On 06/27, Jonathan Tan wrote: > 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. > > 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 <jonathantanmy@xxxxxxxxxx> > --- > v2 is exactly the same as the original, except with user-facing > documentation in Documentation/fetch-options.txt. > > > What's the plan to expose this "feature" to end-users? There is no > > end-user facing documentation added by this patch, and in-code > > comments only talk about what (mechanical) effect the option has, > > but not when a user may want to use the feature, or how the user > > would best decide the set of commits to pass to this new option. > > Jonathan Nieder also mentioned this. Lack of documentation was an > oversight, sorry. I've added it in this version. > > > Would something like this > > > > git fetch $(git for-each-ref \ > > --format=--nego-tip="%(objectname)" \ > > refs/remotes/linux-next/) \ > > linux-next > > > > be an expected typical way to pull from one remote, exposing only > > the tips of refs we got from that remote and not the ones we > > obtained from other places? > > Yes, that is one way. Alternatively, if the user is only fetching one > branch, they may also want to specify a single branch. > --- > Documentation/fetch-options.txt | 12 +++++++ > builtin/fetch.c | 21 +++++++++++++ > fetch-pack.c | 19 ++++++++++-- > fetch-pack.h | 7 +++++ > t/t5510-fetch.sh | 55 +++++++++++++++++++++++++++++++++ > transport-helper.c | 3 ++ > transport.c | 1 + > transport.h | 10 ++++++ > 8 files changed, 126 insertions(+), 2 deletions(-) > > diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt > index 97d3217df9..80c4c94595 100644 > --- a/Documentation/fetch-options.txt > +++ b/Documentation/fetch-options.txt > @@ -42,6 +42,18 @@ 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 commit. > + 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 seems like a pretty difficult to use feature, requiring that I provide the actual OIDs. I think a much better UI would probably be to accept a number of different things ranging from exact OIDs to actual ref names or even better, allowing for ref-patterns which include globs. That way I can do the following: git fetch --negotiation-tip=refs/remotes/my-remote/* my-remote in order to easily limit the tips to all the refs I have from that particular remote. > ++ > +This option may be specified more than once; if so, Git will report > +commits reachable from any of the given commits. > + > 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 ea5b9669ad..12daec0f3b 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", &family, N_("use IPv6 addresses only"), > TRANSPORT_FAMILY_IPV6), > + OPT_STRING_LIST(0, "negotiation-tip", &negotiation_tip, N_("revision"), > + N_("report that we have only objects reachable from this object")), > OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options), > OPT_END() > }; > @@ -1075,6 +1078,24 @@ static struct transport *prepare_transport(struct remote *remote, int deepen) > filter_options.filter_spec); > set_option(transport, TRANS_OPT_FROM_PROMISOR, "1"); > } > + if (negotiation_tip.nr) { > + struct oid_array *oids; > + if (transport->smart_options) { > + int i; > + oids = xcalloc(1, sizeof(*oids)); > + for (i = 0; i < negotiation_tip.nr; i++) { > + struct object_id oid; > + if (get_oid(negotiation_tip.items[i].string, > + &oid)) > + die("%s is not a valid object", > + negotiation_tip.items[i].string); > + oid_array_append(oids, &oid); > + } > + transport->smart_options->negotiation_tips = oids; > + } else { > + warning("Ignoring --negotiation-tip because the protocol does not support it."); > + } > + } > return transport; > } > > diff --git a/fetch-pack.c b/fetch-pack.c > index ba12085c4a..c66bd49bd1 100644 > --- a/fetch-pack.c > +++ b/fetch-pack.c > @@ -213,6 +213,21 @@ static int next_flush(int stateless_rpc, int count) > return count; > } > > +static void mark_tips(struct fetch_negotiator *negotiator, > + const struct oid_array *negotiation_tips) > +{ > + int i; > + if (!negotiation_tips) { > + for_each_ref(rev_list_insert_ref_oid, negotiator); > + return; > + } > + > + for (i = 0; i < negotiation_tips->nr; i++) > + rev_list_insert_ref(negotiator, NULL, > + &negotiation_tips->oid[i]); > + return; > +} > + > static int find_common(struct fetch_negotiator *negotiator, > struct fetch_pack_args *args, > int fd[2], struct object_id *result_oid, > @@ -230,7 +245,7 @@ static int find_common(struct fetch_negotiator *negotiator, > if (args->stateless_rpc && multi_ack == 1) > die(_("--stateless-rpc requires