clone: request the 'bundle-uri' command when available

Set up all the needed client parts of the 'bundle-uri' protocol v2
command, without actually doing anything with the bundle URIs.

If the server says it supports 'bundle-uri' teach Git to issue the
'bundle-uri' command after the 'ls-refs' during 'git clone'. The
returned key=value pairs are passed to the bundle list code which is
tested using a different ingest mechanism in t5750-bundle-uri-parse.sh.

At this point, Git does nothing with that bundle list. It will not
download any of the bundles. That will come in a later change after
these protocol bits are finalized.

The no-op client is initially used only by 'git clone' to test the basic
functionality, and eventually will bootstrap the initial download of Git
objects during a fresh clone. The bundle URI client will not be
integrated into other fetches until a mechanism is created to select a
subset of bundles for download.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/clone.c b/builtin/clone.c
index 0e4348686b6efb13bc1aa8847f8012a416e2080c..5866873d2693dc5ccfce518d41528884eacd2c29 100644 (file)
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1271,6 +1271,12 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
        if (refs)
                mapped_refs = wanted_peer_refs(refs, &remote->fetch);
 
+       /*
+        * Populate transport->got_remote_bundle_uri and
+        * transport->bundle_uri. We might get nothing.
+        */
+       transport_get_remote_bundle_uri(transport);
+
        if (mapped_refs) {
                int hash_algo = hash_algo_by_ptr(transport_get_hash_algo(transport));
 

diff --git a/connect.c b/connect.c
index 5ea53deda23527ded642449fa9d803cc12e34477..624a10f18eec6ee623ad3788b7cf904fa50f72ae 100644 (file)
--- a/connect.c
+++ b/connect.c
@@ -15,6 +15,7 @@
 #include "version.h"
 #include "protocol.h"
 #include "alias.h"
+#include "bundle-uri.h"
 
 static char *server_capabilities_v1;
 static struct strvec server_capabilities_v2 = STRVEC_INIT;
@@ -491,6 +492,49 @@ static void send_capabilities(int fd_out, struct packet_reader *reader)
        }
 }
 
+int get_remote_bundle_uri(int fd_out, struct packet_reader *reader,
+                         struct bundle_list *bundles, int stateless_rpc)
+{
+       int line_nr = 1;
+
+       /* Assert bundle-uri support */
+       server_supports_v2("bundle-uri", 1);
+
+       /* (Re-)send capabilities */
+       send_capabilities(fd_out, reader);
+
+       /* Send command */
+       packet_write_fmt(fd_out, "command=bundle-uri\n");
+       packet_delim(fd_out);
+
+       packet_flush(fd_out);
+
+       /* Process response from server */
+       while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+               const char *line = reader->line;
+               line_nr++;
+
+               if (!bundle_uri_parse_line(bundles, line))
+                       continue;
+
+               return error(_("error on bundle-uri response line %d: %s"),
+                            line_nr, line);
+       }
+
+       if (reader->status != PACKET_READ_FLUSH)
+               return error(_("expected flush after bundle-uri listing"));
+
+       /*
+        * Might die(), but obscure enough that that's OK, e.g. in
+        * serve.c we'll call BUG() on its equivalent (the
+        * PACKET_READ_RESPONSE_END check).
+        */
+       check_stateless_delimiter(stateless_rpc, reader,
+                                 _("expected response end packet after ref listing"));
+
+       return 0;
+}
+
 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
                             struct ref **list, int for_push,
                             struct transport_ls_refs_options *transport_options,

diff --git a/remote.h b/remote.h
index 1c4621b414bdc0372613e58c3b2133b84004d1e7..1ebbe42792ec67230b62dbbe4cb8ed9646576858 100644 (file)
--- a/remote.h
+++ b/remote.h
@@ -234,6 +234,11 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
                             const struct string_list *server_options,
                             int stateless_rpc);
 
+/* Used for protocol v2 in order to retrieve refs from a remote */
+struct bundle_list;
+int get_remote_bundle_uri(int fd_out, struct packet_reader *reader,
+                         struct bundle_list *bundles, int stateless_rpc);
+
 int resolve_remote_symref(struct ref *ref, struct ref *list);
 
