// BroadcastBlock will either propagate a block to a subset of it's peers, or
// will only announce it's availability (depending what's requested).
func (pm *ProtocolManager) BroadcastBlock(block *types.Block, propagate bool) {
hash := block.Hash()
peers := pm.peers.PeersWithoutBlock(hash)
// If propagation is requested, send to a subset of the peer
if propagate {
// Calculate the TD of the block (it's not imported yet, so block.Td is not valid)
var td *big.Int
if parent := pm.chainman.GetBlock(block.ParentHash()); parent != nil {
td = new(big.Int).Add(parent.Td, block.Difficulty())
} else {
glog.V(logger.Error).Infof("propagating dangling block #%d [%x]", block.NumberU64(), hash[:4])
return
}
// Send the block to a subset of our peers
transfer := peers[:int(math.Sqrt(float64(len(peers))))]
for _, peer := range transfer {
peer.SendNewBlock(block, td)
}
glog.V(logger.Detail).Infof("propagated block %x to %d peers in %v", hash[:4], len(transfer), time.Since(block.ReceivedAt))
}
// Otherwise if the block is indeed in out own chain, announce it
if pm.chainman.HasBlock(hash) {
for _, peer := range peers {
peer.SendNewBlockHashes([]common.Hash{hash})
}
glog.V(logger.Detail).Infof("announced block %x to %d peers in %v", hash[:4], len(peers), time.Since(block.ReceivedAt))
}
}
// CalcTD computes the total difficulty of block.
func CalcTD(block, parent *types.Block) *big.Int {
if parent == nil {
return block.Difficulty()
}
d := block.Difficulty()
d.Add(d, parent.Td)
return d
}
// WriteBlock writes the block to the chain.
func (self *BlockChain) WriteBlock(block *types.Block) (status writeStatus, err error) {
self.wg.Add(1)
defer self.wg.Done()
// Calculate the total difficulty of the block
ptd := self.GetTd(block.ParentHash())
if ptd == nil {
return NonStatTy, ParentError(block.ParentHash())
}
localTd := self.GetTd(self.currentBlock.Hash())
externTd := new(big.Int).Add(block.Difficulty(), ptd)
// Make sure no inconsistent state is leaked during insertion
self.mu.Lock()
defer self.mu.Unlock()
// If the total difficulty is higher than our known, add it to the canonical chain
// Second clause in the if statement reduces the vulnerability to selfish mining.
// Please refer to http://www.cs.cornell.edu/~ie53/publications/btcProcFC.pdf
if externTd.Cmp(localTd) > 0 || (externTd.Cmp(localTd) == 0 && mrand.Float64() < 0.5) {
// Reorganize the chain if the parent is not the head block
if block.ParentHash() != self.currentBlock.Hash() {
if err := self.reorg(self.currentBlock, block); err != nil {
return NonStatTy, err
}
}
// Insert the block as the new head of the chain
self.insert(block)
status = CanonStatTy
} else {
status = SideStatTy
}
// Irrelevant of the canonical status, write the block itself to the database
if err := WriteTd(self.chainDb, block.Hash(), externTd); err != nil {
glog.Fatalf("failed to write block total difficulty: %v", err)
}
if err := WriteBlock(self.chainDb, block); err != nil {
glog.Fatalf("filed to write block contents: %v", err)
}
self.futureBlocks.Remove(block.Hash())
return
}
func NewBlockRes(block *types.Block, td *big.Int, fullTx bool) *BlockRes {
if block == nil {
return nil
}
res := new(BlockRes)
res.fullTx = fullTx
res.BlockNumber = newHexNum(block.Number())
res.BlockHash = newHexData(block.Hash())
res.ParentHash = newHexData(block.ParentHash())
res.Nonce = newHexData(block.Nonce())
res.Sha3Uncles = newHexData(block.UncleHash())
res.LogsBloom = newHexData(block.Bloom())
res.TransactionRoot = newHexData(block.TxHash())
res.StateRoot = newHexData(block.Root())
res.ReceiptRoot = newHexData(block.ReceiptHash())
res.Miner = newHexData(block.Coinbase())
res.Difficulty = newHexNum(block.Difficulty())
res.TotalDifficulty = newHexNum(td)
res.Size = newHexNum(block.Size().Int64())
res.ExtraData = newHexData(block.Extra())
res.GasLimit = newHexNum(block.GasLimit())
res.GasUsed = newHexNum(block.GasUsed())
res.UnixTimestamp = newHexNum(block.Time())
txs := block.Transactions()
res.Transactions = make([]*TransactionRes, len(txs))
for i, tx := range txs {
res.Transactions[i] = NewTransactionRes(tx)
res.Transactions[i].BlockHash = res.BlockHash
res.Transactions[i].BlockNumber = res.BlockNumber
res.Transactions[i].TxIndex = newHexNum(i)
}
uncles := block.Uncles()
res.Uncles = make([]*UncleRes, len(uncles))
for i, uncle := range uncles {
res.Uncles[i] = NewUncleRes(uncle)
}
return res
}
// ResetWithGenesisBlock purges the entire blockchain, restoring it to the
// specified genesis state.
