[PATCH v3 0/3] object-info: add option for retrieving object info

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 fetch. 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 instead and the relevant information is returned.

Patch 1 is a small refactor. Patch 2 adds a config option for advertisement of object-info. Patch 3 is the main implementation of fetch object-info.

Major changes since v2:
 * Added a fallback for servers that do not
   allow object-info
 * Refactored the fetch object-info code by moving it to fetch_refs in
   the vtable rather than having its own function in the vtable. This
   allows for the code to easily transition to the fallback if
   object-info fails.

Calvin Wan (3):
  fetch-pack: refactor how packet is written to be more generic
  objectinfo.advertise: add config option to advertise object-info
  object-info: add option for retrieving object info

 Documentation/config/transfer.txt |   4 +
 Documentation/fetch-options.txt   |   5 ++
 Documentation/git-fetch.txt       |   1 +
 builtin/fetch.c                   |  36 +++++++-
 fetch-pack.c                      |  66 ++++++++++----
 fetch-pack.h                      |   9 ++
 protocol-caps.c                   |  11 +++
 protocol-caps.h                   |   6 ++
 serve.c                           |   2 +-
 t/t5583-fetch-object-info.sh      | 138 ++++++++++++++++++++++++++++++
 transport-helper.c                |   8 +-
 transport-internal.h              |   1 +
 transport.c                       |  75 +++++++++++++++-
 transport.h                       |   9 ++
 14 files changed, 349 insertions(+), 22 deletions(-)
 create mode 100755 t/t5583-fetch-object-info.sh

base-commit: f01e51a7cfd75131b7266131b1f7540ce0a8e5c1