path: root/miner/worker.go

package miner

import (
    "fmt"
    "math/big"
    "sort"
    "sync"

    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/ethutil"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/pow"
    "github.com/ethereum/go-ethereum/state"
    "gopkg.in/fatih/set.v0"
)

type environment struct {
    totalUsedGas *big.Int
    state        *state.StateDB
    coinbase     *state.StateObject
    block        *types.Block
    ancestors    *set.Set
    uncles       *set.Set
}

func env(block *types.Block, eth core.Backend) *environment {
    state := state.New(block.Root(), eth.Db())
    env := &environment{
        totalUsedGas: new(big.Int),
        state:        state,
        block:        block,
        ancestors:    set.New(),
        uncles:       set.New(),
        coinbase:     state.GetOrNewStateObject(block.Coinbase()),
    }
    for _, ancestor := range eth.ChainManager().GetAncestors(block, 7) {
        env.ancestors.Add(string(ancestor.Hash()))
    }

    return env
}

type Work struct {
    Number uint64
    Nonce  []byte
}

type Agent interface {
    Work() chan<- *types.Block
    SetWorkCh(chan<- Work)
    Stop()
    Start()
    Pow() pow.PoW
}

type worker struct {
    mu     sync.Mutex
    agents []Agent
    recv   chan Work
    mux    *event.TypeMux
    quit   chan struct{}
    pow    pow.PoW

    eth      core.Backend
    chain    *core.ChainManager
    proc     *core.BlockProcessor
    coinbase []byte

    current *environment

    mining bool
}

func newWorker(coinbase []byte, eth core.Backend) *worker {
    return &worker{
        eth:      eth,
        mux:      eth.EventMux(),
        recv:     make(chan Work),
        chain:    eth.ChainManager(),
        proc:     eth.BlockProcessor(),
        coinbase: coinbase,
    }
}

func (self *worker) start() {
    self.mining = true

    self.quit = make(chan struct{})

    // spin up agents
    for _, agent := range self.agents {
        agent.Start()
    }

    go self.update()
    go self.wait()
}

func (self *worker) stop() {
    self.mining = false

    close(self.quit)
}

func (self *worker) register(agent Agent) {
    self.agents = append(self.agents, agent)
    agent.SetWorkCh(self.recv)
}

func (self *worker) update() {
    events := self.mux.Subscribe(core.ChainEvent{}, core.NewMinedBlockEvent{})

out:
    for {
        select {
        case event := <-events.Chan():
            switch ev := event.(type) {
            case core.ChainEvent:
                if self.current.block != ev.Block {
                    self.commitNewWork()
                }
            case core.NewMinedBlockEvent:
                self.commitNewWork()
            }
        case <-self.quit:
            // stop all agents
            for _, agent := range self.agents {
                agent.Stop()
            }
            break out
        }
    }

    events.Unsubscribe()
}

func (self *worker) wait() {
    for {
        for work := range self.recv {
            block := self.current.block
            if block.Number().Uint64() == work.Number && block.Nonce() == nil {
                self.current.block.Header().Nonce = work.Nonce

                if err := self.chain.InsertChain(types.Blocks{self.current.block}); err == nil {
                    self.mux.Post(core.NewMinedBlockEvent{self.current.block})
                } else {
                    self.commitNewWork()
                }
            }
            break
        }
    }
}

func (self *worker) push() {
    if self.mining {
        self.current.block.Header().GasUsed = self.current.totalUsedGas
        self.current.block.SetRoot(self.current.state.Root())

        // push new work to agents
        for _, agent := range self.agents {
            agent.Work() <- self.current.block
        }
    }
}

func (self *worker) commitNewWork() {
    self.mu.Lock()
    defer self.mu.Unlock()

    self.current = env(self.chain.NewBlock(self.coinbase), self.eth)
    parent := self.chain.GetBlock(self.current.block.ParentHash())
    self.current.coinbase.SetGasPool(core.CalcGasLimit(parent, self.current.block))

    transactions := self.eth.TxPool().GetTransactions()
    sort.Sort(types.TxByNonce{transactions})

    minerlogger.Infof("committing new work with %d txs\n", len(transactions))
    // Keep track of transactions which return errors so they can be removed
    var remove types.Transactions
gasLimit:
    for _, tx := range transactions {
        err := self.commitTransaction(tx)
        switch {
        case core.IsNonceErr(err):
            // Remove invalid transactions
            remove = append(remove, tx)
        case state.IsGasLimitErr(err):
            // Break on gas limit
            break gasLimit
        }

        if err != nil {
            minerlogger.Infoln(err)
        }
    }
    self.eth.TxPool().RemoveSet(remove)

    self.current.coinbase.AddBalance(core.BlockReward)

    self.current.state.Update(ethutil.Big0)
    self.push()
}

var (
    inclusionReward = new(big.Int).Div(core.BlockReward, big.NewInt(32))
    _uncleReward    = new(big.Int).Mul(core.BlockReward, big.NewInt(15))
    uncleReward     = new(big.Int).Div(_uncleReward, big.NewInt(16))
)

func (self *worker) commitUncle(uncle *types.Header) error {
    if self.current.uncles.Has(string(uncle.Hash())) {
        // Error not unique
        return core.UncleError("Uncle not unique")
    }
    self.current.uncles.Add(string(uncle.Hash()))

    if !self.current.ancestors.Has(string(uncle.ParentHash)) {
        return core.UncleError(fmt.Sprintf("Uncle's parent unknown (%x)", uncle.ParentHash[0:4]))
    }

    if !self.pow.Verify(types.NewBlockWithHeader(uncle)) {
        return core.ValidationError("Uncle's nonce is invalid (= %v)", ethutil.Bytes2Hex(uncle.Nonce))
    }

    uncleAccount := self.current.state.GetAccount(uncle.Coinbase)
    uncleAccount.AddBalance(uncleReward)

    self.current.coinbase.AddBalance(uncleReward)

    return nil
}

func (self *worker) commitTransaction(tx *types.Transaction) error {
    //fmt.Printf("proc %x %v\n", tx.Hash()[:3], tx.Nonce())
    receipt, _, err := self.proc.ApplyTransaction(self.current.coinbase, self.current.state, self.current.block, tx, self.current.totalUsedGas, true)
    if err != nil && (core.IsNonceErr(err) || state.IsGasLimitErr(err)) {
        return err
    }

    self.current.block.AddTransaction(tx)
    self.current.block.AddReceipt(receipt)

    return nil
}