 /*

diff --git a/t/lib-bundle-uri-protocol.sh b/t/lib-bundle-uri-protocol.sh
index 2da22a39cb8e3814f4193e36ed0e6ce89c6404d8..d44c6e10f9ea242c2f39cc0e4651c5b6dbea6fb0 100644 (file)
--- a/t/lib-bundle-uri-protocol.sh
+++ b/t/lib-bundle-uri-protocol.sh
@@ -83,3 +83,22 @@ test_expect_success "connect with $BUNDLE_URI_PROTOCOL:// using protocol v2: hav
        # Server advertised bundle-uri capability
        grep "< bundle-uri" log
 '
+
+test_expect_success "clone with $BUNDLE_URI_PROTOCOL:// using protocol v2: request bundle-uris" '
+       test_when_finished "rm -rf log cloned" &&
+
+       GIT_TRACE_PACKET="$PWD/log" \
+       git \
+               -c protocol.version=2 \
+               clone "$BUNDLE_URI_REPO_URI" cloned \
+               >actual 2>err &&
+
+       # Server responded using protocol v2
+       grep "< version 2" log &&
+
+       # Server advertised bundle-uri capability
+       grep "< bundle-uri" log &&
+
+       # Client issued bundle-uri command
+       grep "> command=bundle-uri" log
+'

diff --git a/transport-helper.c b/transport-helper.c
index e95267a4ab54dc12318435d157d1fdd37821f567..3ea7c2bb5ad8c462ae0f54c9466af210bc27d0c2 100644 (file)
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -1267,9 +1267,22 @@ static struct ref *get_refs_list_using_list(struct transport *transport,
        return ret;
 }
 
+static int get_bundle_uri(struct transport *transport)
+{
+       get_helper(transport);
+
+       if (process_connect(transport, 0)) {
+               do_take_over(transport);
+               return transport->vtable->get_bundle_uri(transport);
+       }
+
+       return -1;
+}
+
 static struct transport_vtable vtable = {
        .set_option     = set_helper_option,
        .get_refs_list  = get_refs_list,
+       .get_bundle_uri = get_bundle_uri,
        .fetch_refs     = fetch_refs,
        .push_refs      = push_refs,
        .connect        = connect_helper,

diff --git a/transport-internal.h b/transport-internal.h
index c4ca0b733acbdbe7fc7a5906490e396240ec7b06..90ea749e5cfbf7de994a8747186ad5fb3ae7c653 100644 (file)
--- a/transport-internal.h
+++ b/transport-internal.h
@@ -26,6 +26,13 @@ struct transport_vtable {
        struct ref *(*get_refs_list)(struct transport *transport, int for_push,
                                     struct transport_ls_refs_options *transport_options);
 
+       /**
+        * Populates the remote side's bundle-uri under protocol v2,
+        * if the "bundle-uri" capability was advertised. Returns 0 if
+        * OK, negative values on error.
+        */
+       int (*get_bundle_uri)(struct transport *transport);
+
        /**
         * Fetch the objects for the given refs. Note that this gets
         * an array, and should ignore the list structure.

diff --git a/transport.c b/transport.c
index e7b97194c103a3a7fad6d4174e40c96db9ff2a4c..b6f279e92cb01bc204b1a242593a5ad670fc2e23 100644 (file)
--- a/transport.c
+++ b/transport.c
@@ -22,6 +22,7 @@
 #include "protocol.h"
 #include "object-store.h"
 #include "color.h"
+#include "bundle-uri.h"
 
 static int transport_use_color = -1;
 static char transport_colors[][COLOR_MAXLEN] = {
@@ -359,6 +360,32 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
        return handshake(transport, for_push, options, 1);
 }
 
+static int get_bundle_uri(struct transport *transport)
+{
+       struct git_transport_data *data = transport->data;
+       struct packet_reader reader;
+       int stateless_rpc = transport->stateless_rpc;
+
+       if (!transport->bundles) {
+               CALLOC_ARRAY(transport->bundles, 1);
+               init_bundle_list(transport->bundles);
+       }
+
+       /*
+        * "Support" protocol v0 and v2 without bundle-uri support by
+        * silently degrading to a NOOP.
+        */
+       if (!server_supports_v2("bundle-uri", 0))
+               return 0;
+
+       packet_reader_init(&reader, data->fd[0], NULL, 0,
+                          PACKET_READ_CHOMP_NEWLINE |
+                          PACKET_READ_GENTLE_ON_EOF);
+
+       return get_remote_bundle_uri(data->fd[1], &reader,
+                                    transport->bundles, stateless_rpc);
+}
+
 static int fetch_refs_via_pack(struct transport *transport,
                               int nr_heads, struct ref **to_fetch)
 {
@@ -902,6 +929,7 @@ static int disconnect_git(struct transport *transport)
 
