs_tmp : transport->remote_refs,
>                                   to_fetch, nr_heads, &data->shallow,

I can't say that I'm a fan of this change. While it may make it clear
that the two calls are identical, it makes it more difficult to reason
about the distinct v0, v1, and v2 cases. It also makes it more
difficult to extend or make changes to one or another case, should
that become necessary in the future.

  reply index

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-13 18:04 [PATCH 0/6] remote-curl: partial fix for a deadlock with stateless rpc Denton Liu
2020-05-13 18:04 ` [PATCH 1/6] remote-curl: fix typo Denton Liu
2020-05-13 18:04 ` [PATCH 2/6] remote-curl: remove label indentation Denton Liu
2020-05-13 18:04 ` [PATCH 3/6] transport: combine common cases with a fallthrough Denton Liu
2020-05-13 23:14   ` Eric Sunshine [this message]
2020-05-18  9:18     ` Denton Liu
2020-05-18 17:43       ` Eric Sunshine
2020-05-13 18:04 ` [PATCH 4/6] pkt-line: extern packet_length() Denton Liu
2020-05-13 23:23   ` Eric Sunshine
2020-05-15 20:56   ` Jeff King
2020-05-15 20:57     ` Jeff King
2020-05-13 18:04 ` [PATCH 5/6] remote-curl: error on incomplete packet Denton Liu
2020-05-15 21:38   ` Jeff King
2020-05-18  9:08     ` Denton Liu
2020-05-18 15:49       ` Jeff King
2020-05-13 18:04 ` [PATCH 6/6] remote-curl: ensure last packet is a flush Denton Liu
2020-05-15 21:02   ` Denton Liu
2020-05-15 21:41     ` Jeff King
2020-05-18 16:34       ` Junio C Hamano
2020-05-18 16:52         ` Jeff King
2020-05-18 21:00           ` Jeff King
2020-05-18 15:47 ` [PATCH v2 0/7] remote-curl: fix deadlocks when remote server disconnects Denton Liu
2020-05-18 15:47   ` [PATCH v2 1/7] remote-curl: fix typo Denton Liu
2020-05-18 15:47   ` [PATCH v2 2/7] remote-curl: remove label indentation Denton Liu
2020-05-18 18:37     ` Junio C Hamano
2020-05-18 15:47   ` [PATCH v2 3/7] transport: extract common fetch_pack() call Denton Liu
2020-05-18 18:40     ` Junio C Hamano
2020-05-18 15:47   ` [PATCH v2 4/7] pkt-line: extern packet_length() Denton Liu
2020-05-18 16:04     ` Jeff King
2020-05-18 17:50       ` Eric Sunshine
2020-05-18 20:08         ` Jeff King
2020-05-18 18:44       ` Junio C Hamano
2020-05-18 15:47   ` [PATCH v2 5/7] remote-curl: error on incomplete packet Denton Liu
2020-05-18 16:22     ` Jeff King
2020-05-18 16:51       ` Denton Liu
2020-05-18 15:47   ` [PATCH v2 6/7] pkt-line: PACKET_READ_RESPONSE_END Denton Liu
2020-05-18 15:47   ` [PATCH v2 7/7] stateless-connect: send response end packet Denton Liu
2020-05-18 16:43     ` Jeff King
2020-05-18 17:12       ` Denton Liu
2020-05-18 17:26         ` Jeff King
2020-05-18 16:50   ` [PATCH v2 0/7] remote-curl: fix deadlocks when remote server disconnects Jeff King
2020-05-18 17:36     ` Denton Liu
2020-05-18 20:58       ` Jeff King
2020-05-18 22:52         ` Junio C Hamano
2020-05-19  2:38           ` Jeff King
2020-05-18 19:36     ` Junio C Hamano
2020-05-19 10:53   ` [PATCH v3 " Denton Liu
2020-05-19 10:53     ` [PATCH v3 1/7] remote-curl: fix typo Denton Liu
2020-05-19 10:53     ` [PATCH v3 2/7] remote-curl: remove label indentation Denton Liu
2020-05-19 10:53     ` [PATCH v3 3/7] transport: extract common fetch_pack() call Denton Liu
2020-05-19 10:53     ` [PATCH v3 4/7] pkt-line: extern packet_length() Denton Liu
2020-05-19 16:23       ` Eric Sunshine
2020-05-19 10:53     ` [PATCH v3 5/7] remote-curl: error on incomplete packet Denton Liu
2020-05-19 10:53     ` [PATCH v3 6/7] pkt-line: define PACKET_READ_RESPONSE_END Denton Liu
2020-05-19 10:54     ` [PATCH v3 7/7] stateless-connect: send response end packet Denton Liu
2020-05-19 18:40     ` [PATCH v3 0/7] remote-curl: fix deadlocks when remote server disconnects Jeff King
2020-05-19 21:14       ` Denton Liu
2020-05-19 20:51     ` [PATCH v3 8/7] fixup! pkt-line: extern packet_length() Denton Liu
2020-05-22 13:33     ` [PATCH v3 9/9] fixup! remote-curl: error on incomplete packet Denton Liu
2020-05-22 15:54       ` Jeff King
2020-05-22 16:05         ` Denton Liu
2020-05-22 16:31           ` Jeff King

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