Re: Question About Git V2 Protocol & SHA256

Hi Peff,

Thank you for the quick response! That is very helpful and I think I have all the information I need.

Appreciate it a lot! Zhichen

On 9/29/20, 3:13 PM, "Jeff King" <peff@peff.net> wrote:

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    On Tue, Sep 29, 2020 at 01:17:59AM +0000, Wu, Zhichen wrote:

    > 1. Since v2 protocol has been launched for 2 years, is there any plan
    >    in the near future about v1 deprecation?

    I suppose it depends what you mean by deprecation.

    v2 is not even the default yet (but hopefully will be soon, perhaps in
    the next release).

    Once that happens, I doubt that we will add new capabilities or features
    to v1 in general. Old versions of Git would not be able to take
    advantage of them anyway, and new ones would be using v2.

    But I don't think v1 will go away for a long time. There will still be
    v1 clients and v1 servers hanging around for many years, and modern
    versions of Git will need to speak both.

    > 2. I see v2 has a capability called “object-format” that provides SHA1
    >    option. I’m wondering if that capability will be the only way for
    >    client and server to start using SHA256? Or put it as another word,
    >    will v2 protocol be the prerequisite of SHA256?

    I think it would be impossible to handle object-format via v1, because
    the v1 protocol writes the ref advertisement before any capabilities are
    negotiated. So I think v1 must implicitly remain sha1-only (and a sha256
    repository on the server side would need to either reject a v1 client,
    or back-translate as it would for a v2 client which asks for sha1).

    -Peff