From f2047cc503421e99f9dad66e1fe95e660ade9ea3 Mon Sep 17 00:00:00 2001
From: Elizabeth Engelman <emengelman@gmail.com>
Date: Thu, 14 Feb 2019 15:46:03 -0600
Subject: [PATCH] Address PR comments

---
 cmd/geth/config.go |  9 ++++-----
 core/blockchain.go | 26 ++++++++------------------
 2 files changed, 12 insertions(+), 23 deletions(-)

diff --git a/cmd/geth/config.go b/cmd/geth/config.go
index 54575ecb2b62..aafaa1375f82 100644
--- a/cmd/geth/config.go
+++ b/cmd/geth/config.go
@@ -155,12 +155,14 @@ func makeFullNode(ctx *cli.Context) *node.Node {
 	if ctx.GlobalIsSet(utils.ConstantinopleOverrideFlag.Name) {
 		cfg.Eth.ConstantinopleOverride = new(big.Int).SetUint64(ctx.GlobalUint64(utils.ConstantinopleOverrideFlag.Name))
 	}
+
+	utils.RegisterEthService(stack, &cfg.Eth)
+
 	if ctx.GlobalBool(utils.StateDiffFlag.Name) {
 		cfg.Eth.StateDiff = true
+		utils.RegisterStateDiffService(stack, ctx)
 	}
 
-	utils.RegisterEthService(stack, &cfg.Eth)
-
 	if ctx.GlobalBool(utils.DashboardEnabledFlag.Name) {
 		utils.RegisterDashboardService(stack, &cfg.Dashboard, gitCommit)
 	}
@@ -185,9 +187,6 @@ func makeFullNode(ctx *cli.Context) *node.Node {
 		utils.RegisterEthStatsService(stack, cfg.Ethstats.URL)
 	}
 
-	if ctx.GlobalBool(utils.StateDiffFlag.Name) {
-		utils.RegisterStateDiffService(stack, ctx)
-	}
 	return stack
 }
 
diff --git a/core/blockchain.go b/core/blockchain.go
index 601a141181b8..ba96e69aeb3c 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -929,9 +929,6 @@ func (bc *BlockChain) WriteBlockWithoutState(block *types.Block, td *big.Int) (e
 
 func (bc *BlockChain) AddToStateDiffProcessedCollection(hash common.Hash) {
 	count, ok := bc.stateDiffsProcessed[hash]
-	if count > 1 {
-		log.Error("count is too high", "count", count, "hash", hash.Hex())
-	}
 
 	if ok {
 		count++
@@ -1015,28 +1012,14 @@ func (bc *BlockChain) WriteBlockWithState(block *types.Block, receipts []*types.
 				}
 
 				if bc.cacheConfig.ProcessStateDiffs {
-					count, ok := bc.stateDiffsProcessed[root.(common.Hash)]
-					//if we haven't processed the statediff for a given state root and it's child, don't dereference it yet
-					if !ok {
-						log.Debug("Current root NOT found root in stateDiffsProcessed", "root", root.(common.Hash).Hex())
-						bc.triegc.Push(root, number)
-						break
-					}
-					if count < 2 {
-						log.Debug("Current root has not yet been processed for it's child", "root", root.(common.Hash).Hex())
+					if !bc.allowedRootToBeDereferenced(root.(common.Hash)) {
 						bc.triegc.Push(root, number)
 						break
 					} else {
-						log.Debug("Current root found in stateDiffsProcessed collection with a count of 2, okay to dereference",
-							"root", root.(common.Hash).Hex(),
-							"blockNumber", uint64(-number),
-							"size of stateDiffsProcessed", len(bc.stateDiffsProcessed))
-
 						delete(bc.stateDiffsProcessed, root.(common.Hash))
 					}
 				}
 
-				log.Debug("Dereferencing", "root", root.(common.Hash).Hex())
 				triedb.Dereference(root.(common.Hash))
 			}
 		}
@@ -1091,6 +1074,13 @@ func (bc *BlockChain) WriteBlockWithState(block *types.Block, receipts []*types.
 	return status, nil
 }
 
+//if we haven't processed the statediff for a given state root and it's child, don't dereference it yet
+func (bc *BlockChain) allowedRootToBeDereferenced(root common.Hash) bool {
+	diffProcessedForSelfAndChildCount := 2
+	count := bc.stateDiffsProcessed[root]
+	return count >= diffProcessedForSelfAndChildCount
+}
+
 // addFutureBlock checks if the block is within the max allowed window to get
 // accepted for future processing, and returns an error if the block is too far
 // ahead and was not added.