core, eth, trie, xeth: merged state, chain, extra databases in one

21 files changed, 223 insertions, 187 deletions

diff --git a/cmd/geth/chaincmd.go b/cmd/geth/chaincmd.go
index 2d8eb15c2..876b8c6ba 100644
--- a/cmd/geth/chaincmd.go
+++ b/cmd/geth/chaincmd.go
@@ -74,10 +74,10 @@ func importChain(ctx *cli.Context) {
 	if len(ctx.Args()) != 1 {
 		utils.Fatalf("This command requires an argument.")
 	}
-	chain, blockDB, stateDB, extraDB := utils.MakeChain(ctx)
+	chain, chainDb := utils.MakeChain(ctx)
 	start := time.Now()
 	err := utils.ImportChain(chain, ctx.Args().First())
-	closeAll(blockDB, stateDB, extraDB)
+	chainDb.Close()
 	if err != nil {
 		utils.Fatalf("Import error: %v", err)
 	}
@@ -88,7 +88,7 @@ func exportChain(ctx *cli.Context) {
 	if len(ctx.Args()) < 1 {
 		utils.Fatalf("This command requires an argument.")
 	}
-	chain, _, _, _ := utils.MakeChain(ctx)
+	chain, _ := utils.MakeChain(ctx)
 	start := time.Now()
 
 	var err error
@@ -136,8 +136,8 @@ func removeDB(ctx *cli.Context) {
 func upgradeDB(ctx *cli.Context) {
 	glog.Infoln("Upgrading blockchain database")
 
-	chain, blockDB, stateDB, extraDB := utils.MakeChain(ctx)
-	v, _ := blockDB.Get([]byte("BlockchainVersion"))
+	chain, chainDb := utils.MakeChain(ctx)
+	v, _ := chainDb.Get([]byte("BlockchainVersion"))
 	bcVersion := int(common.NewValue(v).Uint())
 	if bcVersion == 0 {
 		bcVersion = core.BlockChainVersion
@@ -149,15 +149,14 @@ func upgradeDB(ctx *cli.Context) {
 	if err := utils.ExportChain(chain, exportFile); err != nil {
 		utils.Fatalf("Unable to export chain for reimport %s", err)
 	}
-	closeAll(blockDB, stateDB, extraDB)
-	os.RemoveAll(filepath.Join(ctx.GlobalString(utils.DataDirFlag.Name), "blockchain"))
-	os.RemoveAll(filepath.Join(ctx.GlobalString(utils.DataDirFlag.Name), "state"))
+	chainDb.Close()
+	os.RemoveAll(filepath.Join(ctx.GlobalString(utils.DataDirFlag.Name), "chaindata"))
 
 	// Import the chain file.
-	chain, blockDB, stateDB, extraDB = utils.MakeChain(ctx)
-	blockDB.Put([]byte("BlockchainVersion"), common.NewValue(core.BlockChainVersion).Bytes())
+	chain, chainDb = utils.MakeChain(ctx)
+	chainDb.Put([]byte("BlockchainVersion"), common.NewValue(core.BlockChainVersion).Bytes())
 	err := utils.ImportChain(chain, exportFile)
-	closeAll(blockDB, stateDB, extraDB)
+	chainDb.Close()
 	if err != nil {
 		utils.Fatalf("Import error %v (a backup is made in %s, use the import command to import it)", err, exportFile)
 	} else {
@@ -167,7 +166,7 @@ func upgradeDB(ctx *cli.Context) {
 }
 
 func dump(ctx *cli.Context) {
-	chain, _, stateDB, _ := utils.MakeChain(ctx)
+	chain, chainDb := utils.MakeChain(ctx)
 	for _, arg := range ctx.Args() {
 		var block *types.Block
 		if hashish(arg) {
@@ -180,10 +179,11 @@ func dump(ctx *cli.Context) {
 			fmt.Println("{}")
 			utils.Fatalf("block not found")
 		} else {
-			state := state.New(block.Root(), stateDB)
+			state := state.New(block.Root(), chainDb)
 			fmt.Printf("%s\n", state.Dump())
 		}
 	}
+	chainDb.Close()
 }
 
 // hashish returns true for strings that look like hashes.
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index cf969805d..e0ea7116d 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -435,23 +435,17 @@ func SetupLogger(ctx *cli.Context) {
 }
 
 // MakeChain creates a chain manager from set command line flags.
-func MakeChain(ctx *cli.Context) (chain *core.ChainManager, blockDB, stateDB, extraDB common.Database) {
+func MakeChain(ctx *cli.Context) (chain *core.ChainManager, chainDb common.Database) {
 	datadir := ctx.GlobalString(DataDirFlag.Name)
 	cache := ctx.GlobalInt(CacheFlag.Name)
 
 	var err error
-	if blockDB, err = ethdb.NewLDBDatabase(filepath.Join(datadir, "blockchain"), cache); err != nil {
-		Fatalf("Could not open database: %v", err)
-	}
-	if stateDB, err = ethdb.NewLDBDatabase(filepath.Join(datadir, "state"), cache); err != nil {
-		Fatalf("Could not open database: %v", err)
-	}
-	if extraDB, err = ethdb.NewLDBDatabase(filepath.Join(datadir, "extra"), cache); err != nil {
+	if chainDb, err = ethdb.NewLDBDatabase(filepath.Join(datadir, "chaindata"), cache); err != nil {
 		Fatalf("Could not open database: %v", err)
 	}
 	if ctx.GlobalBool(OlympicFlag.Name) {
 		InitOlympic()
-		_, err := core.WriteTestNetGenesisBlock(stateDB, blockDB, 42)
+		_, err := core.WriteTestNetGenesisBlock(chainDb, 42)
 		if err != nil {
 			glog.Fatalln(err)
 		}
@@ -460,14 +454,14 @@ func MakeChain(ctx *cli.Context) (chain *core.ChainManager, blockDB, stateDB, ex
 	eventMux := new(event.TypeMux)
 	pow := ethash.New()
 	//genesis := core.GenesisBlock(uint64(ctx.GlobalInt(GenesisNonceFlag.Name)), blockDB)
-	chain, err = core.NewChainManager(blockDB, stateDB, extraDB, pow, eventMux)
+	chain, err = core.NewChainManager(chainDb, pow, eventMux)
 	if err != nil {
 		Fatalf("Could not start chainmanager: %v", err)
 	}
 
-	proc := core.NewBlockProcessor(stateDB, extraDB, pow, chain, eventMux)
+	proc := core.NewBlockProcessor(chainDb, pow, chain, eventMux)
 	chain.SetProcessor(proc)
-	return chain, blockDB, stateDB, extraDB
+	return chain, chainDb
 }
 
 // MakeChain creates an account manager from set command line flags.
diff --git a/core/bench_test.go b/core/bench_test.go
index 67ba15970..baae8a7a5 100644
--- a/core/bench_test.go
+++ b/core/bench_test.go
@@ -168,8 +168,8 @@ func benchInsertChain(b *testing.B, disk bool, gen func(int, *BlockGen)) {
 	// Time the insertion of the new chain.
 	// State and blocks are stored in the same DB.
 	evmux := new(event.TypeMux)
-	chainman, _ := NewChainManager(db, db, db, FakePow{}, evmux)
-	chainman.SetProcessor(NewBlockProcessor(db, db, FakePow{}, chainman, evmux))
+	chainman, _ := NewChainManager(db, FakePow{}, evmux)
+	chainman.SetProcessor(NewBlockProcessor(db, FakePow{}, chainman, evmux))
 	defer chainman.Stop()
 	b.ReportAllocs()
 	b.ResetTimer()
diff --git a/core/block_processor.go b/core/block_processor.go
index 5a2ad8377..38bf772fb 100644
--- a/core/block_processor.go
+++ b/core/block_processor.go
@@ -41,8 +41,7 @@ const (
 )
 
 type BlockProcessor struct {
-	db      common.Database
-	extraDb common.Database
+	chainDb common.Database
 	// Mutex for locking the block processor. Blocks can only be handled one at a time
 	mutex sync.Mutex
 	// Canonical block chain
@@ -57,10 +56,9 @@ type BlockProcessor struct {
 	eventMux *event.TypeMux
 }
 
-func NewBlockProcessor(db, extra common.Database, pow pow.PoW, chainManager *ChainManager, eventMux *event.TypeMux) *BlockProcessor {
+func NewBlockProcessor(db common.Database, pow pow.PoW, chainManager *ChainManager, eventMux *event.TypeMux) *BlockProcessor {
 	sm := &BlockProcessor{
-		db:       db,
-		extraDb:  extra,
+		chainDb:  db,
 		mem:      make(map[string]*big.Int),
 		Pow:      pow,
 		bc:       chainManager,
@@ -201,7 +199,7 @@ func (sm *BlockProcessor) Process(block *types.Block) (logs state.Logs, receipts
 
 func (sm *BlockProcessor) processWithParent(block, parent *types.Block) (logs state.Logs, receipts types.Receipts, err error) {
 	// Create a new state based on the parent's root (e.g., create copy)
-	state := state.New(parent.Root(), sm.db)
+	state := state.New(parent.Root(), sm.chainDb)
 	header := block.Header()
 	uncles := block.Uncles()
 	txs := block.Transactions()
@@ -342,7 +340,7 @@ func (sm *BlockProcessor) VerifyUncles(statedb *state.StateDB, block, parent *ty
 // GetBlockReceipts returns the receipts beloniging to the block hash
 func (sm *BlockProcessor) GetBlockReceipts(bhash common.Hash) types.Receipts {
 	if block := sm.ChainManager().GetBlock(bhash); block != nil {
-		return GetBlockReceipts(sm.extraDb, block.Hash())
+		return GetBlockReceipts(sm.chainDb, block.Hash())
 	}
 
 	return nil
@@ -352,7 +350,7 @@ func (sm *BlockProcessor) GetBlockReceipts(bhash common.Hash) types.Receipts {
 // where it tries to get it from the (updated) method which gets them from the receipts or
 // the depricated way by re-processing the block.
 func (sm *BlockProcessor) GetLogs(block *types.Block) (logs state.Logs, err error) {
-	receipts := GetBlockReceipts(sm.extraDb, block.Hash())
+	receipts := GetBlockReceipts(sm.chainDb, block.Hash())
 	if len(receipts) > 0 {
 		// coalesce logs
 		for _, receipt := range receipts {
@@ -364,7 +362,7 @@ func (sm *BlockProcessor) GetLogs(block *types.Block) (logs state.Logs, err erro
 	// TODO: remove backward compatibility
 	var (
 		parent = sm.bc.GetBlock(block.ParentHash())
-		state  = state.New(parent.Root(), sm.db)
+		state  = state.New(parent.Root(), sm.chainDb)
 	)
 
 	sm.TransitionState(state, parent, block, true)
diff --git a/core/block_processor_test.go b/core/block_processor_test.go
index f48ce9607..4525f417b 100644
--- a/core/block_processor_test.go
+++ b/core/block_processor_test.go
@@ -33,19 +33,19 @@ func proc() (*BlockProcessor, *ChainManager) {
 	db, _ := ethdb.NewMemDatabase()
 	var mux event.TypeMux
 
-	WriteTestNetGenesisBlock(db, db, 0)
-	chainMan, err := NewChainManager(db, db, db, thePow(), &mux)
+	WriteTestNetGenesisBlock(db, 0)
+	chainMan, err := NewChainManager(db, thePow(), &mux)
 	if err != nil {
 		fmt.Println(err)
 	}
-	return NewBlockProcessor(db, db, ezp.New(), chainMan, &mux), chainMan
+	return NewBlockProcessor(db, ezp.New(), chainMan, &mux), chainMan
 }
 
 func TestNumber(t *testing.T) {
 	pow := ezp.New()
 	_, chain := proc()
 
-	statedb := state.New(chain.Genesis().Root(), chain.stateDb)
+	statedb := state.New(chain.Genesis().Root(), chain.chainDb)
 	header := makeHeader(chain.Genesis(), statedb)
 	header.Number = big.NewInt(3)
 	err := ValidateHeader(pow, header, chain.Genesis(), false)
diff --git a/core/chain_makers.go b/core/chain_makers.go
index 85a6175dc..0bb1df95a 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -184,9 +184,9 @@ func makeHeader(parent *types.Block, state *state.StateDB) *types.Header {
 func newCanonical(n int, db common.Database) (*BlockProcessor, error) {
 	evmux := &event.TypeMux{}
 
-	WriteTestNetGenesisBlock(db, db, 0)
-	chainman, _ := NewChainManager(db, db, db, FakePow{}, evmux)
-	bman := NewBlockProcessor(db, db, FakePow{}, chainman, evmux)
+	WriteTestNetGenesisBlock(db, 0)
+	chainman, _ := NewChainManager(db, FakePow{}, evmux)
+	bman := NewBlockProcessor(db, FakePow{}, chainman, evmux)
 	bman.bc.SetProcessor(bman)
 	parent := bman.bc.CurrentBlock()
 	if n == 0 {
diff --git a/core/chain_makers_test.go b/core/chain_makers_test.go
index 98a585f9b..1c868624d 100644
--- a/core/chain_makers_test.go
+++ b/core/chain_makers_test.go
@@ -77,8 +77,8 @@ func ExampleGenerateChain() {
 
