package core import ( "bytes" "fmt" "io" "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/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/rlp" ) var ( chainlogger = logger.NewLogger("CHAIN") jsonlogger = logger.NewJsonLogger() blockHashPre = []byte("block-hash-") blockNumPre = []byte("block-num-") ) const ( blockCacheLimit = 10000 maxFutureBlocks = 256 ) func CalcDifficulty(block, parent *types.Header) *big.Int { diff := new(big.Int) adjust := new(big.Int).Div(parent.Difficulty, params.DifficultyBoundDivisor) if big.NewInt(int64(block.Time)-int64(parent.Time)).Cmp(params.DurationLimit) < 0 { diff.Add(parent.Difficulty, adjust) } else { diff.Sub(parent.Difficulty, adjust) } if diff.Cmp(params.MinimumDifficulty) < 0 { return params.MinimumDifficulty } return diff } func CalculateTD(block, parent *types.Block) *big.Int { if parent == nil { return block.Difficulty() } td := new(big.Int).Add(parent.Td, block.Header().Difficulty) return td } func CalcGasLimit(parent *types.Block) *big.Int { // ((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)) return common.BigMax(params.GenesisGasLimit, result) } type ChainManager struct { //eth EthManager blockDb common.Database stateDb common.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 common.Hash currentGasLimit *big.Int transState *state.StateDB txState *state.ManagedState cache *BlockCache futureBlocks *BlockCache quit chan struct{} wg sync.WaitGroup } func NewChainManager(blockDb, stateDb common.Database, mux *event.TypeMux) *ChainManager { bc := &ChainManager{ blockDb: blockDb, stateDb: stateDb, genesisBlock: GenesisBlock(stateDb), eventMux: mux, quit: make(chan struct{}), cache: NewBlockCache(blockCacheLimit), } bc.setLastState() // Check the current state of the block hashes and make sure that we do not have any of the bad blocks in our chain for _, hash := range badHashes { if block := bc.GetBlock(hash); block != nil { glog.V(logger.Error).Infof("Found bad hash. Reorganising chain to state %x\n", block.ParentHash().Bytes()[:4]) block = bc.GetBlock(block.ParentHash()) if block == nil { glog.Fatal("Unable to complete. Parent block not found. Corrupted DB?") } bc.SetHead(block) glog.V(logger.Error).Infoln("Chain reorg was successfull. Resuming normal operation") } } bc.transState = bc.State().Copy() // Take ownership of this particular state bc.txState = state.ManageState(bc.State().Copy()) bc.futureBlocks = NewBlockCache(maxFutureBlocks) bc.makeCache() go bc.update() return bc } func (bc *ChainManager) SetHead(head *types.Block) { bc.mu.Lock() defer bc.mu.Unlock() for block := bc.currentBlock; block != nil && block.Hash() != head.Hash(); block = bc.GetBlock(block.Header().ParentHash) { bc.removeBlock(block) } bc.cache = NewBlockCache(blockCacheLimit) bc.currentBlock = head bc.makeCache() statedb := state.New(head.Root(), bc.stateDb) bc.txState = state.ManageState(statedb) bc.transState = statedb.Copy() bc.setTotalDifficulty(head.Td) bc.insert(head) bc.setLastState() } func (self *ChainManager) Td() *big.Int { self.mu.RLock() defer self.mu.RUnlock() return self.td } func (self *ChainManager) GasLimit() *big.Int { return self.currentGasLimit } func (self *ChainManager) LastBlockHash() common.Hash { 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 common.Hash, genesisBlock common.Hash) { self.mu.RLock() defer self.mu.RUnlock() return self.td, self.currentBlock.Hash(), self.genesisBlock.Hash() } func (self *ChainManager) SetProcessor(proc types.BlockProcessor) { self.processor = proc } func (self *ChainManager) State() *state.StateDB { return state.New(self.CurrentBlock().Root(), self.stateDb) } func (self *ChainManager) TransState() *state.StateDB { self.tsmu.RLock() defer self.tsmu.RUnlock() return self.transState } func (self *ChainManager) TxState() *state.ManagedState { self.tsmu.RLock() defer self.tsmu.RUnlock() return