1 files changed, 17 insertions, 10 deletions
diff --git a/light/nodeset.go b/light/nodeset.go
index ffdb71bb7..245b5eb76 100644
--- a/light/nodeset.go
+++ b/light/nodeset.go
@@ -29,7 +29,9 @@ import (
 // NodeSet stores a set of trie nodes. It implements trie.Database and can also
 // act as a cache for another trie.Database.
 type NodeSet struct {
-	db       map[string][]byte
+	nodes map[string][]byte
+	order []string
+
 	dataSize int
 	lock     sync.RWMutex
 }
@@ -37,7 +39,7 @@ type NodeSet struct {
 // NewNodeSet creates an empty node set
 func NewNodeSet() *NodeSet {
 	return &NodeSet{
-		db: make(map[string][]byte),
+		nodes: make(map[string][]byte),
 	}
 }
 
@@ -46,10 +48,15 @@ func (db *NodeSet) Put(key []byte, value []byte) error {
 	db.lock.Lock()
 	defer db.lock.Unlock()
 
-	if _, ok := db.db[string(key)]; !ok {
-		db.db[string(key)] = common.CopyBytes(value)
-		db.dataSize += len(value)
+	if _, ok := db.nodes[string(key)]; ok {
+		return nil
 	}
+	keystr := string(key)
+
+	db.nodes[keystr] = common.CopyBytes(value)
+	db.order = append(db.order, keystr)
+	db.dataSize += len(value)
+
 	return nil
 }
 
@@ -58,7 +65,7 @@ func (db *NodeSet) Get(key []byte) ([]byte, error) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
-	if entry, ok := db.db[string(key)]; ok {
+	if entry, ok := db.nodes[string(key)]; ok {
 		return entry, nil
 	}
 	return nil, errors.New("not found")
@@ -75,7 +82,7 @@ func (db *NodeSet) KeyCount() int {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
-	return len(db.db)
+	return len(db.nodes)
 }
 
 // DataSize returns the aggregated data size of nodes in the set
@@ -92,8 +99,8 @@ func (db *NodeSet) NodeList() NodeList {
 	defer db.lock.RUnlock()
 
 	var values NodeList
-	for _, value := range db.db {
-		values = append(values, value)
+	for _, key := range db.order {
+		values = append(values, db.nodes[key])
 	}
 	return values
 }
@@ -103,7 +110,7 @@ func (db *NodeSet) Store(target ethdb.Putter) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
-	for key, value := range db.db {
+	for key, value := range db.nodes {
 		target.Put([]byte(key), value)
 	}
 }