 	// Import the chain. This runs all block validation rules.
 	evmux := &event.TypeMux{}
-	chainman, _ := NewChainManager(db, db, db, FakePow{}, evmux)
-	chainman.SetProcessor(NewBlockProcessor(db, db, FakePow{}, chainman, evmux))
+	chainman, _ := NewChainManager(db, FakePow{}, evmux)
+	chainman.SetProcessor(NewBlockProcessor(db, FakePow{}, chainman, evmux))
 	if i, err := chainman.InsertChain(chain); err != nil {
 		fmt.Printf("insert error (block %d): %v\n", i, err)
 		return
diff --git a/core/chain_manager.go b/core/chain_manager.go
index fc1d1304f..87353b944 100644
--- a/core/chain_manager.go
+++ b/core/chain_manager.go
@@ -56,9 +56,7 @@ const (
 
 type ChainManager struct {
 	//eth          EthManager
-	blockDb      common.Database
-	stateDb      common.Database
-	extraDb      common.Database
+	chainDb      common.Database
 	processor    types.BlockProcessor
 	eventMux     *event.TypeMux
 	genesisBlock *types.Block
@@ -85,12 +83,10 @@ type ChainManager struct {
 	pow pow.PoW
 }
 
-func NewChainManager(blockDb, stateDb, extraDb common.Database, pow pow.PoW, mux *event.TypeMux) (*ChainManager, error) {
+func NewChainManager(chainDb common.Database, pow pow.PoW, mux *event.TypeMux) (*ChainManager, error) {
 	cache, _ := lru.New(blockCacheLimit)
 	bc := &ChainManager{
-		blockDb:  blockDb,
-		stateDb:  stateDb,
-		extraDb:  extraDb,
+		chainDb:  chainDb,
 		eventMux: mux,
 		quit:     make(chan struct{}),
 		cache:    cache,
@@ -103,7 +99,7 @@ func NewChainManager(blockDb, stateDb, extraDb common.Database, pow pow.PoW, mux
 		if err != nil {
 			return nil, err
 		}
-		bc.genesisBlock, err = WriteGenesisBlock(stateDb, blockDb, reader)
+		bc.genesisBlock, err = WriteGenesisBlock(chainDb, reader)
 		if err != nil {
 			return nil, err
 		}
@@ -195,15 +191,15 @@ func (self *ChainManager) SetProcessor(proc types.BlockProcessor) {
 }
 
 func (self *ChainManager) State() *state.StateDB {
-	return state.New(self.CurrentBlock().Root(), self.stateDb)
+	return state.New(self.CurrentBlock().Root(), self.chainDb)
 }
 
 func (bc *ChainManager) recover() bool {
-	data, _ := bc.blockDb.Get([]byte("checkpoint"))
+	data, _ := bc.chainDb.Get([]byte("checkpoint"))
 	if len(data) != 0 {
 		block := bc.GetBlock(common.BytesToHash(data))
 		if block != nil {
-			err := bc.blockDb.Put([]byte("LastBlock"), block.Hash().Bytes())
+			err := bc.chainDb.Put([]byte("LastBlock"), block.Hash().Bytes())
 			if err != nil {
 				glog.Fatalln("db write err:", err)
 			}
@@ -217,7 +213,7 @@ func (bc *ChainManager) recover() bool {
 }
 
 func (bc *ChainManager) setLastState() error {
-	data, _ := bc.blockDb.Get([]byte("LastBlock"))
+	data, _ := bc.chainDb.Get([]byte("LastBlock"))
 	if len(data) != 0 {
 		block := bc.GetBlock(common.BytesToHash(data))
 		if block != nil {
@@ -264,7 +260,7 @@ func (bc *ChainManager) Reset() {
 	bc.cache, _ = lru.New(blockCacheLimit)
 
 	// Prepare the genesis block
-	err := WriteBlock(bc.blockDb, bc.genesisBlock)
+	err := WriteBlock(bc.chainDb, bc.genesisBlock)
 	if err != nil {
 		glog.Fatalln("db err:", err)
 	}
@@ -277,7 +273,7 @@ func (bc *ChainManager) Reset() {
 }
 
 func (bc *ChainManager) removeBlock(block *types.Block) {
-	bc.blockDb.Delete(append(blockHashPre, block.Hash().Bytes()...))
+	bc.chainDb.Delete(append(blockHashPre, block.Hash().Bytes()...))
 }
 
 func (bc *ChainManager) ResetWithGenesisBlock(gb *types.Block) {
@@ -292,7 +288,7 @@ func (bc *ChainManager) ResetWithGenesisBlock(gb *types.Block) {
 	gb.Td = gb.Difficulty()
 	bc.genesisBlock = gb
 
-	err := WriteBlock(bc.blockDb, bc.genesisBlock)
+	err := WriteBlock(bc.chainDb, bc.genesisBlock)
 	if err != nil {
 		glog.Fatalln("db err:", err)
 	}
@@ -339,14 +335,14 @@ func (self *ChainManager) ExportN(w io.Writer, first uint64, last uint64) error
 // insert injects a block into the current chain block chain. Note, this function
 // assumes that the `mu` mutex is held!
 func (bc *ChainManager) insert(block *types.Block) {
-	err := WriteHead(bc.blockDb, block)
+	err := WriteHead(bc.chainDb, block)
 	if err != nil {
 		glog.Fatal("db write fail:", err)
 	}
 
 	bc.checkpoint++
 	if bc.checkpoint > checkpointLimit {
-		err = bc.blockDb.Put([]byte("checkpoint"), block.Hash().Bytes())
+		err = bc.chainDb.Put([]byte("checkpoint"), block.Hash().Bytes())
 		if err != nil {
 			glog.Fatal("db write fail:", err)
 		}
@@ -369,7 +365,7 @@ func (bc *ChainManager) HasBlock(hash common.Hash) bool {
 		return true
 	}
 
-	data, _ := bc.blockDb.Get(append(blockHashPre, hash[:]...))
+	data, _ := bc.chainDb.Get(append(blockHashPre, hash[:]...))
 	return len(data) != 0
 }
 
@@ -399,7 +395,7 @@ func (self *ChainManager) GetBlock(hash common.Hash) *types.Block {
 		return block.(*types.Block)
 	}
 
-	block := GetBlockByHash(self.blockDb, hash)
+	block := GetBlockByHash(self.chainDb, hash)
 	if block == nil {
 		return nil
 	}
@@ -433,7 +429,7 @@ func (self *ChainManager) GetBlocksFromHash(hash common.Hash, n int) (blocks []*
 
 // non blocking version
 func (self *ChainManager) getBlockByNumber(num uint64) *types.Block {
-	return GetBlockByNumber(self.blockDb, num)
+	return GetBlockByNumber(self.chainDb, num)
 }
 
 func (self *ChainManager) GetUnclesInChain(block *types.Block, length int) (uncles []*types.Header) {
@@ -521,7 +517,7 @@ func (self *ChainManager) WriteBlock(block *types.Block, queued bool) (status wr
 		status = SideStatTy
 	}
 
