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 <jonathantanmy@xxxxxxxxxx> --- 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=<commit|glob>:: + 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", &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() }; @@ -1049,6 +1052,40 @@ static void set_option(struct transport *transport, const char *name, const char name, transport->url); } + +static int add_oid(const char *refname, const struct object_id *oid, int flags, + void *cb_data) +{ + struct oid_array *oids = cb_data; + + oid_array_append(oids, oid); + return 0; +} + +static void add_negotiation_tips(struct git_transport_options *smart_options) +{ + struct oid_array *oids = xcalloc(1, sizeof(*oids)); + int i; + + for (i = 0; i < negotiation_tip.nr; i++) { + const char *s = negotiation_tip.items[i].string; + int old_nr; + if (!has_glob_specials(s)) { + struct object_id oid; + if (get_oid(s, &oid)) + die("%s is not a valid object", s); + oid_array_append(oids, &oid); + continue; + } + old_nr = oids->nr; + for_each_glob_ref(add_oid, s, oids); + if (old_nr == oids->nr) + warning("Ignoring --negotiation-tip=%s because it does not match any refs", + s); + } + smart_options->negotiation_tips = oids; +} + static struct transport *prepare_transport(struct remote *remote, int deepen) { struct transport *transport; @@ -1075,6 +1112,12 @@ 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) { + if (transport->smart_options) + add_negotiation_tips(transport->smart_options); + 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 ba12085c4..1e50d9008 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -213,6 +213,22 @@ 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 +246,7 @@ 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 +1311,7 @@ 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 bb45a366a..1859ee927 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 e402aee6a..4e6d049b9 100755 --- a/t/t5510-fetch.sh +++ b/t/t5510-fetch.sh @@ -865,4 +865,82 @@ test_expect_success C_LOCALE_OUTPUT 'fetch compact output' ' test_cmp expect actual ' +setup_negotiation_tip () { + SERVER="$1" + URL="$2" + USE_PROTOCOL_V2="$3" + + rm -rf "$SERVER" client trace && + 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 "$URL" client && + + if test "$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 "$SERVER" tag -d alpha_1 alpha_2 beta_1 beta_2 +} + +check_negotiation_tip () { + # Ensure that {alpha,beta}_1 are sent as "have", but not {alpha_beta}_2 + ALPHA_1=$(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 $BETA_2" trace +} + +test_expect_success '--negotiation-tip limits "have" lines sent' ' + setup_negotiation_tip server server 0 && + GIT_TRACE_PACKET="$(pwd)/trace" git -C client fetch \ + --negotiation-tip=alpha_1 --negotiation-tip=beta_1 \ + origin alpha_s beta_s && + check_negotiation_tip +' + +test_expect_success '--negotiation-tip understands globs' ' + setup_negotiation_tip server server 0 && + GIT_TRACE_PACKET="$(pwd)/trace" git -C client fetch \ + --negotiation-tip=*_1 \ + origin alpha_s beta_s && + check_negotiation_tip +' + +test_expect_success '--negotiation-tip understands abbreviated SHA-1' ' + setup_negotiation_tip server server 0 && + GIT_TRACE_PACKET="$(pwd)/trace" git -C client fetch \ + --negotiation-tip=$(git -C client rev-parse --short alpha_1) \ + --negotiation-tip=$(git -C client rev-parse --short beta_1) \ + origin alpha_s beta_s && + check_negotiation_tip +' + +. "$TEST_DIRECTORY"/lib-httpd.sh +start_httpd + +test_expect_success '--negotiation-tip limits "have" lines sent with HTTP protocol v2' ' + setup_negotiation_tip "$HTTPD_DOCUMENT_ROOT_PATH/server" \ + "$HTTPD_URL/smart/server" 1 && + GIT_TRACE_PACKET="$(pwd)/trace" git -C client fetch \ + --negotiation-tip=alpha_1 --negotiation-tip=beta_1 \ + origin alpha_s beta_s && + check_negotiation_tip +' + +stop_httpd + test_done diff --git a/transport-helper.c b/transport-helper.c index 1f8ff7e94..ad8f7c772 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 a32da30de..9f10f8ad9 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 7792b0858..d31be5be6 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 { -- 2.18.0.399.gad0ab374a1-goog
