receive-pack: implement advertising and receiving push options

The pre/post receive hook may be interested in more information from the
user. This information can be transmitted when both client and server
support the "push-options" capability, which when used is a phase directly
after update commands ended by a flush pkt.

Similar to the atomic option, the server capability can be disabled via
the `receive.advertisePushOptions` config variable. While documenting
this, fix a nit in the `receive.advertiseAtomic` wording.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config.txt b/Documentation/config.txt
index e208af118d9e0db34e88b9170de2c1f2ad338578..25b5db1c23a44844589f1da2694cc26e8e02865e 100644 (file)
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -2410,8 +2410,13 @@ rebase.instructionFormat
 
 receive.advertiseAtomic::
        By default, git-receive-pack will advertise the atomic push
-       capability to its clients. If you don't want to this capability
-       to be advertised, set this variable to false.
+       capability to its clients. If you don't want to advertise this
+       capability, set this variable to false.
+
+receive.advertisePushOptions::
+       By default, git-receive-pack will advertise the push options
+       capability to its clients. If you don't want to advertise this
+       capability, set this variable to false.
 
 receive.autogc::
        By default, git-receive-pack will run "git-gc --auto" after

diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt
index 8b363438021bf1ac635042b002976ad75816caed..7a2ed30cfc572cea52e294331bbc7487369c65aa 100644 (file)
--- a/Documentation/technical/pack-protocol.txt
+++ b/Documentation/technical/pack-protocol.txt
@@ -454,7 +454,8 @@ The reference discovery phase is done nearly the same way as it is in the
 fetching protocol. Each reference obj-id and name on the server is sent
 in packet-line format to the client, followed by a flush-pkt.  The only
 real difference is that the capability listing is different - the only
-possible values are 'report-status', 'delete-refs' and 'ofs-delta'.
+possible values are 'report-status', 'delete-refs', 'ofs-delta' and
+'push-options'.
 
 Reference Update Request and Packfile Transfer
 ----------------------------------------------
@@ -465,9 +466,10 @@ that it wants to update, it sends a line listing the obj-id currently on
 the server, the obj-id the client would like to update it to and the name
 of the reference.
 
-This list is followed by a flush-pkt and then the packfile that should
-contain all the objects that the server will need to complete the new
-references.
+This list is followed by a flush-pkt. Then the push options are transmitted
+one per packet followed by another flush-pkt. After that the packfile that
+should contain all the objects that the server will need to complete the new
+references will be sent.
 
 ----
   update-request    =  *shallow ( command-list | push-cert ) [packfile]

diff --git a/Documentation/technical/protocol-capabilities.txt b/Documentation/technical/protocol-capabilities.txt
index eaab6b4ac723c9f5d7dde9d70fe7e01d234e7734..4c28d3a8aea3312190d859e4accb70f9d28973bf 100644 (file)
--- a/Documentation/technical/protocol-capabilities.txt
+++ b/Documentation/technical/protocol-capabilities.txt
@@ -253,6 +253,15 @@ atomic pushes. If the pushing client requests this capability, the server
 will update the refs in one atomic transaction. Either all refs are
 updated or none.
 
+push-options
+------------
+
+If the server sends the 'push-options' capability it is able to accept
+push options after the update commands have been sent, but before the
+packfile is streamed. If the pushing client requests this capability,
+the server will pass the options to the pre- and post- receive hooks
+that process this push request.
+
 allow-tip-sha1-in-want
 ----------------------
 

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 6cdd2c6b59f70a63ef01311cec7854960ca92735..3c9360aa6dfee96d3101a58b3c8bd899e51b4db3 100644 (file)
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -44,10 +44,12 @@ static struct strbuf fsck_msg_types = STRBUF_INIT;
 static int receive_unpack_limit = -1;
 static int transfer_unpack_limit = -1;
 static int advertise_atomic_push = 1;
+static int advertise_push_options;
 static int unpack_limit = 100;
 static int report_status;
 static int use_sideband;
 static int use_atomic;
+static int use_push_options;
 static int quiet;
 static int prefer_ofs_delta = 1;
 static int auto_update_server_info;
@@ -193,6 +195,11 @@ static int receive_pack_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
+       if (strcmp(var, "receive.advertisepushoptions") == 0) {
+               advertise_push_options = git_config_bool(var, value);
+               return 0;
+       }
+
        return git_default_config(var, value, cb);
 }
 
@@ -211,6 +218,8 @@ static void show_ref(const char *path, const unsigned char *sha1)
                        strbuf_addstr(&cap, " ofs-delta");
                if (push_cert_nonce)
                        strbuf_addf(&cap, " push-cert=%s", push_cert_nonce);
+               if (advertise_push_options)
+                       strbuf_addstr(&cap, " push-options");
                strbuf_addf(&cap, " agent=%s", git_user_agent_sanitized());
                packet_write(1, "%s %s%c%s\n",
                             sha1_to_hex(sha1), path, 0, cap.buf);
@@ -1455,6 +1464,9 @@ static struct command *read_head_info(struct sha1_array *shallow)
                        if (advertise_atomic_push
                            && parse_feature_request(feature_list, "atomic"))
                                use_atomic = 1;
+                       if (advertise_push_options
+                           && parse_feature_request(feature_list, "push-options"))
+                               use_push_options = 1;
                }
 
                if (!strcmp(line, "push-cert")) {
@@ -1487,6 +1499,21 @@ static struct command *read_head_info(struct sha1_array *shallow)
        return commands;
 }
 
+static void read_push_options(struct string_list *options)
+{
+       while (1) {
+               char *line;
+               int len;
+
+               line = packet_read_line(0, &len);
+
+               if (!line)
+                       break;
+
+               string_list_append(options, line);
+       }
+}
+
 static const char *parse_pack_header(struct pack_header *hdr)
 {
        switch (read_pack_header(0, hdr)) {
@@ -1774,6 +1801,9 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
                const char *unpack_status = NULL;
                struct string_list push_options = STRING_LIST_INIT_DUP;
 
+               if (use_push_options)
+                       read_push_options(&push_options);
+
                prepare_shallow_info(&si, &shallow);
                if (!si.nr_ours && !si.nr_theirs)
                        shallow_update = 0;