Report amount of data gathered from environment

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

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);