Re: [PATCH v5 0/6] cat-file: add --batch-command remote-object-info command

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Calvin

On 29/07/2022 00:02, Calvin Wan wrote:
> 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.
> 
> Add `--object-info` option to `cat-file --batch-command`. 

This part of the cover letter seems to have been left over from a 
previous iteration. I noticed that in patch 6 there is a reference to 
'--object-info' in an error message as well.

This might be a daft question but could we teach cat-file to check if an 
object is available locally and if it is not retrieve just the metadata 
from the remote rather than adding a new command to --batch-command? 
That way it would be transparent to the user and they would not have to 
worry about whether they might be querying a remote object or not.

Best Wishes

Phillip

> This option
> allows the client to make an object-info command request to a server
> that supports protocol v2. If the server is v2, but does not allow for
> the object-info command request, the entire object is fetched and the
> relevant object info is returned.
> 
> === Changes since v4 ===
>   - Instead of making 2 rounds trips to determine whether the server can
>     handle the client object-info request, the server now advertises the
>     features it can send back so the client can immediately fallback to
>     fetch if any feature is not supported
>   - Fixed nits and clarified some documentation/commit messages
> 
> Signed-off-by: Calvin Wan <calvinwan@google.com>
> Helped-by: Jonathan Tan <jonathantanmy@google.com>
> 
> Calvin Wan (6):
>    fetch-pack: refactor packet writing
>    fetch-pack: move fetch initialization
>    protocol-caps: initialization bug fix
>    serve: advertise object-info feature
>    transport: add client support for object-info
>    cat-file: add remote-object-info to batch-command
> 
>   Documentation/git-cat-file.txt |  16 +-
>   builtin/cat-file.c             | 225 ++++++++++++++++-----
>   fetch-pack.c                   |  52 +++--
>   fetch-pack.h                   |  10 +
>   object-file.c                  |  11 ++
>   object-store.h                 |   3 +
>   protocol-caps.c                |   2 +-
>   serve.c                        |  10 +-
>   t/t1006-cat-file.sh            | 348 +++++++++++++++++++++++++++++++++
>   t/t5555-http-smart-common.sh   |   2 +-
>   t/t5701-git-serve.sh           |   2 +-
>   transport-helper.c             |   7 +-
>   transport.c                    | 110 ++++++++++-
>   transport.h                    |  11 ++
>   14 files changed, 734 insertions(+), 75 deletions(-)
> 
> 
> base-commit: 9dd64cb4d310986dd7b8ca7fff92f9b61e0bd21a