From: Jonathan Tan <jonathantanmy@google.com>
To: Calvin Wan <calvinwan@google.com>
Cc: Jonathan Tan <jonathantanmy@google.com>,
git@vger.kernel.org, gitster@pobox.com, philipoakley@iee.email,
johncai86@gmail.com, me@ttaylorr.com
Subject: Re: [PATCH v4 5/8] transport: add client side capability to request object-info
Date: Tue, 3 May 2022 16:15:58 -0700 [thread overview]
Message-ID: <20220503231558.4172288-1-jonathantanmy@google.com> (raw)
In-Reply-To: <20220502170904.2770649-6-calvinwan@google.com>
Calvin Wan <calvinwan@google.com> writes:
> Sometimes it is useful to get information about an object without having
> to download it completely. The server logic has already been implemented
> as “a2ba162cda (object-info: support for retrieving object info,
> 2021-04-20)”. This patch implements the client option for it. Currently,
> only 'size' is supported and the server must be v2, however future
> patches can implement additional options.
>
> The question of version mismatch often comes up with client/server
> relationships. There are two cases to consider here (assuming either
> client or server functionality for object-info changes between the
> different versions):
>
> 1. client version > server version
> - client can request additional attributes from server
> 2. server version > client version
> - server can return additional info to the client
>
> The second case is a non-issue since the client would never be able to
> request additional info from the server. In order to solve the first
> case, recall an earlier patch where the server sends back the attributes
> even if no object ids are sent by the client. This allows the client to
> first check whether the server can accept the requested attributes
> before sending the entire request.
From this description, it seems like the intention is to send an
object-info request, and then if the server responds in a certain way
(here, sending back the attributes - presumably without sending any
actual information), then we know that the server doesn't support our
request and we need to fall back. As Junio says [1], this requires one
RTT more than necessary. We could just determine if the server supports
the attributes we want by using capabilities (without needing to send
the request to check).
[1] https://lore.kernel.org/git/xmqqilqnsaep.fsf@gitster.g/
next prev parent reply other threads:[~2022-05-03 23:16 UTC|newest]
Thread overview: 103+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-08 23:19 [PATCH] fetch —object-info-format: client option for object-info Calvin Wan
2022-02-08 23:56 ` [PATCH v2] " Calvin Wan
2022-02-09 12:48 ` Philip Oakley
2022-02-10 22:32 ` Calvin Wan
2022-02-09 20:41 ` [PATCH v2] fetch object-info-format: " Jonathan Tan
2022-02-10 22:58 ` Calvin Wan
2022-03-28 19:11 ` [PATCH v3 0/3] object-info: add option for retrieving object info Calvin Wan
2022-03-28 19:11 ` [PATCH v3 1/3] fetch-pack: refactor packet writing and fetch options Calvin Wan
2022-03-29 22:54 ` Junio C Hamano
2022-03-29 23:01 ` Taylor Blau
2022-03-30 21:55 ` Jonathan Tan
2022-03-28 19:11 ` [PATCH v3 2/3] transfer.advertiseObjectInfo: add object-info config Calvin Wan
2022-03-29 22:34 ` Junio C Hamano
2022-03-29 22:48 ` Calvin Wan
2022-03-29 23:09 ` Taylor Blau
2022-03-28 19:11 ` [PATCH v3 3/3] object-info: add option for retrieving object info Calvin Wan
2022-03-29 19:57 ` Junio C Hamano
2022-03-29 22:54 ` Junio C Hamano
2022-03-30 0:49 ` Junio C Hamano
2022-03-30 22:31 ` Calvin Wan
2022-03-30 22:43 ` Jonathan Tan
2022-03-30 23:42 ` Junio C Hamano
2022-03-29 23:19 ` Taylor Blau
2022-03-30 22:47 ` Calvin Wan
2022-03-30 22:06 ` John Cai
