Support taking over transports

Add support for taking over transports that turn out to be smart.

Signed-off-by: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/transport-helper.c b/transport-helper.c
index 271af345e45038a0ca59e27e966ca6a6c4be9f25..97eed6cbf6bb7e076bd46f5d59cb5e66ac47ccc5 100644 (file)
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -22,6 +22,10 @@ struct helper_data
        /* These go from remote name (as in "list") to private name */
        struct refspec *refspecs;
        int refspec_nr;
+       /* Transport options for fetch-pack/send-pack (should one of
+        * those be invoked).
+        */
+       struct git_transport_options transport_options;
 };
 
 static void sendline(struct helper_data *helper, struct strbuf *buffer)
@@ -81,6 +85,7 @@ static struct child_process *get_helper(struct transport *transport)
        const char **refspecs = NULL;
        int refspec_nr = 0;
        int refspec_alloc = 0;
+       int duped;
 
        if (data->helper)
                return data->helper;
@@ -99,9 +104,19 @@ static struct child_process *get_helper(struct transport *transport)
                die("Unable to run helper: git %s", helper->argv[0]);
        data->helper = helper;
 
+       /*
+        * Open the output as FILE* so strbuf_getline() can be used.
+        * Do this with duped fd because fclose() will close the fd,
+        * and stuff like taking over will require the fd to remain.
+        *
+        */
+       duped = dup(helper->out);
+       if (duped < 0)
+               die_errno("Can't dup helper output fd");
+       data->out = xfdopen(duped, "r");
+
        write_constant(helper->in, "capabilities\n");
 
-       data->out = xfdopen(helper->out, "r");
        while (1) {
                const char *capname;
                int mandatory = 0;
@@ -163,6 +178,7 @@ static int disconnect_helper(struct transport *transport)
                strbuf_addf(&buf, "\n");
                sendline(data, &buf);
                close(data->helper->in);
+               close(data->helper->out);
                fclose(data->out);
                finish_command(data->helper);
                free((char *)data->helper->argv[0]);
@@ -583,5 +599,6 @@ int transport_helper_init(struct transport *transport, const char *name)
        transport->fetch = fetch;
        transport->push_refs = push_refs;
        transport->disconnect = release_helper;
+       transport->smart_options = &(data->transport_options);
        return 0;
 }

diff --git a/transport.c b/transport.c
index e6eb20ea947eb54ebc3cc78d38f6b3dae1864195..ad25b98ae1d094167dfe0c9152b55e953409aa21 100644 (file)
--- a/transport.c
+++ b/transport.c
@@ -398,6 +398,7 @@ struct git_transport_data {
        struct git_transport_options options;
        struct child_process *conn;
        int fd[2];
+       unsigned got_remote_heads : 1;
        struct extra_have_objects extra_have;
 };
 
@@ -432,10 +433,15 @@ static int set_git_option(struct git_transport_options *opts,
 static int connect_setup(struct transport *transport, int for_push, int verbose)
 {
        struct git_transport_data *data = transport->data;
+
+       if (data->conn)
+               return 0;
+
        data->conn = git_connect(data->fd, transport->url,
                                 for_push ? data->options.receivepack :
                                 data->options.uploadpack,
                                 verbose ? CONNECT_VERBOSE : 0);
+
        return 0;
 }
 
@@ -447,6 +453,7 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
        connect_setup(transport, for_push, 0);
        get_remote_heads(data->fd[0], &refs, 0, NULL,
                         for_push ? REF_NORMAL : 0, &data->extra_have);
+       data->got_remote_heads = 1;
 
        return refs;
 }
@@ -477,9 +484,10 @@ static int fetch_refs_via_pack(struct transport *transport,
        for (i = 0; i < nr_heads; i++)
                origh[i] = heads[i] = xstrdup(to_fetch[i]->name);
 
-       if (!data->conn) {
+       if (!data->got_remote_heads) {
                connect_setup(transport, 0, 0);
                get_remote_heads(data->fd[0], &refs_tmp, 0, NULL, 0, NULL);
+               data->got_remote_heads = 1;
        }
 
        refs = fetch_pack(&args, data->fd, data->conn,
@@ -490,6 +498,7 @@ static int fetch_refs_via_pack(struct transport *transport,
        if (finish_connect(data->conn))
                refs = NULL;
        data->conn = NULL;
+       data->got_remote_heads = 0;
 
        free_refs(refs_tmp);
 
