Golang Block.Difficulty方法代码示例

// 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.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
}

func NewBlockRes(block *types.Block, 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.Miner = newHexData(block.Coinbase())
	res.Difficulty = newHexNum(block.Difficulty())
	res.TotalDifficulty = newHexNum(block.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
}

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()
}

// 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
}

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(25)) // block time is fixed at 25 seconds
	}
	return &types.Header{
		Root:       state.Root(),
		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,
	}
}