package ethchain
import (
"bytes"
"fmt"
"github.com/ethereum/eth-go/ethutil"
"github.com/ethereum/eth-go/ethwire"
"math/big"
"sync"
"time"
)
type BlockProcessor interface {
ProcessBlock(block *Block)
}
type EthManager interface {
StateManager() *StateManager
BlockChain() *BlockChain
TxPool() *TxPool
Broadcast(msgType ethwire.MsgType, data []interface{})
Reactor() *ethutil.ReactorEngine
}
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 *BlockChain
// States for addresses. You can watch any address
// at any given time
stateObjectCache *StateObjectCache
// Stack for processing contracts
stack *Stack
// non-persistent key/value memory storage
mem map[string]*big.Int
Pow PoW
Ethereum EthManager
SecondaryBlockProcessor BlockProcessor
// The managed states
// Processor state. Anything processed will be applied to this
// state
procState *State
// Comparative state it used for comparing and validating end
// results
compState *State
// It's generally know that a map is faster for small lookups than arrays
// we'll eventually have to make a decision if the map grows too large
watchedAddresses map[string]bool
}
func NewStateManager(ethereum EthManager) *StateManager {
sm := &StateManager{
stack: NewStack(),
mem: make(map[string]*big.Int),
Pow: &EasyPow{},
Ethereum: ethereum,
stateObjectCache: NewStateObjectCache(),
bc: ethereum.BlockChain(),
watchedAddresses: make(map[string]bool),
}
sm.procState = ethereum.BlockChain().CurrentBlock.State()
return sm
}
func (sm *StateManager) ProcState() *State {
return sm.procState
}
// Watches any given address and puts it in the address state store
func (sm *StateManager) WatchAddr(addr []byte) *CachedStateObject {
//XXX account := sm.bc.CurrentBlock.state.GetAccount(addr)
account := sm.procState.GetAccount(addr)
return sm.stateObjectCache.Add(addr, account)
}
func (sm *StateManager) GetAddrState(addr []byte) *CachedStateObject {
account := sm.stateObjectCache.Get(addr)
if account == nil {
a := sm.procState.GetAccount(addr)
account = &CachedStateObject{Nonce: a.Nonce, Object: a}
}
return account
}
func (sm *StateManager) BlockChain() *BlockChain {
return sm.bc
}
func (sm *StateManager) MakeContract(tx *Transaction) *StateObject {
contract := MakeContract(tx, sm.procState)
if contract != nil {
sm.procState.states[string(tx.Hash()[12:])] = contract.state
return contract
}
return nil
}
// Apply transactions uses the transaction passed to it and applies them onto
// the current processing state.
func (sm *StateManager) ApplyTransactions(block *Block, txs []*Transaction) {
// Process each transaction/contract
for _, tx := range txs {
fmt.Printf("Processing Tx: %x\n", tx.Hash())
// If there's no recipient, it's a contract
// Check if this is a contract creation traction and if so
// create a contract of this tx.
if tx.IsContract() {
err := sm.Ethereum.TxPool().ProcessTransaction(tx, block, false)
if err == nil {
contract := sm.MakeContract(tx)
if contract != nil {
sm.EvalScript(contract.Init(), contract, tx, block)
fmt.Printf("state root of contract %x\n", contract.State().Root())
} else {
ethutil.Config.Log.Infoln("[STATE] Unable to create contract")
}
} else {
ethutil.Config.Log.Infoln("[STATE] contract create:", err)
}
} else {
err := sm.Ethereum.TxPool().ProcessTransaction(tx, block, false)
contract := sm.procState.GetContract(tx.Recipient)
if err == nil && len(contract.Script()) > 0 {
sm.EvalScript(contract.Script(), contract, tx, block)
} else if err != nil {
ethutil.Config.Log.Infoln("[STATE] process:", err)
}
}
}
}
// The prepare function, prepares the state manager for the next
// "ProcessBlock" action.
func (sm *StateManager) Prepare(processor *State, comparative *State) {
sm.compState = comparative
sm.procState = processor
}
// Default prepare function
func (sm *StateManager) PrepareDefault(block *Block) {
sm.Prepare(sm.BlockChain().CurrentBlock.State(), block.State())
}
// Block processing and validating with a given (temporarily) state
func (sm *StateManager) ProcessBlock(block *Block, dontReact bool) error {
// Processing a blocks may never happen simultaneously
sm.mutex.Lock()
defer sm.mutex.Unlock()
// 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 sm.bc.CurrentBlock.Undo()
hash := block.Hash()
if sm.bc.HasBlock(hash) {
fmt.Println("[SM] We already have this block, ignoring")
return nil
}
// Check if we have the parent hash, if it isn't known we discard it
// Reasons might be catching up or simply an invalid block
if !sm.bc.HasBlock(block.PrevHash) && sm.bc.CurrentBlock != nil {
return ParentError(block.PrevHash)
}
// Process the transactions on to current block
sm.ApplyTransactions(sm.bc.CurrentBlock, block.Transactions())
// Block validation
if err := sm.ValidateBlock(block); err != nil {
fmt.Println("[SM] Error validating block:", err)
return err
}
// I'm not sure, but I don't know if there should be thrown
// any errors at this time.
