core, eth, trie: direct state trie synchronization

core/state/sync.go

@@ -0,0 +1,98 @@
+// 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/crypto/sha3"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+type StateSync struct {
+	db          ethdb.Database
+	sync        *trie.TrieSync
+	codeReqs    map[common.Hash]struct{} // requested but not yet written to database
+	codeReqList []common.Hash            // requested since last Missing
+}
+
+var sha3_nil = common.BytesToHash(sha3.NewKeccak256().Sum(nil))
+
+func NewStateSync(root common.Hash, db ethdb.Database) *StateSync {
+	ss := &StateSync{
+		db:       db,
+		codeReqs: make(map[common.Hash]struct{}),
+	}
+	ss.codeReqs[sha3_nil] = struct{}{} // never request the nil hash
+	ss.sync = trie.NewTrieSync(root, db, ss.leafFound)
+	return ss
+}
+
+func (self *StateSync) leafFound(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
+	}
+	self.sync.AddSubTrie(obj.Root, 64, parent, nil)
+
+	codehash := common.BytesToHash(obj.CodeHash)
+	if _, ok := self.codeReqs[codehash]; !ok {
+		code, _ := self.db.Get(obj.CodeHash)
+		if code == nil {
+			self.codeReqs[codehash] = struct{}{}
+			self.codeReqList = append(self.codeReqList, codehash)
+		}
+	}
+	return nil
+}
+
+func (self *StateSync) Missing(max int) []common.Hash {
+	cr := len(self.codeReqList)
+	gh := 0
+	if max != 0 {
+		if cr > max {
+			cr = max
+		}
+		gh = max - cr
+	}
+	list := append(self.sync.Missing(gh), self.codeReqList[:cr]...)
+	self.codeReqList = self.codeReqList[cr:]
+	return list
+}
+
+func (self *StateSync) Process(list []trie.SyncResult) error {
+	for i := 0; i < len(list); i++ {
+		if _, ok := self.codeReqs[list[i].Hash]; ok { // code data, not a node
+			self.db.Put(list[i].Hash[:], list[i].Data)
+			delete(self.codeReqs, list[i].Hash)
+			list[i] = list[len(list)-1]
+			list = list[:len(list)-1]
+			i--
+		}
+	}
+	_, err := self.sync.Process(list)
+	return err
+}