From f5f29e1c59f4f3430b3fb95f0b1bb7638a65540a Mon Sep 17 00:00:00 2001
From: Richard Fuchs <rfuchs@sipwise.com>
Date: Tue, 31 Aug 2021 15:56:11 -0400
Subject: [PATCH] TT#101150 add min/max/avg tracking for gauge stats

Change-Id: I6a682f2bb98673361a8454f419f8a0fb7d37ef75
---
 daemon/call.c        |  2 ++
 include/call.h       |  5 ++++-
 include/statistics.h | 15 +++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/daemon/call.c b/daemon/call.c
index 27d74d49f..32700d8b7 100644
--- a/daemon/call.c
+++ b/daemon/call.c
@@ -64,6 +64,8 @@ struct xmlrpc_helper {
 
 
 struct global_stats_gauge rtpe_stats_gauge;
+struct global_stats_gauge_min_max rtpe_stats_gauge_graphite_min_max;
+
 struct global_stats_ax rtpe_stats;
 struct global_stats_counter rtpe_stats_interval;
 struct global_stats_counter rtpe_stats_cumulative;
diff --git a/include/call.h b/include/call.h
index 3de93caec..012d74d45 100644
--- a/include/call.h
+++ b/include/call.h
@@ -542,14 +542,17 @@ extern GHashTable *rtpe_callhash;
 extern struct call_iterator_list rtpe_call_iterators[NUM_CALL_ITERATORS];
 
 extern struct global_stats_gauge rtpe_stats_gauge;
+extern struct global_stats_gauge_min_max rtpe_stats_gauge_graphite_min_max;
 
 #define RTPE_GAUGE_SET(field, num) \
 	do { \
 		atomic64_set(&rtpe_stats_gauge.field, num); \
+		RTPE_GAUGE_SET_MIN_MAX(field, rtpe_stats_gauge_graphite_min_max, num); \
 	} while (0)
 #define RTPE_GAUGE_ADD(field, num) \
 	do { \
-		atomic64_add(&rtpe_stats_gauge.field, num); \
+		uint64_t __old = atomic64_add(&rtpe_stats_gauge.field, num); \
+		RTPE_GAUGE_SET_MIN_MAX(field, rtpe_stats_gauge_graphite_min_max, __old + num); \
 	} while (0)
 #define RTPE_GAUGE_INC(field) RTPE_GAUGE_ADD(field, 1)
 #define RTPE_GAUGE_DEC(field) RTPE_GAUGE_ADD(field, -1)
diff --git a/include/statistics.h b/include/statistics.h
index bd59f9782..770eea891 100644
--- a/include/statistics.h
+++ b/include/statistics.h
@@ -26,6 +26,13 @@ struct global_stats_gauge {
 #undef F
 };
 
+struct global_stats_gauge_min_max {
+	struct global_stats_gauge min;
+	struct global_stats_gauge max;
+	struct global_stats_gauge avg; // sum while accumulation is running
+	struct global_stats_gauge count;
+};
+
 // "counter" style stats that are incremental and are kept cumulative or per-interval
 struct global_stats_counter {
 #define F(x) atomic64 x;
@@ -177,6 +184,14 @@ INLINE void stats_counters_min_max_reset(struct global_stats_min_max *mm, struct
 #undef F
 }
 
+#define RTPE_GAUGE_SET_MIN_MAX(field, min_max_struct, val) \
+	do { \
+		atomic64_min(&min_max_struct.min.field, val); \
+		atomic64_max(&min_max_struct.max.field, val); \
+		atomic64_add(&min_max_struct.avg.field, val); \
+		atomic64_inc(&min_max_struct.count.field); \
+	} while (0)
+
 void statistics_init(void);
 void statistics_free(void);