package core import ( "bytes" "fmt" "math/big" "sync" "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/rlp" "github.com/ethereum/go-ethereum/state" ) var chainlogger = logger.NewLogger("CHAIN") type ChainEvent struct { Block *types.Block Td *big.Int } type StateQuery interface { GetAccount(addr []byte) *state.StateObject } func CalcDifficulty(block, parent *types.Block) *big.Int { diff := new(big.Int) adjust := new(big.Int).Rsh(parent.Difficulty(), 10) if block.Time() >= parent.Time()+8 { diff.Sub(parent.Difficulty(), adjust) } else { diff.Add(parent.Difficulty(), adjust) } return diff } func CalculateTD(block, parent *types.Block) *big.Int { 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(parent.Td, uncleDiff) td = td.Add(td, block.Header().Difficulty) return td } func CalcGasLimit(parent, block *types.Block) *big.Int { if block.Number().Cmp(big.NewInt(0)) == 0 { return ethutil.BigPow(10, 6) } // ((1024-1) * parent.gasLimit + (gasUsed * 6 / 5)) / 1024 previous := new(big.Int).Mul(big.NewInt(1024-1), parent.GasLimit()) current := new(big.Rat).Mul(new(big.Rat).SetInt(parent.GasUsed()), big.NewRat(6, 5)) curInt := new(big.Int).Div(current.Num(), current.Denom()) result := new(big.Int).Add(previous, curInt) result.Div(result, big.NewInt(1024)) min := big.NewInt(125000) return ethutil.BigMax(min, result) } type ChainManager struct { //eth EthManager db ethutil.Database processor types.BlockProcessor eventMux *event.TypeMux genesisBlock *types.Block // Last known total difficulty mu sync.RWMutex tsmu sync.RWMutex td *big.Int currentBlock *types.Block lastBlockHash []byte transState *state.StateDB txState *state.StateDB } func NewChainManager(db ethutil.Database, mux *event.TypeMux) *ChainManager { bc := &ChainManager{db: db, genesisBlock: GenesisBlock(db), eventMux: mux} bc.setLastBlock() bc.transState = bc.State().Copy() bc.txState = bc.State().Copy() return bc } func (self *ChainManager) Td() *big.Int { self.mu.RLock() defer self.mu.RUnlock() return self.td } func (self *ChainManager) LastBlockHash() []byte { self.mu.RLock() defer self.mu.RUnlock() return self.lastBlockHash } func (self *ChainManager) CurrentBlock() *types.Block { self.mu.RLock() defer self.mu.RUnlock() return self.currentBlock } func (self *ChainManager) Status() (td *big.Int, currentBlock []byte, genesisBlock []byte) { self.mu.RLock() defer self.mu.RUnlock() return self.td, self.currentBlock.Hash(), self.Genesis().Hash() } func (self *ChainManager) SetProcessor(proc types.BlockProcessor) { self.processor = proc } func (self *ChainManager) State() *state.StateDB { return state.New(self.CurrentBlock().Root(), self.db) } func (self *ChainManager) TransState() *state.StateDB { self.tsmu.RLock() defer self.tsmu.RUnlock() return self.transState } func (self *ChainManager) TxState() *state.StateDB { self.tsmu.RLock() defer self.tsmu.RUnlock() return self.txState } func (self *ChainManager) setTxState(state *state.StateDB) { self.tsmu.Lock() defer self.tsmu.Unlock() self.txState = state } func (self *ChainManager) setTransState(statedb *state.StateDB) { self.transState = statedb } func (bc *ChainManager) setLastBlock() { data, _ := bc.db.Get([]byte("LastBlock")) if len(data) != 0 { var block types.Block rlp.Decode(bytes.NewReader(data), &block) bc.currentBlock = &block bc.lastBlockHash = block.Hash() // Set the last know difficulty (might be 0x0 as initial value, Genesis) bc.td = ethutil.BigD(bc.db.LastKnownTD()) } else { bc.Reset() } chainlogger.Infof("Last block (#%v) %x TD=%v\n", bc.currentBlock.Number(), bc.currentBlock.Hash(), bc.td) } // Block creation & chain handling func (bc *ChainManager) NewBlock(coinbase []byte) *types.Block { bc.mu.RLock() defer bc.mu.RUnlock() var root []byte parentHash := ZeroHash256 if bc.currentBlock != nil { root = bc.currentBlock.Header().Root parentHash = bc.lastBlockHash } block := types.NewBlock( parentHash, coinbase, root, ethutil.BigPow(2, 32), nil, "") block.SetUncles(nil) block.SetTransactions(nil) block.SetReceipts(nil) parent := bc.currentBlock if parent != nil { header := block.Header() header.Difficulty = CalcDifficulty(block, parent) header.Number = new(big.Int).Add(parent.Header().Number, ethutil.Big1) header.GasLimit = CalcGasLimit(parent, block) } return block } func (bc *ChainManager) Reset() { bc.mu.Lock() defer bc.mu.Unlock() for block := bc.currentBlock; block != nil; block = bc.GetBlock(block.Header().ParentHash) { bc.db.Delete(block.Hash()) } // Prepare the genesis block bc.write(bc.genesisBlock) bc.insert(bc.genesisBlock) bc.currentBlock = bc.genesisBlock bc.setTotalDifficulty(ethutil.Big("0")) } func (self *ChainManager) Export() []byte { self.mu.RLock() defer self.mu.RUnlock() chainlogger.Infof("exporting %v blocks...