Add stream meta data to JSON stream metric set

This change adds the uid and gid from the stream
event to the JSON stream metric set.

ldms/src/sampler/json/Plugin_json_stream_sampler.man

@@ -71,6 +71,14 @@ The encoding of all JSON types except strings, dictionaries and lists is
 straightfoward. The coding of Strings, Lists and Dictionaries have additional
 limitations as described below.
 
+.SS "Stream Meta-data"
+.PP
+Stream events include the user-id, and group-id of the application
+publishing the stream data. This data is encoded in the metric set
+with the special names \fBS_uid\fR, and \fBS_gid\fR respectively. The
+intention is that this data can stored in rows as configured by the
+user with a decomposition configuration.
+
 .SS "Encoding Strings"
 Strings are encoded as LDMS_V_BYTE_ARRAY. By default, the length of
 the array is 255 unless an attribute with the name \fINAME\fR_max_len
@@ -117,6 +125,8 @@ results in a metric set as follows:
 .nf
 $ ldms_ls -h localhost -p 10411 -a munge -E example -l
 ovs-5416_example: consistent, last update: Sat Aug 05 11:38:26 2023 -0500 [281178us]
+D s32        S_uid                                      1002
+D s32        S_gid                                      1002
 D s64        component_id                               10001
 D s64        job_id                                     2048
 D list<>     seq                                        [1,2,3]
@@ -145,6 +155,8 @@ results in the following LDMS metric set.
 .RS 4
 .nf
 ovs-5416_dict: consistent, last update: Sat Aug 05 21:14:38 2023 -0500 [839029us]
+D s32         S_uid                                      1002
+D s32         S_gid                                      1002
 M record_type  a_dict_record                             LDMS_V_RECORD_TYPE
 D record[]     a_dict
   attr_2 attr_1
@@ -179,6 +191,8 @@ results in the following LDMS metric set.
 .RS 4
 .nf
 ovs-5416_dict_list: consistent, last update: Sat Aug 05 21:23:11 2023 -0500 [52659us]
+D s32         S_uid                                      1002
+D s32         S_gid                                      1002
 M record_type a_dict_list_record                         LDMS_V_RECORD_TYPE
 D list<>      a_dict_list
   attr_2 attr_1
@@ -187,6 +201,7 @@ D list<>      a_dict_list
 D char[]     schema                                     "dict_list"
 .fi
 .RE
+.PP
 .SH "CONFIG OPTIONS"
 
 .TP

ldms/src/sampler/json/json_stream_sampler.c

@@ -453,7 +453,7 @@ static json_setter_t setter_table[] = {
 
 static int get_schema_for_json(char *name, json_entity_t e, ldms_schema_t *sch)
 {
-	int rc = 0;
+	int i, rc = 0;
 	ldms_schema_t schema;
 	struct schema_entry *entry;
 	struct rbn *rbn;
@@ -492,6 +492,33 @@ static int get_schema_for_json(char *name, json_entity_t e, ldms_schema_t *sch)
 	rbt_init(&entry->attr_tree, str_cmp);
 	rbn_init(&entry->rbn, entry->name);
 
+	/* Add the special JSON stream attributes. These special
+	 * attributes will have metric indices of 0 (uid) and
+	 * 1 (gid)
+	 */
+	const char *stream_meta_attr[] = { "S_uid", "S_gid" };
+	for (i = 0; i < sizeof(stream_meta_attr) / sizeof(stream_meta_attr[0]); i++) {
+		midx = ldms_schema_metric_add(schema, stream_meta_attr[i], LDMS_V_S32);
+		if (midx < 0)
+			goto err_3;
+		ae = calloc(1, sizeof(*ae));
+		if (!ae) {
+			rc = errno;
+			goto err_3;
+		}
+		ae->name = strdup(stream_meta_attr[i]);
+		if (!ae->name) {
+			rc = ENOMEM;
+			free(ae);
+			goto err_3;
+		}
+		ae->type = JSON_INT_VALUE;
+		ae->ridx = -1;
+		ae->midx = midx;
+		rbn_init(&ae->rbn, ae->name);
+		rbt_ins(&entry->attr_tree, &ae->rbn);
+	}
+
 	for (json_attr = json_attr_first(e); json_attr;
 	     json_attr = json_attr_next(json_attr)) {
 
@@ -552,6 +579,7 @@ static int get_schema_for_json(char *name, json_entity_t e, ldms_schema_t *sch)
 		ae->name = strdup(json_attr_name(json_attr)->str);
 		if (!ae->name) {
 			rc = ENOMEM;
+			free(ae);
 			goto err_3;
 		}
 		ae->type = type;
@@ -774,7 +802,6 @@ static void update_set_data(struct json_cfg_inst *inst,
 		entry = container_of(rbn, struct schema_entry, rbn);
 	}
 
-	ldms_transaction_begin(set);
 	for (json_attr = json_attr_first(entity); json_attr;
 	     json_attr = json_attr_next(json_attr)) {
 
@@ -808,7 +835,6 @@ static void update_set_data(struct json_cfg_inst *inst,
 		if (rc)
 			LERROR("Error %d setting the metric value '%s'\n", rc, ae->name);
 	}
-	ldms_transaction_end(set);
 }
 
 static int json_recv_cb(ldms_stream_event_t ev, void *arg)
@@ -865,7 +891,14 @@ static int json_recv_cb(ldms_stream_event_t ev, void *arg)
 		}
 	}
 	free(set_name);
+
+	/* Update the stream meta-data in the set */
+	ldms_transaction_begin(set);
+	ldms_metric_set_s32(set, 0, ev->recv.cred.uid);
+	ldms_metric_set_s32(set, 1, ev->recv.cred.gid);
 	update_set_data(inst, set, entity);
+	ldms_transaction_end(set);
+
 	pthread_mutex_unlock(&inst->lock);
 	return 0;
  err_1: