// Copyright 2014 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 core
import (
"fmt"
"math/big"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/pow"
"gopkg.in/fatih/set.v0"
)
const (
// must be bumped when consensus algorithm is changed, this forces the upgradedb
// command to be run (forces the blocks to be imported again using the new algorithm)
BlockChainVersion = 3
)
type BlockProcessor struct {
chainDb ethdb.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
events event.Subscription
eventMux *event.TypeMux
}
// TODO: type GasPool big.Int
//
// GasPool is implemented by state.StateObject. This is a historical
// coincidence. Gas tracking should move out of StateObject.
// GasPool tracks the amount of gas available during
// execution of the transactions in a block.
type GasPool interface {
AddGas(gas, price *big.Int)
SubGas(gas, price *big.Int) error
}
func NewBlockProcessor(db ethdb.Database, pow pow.PoW, chainManager *ChainManager, eventMux *event.TypeMux) *BlockProcessor {
sm := &BlockProcessor{
chainDb: db,
mem: make(map[string]*big.Int),
Pow: pow,
bc: chainManager,
eventMux: eventMux,
}
return sm
}
func (sm *BlockProcessor) TransitionState(statedb *state.StateDB, parent, block *types.Block, transientProcess bool) (receipts types.Receipts, err error) {
gp := statedb.GetOrNewStateObject(block.Coinbase())
gp.SetGasLimit(block.GasLimit())
// Process the transactions on to parent state
receipts, err = sm.ApplyTransactions(gp, statedb, block, block.Transactions(), transientProcess)
if err != nil {
return nil, err
}
return receipts, nil
}
func (self *BlockProcessor) ApplyTransaction(gp GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *big.Int, transientProcess bool) (*types.Receipt, *big.Int, error) {
_, gas, err := ApplyMessage(NewEnv(statedb, self.bc, tx, header), tx, gp)
if err != nil {
return nil, nil, err
}
// Update the state with pending changes
statedb.SyncIntermediate()
usedGas.Add(usedGas, gas)
receipt := types.NewReceipt(statedb.Root().Bytes(), usedGas)
receipt.TxHash = tx.Hash()
receipt.GasUsed = new(big.Int).Set(gas)
if MessageCreatesContract(tx) {
from, _ := tx.From()
receipt.ContractAddress = crypto.CreateAddress(from, tx.Nonce())
}
logs := statedb.GetLogs(tx.Hash())
receipt.SetLogs(logs)
receipt.Bloom = types.CreateBloom(types.Receipts{receipt})
glog.V(logger.Debug).Infoln(receipt)
// Notify all subscribers
if !transientProcess {
go self.eventMux.Post(TxPostEvent{tx})
go self.eventMux.Post(logs)
}
return receipt, gas, err
}
func (self *BlockProcessor) ChainManager() *ChainManager {
return self.bc
}
func (self *BlockProcessor) ApplyTransactions(gp GasPool, statedb *state.StateDB, block *types.Block, txs types.Transactions, transientProcess bool) (types.Receipts, error) {
var (
receipts types.Receipts
totalUsedGas = big.NewInt(0)
err error
cumulativeSum = new(big.Int)
header = block.Header()
)
for i, tx := range txs {
statedb.StartRecord(tx.Hash(), block.Hash(), i)
receipt, txGas, err := self.ApplyTransaction(gp, statedb, header, tx, totalUsedGas, transientProcess)
if err != nil {
return nil, err
}
if err != nil {
glog.V(logger.Core).Infoln("TX err:", err)
}
receipts = append(receipts, receipt)
cumulativeSum.Add(cumulativeSum, new(big.Int).Mul(txGas, tx.GasPrice()))
}
if block.GasUsed().Cmp(totalUsedGas) != 0 {
return nil, ValidationError(fmt.Sprintf("gas used error (%v / %v)", block.GasUsed(), totalUsedGas))
}
if transientProcess {
go self.eventMux.Post(PendingBlockEvent{block, statedb.Logs()})
