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
type StateQuery interface {
GetAccount(addr []byte) *state.StateObject
}
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 {
td := new(big.Int).Add(parent.Td, block.Header().Difficulty)
return td
}
func CalcGasLimit(parent, block *types.Block) *big.Int {
if block.Number().Cmp(big.NewInt(0)) == 0 {
return common.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))
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
transState *state.StateDB
txState *state.ManagedState
cache *BlockCache
futureBlocks *BlockCache
quit chan struct{}
}
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.setLastBlock()
bc.transState = bc.State().Copy()
// Take ownership of this particular state
bc.txState = state.ManageState(bc.State().Copy())
bc.futureBlocks = NewBlockCache(254)
bc.makeCache()
go bc.update()
return bc
}
func (self *ChainManager) Td() *big.Int {
self.mu.RLock()
defer self.mu.RUnlock()
return self.td
}
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) setLastBlock() {
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()
}
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, 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.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()
}
// 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++ {
if err := self.GetBlockByNumber(nr).EncodeRLP(w); err != nil {
return err
}
}
return nil
}
func (bc *ChainManager) insert(block *types.Block) {
bc.blockDb.Put([]byte("LastBlock"), block.Hash().Bytes())
bc.currentBlock = block
bc.lastBlockHash = block.Hash()
key := append(blockNumPre, block.Number().Bytes()...)
bc.blockDb.Put(key, bc.lastBlockHash.Bytes())
// Push block to cache
bc.cache.Push(block)
}
func (bc *ChainManager) write(block *types.Block) {
enc, _ := rlp.EncodeToBytes((*types.StorageBlock)(block))
key := append(blockHashPre, block.Hash().Bytes()...)
bc.blockDb.Put(key, enc)
}
// 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++ {
parentHash := block.Header().ParentHash
block = self.GetBlock(parentHash)
if block == nil {
break
}
chain = append(chain, block.Hash())
if block.Header().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()
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)
}
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)
}
func (self *ChainManager) InsertChain(chain types.Blocks) error {
// 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 int }
tstart = time.Now()
)
for i, block := range chain {
if block == nil {
continue
}
// 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, logs, err := self.processor.Process(block)
if err != nil {
if IsKnownBlockErr(err) {
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()[:4])
glog.V(logger.Error).Infoln(err)
glog.V(logger.Debug).Infoln(block)
return err
}
block.Td = td
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 td.Cmp(self.td) > 0 {
if block.Header().Number.Cmp(new(big.Int).Add(cblock.Header().Number, common.Big1)) < 0 {
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], td, cblock.Header().Number, chash[:4], self.td)
}
queue[i] = ChainSplitEvent{block, logs}
queueEvent.splitCount++
}
self.setTotalDifficulty(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.setTxState(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 {
queue[i] = ChainSideEvent{block, logs}
queueEvent.sideCount++
}
}
self.mu.Unlock()
stats.processed++
self.futureBlocks.Delete(block.Hash())
}
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 in %v. #%v [%x / %x]\n", stats.processed, stats.queued, tend, end.Number(), start.Hash().Bytes()[:4], end.Hash().Bytes()[:4])
}
go self.eventMux.Post(queueEvent)
return nil
}
func (self *ChainManager) update() {
events := self.eventMux.Subscribe(queueEvent{})
futureTimer := time.NewTicker(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.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.C:
self.procFutureBlocks()
case <-self.quit:
break out
}
}
}