 static struct transport_vtable taken_over_vtable = {
        .get_refs_list  = get_refs_via_connect,
+       .get_bundle_uri = get_bundle_uri,
        .fetch_refs     = fetch_refs_via_pack,
        .push_refs      = git_transport_push,
        .disconnect     = disconnect_git
@@ -1054,6 +1082,7 @@ static struct transport_vtable bundle_vtable = {
 
 static struct transport_vtable builtin_smart_vtable = {
        .get_refs_list  = get_refs_via_connect,
+       .get_bundle_uri = get_bundle_uri,
        .fetch_refs     = fetch_refs_via_pack,
        .push_refs      = git_transport_push,
        .connect        = connect_git,
@@ -1068,6 +1097,9 @@ struct transport *transport_get(struct remote *remote, const char *url)
        ret->progress = isatty(2);
        string_list_init_dup(&ret->pack_lockfiles);
 
+       CALLOC_ARRAY(ret->bundles, 1);
+       init_bundle_list(ret->bundles);
+
        if (!remote)
                BUG("No remote provided to transport_get()");
 
@@ -1482,6 +1514,23 @@ int transport_fetch_refs(struct transport *transport, struct ref *refs)
        return rc;
 }
 
+int transport_get_remote_bundle_uri(struct transport *transport)
+{
+       const struct transport_vtable *vtable = transport->vtable;
+
+       /* Check config only once. */
+       if (transport->got_remote_bundle_uri)
+               return 0;
+       transport->got_remote_bundle_uri = 1;
+
+       if (!vtable->get_bundle_uri)
+               return error(_("bundle-uri operation not supported by protocol"));
+
+       if (vtable->get_bundle_uri(transport) < 0)
+               return error(_("could not retrieve server-advertised bundle-uri list"));
+       return 0;
+}
+
 void transport_unlock_pack(struct transport *transport, unsigned int flags)
 {
        int in_signal_handler = !!(flags & TRANSPORT_UNLOCK_PACK_IN_SIGNAL_HANDLER);
@@ -1512,6 +1561,8 @@ int transport_disconnect(struct transport *transport)
                ret = transport->vtable->disconnect(transport);
        if (transport->got_remote_refs)
                free_refs((void *)transport->remote_refs);
+       clear_bundle_list(transport->bundles);
+       free(transport->bundles);
        free(transport);
        return ret;
 }

diff --git a/transport.h b/transport.h
index b5bf7b3e70418a9ded196bf124b1e445bc8076cb..85150f504fbfb9501109d297223f566cc36fe0e5 100644 (file)
--- a/transport.h
+++ b/transport.h
@@ -62,6 +62,7 @@ enum transport_family {
        TRANSPORT_FAMILY_IPV6
 };
 
+struct bundle_list;
 struct transport {
        const struct transport_vtable *vtable;
 
@@ -76,6 +77,18 @@ struct transport {
         */
        unsigned got_remote_refs : 1;
 
+       /**
+        * Indicates whether we already called get_bundle_uri_list(); set by
+        * transport.c::transport_get_remote_bundle_uri().
+        */
+       unsigned got_remote_bundle_uri : 1;
+
+       /*
+        * The results of "command=bundle-uri", if both sides support
+        * the "bundle-uri" capability.
+        */
+       struct bundle_list *bundles;
+
        /*
         * Transports that call take-over destroys the data specific to
         * the transport type while doing so, and cannot be reused.
@@ -281,6 +294,12 @@ void transport_ls_refs_options_release(struct transport_ls_refs_options *opts);
 const struct ref *transport_get_remote_refs(struct transport *transport,
                                            struct transport_ls_refs_options *transport_options);
 
+/**
+ * Retrieve bundle URI(s) from a remote. Populates "struct
+ * transport"'s "bundle_uri" and "got_remote_bundle_uri".
+ */
+int transport_get_remote_bundle_uri(struct transport *transport);
+
 /*
  * Fetch the hash algorithm used by a remote.
  *