}
return receipts, err
}
func (sm *BlockProcessor) RetryProcess(block *types.Block) (logs state.Logs, err error) {
// Processing a blocks may never happen simultaneously
sm.mutex.Lock()
defer sm.mutex.Unlock()
if !sm.bc.HasBlock(block.ParentHash()) {
return nil, ParentError(block.ParentHash())
}
parent := sm.bc.GetBlock(block.ParentHash())
// FIXME Change to full header validation. See #1225
errch := make(chan bool)
go func() { errch <- sm.Pow.Verify(block) }()
logs, _, err = sm.processWithParent(block, parent)
if !<-errch {
return nil, ValidationError("Block's nonce is invalid (= %x)", block.Nonce)
}
return logs, 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) (logs state.Logs, receipts types.Receipts, err error) {
// Processing a blocks may never happen simultaneously
sm.mutex.Lock()
defer sm.mutex.Unlock()
if sm.bc.HasBlock(block.Hash()) {
return nil, nil, &KnownBlockError{block.Number(), block.Hash()}
}
if !sm.bc.HasBlock(block.ParentHash()) {
return nil, nil, ParentError(block.ParentHash())
}
parent := sm.bc.GetBlock(block.ParentHash())
return sm.processWithParent(block, parent)
}
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.chainDb)
header := block.Header()
uncles := block.Uncles()
txs := block.Transactions()
// Block validation
if err = ValidateHeader(sm.Pow, header, parent, false, false); err != nil {
return
}
// There can be at most two uncles
if len(uncles) > 2 {
return nil, nil, ValidationError("Block can only contain maximum 2 uncles (contained %v)", len(uncles))
}
receipts, err = sm.TransitionState(state, parent, block, false)
if err != nil {
return
}
// 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 rbloom != header.Bloom {
err = fmt.Errorf("unable to replicate block's bloom=%x", rbloom)
return
}
// The transactions Trie's root (R = (Tr [[i, RLP(T1)], [i, RLP(T2)], ... [n, RLP(Tn)]]))
// can be used by light clients to make sure they've received the correct Txs
txSha := types.DeriveSha(txs)
if txSha != header.TxHash {
err = fmt.Errorf("invalid transaction root hash. received=%x calculated=%x", header.TxHash, txSha)
return
}
// Tre receipt Trie's root (R = (Tr [[H1, R1], ... [Hn, R1]]))
receiptSha := types.DeriveSha(receipts)
if receiptSha != header.ReceiptHash {
err = fmt.Errorf("invalid receipt root hash. received=%x calculated=%x", header.ReceiptHash, receiptSha)
return
}
// Verify UncleHash before running other uncle validations
unclesSha := types.CalcUncleHash(uncles)
if unclesSha != header.UncleHash {
err = fmt.Errorf("invalid uncles root hash. received=%x calculated=%x", header.UncleHash, unclesSha)
return
}
// Verify uncles
if err = sm.VerifyUncles(state, block, parent); err != nil {
return
}
// Accumulate static rewards; block reward, uncle's and uncle inclusion.
AccumulateRewards(state, header, uncles)
// Commit state objects/accounts to a temporary trie (does not save)
// used to calculate the state root.
state.SyncObjects()
if header.Root != state.Root() {
err = fmt.Errorf("invalid merkle root. received=%x got=%x", header.Root, state.Root())
return
}
// Sync the current block's state to the database
state.Sync()
return state.Logs(), receipts, nil
}
var (
big8 = big.NewInt(8)
big32 = big.NewInt(32)
)
// AccumulateRewards credits the coinbase of the given block with the
// mining reward. The total reward consists of the static block reward
// and rewards for included uncles. The coinbase of each uncle block is
// also rewarded.
