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) *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,
"")
block.MinGasPrice = big.NewInt(10000000000000)
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
block.Number = new(big.Int).Add(bc.CurrentBlock.Number, ethutil.Big1)
block.GasLimit = block.CalcGasLimit(bc.CurrentBlock)
}
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
}
anOtherBlock := bc.GetBlock(block.PrevHash)
if anOtherBlock == nil {
// We do not want to count the genesis block for difficulty since that's not being sent
log.Println("[CHAIN] At genesis block, breaking")
break
}
curChainDifficulty.Add(curChainDifficulty, bc.CalculateBlockTD(block))
}
log.Println("[CHAIN] Current chain difficulty:", curChainDifficulty)
if chainDifficulty.Cmp(curChainDifficulty) == 1 {
log.Printf("[CHAIN] The incoming Chain beat our asses, resetting to block: %x", commonBlockHash)
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
var returnTo *Block
// Reset to Genesis if that's all the origin there is.
if bytes.Compare(hash, bc.genesisBlock.Hash()) == 0 {
returnTo = bc.genesisBlock
bc.CurrentBlock = bc.genesisBlock
bc.LastBlockHash = bc.genesisBlock.Hash()
bc.LastBlockNumber = 1
} else {
// TODO: Somehow this doesn't really give the right numbers, double check.
// TODO: Change logs into debug lines
returnTo = bc.GetBlock(hash)
bc.CurrentBlock = returnTo
bc.LastBlockHash = returnTo.Hash()
//info := bc.BlockInfo(returnTo)
bc.LastBlockNumber = returnTo.Number.Uint64()
}
// XXX Why are we resetting? This is the block chain, it has nothing to do with states
//bc.Ethereum.StateManager().PrepareDefault(returnTo)
// Manually reset the last sync block
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.CurrentBlock.Number.Uint64()
// Get the parents number
parentNumber := bc.GetBlock(hash).Number.Uint64()
// 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{
"51ba59315b3a95761d0863b05ccc7a7f54703d99",
"e4157b34ea9615cfbde6b4fda419828124b70c78",
"1e12515ce3e0f817a4ddef9ca55788a1d66bd2df",
"6c386a4b26f73c802f34673f7248bb118f97424a",
"cd2a3d9f938e13cd947ec05abc7fe734df8dd826",
"2ef47100e0787b915105fd5e3f4ff6752079d5cb",
"e6716f9544a56c530d868e4bfbacb172315bdead",
"1a26338f0d905e295fccb71fa9ea849ffa12aaf4",
} {
codedAddr := ethutil.FromHex(addr)
account := block.state.GetAccount(codedAddr)
account.Amount = ethutil.Big("1606938044258990275541962092341162602522202993782792835301376") //ethutil.BigPow(2, 200)
block.state.UpdateStateObject(account)
}
}
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 = block.Number.Uint64()
ethutil.Config.Log.Infof("[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())
ethutil.Config.Log.Infof("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()
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")
}
}
