upload-pack: advertise session ID in v0 capabilities

When transfer.advertiseSID is true, advertise upload-pack's session ID
via the new session-id capability.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/upload-pack.c b/upload-pack.c
index 3b858eb457e557592dada080f95f3fe7e218b24b..ebb40992686833528f736e99eeca72935fd0248c 100644 (file)
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -110,6 +110,7 @@ struct upload_pack_data {
        unsigned done : 1;                                      /* v2 only */
        unsigned allow_ref_in_want : 1;                         /* v2 only */
        unsigned allow_sideband_all : 1;                        /* v2 only */
+       unsigned advertise_sid : 1;
 };
 
 static void upload_pack_data_init(struct upload_pack_data *data)
@@ -141,6 +142,7 @@ static void upload_pack_data_init(struct upload_pack_data *data)
        packet_writer_init(&data->writer, 1);
 
        data->keepalive = 5;
+       data->advertise_sid = 0;
 }
 
 static void upload_pack_data_clear(struct upload_pack_data *data)
@@ -1178,6 +1180,11 @@ static void format_symref_info(struct strbuf *buf, struct string_list *symref)
                strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
 }
 
+static void format_session_id(struct strbuf *buf, struct upload_pack_data *d) {
+       if (d->advertise_sid)
+               strbuf_addf(buf, " session-id=%s", trace2_session_id());
+}
+
 static int send_ref(const char *refname, const struct object_id *oid,
                    int flag, void *cb_data)
 {
@@ -1193,9 +1200,11 @@ static int send_ref(const char *refname, const struct object_id *oid,
 
        if (capabilities) {
                struct strbuf symref_info = STRBUF_INIT;
+               struct strbuf session_id = STRBUF_INIT;
 
                format_symref_info(&symref_info, &data->symref);
-               packet_write_fmt(1, "%s %s%c%s%s%s%s%s%s object-format=%s agent=%s\n",
+               format_session_id(&session_id, data);
+               packet_write_fmt(1, "%s %s%c%s%s%s%s%s%s%s object-format=%s agent=%s\n",
                             oid_to_hex(oid), refname_nons,
                             0, capabilities,
                             (data->allow_uor & ALLOW_TIP_SHA1) ?
@@ -1205,9 +1214,11 @@ static int send_ref(const char *refname, const struct object_id *oid,
                             data->stateless_rpc ? " no-done" : "",
                             symref_info.buf,
                             data->allow_filter ? " filter" : "",
+                            session_id.buf,
                             the_hash_algo->name,
                             git_user_agent_sanitized());
                strbuf_release(&symref_info);
+               strbuf_release(&session_id);
        } else {
                packet_write_fmt(1, "%s %s\n", oid_to_hex(oid), refname_nons);
        }
@@ -1299,6 +1310,8 @@ static int upload_pack_config(const char *var, const char *value, void *cb_data)
                data->allow_sideband_all = git_config_bool(var, value);
        } else if (!strcmp("core.precomposeunicode", var)) {
                precomposed_unicode = git_config_bool(var, value);
+       } else if (!strcmp("transfer.advertisesid", var)) {
+               data->advertise_sid = git_config_bool(var, value);
        }
 
        if (current_config_scope() != CONFIG_SCOPE_LOCAL &&