From: Junio C Hamano <gitster@pobox.com>
To: Jonathan Tan <jonathantanmy@google.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH] checkout: send commit provenance during prefetch
Date: Wed, 16 Dec 2020 10:50:06 -0800 [thread overview]
Message-ID: <xmqqa6ud4mch.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <20201215200207.1083655-1-jonathantanmy@google.com> (Jonathan Tan's message of "Tue, 15 Dec 2020 12:02:07 -0800")
Jonathan Tan <jonathantanmy@google.com> writes:
> Therefore, teach the partial clone fetching mechanism to support a
> "provenance" argument, and plumb the commit provenance from checkout to
> the partial clone fetching mechanism.
>
> In the future, other commands can be similarly upgraded. Other possible
> future improvements include better diagnostic messages when a prefetch
> fails.
I am not sure "provenance" is a good word to describe the concept,
but it feels a bit too limiting that you can give only a single
commit, especially when ...
> builtin/checkout.c | 4 ++++
> builtin/index-pack.c | 2 +-
> builtin/pack-objects.c | 2 +-
> diff.c | 2 +-
> diffcore-rename.c | 2 +-
> promisor-remote.c | 12 +++++++++---
> promisor-remote.h | 3 ++-
> sha1-file.c | 2 +-
> t/t5616-partial-clone.sh | 7 +++++--
> unpack-trees.c | 3 ++-
> unpack-trees.h | 7 +++++++
> 11 files changed, 34 insertions(+), 12 deletions(-)
... I see that "diff" already needs lazy blob fetching and we know
diff often is between two commits (think: "git log -p").
> This essentially splits reachability-of-blob, which almost certainly
> requires loading a bitmap, into 2 parts: reachability-of-commit (which,
> from my limited experience, can be more quickly done using a regular
> object walk) and reachability-of-blob-from-commit (which, at worst,
> requires fewer bitmaps to be loaded). I don't have timings for how it
> works in practice, though.
What does the bitmap you have on the serving side typically tell
you? For some selected commits (not all commits) you'd have a
bitmap that says "from this commit, these objects can be reached",
or is it "from this commit, these commits can be reached"?
Thanks.
prev parent reply other threads:[~2020-12-16 18:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 20:02 [PATCH] checkout: send commit provenance during prefetch Jonathan Tan
2020-12-16 14:50 ` Derrick Stolee
2020-12-16 18:50 ` Junio C Hamano [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=xmqqa6ud4mch.fsf@gitster.c.googlers.com \
--to=gitster@pobox.com \
--cc=git@vger.kernel.org \
--cc=jonathantanmy@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).