1 files changed, 70 insertions, 0 deletions
diff --git a/core/state/sync.go b/core/state/sync.go
new file mode 100644
index 000000000..ef2b4b84c
--- /dev/null
+++ b/core/state/sync.go
@@ -0,0 +1,70 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package state
+
+import (
+	"bytes"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+// StateSync is the main state synchronisation scheduler, which provides yet the
+// unknown state hashes to retrieve, accepts node data associated with said hashes
+// and reconstructs the state database step by step until all is done.
+type StateSync trie.TrieSync
+
+// NewStateSync create a new state trie download scheduler.
+func NewStateSync(root common.Hash, database ethdb.Database) *StateSync {
+	var syncer *trie.TrieSync
+
+	callback := func(leaf []byte, parent common.Hash) error {
+		var obj struct {
+			Nonce    uint64
+			Balance  *big.Int
+			Root     common.Hash
+			CodeHash []byte
+		}
+		if err := rlp.Decode(bytes.NewReader(leaf), &obj); err != nil {
+			return err
+		}
+		syncer.AddSubTrie(obj.Root, 64, parent, nil)
+		syncer.AddRawEntry(common.BytesToHash(obj.CodeHash), 64, parent)
+
+		return nil
+	}
+	syncer = trie.NewTrieSync(root, database, callback)
+	return (*StateSync)(syncer)
+}
+
+// Missing retrieves the known missing nodes from the state trie for retrieval.
+func (s *StateSync) Missing(max int) []common.Hash {
+	return (*trie.TrieSync)(s).Missing(max)
+}
+
+// Process injects a batch of retrieved trie nodes data.
+func (s *StateSync) Process(list []trie.SyncResult) (int, error) {
+	return (*trie.TrieSync)(s).Process(list)
+}
+
+// Pending returns the number of state entries currently pending for download.
+func (s *StateSync) Pending() int {
+	return (*trie.TrieSync)(s).Pending()
+}