package ethchain import ( "bytes" "github.com/ethereum/eth-go/ethutil" "github.com/ethereum/eth-go/ethwire" "log" "math" "math/big" ) type BlockChain struct { Ethereum EthManager // The famous, the fabulous Mister GENESIIIIIIS (block) genesisBlock *Block // Last known total difficulty TD *big.Int LastBlockNumber uint64 CurrentBlock *Block LastBlockHash []byte } func NewBlockChain(ethereum EthManager) *BlockChain { bc := &BlockChain{} bc.genesisBlock = NewBlockFromBytes(ethutil.Encode(Genesis)) bc.Ethereum = ethereum bc.setLastBlock() return bc } func (bc *BlockChain) Genesis() *Block { return bc.genesisBlock } func (bc *BlockChain) NewBlock(coinbase []byte, txs []*Transaction) *Block { var root interface{} var lastBlockTime int64 hash := ZeroHash256 if bc.CurrentBlock != nil { root = bc.CurrentBlock.state.trie.Root hash = bc.LastBlockHash lastBlockTime = bc.CurrentBlock.Time } block := CreateBlock( root, hash, coinbase, ethutil.BigPow(2, 32), nil, "", txs) if bc.CurrentBlock != nil { var mul *big.Int if block.Time < lastBlockTime+42 { mul = big.NewInt(1) } else { mul = big.NewInt(-1) } diff := new(big.Int) diff.Add(diff, bc.CurrentBlock.Difficulty) diff.Div(diff, big.NewInt(1024)) diff.Mul(diff, mul) diff.Add(diff, bc.CurrentBlock.Difficulty) block.Difficulty = diff } return block } func (bc *BlockChain) HasBlock(hash []byte) bool { data, _ := ethutil.Config.Db.Get(hash) return len(data) != 0 } // TODO: At one point we might want to save a block by prevHash in the db to optimise this... func (bc *BlockChain) HasBlockWithPrevHash(hash []byte) bool { block := bc.CurrentBlock for ; block != nil; block = bc.GetBlock(block.PrevHash) { if bytes.Compare(hash, block.PrevHash) == 0 { return true } } return false } func (bc *BlockChain) CalculateBlockTD(block *Block) *big.Int { blockDiff := new(big.Int) for _, uncle := range block.Uncles { blockDiff = blockDiff.Add(blockDiff, uncle.Difficulty) } blockDiff = blockDiff.Add(blockDiff, block.Difficulty) return blockDiff } func (bc *BlockChain) FindCanonicalChainFromMsg(msg *ethwire.Msg, commonBlockHash []byte) bool { var blocks []*Block for i := 0; i < (msg.Data.Len() - 1); i++ { block := NewBlockFromRlpValue(msg.Data.Get(i)) blocks = append(blocks, block) } return bc.FindCanonicalChain(blocks, commonBlockHash) } // Is tasked by finding the CanonicalChain and resetting the chain if we are not the Conical one // Return true if we are the using the canonical chain false if not func (bc *BlockChain) FindCanonicalChain(blocks []*Block, commonBlockHash []byte) bool { // 1. Calculate TD of the current chain // 2. Calculate TD of the new chain // Reset state to the correct one chainDifficulty := new(big.Int) // Calculate the entire chain until the block we both have // Start with the newest block we got, all the way back to the common block we both know for _, block := range blocks { if bytes.Compare(block.Hash(), commonBlockHash) == 0 { log.Println("[CHAIN] We have found the common parent block, breaking") break } chainDifficulty.Add(chainDifficulty, bc.CalculateBlockTD(block)) } log.Println("[CHAIN] Incoming chain difficulty:", chainDifficulty) curChainDifficulty := new(big.Int) block := bc.CurrentBlock for i := 0; block != nil; block = bc.GetBlock(block.PrevHash) { i++ if bytes.Compare(block.Hash(), commonBlockHash) == 0 { log.Println("[CHAIN] We have found the common parent block, breaking") break } log.Println("CHECKING BLOGK:", i) curChainDifficulty.Add(curChainDifficulty, bc.CalculateBlockTD(block)) } log.Println("[CHAIN] Current chain difficulty:", curChainDifficulty) if chainDifficulty.Cmp(curChainDifficulty) == 1 { log.Println("[CHAIN] The incoming Chain beat our asses, resetting") bc.ResetTillBlockHash(commonBlockHash) return false } else { log.Println("[CHAIN] Our chain showed the incoming chain who is boss. Ignoring.") return true } } func (bc *BlockChain) ResetTillBlockHash(hash []byte) error { lastBlock := bc.CurrentBlock returnTo := bc.GetBlock(hash) // TODO: REFACTOR TO FUNCTION, Used multiple times bc.CurrentBlock = returnTo bc.LastBlockHash = returnTo.Hash() info := bc.BlockInfo(returnTo) bc.LastBlockNumber = info.Number // END TODO bc.Ethereum.StateManager().PrepareDefault(returnTo) err := ethutil.Config.Db.Delete(lastBlock.Hash()) if err != nil { return err } var block *Block for ; block != nil; block = bc.GetBlock(block.PrevHash) { if bytes.Compare(block.Hash(), hash) == 0 { log.Println("[CHAIN] We have arrived at the the common parent block, breaking") break } err = ethutil.Config.Db.Delete(block.Hash()) if err != nil { return err } } log.Println("[CHAIN] Split chain deleted and reverted to common parent block.") return nil } func (bc *BlockChain) GenesisBlock() *Block { return bc.genesisBlock } // Get chain return blocks from hash up to max in RLP format func (bc *BlockChain) GetChainFromHash(hash []byte, max uint64) []interface{} { var chain []interface{} // Get the current hash to start with currentHash := bc.CurrentBlock.Hash() // Get the last number on the block chain lastNumber := bc.BlockInfo(bc.CurrentBlock).Number // Get the parents number parentNumber := bc.BlockInfoByHash(hash).Number // Get the min amount. We might not have max amount of blocks count := uint64(math.Min(float64(lastNumber-parentNumber), float64(max))) startNumber := parentNumber + count num := lastNumber for ; num > startNumber; currentHash = bc.GetBlock(currentHash).PrevHash { num-- } for i := uint64(0); bytes.Compare(currentHash, hash) != 0 && num >= parentNumber && i < count; i++ { // Get the block of the chain block := bc.GetBlock(currentHash) currentHash = block.PrevHash chain = append(chain, block.Value().Val) num-- } return chain } func (bc *BlockChain) GetChain(hash []byte, amount int) []*Block { genHash := bc.genesisBlock.Hash() block := bc.GetBlock(hash) var blocks []*Block for i := 0; i < amount && block != nil; block = bc.GetBlock(block.PrevHash) { blocks = append([]*Block{block}, blocks...) if bytes.Compare(genHash, block.Hash()) == 0 { break } i++ } return blocks } func AddTestNetFunds(block *Block) { for _, addr := range []string{ "8a40bfaa73256b60764c1bf40675a99083efb075", // Gavin "e6716f9544a56c530d868e4bfbacb172315bdead", // Jeffrey "1e12515ce3e0f817a4ddef9ca55788a1d66bd2df", // Vit "1a26338f0d905e295fccb71fa9ea849ffa12aaf4", // Alex "2ef47100e0787b915105fd5e3f4ff6752079d5cb", // Maran } { //log.Println("2^200 Wei to", addr) codedAddr := ethutil.FromHex(addr) addr := block.state.GetAccount(codedAddr) addr.Amount = ethutil.BigPow(2, 200) block.state.UpdateAccount(codedAddr, addr) } } func (bc *BlockChain) setLastBlock() { data, _ := ethutil.Config.Db.Get([]byte("LastBlock")) if len(data) != 0 { block := NewBlockFromBytes(data) info := bc.BlockInfo(block) bc.CurrentBlock = block bc.LastBlockHash = block.Hash() bc.LastBlockNumber = info.Number log.Printf("[CHAIN] Last known block height #%d\n", bc.LastBlockNumber) } else { AddTestNetFunds(bc.genesisBlock) bc.genesisBlock.state.trie.Sync() // Prepare the genesis block bc.Add(bc.genesisBlock) //log.Printf("root %x\n", bm.bc.genesisBlock.State().Root) //bm.bc.genesisBlock.PrintHash() } // Set the last know difficulty (might be 0x0 as initial value, Genesis) bc.TD = ethutil.BigD(ethutil.Config.Db.LastKnownTD()) log.Printf("Last block: %x\n", bc.CurrentBlock.Hash()) } func (bc *BlockChain) SetTotalDifficulty(td *big.Int) { ethutil.Config.Db.Put([]byte("LastKnownTotalDifficulty"), td.Bytes()) bc.TD = td } // Add a block to the chain and record addition information func (bc *BlockChain) Add(block *Block) { bc.writeBlockInfo(block) // Prepare the genesis block bc.CurrentBlock = block bc.LastBlockHash = block.Hash() encodedBlock := block.RlpEncode() log.Println(encodedBlock) ethutil.Config.Db.Put(block.Hash(), encodedBlock) ethutil.Config.Db.Put([]byte("LastBlock"), encodedBlock) } func (bc *BlockChain) GetBlock(hash []byte) *Block { data, _ := ethutil.Config.Db.Get(hash) if len(data) == 0 { return nil } return NewBlockFromBytes(data) } func (bc *BlockChain) BlockInfoByHash(hash []byte) BlockInfo { bi := BlockInfo{} data, _ := ethutil.Config.Db.Get(append(hash, []byte("Info")...)) bi.RlpDecode(data) return bi } func (bc *BlockChain) BlockInfo(block *Block) BlockInfo { bi := BlockInfo{} data, _ := ethutil.Config.Db.Get(append(block.Hash(), []byte("Info")...)) bi.RlpDecode(data) return bi } // Unexported method for writing extra non-essential block info to the db func (bc *BlockChain) writeBlockInfo(block *Block) { bc.LastBlockNumber++ bi := BlockInfo{Number: bc.LastBlockNumber, Hash: block.Hash(), Parent: block.PrevHash} // For now we use the block hash with the words "info" appended as key ethutil.Config.Db.Put(append(block.Hash(), []byte("Info")...), bi.RlpEncode()) } func (bc *BlockChain) Stop() { if bc.CurrentBlock != nil { log.Println("[CHAIN] Stopped") } }