self.txState } func (self *ChainManager) setTxState(statedb *state.StateDB) { self.tsmu.Lock() defer self.tsmu.Unlock() self.txState = state.ManageState(statedb) } func (self *ChainManager) setTransState(statedb *state.StateDB) { self.transState = statedb } func (bc *ChainManager) setLastState() { data, _ := bc.blockDb.Get([]byte("LastBlock")) if len(data) != 0 { block := bc.GetBlock(common.BytesToHash(data)) bc.currentBlock = block bc.lastBlockHash = block.Hash() // Set the last know difficulty (might be 0x0 as initial value, Genesis) bc.td = common.BigD(bc.blockDb.LastKnownTD()) } else { bc.Reset() } bc.currentGasLimit = CalcGasLimit(bc.currentBlock) if glog.V(logger.Info) { glog.Infof("Last block (#%v) %x TD=%v\n", bc.currentBlock.Number(), bc.currentBlock.Hash(), bc.td) } } func (bc *ChainManager) makeCache() { if bc.cache == nil { bc.cache = NewBlockCache(blockCacheLimit) } // load in last `blockCacheLimit` - 1 blocks. Last block is the current. ancestors := bc.GetAncestors(bc.currentBlock, blockCacheLimit-1) ancestors = append(ancestors, bc.currentBlock) for _, block := range ancestors { bc.cache.Push(block) } } // Block creation & chain handling func (bc *ChainManager) NewBlock(coinbase common.Address) *types.Block { bc.mu.RLock() defer bc.mu.RUnlock() var ( root common.Hash parentHash common.Hash ) if bc.currentBlock != nil { root = bc.currentBlock.Header().Root parentHash = bc.lastBlockHash } block := types.NewBlock( parentHash, coinbase, root, common.BigPow(2, 32), 0, nil) block.SetUncles(nil) block.SetTransactions(nil) block.SetReceipts(nil) parent := bc.currentBlock if parent != nil { header := block.Header() header.Difficulty = CalcDifficulty(block.Header(), parent.Header()) header.Number = new(big.Int).Add(parent.Header().Number, common.Big1) header.GasLimit = CalcGasLimit(parent) } 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.removeBlock(block) } if bc.cache == nil { bc.cache = NewBlockCache(blockCacheLimit) } // Prepare the genesis block bc.write(bc.genesisBlock) bc.insert(bc.genesisBlock) bc.currentBlock = bc.genesisBlock bc.makeCache() bc.setTotalDifficulty(common.Big("0")) } func (bc *ChainManager) removeBlock(block *types.Block) { bc.blockDb.Delete(append(blockHashPre, block.Hash().Bytes()...)) } func (bc *ChainManager) ResetWithGenesisBlock(gb *types.Block) { bc.mu.Lock() defer bc.mu.Unlock() for block := bc.currentBlock; block != nil; block = bc.GetBlock(block.Header().ParentHash) { bc.removeBlock(block) } // Prepare the genesis block bc.genesisBlock = gb bc.write(bc.genesisBlock) bc.insert(bc.genesisBlock) bc.currentBlock = bc.genesisBlock bc.makeCache() bc.td = gb.Difficulty() } // Export writes the active chain to the given writer. func (self *ChainManager) Export(w io.Writer) error { self.mu.RLock() defer self.mu.RUnlock() glog.V(logger.Info).Infof("exporting %v blocks...\n", self.currentBlock.Header().Number) last := self.currentBlock.NumberU64() for nr := uint64(0); nr <= last; nr++ { block := self.GetBlockByNumber(nr) if block == nil { return fmt.Errorf("export failed on #%d: not found", nr) } if err := block.EncodeRLP(w); err != nil { return err } } return nil } func (bc *ChainManager) insert(block *types.Block) { key := append(blockNumPre, block.Number().Bytes()...) bc.blockDb.Put(key, block.Hash().Bytes()) bc.blockDb.Put([]byte("LastBlock"), block.Hash().Bytes()) bc.currentBlock = block bc.lastBlockHash = block.Hash() } func (bc *ChainManager) write(block *types.Block) { enc, _ := rlp.EncodeToBytes((*types.StorageBlock)(block)) key := append(blockHashPre, block.Hash().Bytes()...) bc.blockDb.Put(key, enc) // Push block to cache bc.cache.Push(block) } // Accessors func (bc *ChainManager) Genesis() *types.Block { return bc.genesisBlock } // Block fetching methods func (bc *ChainManager) HasBlock(hash common.Hash) bool { data, _ := bc.blockDb.Get(append(blockHashPre, hash[:]...)) return len(data) != 0 } func (self *ChainManager) GetBlockHashesFromHash(hash common.Hash, max uint64) (chain []common.Hash) { 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++ { block = self.GetBlock(block.ParentHash()) if block == nil { break } chain = append(chain, block.Hash()) if block.Number().Cmp(common.Big0) <= 0 { break } } return } func (self *ChainManager) GetBlock(hash common.Hash) *types.Block { if block := self.cache.Get(hash); block != nil { return block } data, _ := self.blockDb.Get(append(blockHashPre, hash[:]...)) if len(data) == 0 { return nil } var block types.StorageBlock if err := rlp.Decode(bytes.NewReader(data), &block); err != nil { glog.V(logger.Error).Infof("invalid block RLP for hash %x: %v", hash, err) return nil } return (*types.Block)(&block) } func (self *ChainManager) GetBlockByNumber(num uint64) *types.Block { self.mu.RLock() defer self.mu.RUnlock() return self.getBlockByNumber(num) } // non blocking version func (self *ChainManager) getBlockByNumber(num uint64) *types.Block { key, _ := self.blockDb.Get(append(blockNumPre, big.NewInt(int64(num)).Bytes()...)) if len(key) == 0 { return nil } return self.GetBlock(common.BytesToHash(key)) } 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 (bc *ChainManager) setTotalDifficulty(td *big.Int) { bc.blockDb.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() { close(bc.quit) bc.wg.Wait() glog.V(logger.Info).Infoln("Chain manager stopped") } type queueEvent struct { queue []interface{} canonicalCount int sideCount int splitCount int } func (self *ChainManager) procFutureBlocks() { blocks := make([]*types.Block, len(self.futureBlocks.blocks)) self.futureBlocks.Each(func(i int, block *types.Block) { blocks[i] = block }) types.BlockBy(types.Number).Sort(blocks) self.InsertChain(blocks) } // InsertChain will attempt to insert the given chain in to the canonical chain or, otherwise, create a fork. It an error is returned // it will return the index number of the failing block as well an error describing what went wrong (for possible errors see core/errors.go). func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) { self.wg.Add(1) defer self.wg.Done() // A queued approach to delivering events. This is generally faster than direct delivery and requires much less mutex acquiring. var ( queue = make([]interface{}, len(chain)) queueEvent = queueEvent{queue: queue} stats struct{ queued, processed, ignored int } tstart = time.Now() ) for i, block := range chain { if block == nil { continue } // Setting block.Td regardless of error (known for example) prevents errors down the line // in the protocol handler block.Td = new(big.Int).Set(CalculateTD(block, self.GetBlock(block.ParentHash()))) // 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). logs, err := self.processor.Process(block) if err != nil { if IsKnownBlockErr(err) { stats.ignored++ continue } block.Td = new(big.Int) // Do not penelise on future block. We'll need a block queue eventually that will queue // future block for future use if err == BlockFutureErr { block.SetQueued(true) self.futureBlocks.Push(block) stats.queued++ continue } if IsParentErr(err) && self.futureBlocks.Has(block.ParentHash()) { block.SetQueued(true) self.futureBlocks.Push(block) stats.queued++ continue } h := block.Header() glog.V(logger.Error).Infof("INVALID block #%v (%x)\n", h.Number, h.Hash().Bytes()) glog.V(logger.Error).Infoln(err) glog.V(logger.Debug).Infoln(block) return i, err } self.mu.Lock() { cblock := self.currentBlock // 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) // 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 block.Td.Cmp(self.td) > 0 { // Check for chain forks. If H(block.num - 1) != block.parent, we're on a fork and need to do some merging if previous := self.getBlockByNumber(block.NumberU64() - 