-	err = WriteBlock(self.blockDb, block)
+	err = WriteBlock(self.chainDb, block)
 	if err != nil {
 		glog.Fatalln("db err:", err)
 	}
@@ -638,9 +634,9 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
 			queueEvent.canonicalCount++
 
 			// This puts transactions in a extra db for rpc
-			PutTransactions(self.extraDb, block, block.Transactions())
+			PutTransactions(self.chainDb, block, block.Transactions())
 			// store the receipts
-			PutReceipts(self.extraDb, receipts)
+			PutReceipts(self.chainDb, receipts)
 		case SideStatTy:
 			if glog.V(logger.Detail) {
 				glog.Infof("inserted forked block #%d (TD=%v) (%d TXs %d UNCs) (%x...). Took %v\n", block.Number(), block.Difficulty(), len(block.Transactions()), len(block.Uncles()), block.Hash().Bytes()[0:4], time.Since(bstart))
@@ -651,7 +647,7 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
 			queue[i] = ChainSplitEvent{block, logs}
 			queueEvent.splitCount++
 		}
-		PutBlockReceipts(self.extraDb, block, receipts)
+		PutBlockReceipts(self.chainDb, block, receipts)
 
 		stats.processed++
 	}
@@ -733,8 +729,8 @@ func (self *ChainManager) merge(oldBlock, newBlock *types.Block) error {
 		// insert the block in the canonical way, re-writing history
 		self.insert(block)
 		// write canonical receipts and transactions
-		PutTransactions(self.extraDb, block, block.Transactions())
-		PutReceipts(self.extraDb, GetBlockReceipts(self.extraDb, block.Hash()))
+		PutTransactions(self.chainDb, block, block.Transactions())
+		PutReceipts(self.chainDb, GetBlockReceipts(self.chainDb, block.Hash()))
 
 	}
 	self.mu.Unlock()
diff --git a/core/chain_manager_test.go b/core/chain_manager_test.go
index f0c097df6..002dcbe44 100644
--- a/core/chain_manager_test.go
+++ b/core/chain_manager_test.go
@@ -48,14 +48,14 @@ func thePow() pow.PoW {
 
 func theChainManager(db common.Database, t *testing.T) *ChainManager {
 	var eventMux event.TypeMux
-	WriteTestNetGenesisBlock(db, db, 0)
-	chainMan, err := NewChainManager(db, db, db, thePow(), &eventMux)
+	WriteTestNetGenesisBlock(db, 0)
+	chainMan, err := NewChainManager(db, thePow(), &eventMux)
 	if err != nil {
 		t.Error("failed creating chainmanager:", err)
 		t.FailNow()
 		return nil
 	}
-	blockMan := NewBlockProcessor(db, db, nil, chainMan, &eventMux)
+	blockMan := NewBlockProcessor(db, nil, chainMan, &eventMux)
 	chainMan.SetProcessor(blockMan)
 
 	return chainMan
@@ -125,7 +125,7 @@ func testChain(chainB types.Blocks, bman *BlockProcessor) (*big.Int, error) {
 
 		bman.bc.mu.Lock()
 		{
-			WriteBlock(bman.bc.blockDb, block)
+			WriteBlock(bman.bc.chainDb, block)
 		}
 		bman.bc.mu.Unlock()
 	}
@@ -387,7 +387,7 @@ func makeChainWithDiff(genesis *types.Block, d []int, seed byte) []*types.Block
 
 func chm(genesis *types.Block, db common.Database) *ChainManager {
 	var eventMux event.TypeMux
-	bc := &ChainManager{extraDb: db, blockDb: db, stateDb: db, genesisBlock: genesis, eventMux: &eventMux, pow: FakePow{}}
+	bc := &ChainManager{chainDb: db, genesisBlock: genesis, eventMux: &eventMux, pow: FakePow{}}
 	bc.cache, _ = lru.New(100)
 	bc.futureBlocks, _ = lru.New(100)
 	bc.processor = bproc{}
@@ -399,7 +399,7 @@ func chm(genesis *types.Block, db common.Database) *ChainManager {
 func TestReorgLongest(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
 
-	genesis, err := WriteTestNetGenesisBlock(db, db, 0)
+	genesis, err := WriteTestNetGenesisBlock(db, 0)
 	if err != nil {
 		t.Error(err)
 		t.FailNow()
@@ -422,7 +422,7 @@ func TestReorgLongest(t *testing.T) {
 
 func TestReorgShortest(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
-	genesis, err := WriteTestNetGenesisBlock(db, db, 0)
+	genesis, err := WriteTestNetGenesisBlock(db, 0)
 	if err != nil {
 		t.Error(err)
 		t.FailNow()
@@ -446,13 +446,13 @@ func TestReorgShortest(t *testing.T) {
 func TestInsertNonceError(t *testing.T) {
 	for i := 1; i < 25 && !t.Failed(); i++ {
 		db, _ := ethdb.NewMemDatabase()
-		genesis, err := WriteTestNetGenesisBlock(db, db, 0)
+		genesis, err := WriteTestNetGenesisBlock(db, 0)
 		if err != nil {
 			t.Error(err)
 			t.FailNow()
 		}
 		bc := chm(genesis, db)
-		bc.processor = NewBlockProcessor(db, db, bc.pow, bc, bc.eventMux)
+		bc.processor = NewBlockProcessor(db, bc.pow, bc, bc.eventMux)
 		blocks := makeChain(bc.currentBlock, i, db, 0)
 
 		fail := rand.Int() % len(blocks)
diff --git a/core/genesis.go b/core/genesis.go
index 4c0323c17..97afb3a4a 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -33,7 +33,7 @@ import (
 )
 
 // WriteGenesisBlock writes the genesis block to the database as block number 0
-func WriteGenesisBlock(stateDb, blockDb common.Database, reader io.Reader) (*types.Block, error) {
+func WriteGenesisBlock(chainDb common.Database, reader io.Reader) (*types.Block, error) {
 	contents, err := ioutil.ReadAll(reader)
 	if err != nil {
 		return nil, err
@@ -59,7 +59,7 @@ func WriteGenesisBlock(stateDb, blockDb common.Database, reader io.Reader) (*typ
 		return nil, err
 	}
 
-	statedb := state.New(common.Hash{}, stateDb)
+	statedb := state.New(common.Hash{}, chainDb)
 	for addr, account := range genesis.Alloc {
 		address := common.HexToAddress(addr)
 		statedb.AddBalance(address, common.String2Big(account.Balance))
@@ -84,9 +84,9 @@ func WriteGenesisBlock(stateDb, blockDb common.Database, reader io.Reader) (*typ
 	}, nil, nil, nil)
 	block.Td = difficulty
 
