stats: Send all values on reporter update

Currently only counter changes and new item values are being
reported. This makes it cumbersome to configure reporting clients,
since there is nothing like a list of all parameters.

This commit changes this behaviour such that all currently existing
counters and items that would be reported eventually, are passed to
the reporter when it has been reconfigured or enabled. If a counter
has not been incremented, 0 is sent. If a stat item value has not
been added, the last item value (or the default value if there is
none) is resent again.

Note that this will not catch transient counters/items that will be
created later on, e.g. triggered by new peers or subscribers.

To just force this kind of dump on a running reporter, it is
sufficient to invoke the 'enable' command in its configuration node.

Sponsored-by: On-Waves ehf

2 files changed, 26 insertions, 8 deletions

diff --git a/include/osmocom/core/stats.h b/include/osmocom/core/stats.h
index 362d3fb3..39eae088 100644
--- a/include/osmocom/core/stats.h
+++ b/include/osmocom/core/stats.h
@@ -66,6 +66,7 @@ struct osmo_stats_reporter {
 	int fd;
 	struct msgb *buffer;
 	int agg_enabled;
+	int force_single_flush;
 
 	struct llist_head list;
 	int (*open)(struct osmo_stats_reporter *srep);
diff --git a/src/stats.c b/src/stats.c
index fa56f50a..0a1a1486 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -101,6 +101,8 @@ static int update_srep_config(struct osmo_stats_reporter *srep)
 	else
 		srep->running = 1;
 
+	srep->force_single_flush = 1;
+
 	return rc;
 }
 
@@ -582,13 +584,13 @@ static int rate_ctr_handler(
 	struct osmo_stats_reporter *srep;
 	int64_t delta = rate_ctr_difference(ctr);
 
-	if (delta == 0)
-		return 0;
-
 	llist_for_each_entry(srep, &osmo_stats_reporter_list, list) {
 		if (!srep->running)
 			continue;
 
+		if (delta == 0 && !srep->force_single_flush)
+			continue;
+
 		if (!osmo_stats_reporter_check_config(srep,
 			       ctrg->idx, ctrg->desc->class_id))
 			return 0;
@@ -628,12 +630,21 @@ static int osmo_stat_item_handler(
 	struct osmo_stats_reporter *srep;
 	int32_t idx = current_stat_item_index;
 	int32_t value;
+	int have_value;
+
+	have_value = osmo_stat_item_get_next(item, &idx, &value) > 0;
+	if (!have_value)
+		/* Send the last value in case a flush is requested */
+		value = osmo_stat_item_get_last(item);
 
-	while (osmo_stat_item_get_next(item, &idx, &value) > 0) {
+	do {
 		llist_for_each_entry(srep, &osmo_stats_reporter_list, list) {
 			if (!srep->running)
 				continue;
 
+			if (!have_value && !srep->force_single_flush)
+				continue;
+
 			if (!osmo_stats_reporter_check_config(srep,
 					statg->idx, statg->desc->class_id))
 				return 0;
@@ -641,7 +652,12 @@ static int osmo_stat_item_handler(
 			osmo_stats_reporter_send_item(srep, statg,
 				item->desc, value);
 		}
-	}
+
+		if (!have_value)
+			break;
+
+		have_value = osmo_stat_item_get_next(item, &idx, &value) > 0;
+	} while (have_value);
 
 	return 0;
 }
@@ -666,13 +682,13 @@ static int handle_counter(struct osmo_counter *counter, void *sctx_)
 
 	int delta = osmo_counter_difference(counter);
 
-	if (delta == 0)
-		return 0;
-
 	llist_for_each_entry(srep, &osmo_stats_reporter_list, list) {
 		if (!srep->running)
 			continue;
 
+		if (delta == 0 && !srep->force_single_flush)
+			continue;
+
 		osmo_stats_reporter_send_counter(srep, NULL, &desc,
 			counter->value, delta);
 
@@ -694,6 +710,7 @@ static void flush_all_reporters()
 			continue;
 
 		osmo_stats_reporter_send_buffer(srep);
+		srep->force_single_flush = 0;
 	}
 }