From b39c6b99091e43988e3c9034cf1e3a7be5a6fb45 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Sun, 8 Dec 2024 10:14:46 +0000
Subject: [PATCH 1/2] fix: avoid potential divide-by-zero in H/s stats
 calculation

---
 src/init.cpp | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/src/init.cpp b/src/init.cpp
index 1abb710513..1b599eaefd 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -848,20 +848,23 @@ static void PeriodicStats(NodeContext& node)
         LogPrintf("%s: GetUTXOStats failed\n", __func__);
     }
 
-    // short version of GetNetworkHashPS(120, -1);
     CBlockIndex *tip = chainman.ActiveChain().Tip();
-    CBlockIndex *pindex = tip;
-    int64_t minTime = pindex->GetBlockTime();
-    int64_t maxTime = minTime;
-    for (int i = 0; i < 120 && pindex->pprev != nullptr; i++) {
-        pindex = pindex->pprev;
-        int64_t time = pindex->GetBlockTime();
-        minTime = std::min(time, minTime);
-        maxTime = std::max(time, maxTime);
-    }
-    arith_uint256 workDiff = tip->nChainWork - pindex->nChainWork;
-    int64_t timeDiff = maxTime - minTime;
-    double nNetworkHashPS = workDiff.getdouble() / timeDiff;
+    double nNetworkHashPS = [&]() {
+        // Short version of GetNetworkHashPS(120, -1);
+        CBlockIndex *pindex = tip;
+        int64_t minTime = pindex->GetBlockTime();
+        int64_t maxTime = minTime;
+        for (int i = 0; i < 120 && pindex->pprev != nullptr; i++) {
+            pindex = pindex->pprev;
+            int64_t time = pindex->GetBlockTime();
+            minTime = std::min(time, minTime);
+            maxTime = std::max(time, maxTime);
+        }
+        if (minTime == maxTime) return 0.0;
+        arith_uint256 workDiff = tip->nChainWork - pindex->nChainWork;
+        int64_t timeDiff = maxTime - minTime;
+        return workDiff.getdouble() / timeDiff;
+    }();
 
     ::g_stats_client->gaugeDouble("network.hashesPerSecond", nNetworkHashPS);
     ::g_stats_client->gaugeDouble("network.terahashesPerSecond", nNetworkHashPS / 1e12);

From 40070c0337fb07af9e2a0ce62adf782067aa8472 Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Sun, 8 Dec 2024 10:18:13 +0000
Subject: [PATCH 2/2] stats: don't report `network.*hashesPerSecond` if it's
 zero

It's more likely that the stat is broken than the network running with
such low difficulty, the hash rate is reported as zero.
`*hashesPerSecond` are a gauge and we should let the last known good
value linger instead of potentially overwriting it with an improbable
value.
---
 src/init.cpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/init.cpp b/src/init.cpp
index 1b599eaefd..092bc971e2 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -866,10 +866,12 @@ static void PeriodicStats(NodeContext& node)
         return workDiff.getdouble() / timeDiff;
     }();
 
-    ::g_stats_client->gaugeDouble("network.hashesPerSecond", nNetworkHashPS);
-    ::g_stats_client->gaugeDouble("network.terahashesPerSecond", nNetworkHashPS / 1e12);
-    ::g_stats_client->gaugeDouble("network.petahashesPerSecond", nNetworkHashPS / 1e15);
-    ::g_stats_client->gaugeDouble("network.exahashesPerSecond", nNetworkHashPS / 1e18);
+    if (nNetworkHashPS > 0.0) {
+        ::g_stats_client->gaugeDouble("network.hashesPerSecond", nNetworkHashPS);
+        ::g_stats_client->gaugeDouble("network.terahashesPerSecond", nNetworkHashPS / 1e12);
+        ::g_stats_client->gaugeDouble("network.petahashesPerSecond", nNetworkHashPS / 1e15);
+        ::g_stats_client->gaugeDouble("network.exahashesPerSecond", nNetworkHashPS / 1e18);
+    }
     // No need for cs_main, we never use null tip here
     ::g_stats_client->gaugeDouble("network.difficulty", (double)GetDifficulty(tip));