1); previous.Hash() != block.ParentHash() { chash := cblock.Hash() hash := block.Hash() if glog.V(logger.Info) { glog.Infof("Split detected. New head #%v (%x) TD=%v, was #%v (%x) TD=%v\n", block.Header().Number, hash[:4], block.Td, cblock.Header().Number, chash[:4], self.td) } // during split we merge two different chains and create the new canonical chain self.merge(previous, block) queue[i] = ChainSplitEvent{block, logs} queueEvent.splitCount++ } self.setTotalDifficulty(block.Td) self.insert(block) jsonlogger.LogJson(&logger.EthChainNewHead{ BlockHash: block.Hash().Hex(), BlockNumber: block.Number(), ChainHeadHash: cblock.Hash().Hex(), BlockPrevHash: block.ParentHash().Hex(), }) self.setTransState(state.New(block.Root(), self.stateDb)) self.txState.SetState(state.New(block.Root(), self.stateDb)) queue[i] = ChainEvent{block, logs} queueEvent.canonicalCount++ if glog.V(logger.Debug) { glog.Infof("inserted block #%d (%d TXs %d UNCs) (%x...)\n", block.Number(), len(block.Transactions()), len(block.Uncles()), block.Hash().Bytes()[0:4]) } } else { if glog.V(logger.Detail) { glog.Infof("inserted forked block #%d (TD=%v) (%d TXs %d UNCs) (%x...)\n", block.Number(), block.Difficulty(), len(block.Transactions()), len(block.Uncles()), block.Hash().Bytes()[0:4]) } queue[i] = ChainSideEvent{block, logs} queueEvent.sideCount++ } self.futureBlocks.Delete(block.Hash()) } self.mu.Unlock() stats.processed++ } if (stats.queued > 0 || stats.processed > 0) && bool(glog.V(logger.Info)) { tend := time.Since(tstart) start, end := chain[0], chain[len(chain)-1] glog.Infof("imported %d block(s) (%d queued %d ignored) in %v. #%v [%x / %x]\n", stats.processed, stats.queued, stats.ignored, tend, end.Number(), start.Hash().Bytes()[:4], end.Hash().Bytes()[:4]) } go self.eventMux.Post(queueEvent) return 0, nil } // diff takes two blocks, an old chain and a new chain and will reconstruct the blocks and inserts them // to be part of the new canonical chain. func (self *ChainManager) diff(oldBlock, newBlock *types.Block) types.Blocks { glog.V(logger.Debug).Infof("Applying diff to %x & %x\n", oldBlock.Hash().Bytes()[:4], newBlock.Hash().Bytes()[:4]) var newChain types.Blocks // first find common number for newBlock = newBlock; newBlock.NumberU64() != oldBlock.NumberU64(); newBlock = self.GetBlock(newBlock.ParentHash()) { newChain = append(newChain, newBlock) } glog.V(logger.Debug).Infoln("Found common number", newBlock.Number()) for { if oldBlock.Hash() == newBlock.Hash() { break } newChain = append(newChain, newBlock) oldBlock, newBlock = self.GetBlock(oldBlock.ParentHash()), self.GetBlock(newBlock.ParentHash()) } return newChain } // merge merges two different chain to the new canonical chain func (self *ChainManager) merge(oldBlock, newBlock *types.Block) { newChain := self.diff(oldBlock, newBlock) // insert blocks for _, block := range newChain { self.insert(block) } } func (self *ChainManager) update() { events := self.eventMux.Subscribe(queueEvent{}) futureTimer := time.Tick(5 * time.Second) out: for { select { case ev := <-events.Chan(): switch ev := ev.(type) { case queueEvent: for i, event := range ev.queue { switch event := event.(type) { case ChainEvent: // We need some control over the mining operation. Acquiring locks and waiting for the miner to create new block takes too long // and in most cases isn't even necessary. if i+1 == ev.canonicalCount { self.currentGasLimit = CalcGasLimit(event.Block) self.eventMux.Post(ChainHeadEvent{event.Block}) } case ChainSplitEvent: // On chain splits we need to reset the transaction state. We can't be sure whether the actual // state of the accounts are still valid. if i == ev.splitCount { self.setTxState(state.New(event.Block.Root(), self.stateDb)) } } self.eventMux.Post(event) } } case <-futureTimer: self.procFutureBlocks() case <-self.quit: break out } } }