if err := sm.AccumelateRewards(block); err != nil {
fmt.Println("[SM] Error accumulating reward", err)
return err
}
if !sm.compState.Cmp(sm.procState) {
return fmt.Errorf("Invalid merkle root. Expected %x, got %x", sm.compState.trie.Root, sm.procState.trie.Root)
}
// 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
sm.procState.Sync()
// Add the block to the chain
sm.bc.Add(block)
// If there's a block processor present, pass in the block for further
// processing
if sm.SecondaryBlockProcessor != nil {
sm.SecondaryBlockProcessor.ProcessBlock(block)
}
ethutil.Config.Log.Infof("[STATE] Added block #%d (%x)\n", block.BlockInfo().Number, block.Hash())
if dontReact == false {
sm.Ethereum.Reactor().Post("newBlock", block)
}
} else {
fmt.Println("total diff failed")
}
return 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 {
// TODO
// 2. Check if the difficulty is correct
// Check each uncle's previous hash. In order for it to be valid
// is if it has the same block hash as the current
previousBlock := sm.bc.GetBlock(block.PrevHash)
for _, uncle := range block.Uncles {
if bytes.Compare(uncle.PrevHash, previousBlock.PrevHash) != 0 {
return ValidationError("Mismatch uncle's previous hash. Expected %x, got %x", previousBlock.PrevHash, uncle.PrevHash)
}
}
diff := block.Time - sm.bc.CurrentBlock.Time
if diff < 0 {
return ValidationError("Block timestamp less then prev block %v", diff)
}
// 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.Hex(block.Nonce))
}
return nil
}
func CalculateBlockReward(block *Block, uncleLength int) *big.Int {
base := new(big.Int)
for i := 0; i < uncleLength; i++ {
base.Add(base, UncleInclusionReward)
}
return base.Add(base, BlockReward)
}
func CalculateUncleReward(block *Block) *big.Int {
return UncleReward
}
func (sm *StateManager) AccumelateRewards(block *Block) error {
// Get the account associated with the coinbase
account := sm.procState.GetAccount(block.Coinbase)
// Reward amount of ether to the coinbase address
account.AddAmount(CalculateBlockReward(block, len(block.Uncles)))
addr := make([]byte, len(block.Coinbase))
copy(addr, block.Coinbase)
sm.procState.UpdateStateObject(account)
for _, uncle := range block.Uncles {
uncleAccount := sm.procState.GetAccount(uncle.Coinbase)
uncleAccount.AddAmount(CalculateUncleReward(uncle))
sm.procState.UpdateStateObject(uncleAccount)
}
return nil
}
func (sm *StateManager) Stop() {
sm.bc.Stop()
}
func (sm *StateManager) EvalScript(script []byte, object *StateObject, tx *Transaction, block *Block) {
caller := sm.procState.GetAccount(tx.Sender())
closure := NewClosure(caller, object, script, sm.procState, tx.Gas, tx.GasPrice, tx.Value)
vm := NewVm(sm.procState, sm, RuntimeVars{
Origin: caller.Address(),
BlockNumber: block.BlockInfo().Number,
PrevHash: block.PrevHash,
Coinbase: block.Coinbase,
Time: block.Time,
Diff: block.Difficulty,
//Price: tx.GasPrice,
})
closure.Call(vm, tx.Data, nil)
// Update the account (refunds)
sm.procState.UpdateStateObject(caller)
sm.Changed(caller)
sm.procState.UpdateStateObject(object)
sm.Changed(object)
}
// Watch a specific address
func (sm *StateManager) Watch(addr []byte) {
if !sm.watchedAddresses[string(addr)] {
sm.watchedAddresses[string(addr)] = true
}
}
// The following objects are used when changing a value and using the "watched" attribute
// to determine whether the reactor should be used to notify any subscribers on the address
func (sm *StateManager) Changed(stateObject *StateObject) {
if sm.watchedAddresses[string(stateObject.Address())] {
sm.Ethereum.Reactor().Post("addressChanged", stateObject)
}
}
