From b3de53798fb329c2647ff703b3a5ab985f8469fe Mon Sep 17 00:00:00 2001
From: rjl493456442 <garyrong0905@gmail.com>
Date: Sun, 4 Mar 2018 21:11:03 +0800
Subject: [PATCH 1/2] eth/downloader: flush state data before exit

---
 eth/downloader/statesync.go | 20 +++++++++++++-------
 trie/sync.go                |  2 +-
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/eth/downloader/statesync.go b/eth/downloader/statesync.go
index ee6c7b491401..dd866e323cb7 100644
--- a/eth/downloader/statesync.go
+++ b/eth/downloader/statesync.go
@@ -274,16 +274,19 @@ func (s *stateSync) Cancel() error {
 // receive data from peers, rather those are buffered up in the downloader and
 // pushed here async. The reason is to decouple processing from data receipt
 // and timeouts.
-func (s *stateSync) loop() error {
+func (s *stateSync) loop() (err error) {
 	// Listen for new peer events to assign tasks to them
 	newPeer := make(chan *peerConnection, 1024)
 	peerSub := s.d.peers.SubscribeNewPeers(newPeer)
 	defer peerSub.Unsubscribe()
+	defer func() {
+		err = s.commit(true)
+	}()
 
 	// Keep assigning new tasks until the sync completes or aborts
 	for s.sched.Pending() > 0 {
-		if err := s.commit(false); err != nil {
-			return err
+		if err = s.commit(false); err != nil {
+			return
 		}
 		s.assignTasks()
 		// Tasks assigned, wait for something to happen
@@ -307,14 +310,14 @@ func (s *stateSync) loop() error {
 				s.d.dropPeer(req.peer.id)
 			}
 			// Process all the received blobs and check for stale delivery
-			if err := s.process(req); err != nil {
+			if err = s.process(req); err != nil {
 				log.Warn("Node data write error", "err", err)
-				return err
+				return
 			}
 			req.peer.SetNodeDataIdle(len(req.response))
 		}
 	}
-	return s.commit(true)
+	return
 }
 
 func (s *stateSync) commit(force bool) error {
@@ -323,7 +326,10 @@ func (s *stateSync) commit(force bool) error {
 	}
 	start := time.Now()
 	b := s.d.stateDB.NewBatch()
-	s.sched.Commit(b)
+	// Ignore empty write.
+	if written, err := s.sched.Commit(b); written == 0 || err != nil {
+		return err
+	}
 	if err := b.Write(); err != nil {
 		return fmt.Errorf("DB write error: %v", err)
 	}
diff --git a/trie/sync.go b/trie/sync.go
index b573a9f73245..013de7c38f11 100644
--- a/trie/sync.go
+++ b/trie/sync.go
@@ -212,7 +212,7 @@ func (s *TrieSync) Process(results []SyncResult) (bool, int, error) {
 }
 
 // Commit flushes the data stored in the internal membatch out to persistent
-// storage, returning th enumber of items written and any occurred error.
+// storage, returning th number of items written and any occurred error.
 func (s *TrieSync) Commit(dbw ethdb.Putter) (int, error) {
 	// Dump the membatch into a database dbw
 	for i, key := range s.membatch.order {

From 1a243afb4dcbfc2ea935e82d5d7141829ae6332a Mon Sep 17 00:00:00 2001
From: rjl493456442 <garyrong0905@gmail.com>
Date: Fri, 16 Mar 2018 22:49:56 +0800
Subject: [PATCH 2/2] trie, eth: minor fix

---
 eth/downloader/statesync.go | 12 +++++++-----
 trie/sync.go                |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/eth/downloader/statesync.go b/eth/downloader/statesync.go
index dd866e323cb7..d1d3a3d9746a 100644
--- a/eth/downloader/statesync.go
+++ b/eth/downloader/statesync.go
@@ -280,13 +280,16 @@ func (s *stateSync) loop() (err error) {
 	peerSub := s.d.peers.SubscribeNewPeers(newPeer)
 	defer peerSub.Unsubscribe()
 	defer func() {
-		err = s.commit(true)
+		cerr := s.commit(true)
+		if err == nil {
+			err = cerr
+		}
 	}()
 
 	// Keep assigning new tasks until the sync completes or aborts
 	for s.sched.Pending() > 0 {
 		if err = s.commit(false); err != nil {
-			return
+			return err
 		}
 		s.assignTasks()
 		// Tasks assigned, wait for something to happen
@@ -312,12 +315,12 @@ func (s *stateSync) loop() (err error) {
 			// Process all the received blobs and check for stale delivery
 			if err = s.process(req); err != nil {
 				log.Warn("Node data write error", "err", err)
-				return
+				return err
 			}
 			req.peer.SetNodeDataIdle(len(req.response))
 		}
 	}
-	return
+	return nil
 }
 
 func (s *stateSync) commit(force bool) error {
@@ -326,7 +329,6 @@ func (s *stateSync) commit(force bool) error {
 	}
 	start := time.Now()
 	b := s.d.stateDB.NewBatch()
-	// Ignore empty write.
 	if written, err := s.sched.Commit(b); written == 0 || err != nil {
 		return err
 	}
diff --git a/trie/sync.go b/trie/sync.go
index 013de7c38f11..4ae975d0428c 100644
--- a/trie/sync.go
+++ b/trie/sync.go
@@ -212,7 +212,7 @@ func (s *TrieSync) Process(results []SyncResult) (bool, int, error) {
 }
 
 // Commit flushes the data stored in the internal membatch out to persistent
-// storage, returning th number of items written and any occurred error.
+// storage, returning the number of items written and any occurred error.
 func (s *TrieSync) Commit(dbw ethdb.Putter) (int, error) {
 	// Dump the membatch into a database dbw
 	for i, key := range s.membatch.order {