multi_ack_detailed")); > > - for_each_ref(rev_list_insert_ref_oid, negotiator); > + mark_tips(negotiator, args->negotiation_tips); > for_each_cached_alternate(negotiator, insert_one_alternate_object); > > fetching = 0; > @@ -1295,7 +1310,7 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args, > else > state = FETCH_SEND_REQUEST; > > - for_each_ref(rev_list_insert_ref_oid, &negotiator); > + mark_tips(&negotiator, args->negotiation_tips); > for_each_cached_alternate(&negotiator, > insert_one_alternate_object); > break; > diff --git a/fetch-pack.h b/fetch-pack.h > index bb45a366a8..1859ee9275 100644 > --- a/fetch-pack.h > +++ b/fetch-pack.h > @@ -16,6 +16,13 @@ struct fetch_pack_args { > const struct string_list *deepen_not; > struct list_objects_filter_options filter_options; > const struct string_list *server_options; > + > + /* > + * If not NULL, during packfile negotiation, fetch-pack will send "have" > + * lines only with these tips and their ancestors. > + */ > + const struct oid_array *negotiation_tips; > + > unsigned deepen_relative:1; > unsigned quiet:1; > unsigned keep_pack:1; > diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh > index e402aee6a2..ea1b5e53c1 100755 > --- a/t/t5510-fetch.sh > +++ b/t/t5510-fetch.sh > @@ -865,4 +865,59 @@ test_expect_success C_LOCALE_OUTPUT 'fetch compact output' ' > test_cmp expect actual > ' > > +negotiator_tip () { > + SERVER="$1" > + URL="$2" > + USE_PROTOCOL_V2="$3" > + > + rm -rf "$SERVER" client && > + git init "$SERVER" && > + test_commit -C "$SERVER" alpha_1 && > + test_commit -C "$SERVER" alpha_2 && > + git -C "$SERVER" checkout --orphan beta && > + test_commit -C "$SERVER" beta_1 && > + test_commit -C "$SERVER" beta_2 && > + > + git clone "$URL" client && > + > + if [ "$USE_PROTOCOL_V2" -eq 1 ] > + then > + git -C "$SERVER" config protocol.version 2 > + git -C client config protocol.version 2 > + fi && > + > + test_commit -C "$SERVER" beta_s && > + git -C "$SERVER" checkout master && > + test_commit -C "$SERVER" alpha_s && > + git -C "$SERVER" tag -d alpha_1 alpha_2 beta_1 beta_2 && > + > + GIT_TRACE_PACKET="$(pwd)/trace" git -C client fetch \ > + --negotiation-tip=alpha_1 --negotiation-tip=beta_1 \ > + origin alpha_s beta_s && > + > + # Ensure that {alpha,beta}_1 are sent as "have", but not {alpha_beta}_2 > + ALPHA_1=$(git -C client rev-parse alpha_1) && > + grep "fetch> have $ALPHA_1" trace && > + BETA_1=$(git -C client rev-parse beta_1) && > + grep "fetch> have $BETA_1" trace && > + ALPHA_2=$(git -C client rev-parse alpha_2) && > + ! grep "fetch> have $ALPHA_2" trace && > + BETA_2=$(git -C client rev-parse beta_2) && > + ! grep "fetch> have $BETA_2" trace > +} > + > +test_expect_success '--negotiator-tip limits "have" lines sent' ' > + negotiator_tip server server 0 > +' > + > +. "$TEST_DIRECTORY"/lib-httpd.sh > +start_httpd > + > +test_expect_success 'fetch with --filter=blob:limit=0 and HTTP' ' > + negotiator_tip "$HTTPD_DOCUMENT_ROOT_PATH/server" \ > + "$HTTPD_URL/smart/server" 1 > +' > + > +stop_httpd > + > test_done > diff --git a/transport-helper.c b/transport-helper.c > index 1f8ff7e942..ad8f7c7726 100644 > --- a/transport-helper.c > +++ b/transport-helper.c > @@ -684,6 +684,9 @@ static int fetch(struct transport *transport, > transport, "filter", > data->transport_options.filter_options.filter_spec); > > + if (data->transport_options.negotiation_tips) > + warning("Ignoring --negotiation-tip because the protocol does not support it."); > + > if (data->fetch) > return fetch_with_fetch(transport, nr_heads, to_fetch); > > diff --git a/transport.c b/transport.c > index a32da30dee..9f10f8ad9f 100644 > --- a/transport.c > +++ b/transport.c > @@ -318,6 +318,7 @@ static int fetch_refs_via_pack(struct transport *transport, > args.filter_options = data->options.filter_options; > args.stateless_rpc = transport->stateless_rpc; > args.server_options = transport->server_options; > + args.negotiation_tips = data->options.negotiation_tips; > > if (!data->got_remote_heads) > refs_tmp = get_refs_via_connect(transport, 0, NULL); > diff --git a/transport.h b/transport.h > index 7792b08582..d31be5be63 100644 > --- a/transport.h > +++ b/transport.h > @@ -25,6 +25,16 @@ struct git_transport_options { > const char *receivepack; > struct push_cas_option *cas; > struct list_objects_filter_options filter_options; > + > + /* > + * This is only used during fetch. See the documentation of > + * negotiation_tips in struct fetch_pack_args. > + * > + * This field is only supported by transports that support connect or > + * stateless_connect. Set this field directly instead of using > + * transport_set_option(). > + */ > + struct oid_array *negotiation_tips; > }; > > enum transport_family { > -- > 2.18.0.rc2.346.g013aa6912e-goog > -- Brandon Williams