@@ -718,12 +727,13 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
        struct send_pack_args args;
        int ret;
 
-       if (!data->conn) {
+       if (!data->got_remote_heads) {
                struct ref *tmp_refs;
                connect_setup(transport, 1, 0);
 
                get_remote_heads(data->fd[0], &tmp_refs, 0, NULL, REF_NORMAL,
                                 NULL);
+               data->got_remote_heads = 1;
        }
 
        memset(&args, 0, sizeof(args));
@@ -741,6 +751,7 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
        close(data->fd[0]);
        ret |= finish_connect(data->conn);
        data->conn = NULL;
+       data->got_remote_heads = 0;
 
        return ret;
 }
@@ -749,7 +760,8 @@ static int disconnect_git(struct transport *transport)
 {
        struct git_transport_data *data = transport->data;
        if (data->conn) {
-               packet_flush(data->fd[1]);
+               if (data->got_remote_heads)
+                       packet_flush(data->fd[1]);
                close(data->fd[0]);
                close(data->fd[1]);
                finish_connect(data->conn);
@@ -759,6 +771,32 @@ static int disconnect_git(struct transport *transport)
        return 0;
 }
 
+void transport_take_over(struct transport *transport,
+                        struct child_process *child)
+{
+       struct git_transport_data *data;
+
+       if (!transport->smart_options)
+               die("Bug detected: Taking over transport requires non-NULL "
+                   "smart_options field.");
+
+       data = xcalloc(1, sizeof(*data));
+       data->options = *transport->smart_options;
+       data->conn = child;
+       data->fd[0] = data->conn->out;
+       data->fd[1] = data->conn->in;
+       data->got_remote_heads = 0;
+       transport->data = data;
+
+       transport->set_option = NULL;
+       transport->get_refs_list = get_refs_via_connect;
+       transport->fetch = fetch_refs_via_pack;
+       transport->push = NULL;
+       transport->push_refs = git_transport_push;
+       transport->disconnect = disconnect_git;
+       transport->smart_options = &(data->options);
+}
+
 static int is_local(const char *url)
 {
        const char *colon = strchr(url, ':');
@@ -867,6 +905,7 @@ struct transport *transport_get(struct remote *remote, const char *url)
                ret->smart_options = &(data->options);
 
                data->conn = NULL;
+               data->got_remote_heads = 0;
        } else if (!prefixcmp(url, "http://")
                || !prefixcmp(url, "https://")
                || !prefixcmp(url, "ftp://")) {
@@ -927,9 +966,9 @@ int transport_push(struct transport *transport,
        *nonfastforward = 0;
        verify_remote_names(refspec_nr, refspec);
 
-       if (transport->push)
+       if (transport->push) {
                return transport->push(transport, refspec_nr, refspec, flags);
-       if (transport->push_refs) {
+       } else if (transport->push_refs) {
                struct ref *remote_refs =
                        transport->get_refs_list(transport, 1);
                struct ref *local_refs = get_local_heads();
@@ -973,6 +1012,7 @@ const struct ref *transport_get_remote_refs(struct transport *transport)
 {
        if (!transport->remote_refs)
                transport->remote_refs = transport->get_refs_list(transport, 0);
+
        return transport->remote_refs;
 }
 
@@ -1007,6 +1047,7 @@ int transport_fetch_refs(struct transport *transport, struct ref *refs)
        }
 
        rc = transport->fetch(transport, nr_heads, heads);
+
        free(heads);
        return rc;
 }

diff --git a/transport.h b/transport.h
index e90c285bbc740af192d72fabfa4c4e8ed7cb8131..781db2ec82cce20e75a795e1ed3e31a63a6ff58e 100644 (file)
--- a/transport.h
+++ b/transport.h
@@ -130,6 +130,8 @@ int transport_fetch_refs(struct transport *transport, struct ref *refs);
 void transport_unlock_pack(struct transport *transport);
 int transport_disconnect(struct transport *transport);
 char *transport_anonymize_url(const char *url);
+void transport_take_over(struct transport *transport,
+                        struct child_process *child);
 
 /* Transport methods defined outside transport.c */
 int transport_helper_init(struct transport *transport, const char *name);