func AccumulateRewards(statedb *state.StateDB, header *types.Header, uncles []*types.Header) {
reward := new(big.Int).Set(BlockReward)
r := new(big.Int)
for _, uncle := range uncles {
r.Add(uncle.Number, big8)
r.Sub(r, header.Number)
r.Mul(r, BlockReward)
r.Div(r, big8)
statedb.AddBalance(uncle.Coinbase, r)
r.Div(BlockReward, big32)
reward.Add(reward, r)
}
statedb.AddBalance(header.Coinbase, reward)
}
func (sm *BlockProcessor) VerifyUncles(statedb *state.StateDB, block, parent *types.Block) error {
uncles := set.New()
ancestors := make(map[common.Hash]*types.Block)
for _, ancestor := range sm.bc.GetBlocksFromHash(block.ParentHash(), 7) {
ancestors[ancestor.Hash()] = ancestor
// Include ancestors uncles in the uncle set. Uncles must be unique.
for _, uncle := range ancestor.Uncles() {
uncles.Add(uncle.Hash())
}
}
ancestors[block.Hash()] = block
uncles.Add(block.Hash())
for i, uncle := range block.Uncles() {
hash := uncle.Hash()
if uncles.Has(hash) {
// Error not unique
return UncleError("uncle[%d](%x) not unique", i, hash[:4])
}
uncles.Add(hash)
if ancestors[hash] != nil {
branch := fmt.Sprintf(" O - %x\n |\n", block.Hash())
for h := range ancestors {
branch += fmt.Sprintf(" O - %x\n |\n", h)
}
glog.Infoln(branch)
return UncleError("uncle[%d](%x) is ancestor", i, hash[:4])
}
if ancestors[uncle.ParentHash] == nil || uncle.ParentHash == parent.Hash() {
return UncleError("uncle[%d](%x)'s parent is not ancestor (%x)", i, hash[:4], uncle.ParentHash[0:4])
}
if err := ValidateHeader(sm.Pow, uncle, ancestors[uncle.ParentHash], true, true); err != nil {
return ValidationError(fmt.Sprintf("uncle[%d](%x) header invalid: %v", i, hash[:4], err))
}
}
return nil
}
// 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.chainDb, block.Hash())
}
return nil
}
// GetLogs returns the logs of the given block. This method is using a two step approach
// 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.chainDb, block.Hash())
// coalesce logs
for _, receipt := range receipts {
logs = append(logs, receipt.Logs()...)
}
return logs, nil
}
// See YP section 4.3.4. "Block Header Validity"
// Validates a block. Returns an error if the block is invalid.
func ValidateHeader(pow pow.PoW, block *types.Header, parent *types.Block, checkPow, uncle bool) error {
if big.NewInt(int64(len(block.Extra))).Cmp(params.MaximumExtraDataSize) == 1 {
return fmt.Errorf("Block extra data too long (%d)", len(block.Extra))
}
if uncle {
if block.Time.Cmp(common.MaxBig) == 1 {
return BlockTSTooBigErr
}
} else {
if block.Time.Cmp(big.NewInt(time.Now().Unix())) == 1 {
return BlockFutureErr
}
}
if block.Time.Cmp(parent.Time()) != 1 {
return BlockEqualTSErr
}
expd := CalcDifficulty(block.Time.Uint64(), parent.Time().Uint64(), parent.Number(), parent.Difficulty())
if expd.Cmp(block.Difficulty) != 0 {
return fmt.Errorf("Difficulty check failed for block %v, %v", block.Difficulty, expd)
}
var a, b *big.Int
a = parent.GasLimit()
a = a.Sub(a, block.GasLimit)
a.Abs(a)
b = parent.GasLimit()
b = b.Div(b, params.GasLimitBoundDivisor)
if !(a.Cmp(b) < 0) || (block.GasLimit.Cmp(params.MinGasLimit) == -1) {
return fmt.Errorf("GasLimit check failed for block %v (%v > %v)", block.GasLimit, a, b)
}
num := parent.Number()
num.Sub(block.Number, num)
if num.Cmp(big.NewInt(1)) != 0 {
return BlockNumberErr
}
if checkPow {
// Verify the nonce of the block. Return an error if it's not valid
if !pow.Verify(types.NewBlockWithHeader(block)) {
return ValidationError("Block's nonce is invalid (= %x)", block.Nonce)
}
}
return nil
}