Golang Block.Difficulty方法代碼示例

// 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.blockchain.GetBlock(block.ParentHash()); parent != nil {
			td = new(big.Int).Add(block.Difficulty(), pm.blockchain.GetTd(block.ParentHash()))
		} 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.blockchain.HasBlock(hash) {
		for _, peer := range peers {
			if peer.version < eth62 {
				peer.SendNewBlockHashes61([]common.Hash{hash})
			} else {
				peer.SendNewBlockHashes([]common.Hash{hash}, []uint64{block.NumberU64()})
			}
		}
		glog.V(logger.Detail).Infof("announced block %x to %d peers in %v", hash[:4], len(peers), time.Since(block.ReceivedAt))
	}
}

// ResetWithGenesisBlock purges the entire blockchain, restoring it to the
// specified genesis state.
func (bc *ChainManager) ResetWithGenesisBlock(genesis *types.Block) {
	bc.mu.Lock()
	defer bc.mu.Unlock()

	// Dump the entire block chain and purge the caches
	for block := bc.currentBlock; block != nil; block = bc.GetBlock(block.ParentHash()) {
		DeleteBlock(bc.chainDb, block.Hash())
	}
	bc.headerCache.Purge()
	bc.bodyCache.Purge()
	bc.bodyRLPCache.Purge()
	bc.blockCache.Purge()
	bc.futureBlocks.Purge()

	// Prepare the genesis block and reinitialize 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.setTotalDifficulty(genesis.Difficulty())
}

// 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
}

func CalculateTD(block, parent *types.Block) *big.Int {
	if parent == nil {
		return block.Difficulty()
	}

	td := new(big.Int).Add(parent.Td, block.Header().Difficulty)

	return td
}

func makeHeader(parent *types.Block, state *state.StateDB) *types.Header {
	time := parent.Time() + 10 // block time is fixed at 10 seconds
	return &types.Header{
		Root:       state.Root(),
		ParentHash: parent.Hash(),
		Coinbase:   parent.Coinbase(),
		Difficulty: CalcDifficulty(int64(time), int64(parent.Time()), parent.Difficulty()),
		GasLimit:   CalcGasLimit(parent),
		GasUsed:    new(big.Int),
		Number:     new(big.Int).Add(parent.Number(), common.Big1),
		Time:       uint64(time),
	}
}

// WriteBlock writes the block to the chain.
func (self *ChainManager) 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)

	self.mu.RLock()
	cblock := self.currentBlock
	self.mu.RUnlock()

	// 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 {
		// chain fork
		if block.ParentHash() != cblock.Hash() {
			// during split we merge two different chains and create the new canonical chain
			err := self.reorg(cblock, block)
			if err != nil {
				return NonStatTy, err
			}
		}
		status = CanonStatTy

		self.mu.Lock()
		self.setTotalDifficulty(td)
		self.insert(block)
		self.mu.Unlock()
	} else {
		status = SideStatTy
	}

	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)
	}
	// Delete from future blocks
	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.Header().ParentHash) {
		bc.removeBlock(block)
	}

	// Prepare the genesis block
	gb.Td = gb.Difficulty()
	bc.genesisBlock = gb
	bc.write(bc.genesisBlock)
	bc.insert(bc.genesisBlock)
	bc.currentBlock = bc.genesisBlock
	bc.makeCache()
	bc.td = gb.Difficulty()
}

// 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) {
		// Reorganise 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 := self.hc.WriteTd(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("failed to write block contents: %v", err)
	}

	self.futureBlocks.Remove(block.Hash())

	return
}

// 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 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))
	}

	expd := CalcDifficulty(int64(block.Time), int64(parent.Time()), 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)
	}

	if int64(block.Time) > time.Now().Unix() {
		return BlockFutureErr
	}

	num := parent.Number()
	num.Sub(block.Number, num)
	if num.Cmp(big.NewInt(1)) != 0 {
		return BlockNumberErr
	}

	if block.Time <= uint64(parent.Time()) {
		return BlockEqualTSErr //ValidationError("Block timestamp equal or less than previous block (%v - %v)", block.Time, parent.Time)
	}

	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
}

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,
	}
}