2022-03-31 19:56 ` Calvin Wan
2022-04-01 16:16 ` Junio C Hamano
2022-03-30 22:07 ` Jonathan Tan
2022-03-30 22:12 ` Josh Steadmon
2022-03-30 22:46 ` Calvin Wan
2022-03-29 20:35 ` [PATCH v3 0/3] " Junio C Hamano
2022-03-29 22:40 ` Calvin Wan
2022-03-31 1:50 ` Junio C Hamano
2022-05-02 17:08 ` [PATCH v4 0/8] cat-file: add --batch-command remote-object-info command Calvin Wan
2022-05-02 17:08 ` [PATCH v4 1/8] fetch-pack: refactor packet writing Calvin Wan
2022-05-02 17:08 ` [PATCH v4 2/8] fetch-pack: move fetch default settings Calvin Wan
2022-05-02 22:58 ` Junio C Hamano
2022-05-03 23:06 ` Jonathan Tan
2022-05-05 18:13 ` Calvin Wan
2022-05-02 17:08 ` [PATCH v4 3/8] object-store: add function to free object_info contents Calvin Wan
2022-05-02 23:23 ` Junio C Hamano
2022-05-04 19:09 ` Junio C Hamano
2022-05-05 0:15 ` Junio C Hamano
2022-05-05 16:47 ` Calvin Wan
2022-05-05 17:01 ` Junio C Hamano
2022-05-02 17:09 ` [PATCH v4 4/8] object-info: send attribute packet regardless of object ids Calvin Wan
2022-05-03 0:05 ` Junio C Hamano
2022-05-03 19:21 ` Calvin Wan
2022-05-03 23:11 ` Jonathan Tan
2022-05-02 17:09 ` [PATCH v4 5/8] transport: add client side capability to request object-info Calvin Wan
2022-05-03 0:54 ` Junio C Hamano
2022-05-03 18:58 ` Calvin Wan
2022-05-04 15:42 ` Junio C Hamano
2022-05-03 23:15 ` Jonathan Tan [this message]
2022-05-04 15:50 ` Junio C Hamano
2022-05-02 17:09 ` [PATCH v4 6/8] transport: add object-info fallback to fetch Calvin Wan
2022-05-03 23:27 ` Jonathan Tan
2022-05-02 17:09 ` [PATCH v4 7/8] cat-file: move parse_cmd and DEFAULT_FORMAT up Calvin Wan
2022-05-02 17:09 ` [PATCH v4 8/8] cat-file: add --batch-command remote-object-info command Calvin Wan
2022-05-04 21:27 ` Jonathan Tan
2022-05-05 18:13 ` Calvin Wan
2022-05-05 18:44 ` Junio C Hamano
2022-05-05 19:09 ` Junio C Hamano
2022-05-05 19:19 ` Calvin Wan
2022-07-31 15:24 ` ZheNing Hu
2022-08-08 17:43 ` Calvin Wan
2022-07-28 23:02 ` [PATCH v5 0/6] " Calvin Wan
2022-07-28 23:56 ` Junio C Hamano
2022-07-29 0:02 ` Junio C Hamano
2022-07-31 8:41 ` Phillip Wood
2022-08-04 22:57 ` Calvin Wan
2022-09-30 23:23 ` Junio C Hamano
2022-07-28 23:02 ` [PATCH v5 1/6] fetch-pack: refactor packet writing Calvin Wan
2022-07-28 23:02 ` [PATCH v5 2/6] fetch-pack: move fetch initialization Calvin Wan
2022-07-28 23:02 ` [PATCH v5 3/6] protocol-caps: initialization bug fix Calvin Wan
2022-07-29 17:51 ` Junio C Hamano
2022-07-28 23:02 ` [PATCH v5 4/6] serve: advertise object-info feature Calvin Wan
2022-07-29 17:57 ` Junio C Hamano
2022-08-01 18:28 ` Calvin Wan
2022-08-01 18:44 ` Ævar Arnfjörð Bjarmason
2022-08-01 18:47 ` Junio C Hamano
2022-08-01 18:58 ` Calvin Wan
2022-07-28 23:02 ` [PATCH v5 5/6] transport: add client support for object-info Calvin Wan
2022-07-29 18:06 ` Junio C Hamano
2022-08-04 20:28 ` Calvin Wan
2022-08-01 13:30 ` Phillip Wood
2022-08-04 22:20 ` Calvin Wan
2022-08-08 10:07 ` Phillip Wood
2022-08-01 14:26 ` Phillip Wood
2022-08-08 9:16 ` Phillip Wood
2022-07-28 23:02 ` [PATCH v5 6/6] cat-file: add remote-object-info to batch-command Calvin Wan
2022-07-29 6:25 ` Ævar Arnfjörð Bjarmason
2022-08-07 5:50 ` ZheNing Hu
2022-08-08 18:07 ` Calvin Wan
2022-08-11 10:58 ` Ævar Arnfjörð Bjarmason
2022-07-29 18:21 ` Junio C Hamano
2022-08-08 18:37 ` Calvin Wan
2022-09-28 13:12 ` Ævar Arnfjörð Bjarmason
2022-07-31 15:02 ` [PATCH v4 0/8] cat-file: add --batch-command remote-object-info command ZheNing Hu
2022-08-08 17:32 ` Calvin Wan
2022-08-13 22:17 ` Junio C Hamano
2022-02-09 19:09 ` [PATCH] fetch —object-info-format: client option for object-info John Cai
2022-02-10 22:49 ` Calvin Wan
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