package core import ( "bytes" "fmt" "math/big" "sync" "time" "github.com/ethereum/go-ethereum/core/types" "github.com/ethereum/go-ethereum/ethutil" "github.com/ethereum/go-ethereum/event" "github.com/ethereum/go-ethereum/logger" "github.com/ethereum/go-ethereum/pow" "github.com/ethereum/go-ethereum/state" "gopkg.in/fatih/set.v0" ) type PendingBlockEvent struct { Block *types.Block } var statelogger = logger.NewLogger("BLOCK") type BlockProcessor struct { db ethutil.Database // 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.PoW txpool *TxPool // 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 *types.Block events event.Subscription eventMux *event.TypeMux } func NewBlockProcessor(db ethutil.Database, pow pow.PoW, txpool *TxPool, chainManager *ChainManager, eventMux *event.TypeMux) *BlockProcessor { sm := &BlockProcessor{ db: db, mem: make(map[string]*big.Int), Pow: pow, bc: chainManager, eventMux: eventMux, txpool: txpool, } return sm } func (sm *BlockProcessor) TransitionState(statedb *state.StateDB, parent, block *types.Block, transientProcess bool) (receipts types.Receipts, err error) { coinbase := statedb.GetOrNewStateObject(block.Header().Coinbase) coinbase.SetGasPool(block.Header().GasLimit) // Process the transactions on to parent state receipts, _, _, _, err = sm.ApplyTransactions(coinbase, statedb, block, block.Transactions(), transientProcess) if err != nil { return nil, err } return receipts, nil } func (self *BlockProcessor) ApplyTransaction(coinbase *state.StateObject, statedb *state.StateDB, block *types.Block, tx *types.Transaction, usedGas *big.Int, transientProcess bool) (*types.Receipt, *big.Int, error) { // If we are mining this block and validating we want to set the logs back to 0 statedb.EmptyLogs() txGas := new(big.Int).Set(tx.Gas()) cb := statedb.GetStateObject(coinbase.Address()) st := NewStateTransition(NewEnv(statedb, self.bc, tx, block), tx, cb) _, err := st.TransitionState() if err != nil && (IsNonceErr(err) || state.IsGasLimitErr(err)) { return nil, nil, err } txGas.Sub(txGas, st.gas) // Update the state with pending changes statedb.Update(txGas) cumulative := new(big.Int).Set(usedGas.Add(usedGas, txGas)) receipt := types.NewReceipt(statedb.Root(), cumulative) receipt.SetLogs(statedb.Logs()) receipt.Bloom = types.CreateBloom(types.Receipts{receipt}) chainlogger.Debugln(receipt) // Notify all subscribers if !transientProcess { go self.eventMux.Post(TxPostEvent{tx}) logs := statedb.Logs() go self.eventMux.Post(logs) } return receipt, txGas, err } func (self *BlockProcessor) ChainManager() *ChainManager { return self.bc } func (self *BlockProcessor) ApplyTransactions(coinbase *state.StateObject, statedb *state.StateDB, block *types.Block, txs types.Transactions, transientProcess bool) (types.Receipts, types.Transactions, types.Transactions, types.Transactions, error) { var ( receipts types.Receipts handled, unhandled types.Transactions erroneous types.Transactions totalUsedGas = big.NewInt(0) err error cumulativeSum = new(big.Int) ) for _, tx := range txs { receipt, txGas, err := self.ApplyTransaction(coinbase, statedb, block, tx, totalUsedGas, transientProcess) if err != nil { switch { case IsNonceErr(err): return nil, nil, nil, nil, err case state.IsGasLimitErr(err): return nil, nil, nil, nil, err default: statelogger.Infoln(err) erroneous = append(erroneous, tx) err = nil } } receipts = append(receipts, receipt) handled = append(handled, tx) cumulativeSum.Add(cumulativeSum, new(big.Int).Mul(txGas, tx.GasPrice())) } block.Reward = cumulativeSum block.Header().GasUsed = totalUsedGas if transientProcess { go self.eventMux.Post(PendingBlockEvent{block}) } return receipts, handled, unhandled, erroneous, err } // Process block will attempt to process the given block's transactions and applies them // on top of the block's parent state (given it exists) and will return wether it was // successful or not. func (sm *BlockProcessor) Process(block *types.Block) (td *big.Int, err error) { // Processing a blocks may never happen simultaneously sm.mutex.Lock() defer sm.mutex.Unlock() header := block.Header() if sm.bc.HasBlock(header.Hash()) { return nil, &KnownBlockError{header.Number, header.Hash()} } if !sm.bc.HasBlock(header.ParentHash) { return nil, ParentError(header.ParentHash) } parent := sm.bc.GetBlock(header.ParentHash) return sm.processWithParent(block, parent) } func (sm *BlockProcessor) processWithParent(block, parent *types.Block) (td *big.Int, err error) { sm.lastAttemptedBlock = block // Create a new state based on the parent's root (e.g., create copy) state := state.New(parent.Root(), sm.db) // Block validation if err = sm.ValidateHeader(block.Header(), parent.Header()); err != nil { return } // There can be at most two uncles if len(block.Uncles()) > 2 { return nil, ValidationError("Block can only contain one uncle (contained %v)", len(block.Uncles())) } receipts, err := sm.TransitionState(state, parent, block, false) if err != nil { return } header := block.Header() // Validate the received block's bloom with the one derived from the generated receipts. // For valid blocks this should always validate to true. rbloom := types.CreateBloom(receipts) if bytes.Compare(rbloom, header.Bloom) != 0 { err = fmt.Errorf("unable to replicate block's bloom=%x", rbloom) return } // The transactions Trie's root (R = (Tr [[H1, T1], [H2, T2], ... [Hn, Tn]])) // can be used by light clients to make sure they've received the correct Txs txSha := types.DeriveSha(block.Transactions()) if bytes.Compare(txSha, header.TxHash) != 0 { err = fmt.Errorf("validating transaction root. received=%x got=%x", header.TxHash, txSha) return } // Tre receipt Trie's root (R = (Tr [[H1, R1], ... [Hn, R1]])) receiptSha := types.DeriveSha(receipts) if bytes.Compare(receiptSha, header.ReceiptHash) != 0 { err = fmt.Errorf("validating receipt root. received=%x got=%x", header.ReceiptHash, receiptSha) return } // Accumulate static rewards; block reward, uncle's and uncle inclusion. if err = sm.AccumulateRewards(state, block, parent); err != nil { return } // Commit state objects/accounts to a temporary trie (does not save) // used to calculate the state root. state.Update(ethutil.Big0) if !bytes.Equal(header.Root, state.Root()) { err = fmt.Errorf("invalid merkle root. received=%x got=%x", header.Root, state.Root()) return } // Calculate the td for this block td = CalculateTD(block, parent) // Sync the current block's state to the database state.Sync() // Remove transactions from the pool sm.txpool.RemoveSet(block.Transactions()) chainlogger.Infof("processed block #%d (%x...)\n", header.Number, block.Hash()[0:4]) return td, nil } // 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 *BlockProcessor) ValidateHeader(block, parent *types.Header) error { if len(block.Extra) > 1024 { return fmt.Errorf("Block extra data too long (%d)", len(block.Extra)) } expd := CalcDifficulty(block, parent) if expd.Cmp(block.Difficulty) != 0 { return fmt.Errorf("Difficulty check failed for block %v, %v", block.Difficulty, expd) } // block.gasLimit - parent.gasLimit <= parent.gasLimit / 1024 a := new(big.Int).Sub(block.GasLimit, parent.GasLimit) b := new(big.Int).Div(parent.GasLimit, big.NewInt(1024)) if a.Cmp(b) > 0 { return fmt.Errorf("GasLimit check failed for block %v (%v > %v)", block.GasLimit, a, b) } if block.Time <= parent.Time { return ValidationError("Block timestamp equal or less than previous block (%v - %v)", block.Time, parent.Time) } if int64(block.Time) > time.Now().Unix() { return BlockFutureErr } if new(big.Int).Sub(block.Number, parent.Number).Cmp(big.NewInt(1)) != 0 { return BlockNumberErr } // Verify the nonce of the block. Return an error if it's not valid if !sm.Pow.Verify(types.NewBlockWithHeader(block)) { return ValidationError("Block's nonce is invalid (= %x)", block.Nonce) } return nil } func (sm *BlockProcessor) AccumulateRewards(statedb *state.StateDB, block, parent *types.Block) error { reward := new(big.Int).Set(BlockReward) ancestors := set.New() uncles := set.New() ancestorHeaders := make(map[string]*types.Header) for _, ancestor := range sm.bc.GetAncestors(block, 7) { hash := string(ancestor.Hash()) ancestorHeaders[hash] = ancestor.Header() ancestors.Add(hash) // Include ancestors uncles in the uncle set. Uncles must be unique. for _, uncle := range ancestor.Uncles() { uncles.Add(string(uncle.Hash())) } } uncles.Add(string(block.Hash())) for _, uncle := range block.Uncles() { if uncles.Has(string(uncle.Hash())) { // Error not unique return UncleError("Uncle not unique") } uncles.Add(string(uncle.Hash())) if ancestors.Has(string(uncle.Hash())) { return UncleError("Uncle is ancestor") } if !ancestors.Has(string(uncle.ParentHash)) { return UncleError(fmt.Sprintf("Uncle's parent unknown (%x)", uncle.ParentHash[0:4])) } if err := sm.ValidateHeader(uncle, ancestorHeaders[string(uncle.ParentHash)]); err != nil { return ValidationError(fmt.Sprintf("%v", err)) } if !sm.Pow.Verify(types.NewBlockWithHeader(uncle)) { return ValidationError("Uncle's nonce is invalid (= %x)", uncle.Nonce) } r := new(big.Int) r.Mul(BlockReward, big.NewInt(15)).Div(r, big.NewInt(16)) statedb.AddBalance(uncle.Coinbase, r) reward.Add(reward, new(big.Int).Div(BlockReward, big.NewInt(32))) } // Get the account associated with the coinbase statedb.AddBalance(block.Header().Coinbase, reward) return nil } func (sm *BlockProcessor) GetLogs(block *types.Block) (logs state.Logs, err error) { if !sm.bc.HasBlock(block.Header().ParentHash) { return nil, ParentError(block.Header().ParentHash) } sm.lastAttemptedBlock = block var ( parent = sm.bc.GetBlock(block.Header().ParentHash) state = state.New(parent.Root(), sm.db) ) sm.TransitionState(state, parent, block, true) sm.AccumulateRewards(state, block, parent) return state.Logs(), nil }