-	if block := GetBlockByHash(blockDb, block.Hash()); block != nil {
+	if block := GetBlockByHash(chainDb, block.Hash()); block != nil {
 		glog.V(logger.Info).Infoln("Genesis block already in chain. Writing canonical number")
-		err := WriteCanonNumber(blockDb, block)
+		err := WriteCanonNumber(chainDb, block)
 		if err != nil {
 			return nil, err
 		}
@@ -95,11 +95,11 @@ func WriteGenesisBlock(stateDb, blockDb common.Database, reader io.Reader) (*typ
 
 	statedb.Sync()
 
-	err = WriteBlock(blockDb, block)
+	err = WriteBlock(chainDb, block)
 	if err != nil {
 		return nil, err
 	}
-	err = WriteHead(blockDb, block)
+	err = WriteHead(chainDb, block)
 	if err != nil {
 		return nil, err
 	}
@@ -133,11 +133,11 @@ func WriteGenesisBlockForTesting(db common.Database, addr common.Address, balanc
 		"0x%x":{"balance":"0x%x"}
 	}
 }`, types.EncodeNonce(0), params.GenesisGasLimit.Bytes(), params.GenesisDifficulty.Bytes(), addr, balance.Bytes())
-	block, _ := WriteGenesisBlock(db, db, strings.NewReader(testGenesis))
+	block, _ := WriteGenesisBlock(db, strings.NewReader(testGenesis))
 	return block
 }
 
-func WriteTestNetGenesisBlock(stateDb, blockDb common.Database, nonce uint64) (*types.Block, error) {
+func WriteTestNetGenesisBlock(chainDb common.Database, nonce uint64) (*types.Block, error) {
 	testGenesis := fmt.Sprintf(`{
 	"nonce":"0x%x",
 	"gasLimit":"0x%x",
@@ -157,5 +157,5 @@ func WriteTestNetGenesisBlock(stateDb, blockDb common.Database, nonce uint64) (*
 		"1a26338f0d905e295fccb71fa9ea849ffa12aaf4": {"balance": "1606938044258990275541962092341162602522202993782792835301376"}
 	}
 }`, types.EncodeNonce(nonce), params.GenesisGasLimit.Bytes(), params.GenesisDifficulty.Bytes())
-	return WriteGenesisBlock(stateDb, blockDb, strings.NewReader(testGenesis))
+	return WriteGenesisBlock(chainDb, strings.NewReader(testGenesis))
 }
diff --git a/core/manager.go b/core/manager.go
index a07c32659..8b0401b03 100644
--- a/core/manager.go
+++ b/core/manager.go
@@ -28,8 +28,7 @@ type Backend interface {
 	BlockProcessor() *BlockProcessor
 	ChainManager() *ChainManager
 	TxPool() *TxPool
-	BlockDb() common.Database
-	StateDb() common.Database
-	ExtraDb() common.Database
+	ChainDb() common.Database
+	DappDb() common.Database
 	EventMux() *event.TypeMux
 }
diff --git a/eth/backend.go b/eth/backend.go
index ed46a4ab3..c9b71803f 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -45,6 +45,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/p2p/nat"
+	"github.com/ethereum/go-ethereum/trie"
 	"github.com/ethereum/go-ethereum/whisper"
 )
 
@@ -206,9 +207,8 @@ type Ethereum struct {
 	shutdownChan chan bool
 
 	// DB interfaces
-	blockDb common.Database // Block chain database
-	stateDb common.Database // State changes database
-	extraDb common.Database // Extra database (txs, etc)
+	chainDb common.Database // Block chain databe
+	dappDb  common.Database // Dapp database
 
 	// Closed when databases are flushed and closed
 	databasesClosed chan bool
@@ -266,27 +266,27 @@ func New(config *Config) (*Ethereum, error) {
 	if newdb == nil {
 		newdb = func(path string) (common.Database, error) { return ethdb.NewLDBDatabase(path, config.DatabaseCache) }
 	}
-	blockDb, err := newdb(filepath.Join(config.DataDir, "blockchain"))
-	if err != nil {
-		return nil, fmt.Errorf("blockchain db err: %v", err)
-	}
-	if db, ok := blockDb.(*ethdb.LDBDatabase); ok {
-		db.Meter("eth/db/block/")
+
+	// attempt to merge database together, upgrading from an old version
+	if err := mergeDatabases(config.DataDir, newdb); err != nil {
+		return nil, err
 	}
-	stateDb, err := newdb(filepath.Join(config.DataDir, "state"))
+
+	chainDb, err := newdb(filepath.Join(config.DataDir, "chaindata"))
 	if err != nil {
-		return nil, fmt.Errorf("state db err: %v", err)
+		return nil, fmt.Errorf("blockchain db err: %v", err)
 	}
-	if db, ok := stateDb.(*ethdb.LDBDatabase); ok {
-		db.Meter("eth/db/state/")
+	if db, ok := chainDb.(*ethdb.LDBDatabase); ok {
+		db.Meter("eth/db/chaindata/")
 	}
-	extraDb, err := newdb(filepath.Join(config.DataDir, "extra"))
+	dappDb, err := newdb(filepath.Join(config.DataDir, "dapp"))
 	if err != nil {
-		return nil, fmt.Errorf("extra db err: %v", err)
+		return nil, fmt.Errorf("dapp db err: %v", err)
 	}
-	if db, ok := extraDb.(*ethdb.LDBDatabase); ok {
-		db.Meter("eth/db/extra/")
+	if db, ok := dappDb.(*ethdb.LDBDatabase); ok {
+		db.Meter("eth/db/dapp/")
 	}
+
 	nodeDb := filepath.Join(config.DataDir, "nodes")
 	glog.V(logger.Info).Infof("Protocol Versions: %v, Network Id: %v", ProtocolVersions, config.NetworkId)
 
@@ -296,7 +296,7 @@ func New(config *Config) (*Ethereum, error) {
 			return nil, err
 		}
 
-		block, err := core.WriteGenesisBlock(stateDb, blockDb, fr)
+		block, err := core.WriteGenesisBlock(chainDb, fr)
 		if err != nil {
 			return nil, err
 		}
@@ -304,7 +304,7 @@ func New(config *Config) (*Ethereum, error) {
 	}
 
 	if config.Olympic {
-		_, err := core.WriteTestNetGenesisBlock(stateDb, blockDb, 42)
+		_, err := core.WriteTestNetGenesisBlock(chainDb, 42)
 		if err != nil {
 			return nil, err
 		}
@@ -313,26 +313,25 @@ func New(config *Config) (*Ethereum, error) {
 
