path: root/eth/backend.go

package eth

import (
    "encoding/json"
    "net"
    "sync"

    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/ethutil"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/event/filter"
    ethlogger "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/pow/ezp"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/ethereum/go-ethereum/state"
    "github.com/ethereum/go-ethereum/whisper"
)

const (
    seedNodeAddress = "poc-7.ethdev.com:30300"
)

var logger = ethlogger.NewLogger("SERV")

type Ethereum struct {
    // Channel for shutting down the ethereum
    shutdownChan chan bool
    quit         chan bool

    // DB interface
    db        ethutil.Database
    blacklist p2p.Blacklist

    //*** SERVICES ***
    // State manager for processing new blocks and managing the over all states
    blockManager *core.BlockManager
    txPool       *core.TxPool
    chainManager *core.ChainManager
    blockPool    *BlockPool
    whisper      *whisper.Whisper

    server   *p2p.Server
    eventMux *event.TypeMux
    txSub    event.Subscription
    blockSub event.Subscription

    RpcServer  *rpc.JsonRpcServer
    keyManager *crypto.KeyManager

    clientIdentity p2p.ClientIdentity

    synclock  sync.Mutex
    syncGroup sync.WaitGroup

    filterManager *filter.FilterManager
    //filterMu      sync.RWMutex
    //filterId      int
    //filters       map[int]*core.Filter

    Mining bool
}

func New(db ethutil.Database, identity p2p.ClientIdentity, keyManager *crypto.KeyManager, nat p2p.NAT, port string, maxPeers int) (*Ethereum, error) {

    saveProtocolVersion(db)
    ethutil.Config.Db = db

    eth := &Ethereum{
        shutdownChan:   make(chan bool),
        quit:           make(chan bool),
        db:             db,
        keyManager:     keyManager,
        clientIdentity: identity,
        blacklist:      p2p.NewBlacklist(),
        eventMux:       &event.TypeMux{},
        filters:        make(map[int]*core.Filter),
    }

    eth.txPool = core.NewTxPool(eth)
    eth.chainManager = core.NewChainManager(eth.EventMux())
    eth.blockManager = core.NewBlockManager(eth)
    eth.chainManager.SetProcessor(eth.blockManager)
    eth.whisper = whisper.New()

    hasBlock := eth.chainManager.HasBlock
    insertChain := eth.chainManager.InsertChain
    eth.blockPool = NewBlockPool(hasBlock, insertChain, ezp.Verify)

    // Start services
    eth.txPool.Start()

    ethProto := EthProtocol(eth.txPool, eth.chainManager, eth.blockPool)
    protocols := []p2p.Protocol{ethProto, eth.whisper.Protocol()}

    server := &p2p.Server{
        Identity:   identity,
        MaxPeers:   maxPeers,
        Protocols:  protocols,
        ListenAddr: ":" + port,
        Blacklist:  eth.blacklist,
        NAT:        nat,
    }

    eth.server = server

    return eth, nil
}

func (s *Ethereum) KeyManager() *crypto.KeyManager {
    return s.keyManager
}

func (s *Ethereum) ClientIdentity() p2p.ClientIdentity {
    return s.clientIdentity
}

func (s *Ethereum) ChainManager() *core.ChainManager {
    return s.chainManager
}

func (s *Ethereum) BlockManager() *core.BlockManager {
    return s.blockManager
}

func (s *Ethereum) TxPool() *core.TxPool {
    return s.txPool
}

func (s *Ethereum) BlockPool() *BlockPool {
    return s.blockPool
}

func (s *Ethereum) EventMux() *event.TypeMux {
    return s.eventMux
}
func (self *Ethereum) Db() ethutil.Database {
    return self.db
}

func (s *Ethereum) IsMining() bool {
    return s.Mining
}

func (s *Ethereum) IsListening() bool {
    // XXX TODO
    return false
}

func (s *Ethereum) PeerCount() int {
    return s.server.PeerCount()
}

func (s *Ethereum) Peers() []*p2p.Peer {
    return s.server.Peers()
}

// Start the ethereum
func (s *Ethereum) Start(seed bool) error {
    err := s.server.Start()
    if err != nil {
        return err
    }
    s.blockPool.Start()
    s.whisper.Start()

    go s.filterLoop()

    // broadcast transactions
    s.txSub = s.eventMux.Subscribe(core.TxPreEvent{})
    go s.txBroadcastLoop()

    // broadcast mined blocks
    s.blockSub = s.eventMux.Subscribe(core.NewMinedBlockEvent{})
    go s.blockBroadcastLoop()

