eth/catalyst: adjust eta for themerge (#25601)

* eth/catalyst: adjust eta for themerge

* squash

* squash

* eth/catalyst: address review concerns

eth/catalyst/api.go

@@ -564,16 +564,16 @@ func (api *ConsensusAPI) heartbeat() {
 
 	var (
 		offlineLogged time.Time
+		ttd           = api.eth.BlockChain().Config().TerminalTotalDifficulty
 	)
+	// If the network is not yet merged/merging, don't bother continuing.
+	if ttd == nil {
+		return
+	}
 	for {
 		// Sleep a bit and retrieve the last known consensus updates
 		time.Sleep(5 * time.Second)
 
-		// If the network is not yet merged/merging, don't bother scaring the user
-		ttd := api.eth.BlockChain().Config().TerminalTotalDifficulty
-		if ttd == nil {
-			continue
-		}
 		api.lastTransitionLock.Lock()
 		lastTransitionUpdate := api.lastTransitionUpdate
 		api.lastTransitionLock.Unlock()
@@ -589,7 +589,10 @@ func (api *ConsensusAPI) heartbeat() {
 		// If there have been no updates for the past while, warn the user
 		// that the beacon client is probably offline
 		if api.eth.BlockChain().Config().TerminalTotalDifficultyPassed || api.eth.Merger().TDDReached() {
-			if time.Since(lastForkchoiceUpdate) > beaconUpdateConsensusTimeout && time.Since(lastNewPayloadUpdate) > beaconUpdateConsensusTimeout {
+			if time.Since(lastForkchoiceUpdate) <= beaconUpdateConsensusTimeout || time.Since(lastNewPayloadUpdate) <= beaconUpdateConsensusTimeout {
+				offlineLogged = time.Time{}
+				continue
+			}
 			if time.Since(lastTransitionUpdate) > beaconUpdateExchangeTimeout {
 				if time.Since(offlineLogged) > beaconUpdateWarnFrequency {
 					if lastTransitionUpdate.IsZero() {
@@ -610,68 +613,62 @@ func (api *ConsensusAPI) heartbeat() {
 				offlineLogged = time.Now()
 			}
 			continue
-			} else {
+		}
+		if time.Since(lastTransitionUpdate) <= beaconUpdateExchangeTimeout {
 			offlineLogged = time.Time{}
+			continue
 		}
-		} else {
-			if time.Since(lastTransitionUpdate) > beaconUpdateExchangeTimeout {
 		if time.Since(offlineLogged) > beaconUpdateWarnFrequency {
 			// Retrieve the last few blocks and make a rough estimate as
 			// to when the merge transition should happen
 			var (
 				chain = api.eth.BlockChain()
-						head  = chain.CurrentBlock()
-						htd   = chain.GetTd(head.Hash(), head.NumberU64())
-						eta   time.Duration
+				head  = chain.CurrentHeader()
+				htd   = chain.GetTd(head.Hash(), head.Number.Uint64())
 			)
-					if head.NumberU64() > 0 && htd.Cmp(ttd) < 0 {
+			if htd.Cmp(ttd) >= 0 {
+				if lastTransitionUpdate.IsZero() {
+					log.Warn("Merge already reached, but no beacon client seen. Please launch one to follow the chain!")
+				} else {
+					log.Warn("Merge already reached, but previously seen beacon client is offline. Please ensure it is operational to follow the chain!")
+				}
+				offlineLogged = time.Now()
+				continue
+			}
+			var eta time.Duration
+			if head.Number.Uint64() > 0 {
 				// Accumulate the last 64 difficulties to estimate the growth
-						var diff float64
-
-						block := head
+				var (
+					deltaDiff uint64
+					deltaTime uint64
+					current   = head
+				)
 				for i := 0; i < 64; i++ {
-							diff += float64(block.Difficulty().Uint64())
-							if parent := chain.GetBlock(block.ParentHash(), block.NumberU64()-1); parent == nil {
+					parent := chain.GetHeader(current.ParentHash, current.Number.Uint64()-1)
+					if parent == nil {
 						break
-							} else {
-								block = parent
 					}
+					deltaDiff += current.Difficulty.Uint64()
+					deltaTime += current.Time - parent.Time
+					current = parent
 				}
 				// Estimate an ETA based on the block times and the difficulty growth
-						growth := diff / float64(head.Time()-block.Time()+1) // +1 to avoid div by zero
-						if growth > 0 {
-							if left := new(big.Int).Sub(ttd, htd); left.IsUint64() {
-								eta = time.Duration(float64(left.Uint64())/growth) * time.Second
-							} else {
-								eta = time.Duration(new(big.Int).Div(left, big.NewInt(int64(growth))).Uint64()) * time.Second
-							}
+				if deltaTime > 0 {
+					growth := deltaDiff / deltaTime
+					left := new(big.Int).Sub(ttd, htd)
+					eta = time.Duration(new(big.Int).Div(left, new(big.Int).SetUint64(growth)).Uint64()) * time.Second
 				}
 			}
-					var message string
-					if htd.Cmp(ttd) > 0 {
-						if lastTransitionUpdate.IsZero() {
-							message = "Merge already reached, but no beacon client seen. Please launch one to follow the chain!"
-						} else {
-							message = "Merge already reached, but previously seen beacon client is offline. Please ensure it is operational to follow the chain!"
-						}
-					} else {
+			message := "Merge is configured, but previously seen beacon client is offline. Please ensure it is operational before the transition arrives!"
 			if lastTransitionUpdate.IsZero() {
 				message = "Merge is configured, but no beacon client seen. Please ensure you have one available before the transition arrives!"
-						} else {
-							message = "Merge is configured, but previously seen beacon client is offline. Please ensure it is operational before the transition arrives!"
 			}
-					}
-					if eta == 0 {
+			if eta < time.Second {
 				log.Warn(message)
 			} else {
 				log.Warn(message, "eta", common.PrettyAge(time.Now().Add(-eta))) // weird hack, but duration formatted doesn't handle days
 			}
 			offlineLogged = time.Now()
 		}
-				continue
-			} else {
-				offlineLogged = time.Time{}
-			}
-		}
 	}
 }