 	// This is for testing only.
 	if config.GenesisBlock != nil {
-		core.WriteBlock(blockDb, config.GenesisBlock)
-		core.WriteHead(blockDb, config.GenesisBlock)
+		core.WriteBlock(chainDb, config.GenesisBlock)
+		core.WriteHead(chainDb, config.GenesisBlock)
 	}
 
 	if !config.SkipBcVersionCheck {
-		b, _ := blockDb.Get([]byte("BlockchainVersion"))
+		b, _ := chainDb.Get([]byte("BlockchainVersion"))
 		bcVersion := int(common.NewValue(b).Uint())
 		if bcVersion != config.BlockChainVersion && bcVersion != 0 {
 			return nil, fmt.Errorf("Blockchain DB version mismatch (%d / %d). Run geth upgradedb.\n", bcVersion, config.BlockChainVersion)
 		}
-		saveBlockchainVersion(blockDb, config.BlockChainVersion)
+		saveBlockchainVersion(chainDb, config.BlockChainVersion)
 	}
 	glog.V(logger.Info).Infof("Blockchain DB Version: %d", config.BlockChainVersion)
 
 	eth := &Ethereum{
 		shutdownChan:            make(chan bool),
 		databasesClosed:         make(chan bool),
-		blockDb:                 blockDb,
-		stateDb:                 stateDb,
-		extraDb:                 extraDb,
+		chainDb:                 chainDb,
+		dappDb:                  dappDb,
 		eventMux:                &event.TypeMux{},
 		accountManager:          config.AccountManager,
 		DataDir:                 config.DataDir,
@@ -362,7 +361,7 @@ func New(config *Config) (*Ethereum, error) {
 		eth.pow = ethash.New()
 	}
 	//genesis := core.GenesisBlock(uint64(config.GenesisNonce), stateDb)
-	eth.chainManager, err = core.NewChainManager(blockDb, stateDb, extraDb, eth.pow, eth.EventMux())
+	eth.chainManager, err = core.NewChainManager(chainDb, eth.pow, eth.EventMux())
 	if err != nil {
 		if err == core.ErrNoGenesis {
 			return nil, fmt.Errorf(`Genesis block not found. Please supply a genesis block with the "--genesis /path/to/file" argument`)
@@ -372,7 +371,7 @@ func New(config *Config) (*Ethereum, error) {
 	}
 	eth.txPool = core.NewTxPool(eth.EventMux(), eth.chainManager.State, eth.chainManager.GasLimit)
 
-	eth.blockProcessor = core.NewBlockProcessor(stateDb, extraDb, eth.pow, eth.chainManager, eth.EventMux())
+	eth.blockProcessor = core.NewBlockProcessor(chainDb, eth.pow, eth.chainManager, eth.EventMux())
 	eth.chainManager.SetProcessor(eth.blockProcessor)
 	eth.protocolManager = NewProtocolManager(config.NetworkId, eth.eventMux, eth.txPool, eth.pow, eth.chainManager)
 
@@ -520,9 +519,8 @@ func (s *Ethereum) BlockProcessor() *core.BlockProcessor { return s.blockProcess
 func (s *Ethereum) TxPool() *core.TxPool                 { return s.txPool }
 func (s *Ethereum) Whisper() *whisper.Whisper            { return s.whisper }
 func (s *Ethereum) EventMux() *event.TypeMux             { return s.eventMux }
-func (s *Ethereum) BlockDb() common.Database             { return s.blockDb }
-func (s *Ethereum) StateDb() common.Database             { return s.stateDb }
-func (s *Ethereum) ExtraDb() common.Database             { return s.extraDb }
+func (s *Ethereum) ChainDb() common.Database             { return s.chainDb }
+func (s *Ethereum) DappDb() common.Database              { return s.dappDb }
 func (s *Ethereum) IsListening() bool                    { return true } // Always listening
 func (s *Ethereum) PeerCount() int                       { return s.net.PeerCount() }
 func (s *Ethereum) Peers() []*p2p.Peer                   { return s.net.Peers() }
@@ -569,23 +567,19 @@ done:
 		select {
 		case <-ticker.C:
 			// don't change the order of database flushes
-			if err := s.extraDb.Flush(); err != nil {
-				glog.Fatalf("fatal error: flush extraDb: %v (Restart your node. We are aware of this issue)\n", err)
+			if err := s.dappDb.Flush(); err != nil {
+				glog.Fatalf("fatal error: flush dappDb: %v (Restart your node. We are aware of this issue)\n", err)
 			}
-			if err := s.stateDb.Flush(); err != nil {
-				glog.Fatalf("fatal error: flush stateDb: %v (Restart your node. We are aware of this issue)\n", err)
-			}
-			if err := s.blockDb.Flush(); err != nil {
-				glog.Fatalf("fatal error: flush blockDb: %v (Restart your node. We are aware of this issue)\n", err)
+			if err := s.chainDb.Flush(); err != nil {
+				glog.Fatalf("fatal error: flush chainDb: %v (Restart your node. We are aware of this issue)\n", err)
 			}
 		case <-s.shutdownChan:
 			break done
 		}
 	}
 
-	s.blockDb.Close()
-	s.stateDb.Close()
-	s.extraDb.Close()
+	s.chainDb.Close()
+	s.dappDb.Close()
 
 	close(s.databasesClosed)
 }
@@ -683,14 +677,6 @@ func (self *Ethereum) StartAutoDAG() {
 	}()
 }
 
-// dagFiles(epoch) returns the two alternative DAG filenames (not a path)
-// 1) <revision>-<hex(seedhash[8])> 2) full-R<revision>-<hex(seedhash[8])>
-func dagFiles(epoch uint64) (string, string) {
-	seedHash, _ := ethash.GetSeedHash(epoch * epochLength)
-	dag := fmt.Sprintf("full-R%d-%x", ethashRevision, seedHash[:8])
-	return dag, "full-R" + dag
-}
-
 // stopAutoDAG stops automatic DAG pregeneration by quitting the loop
 func (self *Ethereum) StopAutoDAG() {
 	if self.autodagquit != nil {
@@ -700,20 +686,28 @@ func (self *Ethereum) StopAutoDAG() {
 	glog.V(logger.Info).Infof("Automatic pregeneration of ethash DAG OFF (ethash dir: %s)", ethash.DefaultDir)
 }
 
-/*
-	// The databases were previously tied to protocol versions. Currently we
-	// are moving away from this decision as approaching Frontier. The below
-	// code was left in for now but should eventually be just dropped.
+func (self *Ethereum) Solc() (*compiler.Solidity, error) {
+	var err error
+	if self.solc == nil {
+		self.solc, err = compiler.New(self.SolcPath)
+	}
+	return self.solc, err
+}
 
-	func saveProtocolVersion(db common.Database, protov int) {
-		d, _ := db.Get([]byte("ProtocolVersion"))
-		protocolVersion := common.NewValue(d).Uint()
+// set in js console via admin interface or wrapper from cli flags
+func (self *Ethereum) SetSolc(solcPath string) (*compiler.Solidity, error) {
+	self.SolcPath = solcPath
+	self.solc = nil
+	return self.Solc()
+}
 