func (bc *BlockChain) ResetWithGenesisBlock(genesis *types.Block) {
// Dump the entire block chain and purge the caches
bc.SetHead(0)
bc.mu.Lock()
defer bc.mu.Unlock()
// Prepare the genesis block and reinitialise the chain
if err := WriteTd(bc.chainDb, genesis.Hash(), genesis.Difficulty()); err != nil {
glog.Fatalf("failed to write genesis block TD: %v", err)
}
if err := WriteBlock(bc.chainDb, genesis); err != nil {
glog.Fatalf("failed to write genesis block: %v", err)
}
bc.genesisBlock = genesis
bc.insert(bc.genesisBlock)
bc.currentBlock = bc.genesisBlock
bc.currentHeader = bc.genesisBlock.Header()
bc.currentFastBlock = bc.genesisBlock
}
// WriteBlock writes the block to the chain.
func (self *BlockChain) WriteBlock(block *types.Block) (status writeStatus, err error) {
self.wg.Add(1)
defer self.wg.Done()
// Calculate the total difficulty of the block
ptd := self.GetTd(block.ParentHash())
if ptd == nil {
return NonStatTy, ParentError(block.ParentHash())
}
td := new(big.Int).Add(block.Difficulty(), ptd)
// Make sure no inconsistent state is leaked during insertion
self.mu.Lock()
defer self.mu.Unlock()
// If the total difficulty is higher than our known, add it to the canonical chain
if td.Cmp(self.GetTd(self.currentBlock.Hash())) > 0 {
// Reorganize the chain if the parent is not the head block
if block.ParentHash() != self.currentBlock.Hash() {
if err := self.reorg(self.currentBlock, block); err != nil {
return NonStatTy, err
}
}
// Insert the block as the new head of the chain
self.insert(block)
status = CanonStatTy
} else {
status = SideStatTy
}
// Irrelevant of the canonical status, write the block itself to the database
if err := WriteTd(self.chainDb, block.Hash(), td); err != nil {
glog.Fatalf("failed to write block total difficulty: %v", err)
}
if err := WriteBlock(self.chainDb, block); err != nil {
glog.Fatalf("filed to write block contents: %v", err)
}
self.futureBlocks.Remove(block.Hash())
return
}
func (bc *ChainManager) ResetWithGenesisBlock(gb *types.Block) {
bc.mu.Lock()
defer bc.mu.Unlock()
for block := bc.currentBlock; block != nil; block = bc.GetBlock(block.ParentHash()) {
bc.removeBlock(block)
}
// Prepare the genesis block
gb.Td = gb.Difficulty()
bc.genesisBlock = gb
err := WriteBlock(bc.chainDb, bc.genesisBlock)
if err != nil {
glog.Fatalln("db err:", err)
}
bc.insert(bc.genesisBlock)
bc.currentBlock = bc.genesisBlock
bc.makeCache()
bc.td = gb.Difficulty()
}
func makeHeader(parent *types.Block, state *state.StateDB) *types.Header {
var time *big.Int
if parent.Time() == nil {
time = big.NewInt(10)
} else {
time = new(big.Int).Add(parent.Time(), big.NewInt(10)) // block time is fixed at 10 seconds
}
return &types.Header{
Root: state.IntermediateRoot(),
ParentHash: parent.Hash(),
Coinbase: parent.Coinbase(),
Difficulty: CalcDifficulty(time.Uint64(), new(big.Int).Sub(time, big.NewInt(10)).Uint64(), parent.Number(), parent.Difficulty()),
GasLimit: CalcGasLimit(parent),
GasUsed: new(big.Int),
Number: new(big.Int).Add(parent.Number(), common.Big1),
Time: time,
}
}
// See YP section 4.3.4. "Block Header Validity"
// Validates a block. Returns an error if the block is invalid.
func ValidateHeader(pow pow.PoW, block *types.Header, parent *types.Block, checkPow, uncle bool) error {
if big.NewInt(int64(len(block.Extra))).Cmp(params.MaximumExtraDataSize) == 1 {
return fmt.Errorf("Block extra data too long (%d)", len(block.Extra))
}
if uncle {
if block.Time.Cmp(common.MaxBig) == 1 {
return BlockTSTooBigErr
}
} else {
if block.Time.Cmp(big.NewInt(time.Now().Unix())) == 1 {
return BlockFutureErr
}
}
if block.Time.Cmp(parent.Time()) != 1 {
return BlockEqualTSErr
}
expd := CalcDifficulty(block.Time.Uint64(), parent.Time().Uint64(), parent.Number(), parent.Difficulty())
if expd.Cmp(block.Difficulty) != 0 {
return fmt.Errorf("Difficulty check failed for block %v, %v", block.Difficulty, expd)
}
var a, b *big.Int
a = parent.GasLimit()
a = a.Sub(a, block.GasLimit)
a.Abs(a)
b = parent.GasLimit()
b = b.Div(b, params.GasLimitBoundDivisor)
if !(a.Cmp(b) < 0) || (block.GasLimit.Cmp(params.MinGasLimit) == -1) {
return fmt.Errorf("GasLimit check failed for block %v (%v > %v)", block.GasLimit, a, b)
}
num := parent.Number()
num.Sub(block.Number, num)
if num.Cmp(big.NewInt(1)) != 0 {
return BlockNumberErr
}
if checkPow {
// Verify the nonce of the block. Return an error if it's not valid
if !pow.Verify(types.NewBlockWithHeader(block)) {
return ValidationError("Block's nonce is invalid (= %x)", block.Nonce)
}
}
return nil
}