During negotiation, fetch-pack eventually reports as "have" lines all
commits reachable from all refs. Allow the user to restrict the commits
sent in this way by providing a whitelist of tips; only the tips
themselves and their ancestors will be sent.
Both globs and single objects are supported.
This feature is only supported for protocols that support connect or
stateless-connect (such as HTTP with protocol v2).
This will speed up negotiation when the repository has multiple
relatively independent branches (for example, when a repository
interacts with multiple repositories, such as with linux-next [1] and
torvalds/linux [2]), and the user knows which local branch is likely to
have commits in common with the upstream branch they are fetching.
[1] https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next/
[2] https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux/
Signed-off-by: Jonathan Tan
---
This is on jt/fetch-pack-negotiator.
I noticed that jt/fetch-nego-tip had a version queued with Brandon's
suggestion (of the closing parenthesis) included, but not any of Junio's
suggestions, so here is one with the suggestions from both.
> "git notes"???
>
> As this is to be used in the context of "git fetch", using glob
> e.g. "refs/heads/*", is sensible and good enough. I was actually
> wondering if we want the head-match refs/heads/, but as "git fetch
> origin refs/heads/" does not work that way, I think we shouldn't.
OK - the above was not in the commit message, so I think we're fine. In
the commit message and in the user-facing documentation, I describe this
as a "glob".
> This is a tangent, but didn't ref-in-want wanted to use head-match
> refs/heads/ to match everything under refs/heads/? If the latest
> incarnation wants to do so, we may want to fix that.
I don't recall anything like that - the user still specifies a refspec
(like existing users do), and in the protocol, all wanted refs are
matched by exact name.
> This by itself is not worth a reason to reroll, but please make it a
> habit to have a blank line after the run of decls before the first
> statement, at least while we still forbid decl-after-stmt. The
> result is easier to read that way.
Thanks - I've done it for add_oid() and all the new functions introduced
in this patch.
> Style: "if test ..."
> broken &&-chaining?
Both done.
---
Documentation/fetch-options.txt | 16 +++
builtin/fetch.c | 43 ++
fetch-pack.c| 20 -
fetch-pack.h| 7 +++
t/t5510-fetch.sh| 78 +
transport-helper.c | 3 ++
transport.c | 1 +
transport.h | 10 +
8 files changed, 176 insertions(+), 2 deletions(-)
diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt
index 97d3217df..2d09f87b4 100644
--- a/Documentation/fetch-options.txt
+++ b/Documentation/fetch-options.txt
@@ -42,6 +42,22 @@ the current repository has the same history as the source
repository.
.git/shallow. This option updates .git/shallow and accept such
refs.
+--negotiation-tip=::
+ By default, Git will report, to the server, commits reachable
+ from all local refs to find common commits in an attempt to
+ reduce the size of the to-be-received packfile. If specified,
+ Git will only report commits reachable from the given tips.
+ This is useful to speed up fetches when the user knows which
+ local ref is likely to have commits in common with the
+ upstream ref being fetched.
++
+This option may be specified more than once; if so, Git will report
+commits reachable from any of the given commits.
++
+The argument to this option may be a glob on ref names, a ref, or the (possibly
+abbreviated) SHA-1 of a commit. Specifying a glob is equivalent to specifying
+this option multiple times, one for each matching ref name.
+
ifndef::git-pull[]
--dry-run::
Show what would be done, without making any changes.
diff --git a/builtin/fetch.c b/builtin/fetch.c
index ea5b9669a..49ab6ac06 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -63,6 +63,7 @@ static int shown_url = 0;
static struct refspec refmap = REFSPEC_INIT_FETCH;
static struct list_objects_filter_options filter_options;
static struct string_list server_options = STRING_LIST_INIT_DUP;
+static struct string_list negotiation_tip = STRING_LIST_INIT_NODUP;
static int git_fetch_config(const char *k, const char *v, void *cb)
{
@@ -174,6 +175,8 @@ static struct option builtin_fetch_options[] = {
TRANSPORT_FAMILY_IPV4),
OPT_SET_INT('6', "ipv6", , N_("use IPv6 addresses only"),
TRANSPORT_FAMILY_IPV6),
+ OPT_STRING_LIST(0, "negotiation-tip", _tip, N_("revision"),
+ N_("report that we have only objects reachable from
this object")),