\n", self.currentBlock.Header().Number) blocks := make([]*types.Block, int(self.currentBlock.NumberU64())+1) for block := self.currentBlock; block != nil; block = self.GetBlock(block.Header().ParentHash) { blocks[block.NumberU64()] = block } return ethutil.Encode(blocks) } func (bc *ChainManager) insert(block *types.Block) { encodedBlock := ethutil.Encode(block) bc.db.Put([]byte("LastBlock"), encodedBlock) bc.currentBlock = block bc.lastBlockHash = block.Hash() } func (bc *ChainManager) write(block *types.Block) { encodedBlock := ethutil.Encode(block.RlpDataForStorage()) bc.db.Put(block.Hash(), encodedBlock) } // Accessors func (bc *ChainManager) Genesis() *types.Block { return bc.genesisBlock } // Block fetching methods func (bc *ChainManager) HasBlock(hash []byte) bool { data, _ := bc.db.Get(hash) return len(data) != 0 } func (self *ChainManager) GetBlockHashesFromHash(hash []byte, max uint64) (chain [][]byte) { block := self.GetBlock(hash) if block == nil { return } // XXX Could be optimised by using a different database which only holds hashes (i.e., linked list) for i := uint64(0); i < max; i++ { parentHash := block.Header().ParentHash block = self.GetBlock(parentHash) if block == nil { chainlogger.Infof("GetBlockHashesFromHash Parent UNKNOWN %x\n", parentHash) break } chain = append(chain, block.Hash()) if block.Header().Number.Cmp(ethutil.Big0) <= 0 { break } } return } func (self *ChainManager) GetBlock(hash []byte) *types.Block { data, _ := self.db.Get(hash) if len(data) == 0 { return nil } var block types.Block if err := rlp.Decode(bytes.NewReader(data), &block); err != nil { fmt.Println(err) return nil } return &block } func (self *ChainManager) GetUnclesInChain(block *types.Block, length int) (uncles []*types.Header) { for i := 0; block != nil && i < length; i++ { uncles = append(uncles, block.Uncles()...) block = self.GetBlock(block.ParentHash()) } return } func (self *ChainManager) GetAncestors(block *types.Block, length int) (blocks []*types.Block) { for i := 0; i < length; i++ { block = self.GetBlock(block.ParentHash()) if block == nil { break } blocks = append(blocks, block) } return } func (self *ChainManager) GetBlockByNumber(num uint64) *types.Block { self.mu.RLock() defer self.mu.RUnlock() var block *types.Block if num <= self.currentBlock.Number().Uint64() { block = self.currentBlock for ; block != nil; block = self.GetBlock(block.Header().ParentHash) { if block.Header().Number.Uint64() == num { break } } } return block } func (bc *ChainManager) setTotalDifficulty(td *big.Int) { bc.db.Put([]byte("LTD"), td.Bytes()) bc.td = td } func (self *ChainManager) CalcTotalDiff(block *types.Block) (*big.Int, error) { parent := self.GetBlock(block.Header().ParentHash) if parent == nil { return nil, fmt.Errorf("Unable to calculate total diff without known parent %x", block.Header().ParentHash) } parentTd := parent.Td uncleDiff := new(big.Int) for _, uncle := range block.Uncles() { uncleDiff = uncleDiff.Add(uncleDiff, uncle.Difficulty) } td := new(big.Int) td = td.Add(parentTd, uncleDiff) td = td.Add(td, block.Header().Difficulty) return td, nil } func (bc *ChainManager) Stop() { if bc.CurrentBlock != nil { chainlogger.Infoln("Stopped") } } func (self *ChainManager) InsertChain(chain types.Blocks) error { self.tsmu.Lock() defer self.tsmu.Unlock() for _, block := range chain { // Call in to the block processor and check for errors. It's likely that if one block fails // all others will fail too (unless a known block is returned). td, err := self.processor.Process(block) if err != nil { if IsKnownBlockErr(err) { continue } h := block.Header() chainlogger.Infof("block #%v process failed (%x)\n", h.Number, h.Hash()[:4]) chainlogger.Infoln(block) chainlogger.Infoln(err) return err } block.Td = td var canonical, split bool self.mu.Lock() { // Write block to database. Eventually we'll have to improve on this and throw away blocks that are // not in the canonical chain. self.write(block) cblock := self.currentBlock // Compare the TD of the last known block in the canonical chain to make sure it's greater. // At this point it's possible that a different chain (fork) becomes the new canonical chain. if td.Cmp(self.td) > 0 { if block.Header().Number.Cmp(new(big.Int).Add(cblock.Header().Number, ethutil.Big1)) < 0 { chainlogger.Infof("Split detected. New head #%v (%x) TD=%v, was #%v (%x) TD=%v\n", block.Header().Number, block.Hash()[:4], td, cblock.Header().Number, cblock.Hash()[:4], self.td) split = true } self.setTotalDifficulty(td) self.insert(block) canonical = true } } self.mu.Unlock() if canonical { self.setTransState(state.New(block.Root(), self.db)) self.eventMux.Post(ChainEvent{block, td}) } if split { self.setTxState(state.New(block.Root(), self.db)) self.eventMux.Post(ChainSplitEvent{block}) } } return nil } // Satisfy state query interface func (self *ChainManager) GetAccount(addr []byte) *state.StateObject { return self.State().GetAccount(addr) }