From d43ead5a71e1185d73808a1576473f6df0d46e85 Mon Sep 17 00:00:00 2001
From: Grant Limberg <grant.limberg@zerotier.com>
Date: Wed, 3 May 2023 17:16:06 -0700
Subject: [PATCH] peer latency histogram actually works now

---
 .../core/include/prometheus/histogram.h        | 18 +++++++++---------
 node/Metrics.cpp                               | 15 +++++++++++++--
 node/Metrics.hpp                               |  2 +-
 node/Peer.hpp                                  |  2 +-
 4 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/ext/prometheus-cpp-lite-1.0/core/include/prometheus/histogram.h b/ext/prometheus-cpp-lite-1.0/core/include/prometheus/histogram.h
index ac558fa21..0afe41758 100644
--- a/ext/prometheus-cpp-lite-1.0/core/include/prometheus/histogram.h
+++ b/ext/prometheus-cpp-lite-1.0/core/include/prometheus/histogram.h
@@ -28,15 +28,9 @@ namespace prometheus {
   /// a data race.
   template <typename Value_ = uint64_t>
   class Histogram : public Metric {
-
-      using BucketBoundaries = std::vector<Value_>;
-
-      const BucketBoundaries       bucket_boundaries_;
-      std::vector<Counter<Value_>> bucket_counts_;
-      Gauge<Value_>                sum_;
-
     public:
       using Value  = Value_;
+      using BucketBoundaries = std::vector<Value_>;
       using Family = CustomFamily<Histogram<Value>>;
 
       static const Metric::Type static_type = Metric::Type::Histogram;
@@ -69,7 +63,7 @@ namespace prometheus {
           bucket_boundaries_.begin(),
           std::find_if(
             std::begin(bucket_boundaries_), std::end(bucket_boundaries_),
-            [value](const double boundary) { return boundary >= value; })));
+            [value](const Value boundary) { return boundary >= value; })));
         sum_.Increment(value);
         bucket_counts_[bucket_index].Increment();
       }
@@ -110,7 +104,7 @@ namespace prometheus {
           bucket.cumulative_count = cumulative_count;
           bucket.upper_bound = (i == bucket_boundaries_.size()
                                     ? std::numeric_limits<double>::infinity()
-                                    : bucket_boundaries_[i]);
+                                    : static_cast<double>(bucket_boundaries_[i]));
           metric.histogram.bucket.push_back(std::move(bucket));
         }
         metric.histogram.sample_count = cumulative_count;
@@ -119,6 +113,12 @@ namespace prometheus {
         return metric;
       }
 
+    private:
+      const BucketBoundaries       bucket_boundaries_;
+      std::vector<Counter<Value_>> bucket_counts_;
+      Gauge<Value_>                sum_;
+
+
   };
 
   /// \brief Return a builder to configure and register a Histogram metric.
diff --git a/node/Metrics.cpp b/node/Metrics.cpp
index 8687a264b..64862fa7d 100644
--- a/node/Metrics.cpp
+++ b/node/Metrics.cpp
@@ -177,8 +177,19 @@ namespace ZeroTier {
         { "zt_network_outgoing_packets", "number of outgoing packets per network" };
 
         // PeerMetrics
-        prometheus::CustomFamily<prometheus::Histogram<uint64_t>> peer_latency 
-        { "zt_peer_latency", "peer latency (ms)", {}};
+        prometheus::CustomFamily<prometheus::Histogram<uint64_t>> &peer_latency = 
+        prometheus::Builder<prometheus::Histogram<uint64_t>>()
+            .Name("zt_peer_latency")
+            .Help("peer latency (ms)")
+            .Register(prometheus::simpleapi::registry);
+/*         prometheus::CustomFamily<prometheus::Histogram<uint64_t>>::Build(
+            prometheus::simpleapi::registry,
+            "zt_peer_latency",
+            "peer latency (ms)",
+            {}
+        );
+ */        //{ prometheus::Metric::Type::Histogram, "zt_peer_latency", "peer latency (ms)", {}};
+    
         prometheus::simpleapi::gauge_family_t peer_path_count
         { "zt_peer_path_count", "number of paths to peer" };
         prometheus::simpleapi::counter_family_t peer_incoming_packets
diff --git a/node/Metrics.hpp b/node/Metrics.hpp
index c2c39f7f1..f78a0f157 100644
--- a/node/Metrics.hpp
+++ b/node/Metrics.hpp
@@ -108,7 +108,7 @@ namespace ZeroTier {
         extern prometheus::simpleapi::counter_family_t network_outgoing_packets;
 
         // Peer Metrics
-        extern prometheus::CustomFamily<prometheus::Histogram<uint64_t>> peer_latency;
+        extern prometheus::CustomFamily<prometheus::Histogram<uint64_t>> &peer_latency;
         extern prometheus::simpleapi::gauge_family_t peer_path_count;
         extern prometheus::simpleapi::counter_family_t peer_incoming_packets;
         extern prometheus::simpleapi::counter_family_t peer_outgoing_packets;
diff --git a/node/Peer.hpp b/node/Peer.hpp
index 53c9505bf..cafde0f5c 100644
--- a/node/Peer.hpp
+++ b/node/Peer.hpp
@@ -600,7 +600,7 @@ private:
 
 	SharedPtr<Bond> _bond;
 
-	prometheus::Histogram<uint64_t> _peer_latency;
+	prometheus::Histogram<uint64_t> &_peer_latency;
 	prometheus::simpleapi::gauge_metric_t _alive_path_count;
 	prometheus::simpleapi::gauge_metric_t _dead_path_count;
 	prometheus::simpleapi::counter_metric_t _incoming_packet;