Metadata: add env fields to ease lttng path hierarchy creation for viewer

[lttng-tools.git] / src / bin / lttng-sessiond / ust-metadata.c

diff --git a/src/bin/lttng-sessiond/ust-metadata.c b/src/bin/lttng-sessiond/ust-metadata.c
index a657f7c5d3d26b62472e66ecef3f188e987ee121..7c6cbc63d8370e29d7caf3ac7a2363c385c657b6 100644 (file)
--- a/src/bin/lttng-sessiond/ust-metadata.c
+++ b/src/bin/lttng-sessiond/ust-metadata.c
@@ -217,6 +217,43 @@ void sanitize_ctf_identifier(char *out, const char *in)
        }
 }
 
+static
+int print_escaped_ctf_string(struct ust_registry_session *session, const char *string)
+{
+       int ret;
+       size_t i;
+       char cur;
+
+       i = 0;
+       cur = string[i];
+       while (cur != '\0') {
+               switch (cur) {
+               case '\n':
+                       ret = lttng_metadata_printf(session, "%s", "\\n");
+                       break;
+               case '\\':
+               case '"':
+                       ret = lttng_metadata_printf(session, "%c", '\\');
+                       if (ret) {
+                               goto error;
+                       }
+                       /* We still print the current char */
+                       /* Fallthrough */
+               default:
+                       ret = lttng_metadata_printf(session, "%c", cur);
+                       break;
+               }
+
+               if (ret) {
+                       goto error;
+               }
+
+               cur = string[++i];
+       }
+error:
+       return ret;
+}
+
 /* Called with session registry mutex held. */
 static
 int ust_metadata_enum_statedump(struct ust_registry_session *session,
@@ -869,6 +906,98 @@ int64_t measure_clock_offset(void)
        return offset_best_sample.offset;
 }
 
+static
+int print_metadata_session_information(struct ust_registry_session *registry)
+{
+       int ret;
+       struct ltt_session *session = NULL;
+       char creation_datetime[ISO8601_STR_LEN];
+
+       rcu_read_lock();
+       session = session_find_by_id(registry->tracing_id);
+       if (!session) {
+               ret = -1;
+               goto error;
+       }
+
+       /* Print the trace name */
+       ret = lttng_metadata_printf(registry, " trace_name = \"");
+       if (ret) {
+               goto error;
+       }
+
+       /*
+        * This is necessary since the creation time is present in the session
+        * name when it is generated.
+        */
+       if (session->has_auto_generated_name) {
+               ret = print_escaped_ctf_string(registry, DEFAULT_SESSION_NAME);
+       } else {
+               ret = print_escaped_ctf_string(registry, session->name);
+       }
+       if (ret) {
+               goto error;
+       }
+
+       ret = lttng_metadata_printf(registry, "\";\n");
+       if (ret) {
+               goto error;
+       }
+
+       /* Prepare creation time */
+       ret = time_to_iso8601_str(session->creation_time, creation_datetime,
+                       sizeof(creation_datetime));
+       if (ret) {
+               goto error;
+       }
+
+       /* Output the reste of the information */
+       ret = lttng_metadata_printf(registry,
+                       "       trace_creation_datetime = \"%s\";\n"
+                       "       hostname = \"%s\";\n",
+                       creation_datetime, session->hostname);
+       if (ret) {
+               goto error;
+       }
+
+error:
+       if (session) {
+               session_put(session);
+       }
+       rcu_read_unlock();
+       return ret;
+}
+
+static
+int print_metadata_app_information(struct ust_registry_session *registry,
+               struct ust_app *app)
+{
+       int ret;
+       char datetime[ISO8601_STR_LEN];
+
+       if (!app) {
+               ret = 0;
+               goto end;
+       }
+
+       ret = time_to_iso8601_str(
+                       app->registration_time, datetime, sizeof(datetime));
+       if (ret) {
+               goto end;
+       }
+
+       ret = lttng_metadata_printf(registry,
+                       "       tracer_patchlevel = %u;\n"
+                       "       vpid = %d;\n"
+                       "       procname = \"%s\";\n"
+                       "       vpid_datetime = \"%s\";\n",
+                       app->version.patchlevel, (int) app->pid, app->name,
+                       datetime);
+
+end:
+       return ret;
+}
+
 /*
  * Should be called with session registry mutex held.
  */
@@ -880,7 +1009,6 @@ int ust_metadata_session_statedump(struct ust_registry_session *session,
        char uuid_s[UUID_STR_LEN],
                clock_uuid_s[UUID_STR_LEN];
        int ret = 0;
-       char hostname[HOST_NAME_MAX];
 
        assert(session);
 
@@ -930,40 +1058,36 @@ int ust_metadata_session_statedump(struct ust_registry_session *session,
        if (ret)
                goto end;
 
-       /* ignore error, just use empty string if error. */
-       hostname[0] = '\0';
-       ret = gethostname(hostname, sizeof(hostname));
-       if (ret && errno == ENAMETOOLONG)
-               hostname[HOST_NAME_MAX - 1] = '\0';
        ret = lttng_metadata_printf(session,
                "env {\n"
-               "       hostname = \"%s\";\n"
                "       domain = \"ust\";\n"
                "       tracer_name = \"lttng-ust\";\n"
                "       tracer_major = %u;\n"
-               "       tracer_minor = %u;\n",
-               hostname,
+               "       tracer_minor = %u;\n"
+               "       tracer_buffering_scheme = \"%s\";\n"
+               "       tracer_buffering_id = %u;\n"
+               "       architecture_bit_width = %u;\n",
                major,
-               minor
-               );
-       if (ret)
+               minor,
+               app ? "pid" : "uid",
+               app ? (int) app->pid : (int) session->tracing_uid,
+               session->bits_per_long);
+       if (ret) {
+               goto end;
+       }
+
+       ret = print_metadata_session_information(session);
+       if (ret) {
                goto end;
+       }
 
        /*
         * If per-application registry, we can output extra information
         * about the application.
         */
-       if (app) {
-               ret = lttng_metadata_printf(session,
-                       "       tracer_patchlevel = %u;\n"
-                       "       vpid = %d;\n"
-                       "       procname = \"%s\";\n",
-                       app->version.patchlevel,
-                       (int) app->pid,
-                       app->name
-                       );
-               if (ret)
-                       goto end;
+       ret = print_metadata_app_information(session, app);
+       if (ret) {
+               goto end;
        }
 
        ret = lttng_metadata_printf(session,