-		if protocolVersion == 0 {
-			db.Put([]byte("ProtocolVersion"), common.NewValue(protov).Bytes())
-		}
-	}
-*/
+// dagFiles(epoch) returns the two alternative DAG filenames (not a path)
+// 1) <revision>-<hex(seedhash[8])> 2) full-R<revision>-<hex(seedhash[8])>
+func dagFiles(epoch uint64) (string, string) {
+	seedHash, _ := ethash.GetSeedHash(epoch * epochLength)
+	dag := fmt.Sprintf("full-R%d-%x", ethashRevision, seedHash[:8])
+	return dag, "full-R" + dag
+}
 
 func saveBlockchainVersion(db common.Database, bcVersion int) {
 	d, _ := db.Get([]byte("BlockchainVersion"))
@@ -724,17 +718,69 @@ func saveBlockchainVersion(db common.Database, bcVersion int) {
 	}
 }
 
-func (self *Ethereum) Solc() (*compiler.Solidity, error) {
-	var err error
-	if self.solc == nil {
-		self.solc, err = compiler.New(self.SolcPath)
+// mergeDatabases when required merge old database layout to one single database
+func mergeDatabases(datadir string, newdb func(path string) (common.Database, error)) error {
+	// Check if already upgraded
+	data := filepath.Join(datadir, "chaindata")
+	if _, err := os.Stat(data); !os.IsNotExist(err) {
+		return nil
 	}
-	return self.solc, err
-}
+	// make sure it's not just a clean path
+	chainPath := filepath.Join(datadir, "blockchain")
+	if _, err := os.Stat(chainPath); os.IsNotExist(err) {
+		return nil
+	}
+	glog.Infoln("Database upgrade required. Upgrading...")
 
-// set in js console via admin interface or wrapper from cli flags
-func (self *Ethereum) SetSolc(solcPath string) (*compiler.Solidity, error) {
-	self.SolcPath = solcPath
-	self.solc = nil
-	return self.Solc()
+	database, err := newdb(data)
+	if err != nil {
+		return fmt.Errorf("creating data db err: %v", err)
+	}
+	defer database.Close()
+
+	glog.Infoln("Merging blockchain database...")
+	chainDb, err := newdb(chainPath)
+	if err != nil {
+		return fmt.Errorf("state db err: %v", err)
+	}
+	defer chainDb.Close()
+
+	if db, ok := chainDb.(*ethdb.LDBDatabase); ok {
+		it := db.NewIterator()
+		for it.Next() {
+			database.Put(it.Key(), it.Value())
+		}
+	}
+
+	glog.Infoln("Merging state database...")
+	state := filepath.Join(datadir, "state")
+	stateDb, err := newdb(state)
+	if err != nil {
+		return fmt.Errorf("state db err: %v", err)
+	}
+	defer stateDb.Close()
+
+	if db, ok := chainDb.(*ethdb.LDBDatabase); ok {
+		it := db.NewIterator()
+		for it.Next() {
+			database.Put(append(trie.StatePre, it.Key()...), it.Value())
+		}
+	}
+
+	glog.Infoln("Merging transaction database...")
+	extra := filepath.Join(datadir, "extra")
+	extraDb, err := newdb(extra)
+	if err != nil {
+		return fmt.Errorf("state db err: %v", err)
+	}
+	defer extraDb.Close()
+
+	if db, ok := chainDb.(*ethdb.LDBDatabase); ok {
+		it := db.NewIterator()
+		for it.Next() {
+			database.Put(it.Key(), it.Value())
+		}
+	}
+
+	return nil
 }
diff --git a/eth/protocol_test.go b/eth/protocol_test.go
index a24d98f69..08c9b6a06 100644
--- a/eth/protocol_test.go
+++ b/eth/protocol_test.go
@@ -179,10 +179,10 @@ type testPeer struct {
 
 func newProtocolManagerForTesting(txAdded chan<- []*types.Transaction) *ProtocolManager {
 	db, _ := ethdb.NewMemDatabase()
-	core.WriteTestNetGenesisBlock(db, db, 0)
+	core.WriteTestNetGenesisBlock(db, 0)
 	var (
 		em       = new(event.TypeMux)
-		chain, _ = core.NewChainManager(db, db, db, core.FakePow{}, em)
+		chain, _ = core.NewChainManager(db, core.FakePow{}, em)
 		txpool   = &fakeTxPool{added: txAdded}
 		pm       = NewProtocolManager(NetworkId, em, txpool, core.FakePow{}, chain)
 	)
diff --git a/ethdb/database.go b/ethdb/database.go
index ace56c6c7..9e80e5409 100644
--- a/ethdb/database.go
+++ b/ethdb/database.go
@@ -39,9 +39,8 @@ var OpenFileLimit = 64
 // cacheRatio specifies how the total alloted cache is distributed between the
 // various system databases.
 var cacheRatio = map[string]float64{
-	"blockchain": 1.0 / 13.0,
-	"extra":      2.0 / 13.0,
-	"state":      10.0 / 13.0,
+	"dapp":      2.0 / 13.0,
+	"chaindata": 11.0 / 13.0,
 }
 
 type LDBDatabase struct {
diff --git a/miner/worker.go b/miner/worker.go
index 535ce5144..df3681470 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -100,7 +100,7 @@ type worker struct {
 	eth     core.Backend
 	chain   *core.ChainManager
 	proc    *core.BlockProcessor
-	extraDb common.Database
+	chainDb common.Database
 
 	coinbase common.Address
 	gasPrice *big.Int
@@ -126,7 +126,7 @@ func newWorker(coinbase common.Address, eth core.Backend) *worker {
 	worker := &worker{
 		eth:            eth,
 		mux:            eth.EventMux(),
-		extraDb:        eth.ExtraDb(),
+		chainDb:        eth.ChainDb(),
 		recv:           make(chan *Result, resultQueueSize),
 		gasPrice:       new(big.Int),
 		chain:          eth.ChainManager(),
@@ -291,9 +291,9 @@ func (self *worker) wait() {
 				// check if canon block and write transactions
 				if stat == core.CanonStatTy {
 					// This puts transactions in a extra db for rpc
-					core.PutTransactions(self.extraDb, block, block.Transactions())
+					core.PutTransactions(self.chainDb, block, block.Transactions())
 					// store the receipts
-					core.PutReceipts(self.extraDb, work.receipts)
+					core.PutReceipts(self.chainDb, work.receipts)
 				}
 
 				// broadcast before waiting for validation
@@ -344,7 +344,7 @@ func (self *worker) push(work *Work) {
 
