| Message ID | 20230923152201.14741-3-worldhello.net@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | support remote archive from stateless transport | expand |
Jiang Xin <worldhello.net@gmail.com> writes: > From: Jiang Xin <zhiyou.jx@alibaba-inc.com> > > After successfully connecting to the smart transport by calling > "process_connect_service()" in "connect_helper()", run "do_take_over()" > to replace the old vtable with a new one which has methods ready for > the smart transport connection. The existing pattern among all callers of process_connect() seems to be if (process_connect(...)) { do_take_over(); ... dispatch to the underlying method ... } ... otherwise implement the fallback ... where the return value from process_connect() is the return value of the call it makes to process_connect_service(). And the only other caller of process_connect_service() is connect_helper(), so in that sense, making a call to do_take_over() when process_connect_service() succeeds in the helper does make things consistent. The connect_helper() function being static, the helper transport is the only transport that gets affected, but how has it been working without having this do_take_over() step? An obvious related question is if it has been working so far, would it break if we have do_take_over() added here? In any case, this makes me wonder if we should do the following patch to help developers who may want to add new callers to process_connect_service() by adding calls to process_connect(). transport-helper.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git c/transport-helper.c w/transport-helper.c index 91381be622..566f7473df 100644 --- c/transport-helper.c +++ w/transport-helper.c @@ -646,6 +646,7 @@ static int process_connect(struct transport *transport, struct helper_data *data = transport->data; const char *name; const char *exec; + int ret; name = for_push ? "git-receive-pack" : "git-upload-pack"; if (for_push) @@ -653,7 +654,10 @@ static int process_connect(struct transport *transport, else exec = data->transport_options.uploadpack; - return process_connect_service(transport, name, exec); + ret = process_connect_service(transport, name, exec); + if (ret) + do_take_over(transport); + return ret; } static int connect_helper(struct transport *transport, const char *name, @@ -685,10 +689,8 @@ static int fetch_refs(struct transport *transport, get_helper(transport); - if (process_connect(transport, 0)) { - do_take_over(transport); + if (process_connect(transport, 0)) return transport->vtable->fetch_refs(transport, nr_heads, to_fetch); - } /* * If we reach here, then the server, the client, and/or the transport @@ -1145,10 +1147,8 @@ static int push_refs(struct transport *transport, { struct helper_data *data = transport->data; - if (process_connect(transport, 1)) { - do_take_over(transport); + if (process_connect(transport, 1)) return transport->vtable->push_refs(transport, remote_refs, flags); - } if (!remote_refs) { fprintf(stderr, @@ -1189,11 +1189,9 @@ static struct ref *get_refs_list(struct transport *transport, int for_push, { get_helper(transport); - if (process_connect(transport, for_push)) { - do_take_over(transport); + if (process_connect(transport, for_push)) return transport->vtable->get_refs_list(transport, for_push, transport_options); - } return get_refs_list_using_list(transport, for_push); } @@ -1277,10 +1275,8 @@ static int get_bundle_uri(struct transport *transport) { get_helper(transport); - if (process_connect(transport, 0)) { - do_take_over(transport); + if (process_connect(transport, 0)) return transport->vtable->get_bundle_uri(transport); - } return -1; }
On Tue, Sep 26, 2023 at 5:34 AM Junio C Hamano <gitster@pobox.com> wrote: > > Jiang Xin <worldhello.net@gmail.com> writes: > > > From: Jiang Xin <zhiyou.jx@alibaba-inc.com> > > > > After successfully connecting to the smart transport by calling > > "process_connect_service()" in "connect_helper()", run "do_take_over()" > > to replace the old vtable with a new one which has methods ready for > > the smart transport connection. > > The existing pattern among all callers of process_connect() seems to > be > > if (process_connect(...)) { > do_take_over(); > ... dispatch to the underlying method ... > } > ... otherwise implement the fallback ... > > where the return value from process_connect() is the return value of > the call it makes to process_connect_service(). > > And the only other caller of process_connect_service() is > connect_helper(), so in that sense, making a call to do_take_over() > when process_connect_service() succeeds in the helper does make > things consistent. The connect_helper() function being static, the > helper transport is the only transport that gets affected, but how > has it been working without having this do_take_over() step? An > obvious related question is if it has been working so far, would it > break if we have do_take_over() added here? The connect_helper() function is used as the connect method of the vtable in "transport-helper.c", and we use the function "transport_connect()" in "transport.c" to call this connect method of vtable. The only place that we call transport_connect() to setup a connection is in "builtin/archive.c". So it won't break others if we add do_take_over() in connect_helper(). In fact, it was not "git archive" that made me discover this issue. When I implemented a fetch proxy and added a new caller for transport_connect(), I found that the HTTP protocol didn't work, so I dug it out.
diff --git a/transport-helper.c b/transport-helper.c index 2e127d24a5..3c8802b7a3 100644 --- a/transport-helper.c +++ b/transport-helper.c @@ -668,6 +668,8 @@ static int connect_helper(struct transport *transport, const char *name, fd[0] = data->helper->out; fd[1] = data->helper->in; + + do_take_over(transport); return 0; }