path: root/ethminer/miner.go

package ethminer

import (
    "bytes"
    "github.com/ethereum/eth-go/ethchain"
    "github.com/ethereum/eth-go/ethlog"
    "github.com/ethereum/eth-go/ethreact"
    "github.com/ethereum/eth-go/ethwire"
    "sort"
)

var logger = ethlog.NewLogger("MINER")

type Miner struct {
    pow         ethchain.PoW
    ethereum    ethchain.EthManager
    coinbase    []byte
    reactChan   chan ethreact.Event
    txs         ethchain.Transactions
    uncles      []*ethchain.Block
    block       *ethchain.Block
    powChan     chan []byte
    powQuitChan chan ethreact.Event
    quitChan    chan chan error
}

func (self *Miner) GetPow() ethchain.PoW {
    return self.pow
}

func NewDefaultMiner(coinbase []byte, ethereum ethchain.EthManager) *Miner {
    miner := Miner{
        pow:      &ethchain.EasyPow{},
        ethereum: ethereum,
        coinbase: coinbase,
    }

    return &miner
}

func (miner *Miner) Start() {
    miner.reactChan = make(chan ethreact.Event, 1)   // This is the channel that receives 'updates' when ever a new transaction or block comes in
    miner.powChan = make(chan []byte, 1)             // This is the channel that receives valid sha hashes for a given block
    miner.powQuitChan = make(chan ethreact.Event, 1) // This is the channel that can exit the miner thread
    miner.quitChan = make(chan chan error, 1)

    // Insert initial TXs in our little miner 'pool'
    miner.txs = miner.ethereum.TxPool().Flush()
    miner.block = miner.ethereum.BlockChain().NewBlock(miner.coinbase)

    // Prepare inital block
    //miner.ethereum.StateManager().Prepare(miner.block.State(), miner.block.State())
    go miner.listener()

    reactor := miner.ethereum.Reactor()
    reactor.Subscribe("newBlock", miner.reactChan)
    reactor.Subscribe("newTx:pre", miner.reactChan)

    // We need the quit chan to be a Reactor event.
    // The POW search method is actually blocking and if we don't
    // listen to the reactor events inside of the pow itself
    // The miner overseer will never get the reactor events themselves
    // Only after the miner will find the sha
    reactor.Subscribe("newBlock", miner.powQuitChan)
    reactor.Subscribe("newTx:pre", miner.powQuitChan)

    logger.Infoln("Started")

    reactor.Post("miner:start", miner)
}

func (miner *Miner) listener() {
    for {
        select {
        case status := <-miner.quitChan:
            logger.Infoln("Stopped")
            status <- nil
            return
        case chanMessage := <-miner.reactChan:

            if block, ok := chanMessage.Resource.(*ethchain.Block); ok {
                //logger.Infoln("Got new block via Reactor")
                if bytes.Compare(miner.ethereum.BlockChain().CurrentBlock.Hash(), block.Hash()) == 0 {
                    // TODO: Perhaps continue mining to get some uncle rewards
                    //logger.Infoln("New top block found resetting state")

                    // Filter out which Transactions we have that were not in this block
                    var newtxs []*ethchain.Transaction
                    for _, tx := range miner.txs {
                        found := false
                        for _, othertx := range block.Transactions() {
                            if bytes.Compare(tx.Hash(), othertx.Hash()) == 0 {
                                found = true
                            }
                        }
                        if found == false {
                            newtxs = append(newtxs, tx)
                        }
                    }
                    miner.txs = newtxs

                    // Setup a fresh state to mine on
                    //miner.block = miner.ethereum.BlockChain().NewBlock(miner.coinbase, miner.txs)

                } else {
                    if bytes.Compare(block.PrevHash, miner.ethereum.BlockChain().CurrentBlock.PrevHash) == 0 {
                        logger.Infoln("Adding uncle block")
                        miner.uncles = append(miner.uncles, block)
                    }
                }
            }

            if tx, ok := chanMessage.Resource.(*ethchain.Transaction); ok {
                found := false
                for _, ctx := range miner.txs {
                    if found = bytes.Compare(ctx.Hash(), tx.Hash()) == 0; found {
                        break
                    }

                }
                if found == false {
                    // Undo all previous commits
                    miner.block.Undo()
                    // Apply new transactions
                    miner.txs = append(miner.txs, tx)
                }
            }
        default:
            miner.mineNewBlock()
        }
    }
}

func (miner *Miner) Stop() {
    logger.Infoln("Stopping...")

    miner.powQuitChan <- ethreact.Event{}

    status := make(chan error)
    miner.quitChan <- status
    <-status

    reactor := miner.ethereum.Reactor()
    reactor.Unsubscribe("newBlock", miner.powQuitChan)
    reactor.Unsubscribe("newTx:pre", miner.powQuitChan)
    reactor.Unsubscribe("newBlock", miner.reactChan)
    reactor.Unsubscribe("newTx:pre", miner.reactChan)

    reactor.Post("miner:stop", miner)
}

func (self *Miner) mineNewBlock() {
    stateManager := self.ethereum.StateManager()

    self.block = self.ethereum.BlockChain().NewBlock(self.coinbase)

    // Apply uncles
    if len(self.uncles) > 0 {
        self.block.SetUncles(self.uncles)
    }

    // Sort the transactions by nonce in case of odd network propagation
    sort.Sort(ethchain.TxByNonce{self.txs})

    // Accumulate all valid transactions and apply them to the new state
    // Error may be ignored. It's not important during mining
    parent := self.ethereum.BlockChain().GetBlock(self.block.PrevHash)
    coinbase := self.block.State().GetOrNewStateObject(self.block.Coinbase)
    coinbase.SetGasPool(self.block.CalcGasLimit(parent))
    receipts, txs, unhandledTxs, err := stateManager.ProcessTransactions(coinbase, self.block.State(), self.block, self.block, self.txs)
    if err != nil {
        logger.Debugln(err)
    }
    self.txs = append(txs, unhandledTxs...)
    self.block.SetTxHash(receipts)

    // Set the transactions to the block so the new SHA3 can be calculated
    self.block.SetReceipts(receipts, txs)

    // Accumulate the rewards included for this block
    stateManager.AccumelateRewards(self.block.State(), self.block)

    self.block.State().Update()

    logger.Infof("Mining on block. Includes %v transactions", len(self.txs))

    // Find a valid nonce
    self.block.Nonce = self.pow.Search(self.block, self.powQuitChan)
    if self.block.Nonce != nil {
        err := self.ethereum.StateManager().Process(self.block, false)
        if err != nil {
            logger.Infoln(err)
        } else {
            self.ethereum.Broadcast(ethwire.MsgBlockTy, []interface{}{self.block.Value().Val})
            logger.Infof("🔨  Mined block %x\n", self.block.Hash())
            logger.Infoln(self.block)
            // Gather the new batch of transactions currently in the tx pool
            self.txs = self.ethereum.TxPool().CurrentTransactions()
        }
    }
}