From 0a9fb535489c295cd59bdfeade4faa746f75831c Mon Sep 17 00:00:00 2001
From: Jim Posen <jimpo@coinbase.com>
Date: Wed, 30 Aug 2017 11:27:02 -0700
Subject: [PATCH] blockchain: Add node to block index in maybeAcceptBlock.

This has the same effect but makes it clearer that all blocks written to
the database end up in the block index.
---
 blockchain/accept.go     |  9 +++++++++
 blockchain/blockindex.go | 11 +++++++++++
 blockchain/chain.go      | 18 ------------------
 3 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/blockchain/accept.go b/blockchain/accept.go
index 3d32f8c0..73169ebb 100644
--- a/blockchain/accept.go
+++ b/blockchain/accept.go
@@ -67,6 +67,15 @@ func (b *BlockChain) maybeAcceptBlock(block *btcutil.Block, flags BehaviorFlags)
 		newNode.height = blockHeight
 		newNode.workSum.Add(prevNode.workSum, newNode.workSum)
 	}
+	b.index.AddNode(newNode)
+
+	// Disconnect it from the parent node when the function returns when
+	// running in dry run mode.
+	if dryRun {
+		defer func() {
+			b.index.RemoveNode(newNode)
+		}()
+	}
 
 	// Connect the passed block to the chain while respecting proper chain
 	// selection according to the chain with the most proof of work.  This
diff --git a/blockchain/blockindex.go b/blockchain/blockindex.go
index d65619eb..64d66ffa 100644
--- a/blockchain/blockindex.go
+++ b/blockchain/blockindex.go
@@ -224,3 +224,14 @@ func (bi *blockIndex) AddNode(node *blockNode) {
 	bi.index[node.hash] = node
 	bi.Unlock()
 }
+
+// RemoveNode removes the provided node to the block index.  There is no check
+// whether another node in the index depends on this one, so it is up to caller
+// to avoid that situation.
+//
+// This function is safe for concurrent access.
+func (bi *blockIndex) RemoveNode(node *blockNode) {
+	bi.Lock()
+	delete(bi.index, node.hash)
+	bi.Unlock()
+}
diff --git a/blockchain/chain.go b/blockchain/chain.go
index d1ee628b..04160a09 100644
--- a/blockchain/chain.go
+++ b/blockchain/chain.go
@@ -648,7 +648,6 @@ func (b *BlockChain) connectBlock(node *blockNode, block *btcutil.Block, view *U
 	view.commit()
 
 	// This node is now the end of the best chain.
-	b.index.AddNode(node)
 	b.bestChain.SetTip(node)
 
 	// Update the state for the best block.  Notice how this replaces the
@@ -1044,23 +1043,6 @@ func (b *BlockChain) connectBestChain(node *blockNode, block *btcutil.Block, fla
 			block.Hash())
 	}
 
-	// We're extending (or creating) a side chain which may or may not
-	// become the main chain, but in either case the entry is needed in the
-	// index for future processing.
-	b.index.Lock()
-	b.index.index[node.hash] = node
-	b.index.Unlock()
-
-	// Disconnect it from the parent node when the function returns when
-	// running in dry run mode.
-	if dryRun {
-		defer func() {
-			b.index.Lock()
-			delete(b.index.index, node.hash)
-			b.index.Unlock()
-		}()
-	}
-
 	// We're extending (or creating) a side chain, but the cumulative
 	// work for this new side chain is not enough to make it the new chain.
 	if node.workSum.Cmp(b.bestChain.Tip().workSum) <= 0 {