@matheusbsbs / matheus-bagliano / commits / ac3fda82bf

transport-helper: skip ls-refs if unnecessary

Commit e70a3030e7 ("fetch: do not list refs if fetching only hashes", 2018-10-07) and its ancestors taught Git, as an optimization, to skip the ls-refs step when it is not necessary during a protocol v2 fetch (for example, when lazy fetching a missing object in a partial clone, or when running "git fetch --no-tags <remote> <SHA-1>"). But that was only done for natively supported protocols; in particular, HTTP was not supported. Teach Git to skip ls-refs when using remote helpers that support connect or stateless-connect. To do this, fetch() is made an acceptable entry point. Because fetch() can now be the first function in the vtable called, "get_helper(transport);" has to be added to the beginning of that function to set the transport up (if not yet set up) before process_connect() is invoked. When fetch() is called, the transport could be taken over (this happens if "connect" or "stateless-connect" is successfully run without any "fallback" response), or not. If the transport is taken over, execution continues like execution for natively supported protocols (fetch_refs_via_pack() is executed, which will fetch refs using ls-refs if needed). If not, the remote helper interface will invoke get_refs_list() if it hasn't been invoked yet, preserving existing behavior. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jonathan Tan committed Aug 21, 2019 at 15:20 UTC ac3fda82bfe1c9e99c5838d052c678c78139ee34

2 files changed +46 -6

t/t5702-protocol-v2.sh

+13

@@ -631,6 +631,19 @@ test_expect_success 'fetch with http:// using protocol v2' '

631 grep "git< version 2" log

632 '

633

634 +test_expect_success 'fetch with http:// by hash without tag following with protocol v2 does not list refs' '

635 + test_when_finished "rm -f log" &&

636 +

637 + test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" two_a &&

638 + git -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" rev-parse two_a >two_a_hash &&

639 +

640 + GIT_TRACE_PACKET="$(pwd)/log" git -C http_child -c protocol.version=2 \

641 + fetch --no-tags origin $(cat two_a_hash) &&

642 +

643 + grep "fetch< version 2" log &&

644 + ! grep "fetch> command=ls-refs" log

645 +'

646 +

647 test_expect_success 'fetch from namespaced repo respects namespaces' '

648 test_when_finished "rm -f log" &&

649

transport-helper.c

+33 -6

@@ -33,6 +33,16 @@ struct helper_data {

33 check_connectivity : 1,

34 no_disconnect_req : 1,

35 no_private_update : 1;

36 +

37 + /*

38 + * As an optimization, the transport code may invoke fetch before

39 + * get_refs_list. If this happens, and if the transport helper doesn't

40 + * support connect or stateless_connect, we need to invoke

41 + * get_refs_list ourselves if we haven't already done so. Keep track of

42 + * whether we have invoked get_refs_list.

43 + */

44 + unsigned get_refs_list_called : 1;

45 +

46 char *export_marks;

47 char *import_marks;

48 /* These go from remote name (as in "list") to private name */

@@ -652,17 +662,25 @@ static int connect_helper(struct transport *transport, const char *name,

662 return 0;

663 }

664

665 +static struct ref *get_refs_list_using_list(struct transport *transport,

666 + int for_push);

667 +

668 static int fetch(struct transport *transport,

669 int nr_heads, struct ref **to_fetch)

670 {

671 struct helper_data *data = transport->data;

672 int i, count;

673

674 + get_helper(transport);

675 +

676 if (process_connect(transport, 0)) {

677 do_take_over(transport);

678 return transport->vtable->fetch(transport, nr_heads, to_fetch);

679 }

680

681 + if (!data->get_refs_list_called)

682 + get_refs_list_using_list(transport, 0);

683 +

684 count = 0;

685 for (i = 0; i < nr_heads; i++)

686 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))

@@ -1058,6 +1076,19 @@ static int has_attribute(const char *attrs, const char *attr)

1076

1077 static struct ref *get_refs_list(struct transport *transport, int for_push,

1078 const struct argv_array *ref_prefixes)

1079 +{

1080 + get_helper(transport);

1081 +

1082 + if (process_connect(transport, for_push)) {

1083 + do_take_over(transport);

1084 + return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);

1085 + }

1086 +

1087 + return get_refs_list_using_list(transport, for_push);

1088 +}

1089 +

1090 +static struct ref *get_refs_list_using_list(struct transport *transport,

1091 + int for_push)

1092 {

1093 struct helper_data *data = transport->data;

1094 struct child_process *helper;

@@ -1066,13 +1097,9 @@ static struct ref *get_refs_list(struct transport *transport, int for_push,

1097 struct ref *posn;

1098 struct strbuf buf = STRBUF_INIT;

1099

1100 + data->get_refs_list_called = 1;

1101 helper = get_helper(transport);

1102

1071 - if (process_connect(transport, for_push)) {

1072 - do_take_over(transport);

1073 - return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);

1074 - }

1075 -

1103 if (data->push && for_push)

1104 write_str_in_full(helper->in, "list for-push\n");

1105 else

@@ -1119,7 +1146,7 @@ static struct ref *get_refs_list(struct transport *transport, int for_push,

1146 }

1147

1148 static struct transport_vtable vtable = {

1122 - 0,

1149 + 1,

1150 set_helper_option,

1151 get_refs_list,

1152 fetch,