From d1c02775aa74a0610809ac54bb241ddad61d2d8c Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Tue, 5 Nov 2019 10:54:20 -0800
Subject: [PATCH] Report amount of data gathered from environment

---
 src/crypto/sha512.h | 1 +
 src/random.cpp      | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/src/crypto/sha512.h b/src/crypto/sha512.h
index 4118ac1b18..fc7dd1b87e 100644
--- a/src/crypto/sha512.h
+++ b/src/crypto/sha512.h
@@ -23,6 +23,7 @@ public:
     CSHA512& Write(const unsigned char* data, size_t len);
     void Finalize(unsigned char hash[OUTPUT_SIZE]);
     CSHA512& Reset();
+    uint64_t Size() const { return bytes; }
 };
 
 #endif // BITCOIN_CRYPTO_SHA512_H
diff --git a/src/random.cpp b/src/random.cpp
index 2847aacf6f..3e6398f7b4 100644
--- a/src/random.cpp
+++ b/src/random.cpp
@@ -525,7 +525,9 @@ static void SeedPeriodic(CSHA512& hasher, RNGState& rng)
     SeedTimestamp(hasher);
 
     // Dynamic environment data (performance monitoring, ...)
+    auto old_size = hasher.Size();
     RandAddDynamicEnv(hasher);
+    LogPrintf("Feeding %i bytes of dynamic environment data into RNG\n", hasher.Size() - old_size);
 
     // Strengthen for 10 ms
     SeedStrengthen(hasher, rng, 10000);
@@ -540,10 +542,12 @@ static void SeedStartup(CSHA512& hasher, RNGState& rng) noexcept
     SeedSlow(hasher);
 
     // Dynamic environment data (performance monitoring, ...)
+    auto old_size = hasher.Size();
     RandAddDynamicEnv(hasher);
 
     // Static environment data
     RandAddStaticEnv(hasher);
+    LogPrintf("Feeding %i bytes of environment data into RNG\n", hasher.Size() - old_size);
 
     // Strengthen for 100 ms
     SeedStrengthen(hasher, rng, 100000);