Add: log output during initial header sync (#174)

* Add log output during initial header sync
* Avoid unnecessary "Synchronizing blockheaders" log messages
bitcoin/bitcoin#16774
* remove: "::ChainstateActive()"
* log message
Co-authored-by: Jonas Schnelli <dev@jonasschnelli.ch>

src/validation.cpp

@@ -2610,7 +2610,7 @@ bool CChainState::ActivateBestChainStep(CValidationState& state, const CChainPar
     return true;
 }
 
-static void NotifyHeaderTip() {
+static bool NotifyHeaderTip() {
     bool fNotify = false;
     bool fInitialBlockDownload = false;
     static CBlockIndex* pindexHeaderOld = nullptr;
@@ -2629,6 +2629,7 @@ static void NotifyHeaderTip() {
     if (fNotify) {
         uiInterface.NotifyHeaderTip(fInitialBlockDownload, pindexHeader);
     }
+    return fNotify;
 }
 
 /**
@@ -3401,7 +3402,12 @@ bool ProcessNewBlockHeaders(const std::vector<CBlockHeader>& headers, CValidatio
             }
         }
     }
-    NotifyHeaderTip();
+    if (NotifyHeaderTip()) {
+        LOCK(cs_main);
+        if (IsInitialBlockDownload() && ppindex && *ppindex) {
+            LogPrintf("sync headers, height: %d (~%.2f%%)\n", (*ppindex)->nHeight, 100.0/((*ppindex)->nHeight+(GetAdjustedTime() - (*ppindex)->GetBlockTime()) / Params().GetConsensus().nPowTargetSpacing) * (*ppindex)->nHeight);
+        }
+    }
     return true;
 }