1 files changed, 446 insertions, 0 deletions
diff --git a/ethchain/state_manager.go b/ethchain/state_manager.go
new file mode 100644
index 000000000..1de46b371
--- /dev/null
+++ b/ethchain/state_manager.go
@@ -0,0 +1,446 @@
+package ethchain
+
+import (
+	"bytes"
+	"container/list"
+	"fmt"
+	"math/big"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/ethcrypto"
+	"github.com/ethereum/go-ethereum/ethlog"
+	"github.com/ethereum/go-ethereum/ethstate"
+	"github.com/ethereum/go-ethereum/ethutil"
+	"github.com/ethereum/go-ethereum/ethwire"
+	"github.com/ethereum/go-ethereum/event"
+)
+
+var statelogger = ethlog.NewLogger("STATE")
+
+type Peer interface {
+	Inbound() bool
+	LastSend() time.Time
+	LastPong() int64
+	Host() []byte
+	Port() uint16
+	Version() string
+	PingTime() string
+	Connected() *int32
+	Caps() *ethutil.Value
+}
+
+type EthManager interface {
+	StateManager() *StateManager
+	ChainManager() *ChainManager
+	TxPool() *TxPool
+	Broadcast(msgType ethwire.MsgType, data []interface{})
+	PeerCount() int
+	IsMining() bool
+	IsListening() bool
+	Peers() *list.List
+	KeyManager() *ethcrypto.KeyManager
+	ClientIdentity() ethwire.ClientIdentity
+	Db() ethutil.Database
+	EventMux() *event.TypeMux
+}
+
+type StateManager struct {
+	// Mutex for locking the block processor. Blocks can only be handled one at a time
+	mutex sync.Mutex
+	// Canonical block chain
+	bc *ChainManager
+	// non-persistent key/value memory storage
+	mem map[string]*big.Int
+	// Proof of work used for validating
+	Pow PoW
+	// The ethereum manager interface
+	eth EthManager
+	// The managed states
+	// Transiently state. The trans state isn't ever saved, validated and
+	// it could be used for setting account nonces without effecting
+	// the main states.
+	transState *ethstate.State
+	// Mining state. The mining state is used purely and solely by the mining
+	// operation.
+	miningState *ethstate.State
+
+	// The last attempted block is mainly used for debugging purposes
+	// This does not have to be a valid block and will be set during
+	// 'Process' & canonical validation.
+	lastAttemptedBlock *Block
+
+	events event.Subscription
+}
+
+func NewStateManager(ethereum EthManager) *StateManager {
+	sm := &StateManager{
+		mem: make(map[string]*big.Int),
+		Pow: &EasyPow{},
+		eth: ethereum,
+		bc:  ethereum.ChainManager(),
+	}
+	sm.transState = ethereum.ChainManager().CurrentBlock.State().Copy()
+	sm.miningState = ethereum.ChainManager().CurrentBlock.State().Copy()
+
+	return sm
+}
+
+func (self *StateManager) Start() {
+	statelogger.Debugln("Starting state manager")
+	self.events = self.eth.EventMux().Subscribe(Blocks(nil))
+	go self.updateThread()
+}
+
+func (self *StateManager) Stop() {
+	statelogger.Debugln("Stopping state manager")
+	self.events.Unsubscribe()
+}
+
+func (self *StateManager) updateThread() {
+	for ev := range self.events.Chan() {
+		for _, block := range ev.(Blocks) {
+			err := self.Process(block, false)
+			if err != nil {
+				statelogger.Infoln(err)
+				statelogger.Debugf("Block #%v failed (%x...)\n", block.Number, block.Hash()[0:4])
+				statelogger.Debugln(block)
+				break
+			}
+		}
+	}
+}
+
+func (sm *StateManager) CurrentState() *ethstate.State {
+	return sm.eth.ChainManager().CurrentBlock.State()
+}
+
+func (sm *StateManager) TransState() *ethstate.State {
+	return sm.transState
+}
+
+func (sm *StateManager) MiningState() *ethstate.State {
+	return sm.miningState
+}
+
+func (sm *StateManager) NewMiningState() *ethstate.State {
+	sm.miningState = sm.eth.ChainManager().CurrentBlock.State().Copy()
+
+	return sm.miningState
+}
+
+func (sm *StateManager) ChainManager() *ChainManager {
+	return sm.bc
+}
+
+func (self *StateManager) ProcessTransactions(coinbase *ethstate.StateObject, state *ethstate.State, block, parent *Block, txs Transactions) (Receipts, Transactions, Transactions, error) {
+	var (
+		receipts           Receipts
+		handled, unhandled Transactions
+		totalUsedGas       = big.NewInt(0)
+		err                error
+	)
+
+done:
+	for i, tx := range txs {
+		txGas := new(big.Int).Set(tx.Gas)
+
+		cb := state.GetStateObject(coinbase.Address())
+		st := NewStateTransition(cb, tx, state, block)
+		err = st.TransitionState()
+		if err != nil {
+			statelogger.Infoln(err)
+			switch {
+			case IsNonceErr(err):
+				err = nil // ignore error
+				continue
+			case IsGasLimitErr(err):
+				unhandled = txs[i:]
+