 // makeCurrent creates a new environment for the current cycle.
 func (self *worker) makeCurrent(parent *types.Block, header *types.Header) {
-	state := state.New(parent.Root(), self.eth.StateDb())
+	state := state.New(parent.Root(), self.eth.ChainDb())
 	work := &Work{
 		state:     state,
 		ancestors: set.New(),
diff --git a/rpc/api/debug.go b/rpc/api/debug.go
index cdacd6c62..d325b1720 100644
--- a/rpc/api/debug.go
+++ b/rpc/api/debug.go
@@ -119,7 +119,7 @@ func (self *debugApi) DumpBlock(req *shared.Request) (interface{}, error) {
 		return nil, fmt.Errorf("block #%d not found", args.BlockNumber)
 	}
 
-	stateDb := state.New(block.Root(), self.ethereum.StateDb())
+	stateDb := state.New(block.Root(), self.ethereum.ChainDb())
 	if stateDb == nil {
 		return nil, nil
 	}
diff --git a/tests/block_test_util.go b/tests/block_test_util.go
index 42e4383d1..8cb7b7882 100644
--- a/tests/block_test_util.go
+++ b/tests/block_test_util.go
@@ -204,7 +204,7 @@ func (test *BlockTest) makeEthConfig() *eth.Config {
 // InsertPreState populates the given database with the genesis
 // accounts defined by the test.
 func (t *BlockTest) InsertPreState(ethereum *eth.Ethereum) (*state.StateDB, error) {
-	db := ethereum.StateDb()
+	db := ethereum.ChainDb()
 	statedb := state.New(common.Hash{}, db)
 	for addrString, acct := range t.preAccounts {
 		addr, err := hex.DecodeString(addrString)
diff --git a/trie/cache.go b/trie/cache.go
index 2705b0e45..99d8033a6 100644
--- a/trie/cache.go
+++ b/trie/cache.go
@@ -38,6 +38,8 @@ func NewCache(backend Backend) *Cache {
 }
 
 func (self *Cache) Get(key []byte) []byte {
+	key = append(StatePre, key...)
+
 	data := self.store[string(key)]
 	if data == nil {
 		data, _ = self.backend.Get(key)
@@ -47,8 +49,8 @@ func (self *Cache) Get(key []byte) []byte {
 }
 
 func (self *Cache) Put(key []byte, data []byte) {
-	// write the data to the ldb batch
-	//self.batch.Put(key, rle.Compress(data))
+	key = append(StatePre, key...)
+
 	self.batch.Put(key, data)
 	self.store[string(key)] = data
 }
diff --git a/trie/trie.go b/trie/trie.go
index abf48a850..2970bc185 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -27,6 +27,8 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
+var StatePre = []byte("state-")
+
 func ParanoiaCheck(t1 *Trie, backend Backend) (bool, *Trie) {
 	t2 := New(nil, backend)
 
diff --git a/xeth/state.go b/xeth/state.go
index 16bfb523d..981fe63b7 100644
--- a/xeth/state.go
+++ b/xeth/state.go
@@ -45,7 +45,7 @@ func (self *State) SafeGet(addr string) *Object {
 func (self *State) safeGet(addr string) *state.StateObject {
 	object := self.state.GetStateObject(common.HexToAddress(addr))
 	if object == nil {
-		object = state.NewStateObject(common.HexToAddress(addr), self.xeth.backend.StateDb())
+		object = state.NewStateObject(common.HexToAddress(addr), self.xeth.backend.ChainDb())
 	}
 
 	return object
diff --git a/xeth/xeth.go b/xeth/xeth.go
index 372068c14..b80b62155 100644
--- a/xeth/xeth.go
+++ b/xeth/xeth.go
@@ -213,9 +213,9 @@ func (self *XEth) AtStateNum(num int64) *XEth {
 		st = self.backend.Miner().PendingState().Copy()
 	default:
 		if block := self.getBlockByHeight(num); block != nil {
-			st = state.New(block.Root(), self.backend.StateDb())
+			st = state.New(block.Root(), self.backend.ChainDb())
 		} else {
-			st = state.New(self.backend.ChainManager().GetBlockByNumber(0).Root(), self.backend.StateDb())
+			st = state.New(self.backend.ChainManager().GetBlockByNumber(0).Root(), self.backend.ChainDb())
 		}
 	}
 
@@ -259,7 +259,7 @@ func (self *XEth) UpdateState() (wait chan *big.Int) {
 						wait <- n
 						n = nil
 					}
-					statedb := state.New(ev.Block.Root(), self.backend.StateDb())
+					statedb := state.New(ev.Block.Root(), self.backend.ChainDb())
 					self.state = NewState(self, statedb)
 				}
 			case n, ok = <-wait:
@@ -311,7 +311,7 @@ func (self *XEth) EthBlockByHash(strHash string) *types.Block {
 func (self *XEth) EthTransactionByHash(hash string) (tx *types.Transaction, blhash common.Hash, blnum *big.Int, txi uint64) {
 	// Due to increasing return params and need to determine if this is from transaction pool or
 	// some chain, this probably needs to be refactored for more expressiveness
-	data, _ := self.backend.ExtraDb().Get(common.FromHex(hash))
+	data, _ := self.backend.ChainDb().Get(common.FromHex(hash))
 	if len(data) != 0 {
 		dtx := new(types.Transaction)
 		if err := rlp.DecodeBytes(data, dtx); err != nil {
@@ -330,7 +330,7 @@ func (self *XEth) EthTransactionByHash(hash string) (tx *types.Transaction, blha
 		Index      uint64
 	}
 
-	v, dberr := self.backend.ExtraDb().Get(append(common.FromHex(hash), 0x0001))
+	v, dberr := self.backend.ChainDb().Get(append(common.FromHex(hash), 0x0001))
 	// TODO check specifically for ErrNotFound
 	if dberr != nil {
 		return
@@ -365,7 +365,7 @@ func (self *XEth) GetBlockReceipts(bhash common.Hash) types.Receipts {
 }
 
 func (self *XEth) GetTxReceipt(txhash common.Hash) *types.Receipt {
-	return core.GetReceipt(self.backend.ExtraDb(), txhash)
+	return core.GetReceipt(self.backend.ChainDb(), txhash)
 }
 
 func (self *XEth) GasLimit() *big.Int {
@@ -408,13 +408,13 @@ func (self *XEth) SetSolc(solcPath string) (*compiler.Solidity, error) {
 
 // store DApp value in extra database
 func (self *XEth) DbPut(key, val []byte) bool {
-	self.backend.ExtraDb().Put(append(dappStorePre, key...), val)
+	self.backend.DappDb().Put(append(dappStorePre, key...), val)
 	return true
 }
 
 // retrieve DApp value from extra database
 func (self *XEth) DbGet(key []byte) ([]byte, error) {
-	val, err := self.backend.ExtraDb().Get(append(dappStorePre, key...))
+	val, err := self.backend.DappDb().Get(append(dappStorePre, key...))
 	return val, err
 }