    // TODO: read peers here
    if seed {
        logger.Infof("Connect to seed node %v", seedNodeAddress)
        if err := s.SuggestPeer(seedNodeAddress); err != nil {
            return err
        }
    }

    logger.Infoln("Server started")
    return nil
}

func (self *Ethereum) SuggestPeer(addr string) error {
    netaddr, err := net.ResolveTCPAddr("tcp", addr)
    if err != nil {
        logger.Errorf("couldn't resolve %s:", addr, err)
        return err
    }

    self.server.SuggestPeer(netaddr.IP, netaddr.Port, nil)
    return nil
}

func (s *Ethereum) Stop() {
    // Close the database
    defer s.db.Close()

    close(s.quit)

    s.txSub.Unsubscribe()    // quits txBroadcastLoop
    s.blockSub.Unsubscribe() // quits blockBroadcastLoop

    if s.RpcServer != nil {
        s.RpcServer.Stop()
    }
    s.txPool.Stop()
    s.eventMux.Stop()
    s.blockPool.Stop()
    s.whisper.Stop()

    logger.Infoln("Server stopped")
    close(s.shutdownChan)
}

// This function will wait for a shutdown and resumes main thread execution
func (s *Ethereum) WaitForShutdown() {
    <-s.shutdownChan
}

func WritePeers(path string, addresses []string) {
    if len(addresses) > 0 {
        data, _ := json.MarshalIndent(addresses, "", "    ")
        ethutil.WriteFile(path, data)
    }
}

func ReadPeers(path string) (ips []string, err error) {
    var data string
    data, err = ethutil.ReadAllFile(path)
    if err != nil {
        json.Unmarshal([]byte(data), &ips)
    }
    return
}

// now tx broadcasting is taken out of txPool
// handled here via subscription, efficiency?
func (self *Ethereum) txBroadcastLoop() {
    // automatically stops if unsubscribe
    for obj := range self.txSub.Chan() {
        event := obj.(core.TxPreEvent)
        self.server.Broadcast("eth", TxMsg, []interface{}{event.Tx.RlpData()})
    }
}

func (self *Ethereum) blockBroadcastLoop() {
    // automatically stops if unsubscribe
    for obj := range self.txSub.Chan() {
        event := obj.(core.NewMinedBlockEvent)
        self.server.Broadcast("eth", NewBlockMsg, event.Block.Value().Val)
    }
}

func saveProtocolVersion(db ethutil.Database) {
    d, _ := db.Get([]byte("ProtocolVersion"))
    protocolVersion := ethutil.NewValue(d).Uint()

    if protocolVersion == 0 {
        db.Put([]byte("ProtocolVersion"), ethutil.NewValue(ProtocolVersion).Bytes())
    }
}

// InstallFilter adds filter for blockchain events.
// The filter's callbacks will run for matching blocks and messages.
// The filter should not be modified after it has been installed.
func (self *Ethereum) InstallFilter(filter *core.Filter) (id int) {
    self.filterMu.Lock()
    id = self.filterId
    self.filters[id] = filter
    self.filterId++
    self.filterMu.Unlock()
    return id
}

func (self *Ethereum) UninstallFilter(id int) {
    self.filterMu.Lock()
    delete(self.filters, id)
    self.filterMu.Unlock()
}

// GetFilter retrieves a filter installed using InstallFilter.
// The filter may not be modified.
func (self *Ethereum) GetFilter(id int) *core.Filter {
    self.filterMu.RLock()
    defer self.filterMu.RUnlock()
    return self.filters[id]
}

func (self *Ethereum) filterLoop() {
    // Subscribe to events
    events := self.eventMux.Subscribe(core.NewBlockEvent{}, state.Messages(nil))
    for event := range events.Chan() {
        switch event.(type) {
        case core.NewBlockEvent:
            self.filterMu.RLock()
            for _, filter := range self.filters {
                if filter.BlockCallback != nil {
                    e := event.(core.NewBlockEvent)
                    filter.BlockCallback(e.Block)
                }
            }
            self.filterMu.RUnlock()
        case state.Messages:
            self.filterMu.RLock()
            for _, filter := range self.filters {
                if filter.MessageCallback != nil {
                    e := event.(state.Messages)
                    msgs := filter.FilterMessages(e)
                    if len(msgs) > 0 {
                        filter.MessageCallback(msgs)
                    }
                }
            }
            self.filterMu.RUnlock()
        }
    }
}