+				break done
+			default:
+				statelogger.Infoln(err)
+				err = nil
+				//return nil, nil, nil, err
+			}
+		}
+
+		// Update the state with pending changes
+		state.Update()
+
+		txGas.Sub(txGas, st.gas)
+		accumelative := new(big.Int).Set(totalUsedGas.Add(totalUsedGas, txGas))
+		receipt := &Receipt{tx, ethutil.CopyBytes(state.Root().([]byte)), accumelative}
+
+		if i < len(block.Receipts()) {
+			original := block.Receipts()[i]
+			if !original.Cmp(receipt) {
+				if ethutil.Config.Diff {
+					os.Exit(1)
+				}
+
+				err := fmt.Errorf("#%d receipt failed (r) %v ~ %x  <=>  (c) %v ~ %x (%x...)", i+1, original.CumulativeGasUsed, original.PostState[0:4], receipt.CumulativeGasUsed, receipt.PostState[0:4], receipt.Tx.Hash()[0:4])
+
+				return nil, nil, nil, err
+			}
+		}
+
+		// Notify all subscribers
+		self.eth.EventMux().Post(TxEvent{TxPost, tx})
+
+		receipts = append(receipts, receipt)
+		handled = append(handled, tx)
+
+		if ethutil.Config.Diff && ethutil.Config.DiffType == "all" {
+			state.CreateOutputForDiff()
+		}
+	}
+
+	parent.GasUsed = totalUsedGas
+
+	return receipts, handled, unhandled, err
+}
+
+func (sm *StateManager) Process(block *Block, dontReact bool) (err error) {
+	// Processing a blocks may never happen simultaneously
+	sm.mutex.Lock()
+	defer sm.mutex.Unlock()
+
+	if sm.bc.HasBlock(block.Hash()) {
+		return nil
+	}
+
+	if !sm.bc.HasBlock(block.PrevHash) {
+		return ParentError(block.PrevHash)
+	}
+
+	sm.lastAttemptedBlock = block
+
+	var (
+		parent = sm.bc.GetBlock(block.PrevHash)
+		state  = parent.State()
+	)
+
+	// Defer the Undo on the Trie. If the block processing happened
+	// we don't want to undo but since undo only happens on dirty
+	// nodes this won't happen because Commit would have been called
+	// before that.
+	defer state.Reset()
+
+	if ethutil.Config.Diff && ethutil.Config.DiffType == "all" {
+		fmt.Printf("## %x %x ##\n", block.Hash(), block.Number)
+	}
+
+	receipts, err := sm.ApplyDiff(state, parent, block)
+	if err != nil {
+		return err
+	}
+
+	txSha := CreateTxSha(receipts)
+	if bytes.Compare(txSha, block.TxSha) != 0 {
+		return fmt.Errorf("Error validating tx sha. Received %x, got %x", block.TxSha, txSha)
+	}
+
+	// Block validation
+	if err = sm.ValidateBlock(block); err != nil {
+		statelogger.Errorln("Error validating block:", err)
+		return err
+	}
+
+	if err = sm.AccumelateRewards(state, block, parent); err != nil {
+		statelogger.Errorln("Error accumulating reward", err)
+		return err
+	}
+
+	state.Update()
+
+	if !block.State().Cmp(state) {
+		err = fmt.Errorf("Invalid merkle root.\nrec: %x\nis:  %x", block.State().Trie.Root, state.Trie.Root)
+		return
+	}
+
+	// Calculate the new total difficulty and sync back to the db
+	if sm.CalculateTD(block) {
+		// Sync the current block's state to the database and cancelling out the deferred Undo
+		state.Sync()
+
+		// Add the block to the chain
+		sm.bc.Add(block)
+
+		sm.transState = state.Copy()
+
+		// Create a bloom bin for this block
+		filter := sm.createBloomFilter(state)
+		// Persist the data
+		fk := append([]byte("bloom"), block.Hash()...)
+		sm.eth.Db().Put(fk, filter.Bin())
+
+		statelogger.Infof("Imported block #%d (%x...)\n", block.Number, block.Hash()[0:4])
+		if dontReact == false {
+			sm.eth.EventMux().Post(NewBlockEvent{block})
+
+			state.Manifest().Reset()
+		}
+
+		sm.eth.TxPool().RemoveInvalid(state)
+	} else {
+		statelogger.Errorln("total diff failed")
+	}
+
+	return nil
+}
+
+func (sm *StateManager) ApplyDiff(state *ethstate.State, parent, block *Block) (receipts Receipts, err error) {
+	coinbase := state.GetOrNewStateObject(block.Coinbase)
+	coinbase.SetGasPool(block.CalcGasLimit(parent))
+
+	// Process the transactions on to current block
+	receipts, _, _, err = sm.ProcessTransactions(coinbase, state, block, parent, block.Transactions())
+	if err != nil {
+		return nil, err
+	}
+
+	return receipts, nil
+}
+
+func (sm *StateManager) CalculateTD(block *Block) bool {
+	uncleDiff := new(big.Int)
+	for _, uncle := range block.Uncles {
+		uncleDiff = uncleDiff.Add(uncleDiff, uncle.Difficulty)
+	}
+
+	// TD(genesis_block) = 0 and TD(B) = TD(B.parent) + sum(u.difficulty for u in B.uncles) + B.difficulty
+	td := new(big.Int)
+	td = td.Add(sm.bc.TD, uncleDiff)
+	td = td.Add(td, block.Difficulty)
+
+	// The new TD will only be accepted if the new difficulty is
+	// is greater than the previous.
