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
td *big.Int
lastBlockNumber uint64
currentBlock *types.Block
lastBlockHash []byte
transState *state.StateDB
}
func (self *ChainManager) Td() *big.Int {
self.mu.RLock()
defer self.mu.RUnlock()
return self.td
}
func (self *ChainManager) LastBlockNumber() uint64 {
self.mu.RLock()
defer self.mu.RUnlock()
return self.lastBlockNumber
}
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 NewChainManager(db ethutil.Database, mux *event.TypeMux) *ChainManager {
bc := &ChainManager{db: db, genesisBlock: GenesisBlock(db), eventMux: mux}
bc.setLastBlock()
bc.transState = bc.State().Copy()
return bc
}
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 {
return self.transState
}
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()
bc.lastBlockNumber = block.Header().Number.Uint64()
// 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 (#%d) %x TD=%v\n", bc.lastBlockNumber, 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) {
bc.writeBlockInfo(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
}
// Unexported method for writing extra non-essential block info to the db
func (bc *ChainManager) writeBlockInfo(block *types.Block) {
bc.lastBlockNumber++
}
func (bc *ChainManager) Stop() {
if bc.CurrentBlock != nil {
chainlogger.Infoln("Stopped")
}
}
func (self *ChainManager) InsertChain(chain types.Blocks) error {
for _, block := range chain {
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
self.mu.Lock()
{
self.write(block)
cblock := self.currentBlock
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)
}
self.setTotalDifficulty(td)
self.insert(block)
self.transState = state.New(cblock.Root(), self.db) //state.New(cblock.Trie().Copy())
self.eventMux.Post(ChainEvent{block, td})
}
}
self.mu.Unlock()
self.eventMux.Post(NewBlockEvent{block})
}
return nil
}
// Satisfy state query interface
func (self *ChainManager) GetAccount(addr []byte) *state.StateObject {
return self.State().GetAccount(addr)
}