+	if td.Cmp(sm.bc.TD) > 0 {
+		// Set the new total difficulty back to the block chain
+		sm.bc.SetTotalDifficulty(td)
+
+		return true
+	}
+
+	return false
+}
+
+// Validates the current block. Returns an error if the block was invalid,
+// an uncle or anything that isn't on the current block chain.
+// Validation validates easy over difficult (dagger takes longer time = difficult)
+func (sm *StateManager) ValidateBlock(block *Block) error {
+	// Check each uncle's previous hash. In order for it to be valid
+	// is if it has the same block hash as the current
+	parent := sm.bc.GetBlock(block.PrevHash)
+	/*
+		for _, uncle := range block.Uncles {
+			if bytes.Compare(uncle.PrevHash,parent.PrevHash) != 0 {
+				return ValidationError("Mismatch uncle's previous hash. Expected %x, got %x",parent.PrevHash, uncle.PrevHash)
+			}
+		}
+	*/
+
+	expd := CalcDifficulty(block, parent)
+	if expd.Cmp(block.Difficulty) < 0 {
+		return fmt.Errorf("Difficulty check failed for block %v, %v", block.Difficulty, expd)
+	}
+
+	diff := block.Time - parent.Time
+	if diff < 0 {
+		return ValidationError("Block timestamp less then prev block %v (%v - %v)", diff, block.Time, sm.bc.CurrentBlock.Time)
+	}
+
+	/* XXX
+	// New blocks must be within the 15 minute range of the last block.
+	if diff > int64(15*time.Minute) {
+		return ValidationError("Block is too far in the future of last block (> 15 minutes)")
+	}
+	*/
+
+	// Verify the nonce of the block. Return an error if it's not valid
+	if !sm.Pow.Verify(block.HashNoNonce(), block.Difficulty, block.Nonce) {
+		return ValidationError("Block's nonce is invalid (= %v)", ethutil.Bytes2Hex(block.Nonce))
+	}
+
+	return nil
+}
+
+func (sm *StateManager) AccumelateRewards(state *ethstate.State, block, parent *Block) error {
+	reward := new(big.Int).Set(BlockReward)
+
+	knownUncles := ethutil.Set(parent.Uncles)
+	nonces := ethutil.NewSet(block.Nonce)
+	for _, uncle := range block.Uncles {
+		if nonces.Include(uncle.Nonce) {
+			// Error not unique
+			return UncleError("Uncle not unique")
+		}
+
+		uncleParent := sm.bc.GetBlock(uncle.PrevHash)
+		if uncleParent == nil {
+			return UncleError("Uncle's parent unknown")
+		}
+
+		if uncleParent.Number.Cmp(new(big.Int).Sub(parent.Number, big.NewInt(6))) < 0 {
+			return UncleError("Uncle too old")
+		}
+
+		if knownUncles.Include(uncle.Hash()) {
+			return UncleError("Uncle in chain")
+		}
+
+		nonces.Insert(uncle.Nonce)
+
+		r := new(big.Int)
+		r.Mul(BlockReward, big.NewInt(15)).Div(r, big.NewInt(16))
+
+		uncleAccount := state.GetAccount(uncle.Coinbase)
+		uncleAccount.AddAmount(r)
+
+		reward.Add(reward, new(big.Int).Div(BlockReward, big.NewInt(32)))
+	}
+
+	// Get the account associated with the coinbase
+	account := state.GetAccount(block.Coinbase)
+	// Reward amount of ether to the coinbase address
+	account.AddAmount(reward)
+
+	return nil
+}
+
+// Manifest will handle both creating notifications and generating bloom bin data
+func (sm *StateManager) createBloomFilter(state *ethstate.State) *BloomFilter {
+	bloomf := NewBloomFilter(nil)
+
+	for _, msg := range state.Manifest().Messages {
+		bloomf.Set(msg.To)
+		bloomf.Set(msg.From)
+	}
+
+	sm.eth.EventMux().Post(state.Manifest().Messages)
+
+	return bloomf
+}
+
+func (sm *StateManager) GetMessages(block *Block) (messages []*ethstate.Message, err error) {
+	if !sm.bc.HasBlock(block.PrevHash) {
+		return nil, ParentError(block.PrevHash)
+	}
+
+	sm.lastAttemptedBlock = block
+
+	var (
+		parent = sm.bc.GetBlock(block.PrevHash)
+		state  = parent.State().Copy()
+	)
+
+	defer state.Reset()
+
+	sm.ApplyDiff(state, parent, block)
+
+	sm.AccumelateRewards(state, block, parent)
+
+	return state.Manifest().Messages, nil
+}