path: root/les/backend.go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

// Package les implements the Light Ethereum Subprotocol.
package les

import (
    "fmt"
    "sync"
    "time"

    "github.com/dexon-foundation/dexon/accounts"
    "github.com/dexon-foundation/dexon/common"
    "github.com/dexon-foundation/dexon/common/hexutil"
    "github.com/dexon-foundation/dexon/consensus"
    "github.com/dexon-foundation/dexon/core"
    "github.com/dexon-foundation/dexon/core/bloombits"
    "github.com/dexon-foundation/dexon/core/rawdb"
    "github.com/dexon-foundation/dexon/core/types"
    "github.com/dexon-foundation/dexon/eth"
    "github.com/dexon-foundation/dexon/eth/downloader"
    "github.com/dexon-foundation/dexon/eth/filters"
    "github.com/dexon-foundation/dexon/eth/gasprice"
    "github.com/dexon-foundation/dexon/event"
    "github.com/dexon-foundation/dexon/internal/ethapi"
    "github.com/dexon-foundation/dexon/light"
    "github.com/dexon-foundation/dexon/log"
    "github.com/dexon-foundation/dexon/node"
    "github.com/dexon-foundation/dexon/p2p"
    "github.com/dexon-foundation/dexon/p2p/discv5"
    "github.com/dexon-foundation/dexon/params"
    rpc "github.com/dexon-foundation/dexon/rpc"
)

type LightEthereum struct {
    lesCommons

    odr         *LesOdr
    relay       *LesTxRelay
    chainConfig *params.ChainConfig
    // Channel for shutting down the service
    shutdownChan chan bool

    // Handlers
    peers      *peerSet
    txPool     *light.TxPool
    blockchain *light.LightChain
    serverPool *serverPool
    reqDist    *requestDistributor
    retriever  *retrieveManager

    bloomRequests chan chan *bloombits.Retrieval // Channel receiving bloom data retrieval requests
    bloomIndexer  *core.ChainIndexer

    ApiBackend *LesApiBackend

    eventMux       *event.TypeMux
    engine         consensus.Engine
    accountManager *accounts.Manager

    networkId     uint64
    netRPCService *ethapi.PublicNetAPI

    wg sync.WaitGroup
}

func New(ctx *node.ServiceContext, config *eth.Config) (*LightEthereum, error) {
    chainDb, err := eth.CreateDB(ctx, config, "lightchaindata")
    if err != nil {
        return nil, err
    }
    chainConfig, genesisHash, genesisErr := core.SetupGenesisBlockWithOverride(chainDb, config.Genesis, config.ConstantinopleOverride)
    if _, isCompat := genesisErr.(*params.ConfigCompatError); genesisErr != nil && !isCompat {
        return nil, genesisErr
    }
    log.Info("Initialised chain configuration", "config", chainConfig)

    peers := newPeerSet()
    quitSync := make(chan struct{})

    leth := &LightEthereum{
        lesCommons: lesCommons{
            chainDb: chainDb,
            config:  config,
            iConfig: light.DefaultClientIndexerConfig,
        },
        chainConfig:    chainConfig,
        eventMux:       ctx.EventMux,
        peers:          peers,
        reqDist:        newRequestDistributor(peers, quitSync),
        accountManager: ctx.AccountManager,
        engine:         eth.CreateConsensusEngine(ctx, chainConfig, &config.Ethash, nil, false, chainDb),
        shutdownChan:   make(chan bool),
        networkId:      config.NetworkId,
        bloomRequests:  make(chan chan *bloombits.Retrieval),
        bloomIndexer:   eth.NewBloomIndexer(chainDb, params.BloomBitsBlocksClient, params.HelperTrieConfirmations),
    }

    leth.relay = NewLesTxRelay(peers, leth.reqDist)
    leth.serverPool = newServerPool(chainDb, quitSync, &leth.wg)
    leth.retriever = newRetrieveManager(peers, leth.reqDist, leth.serverPool)

    leth.odr = NewLesOdr(chainDb, light.DefaultClientIndexerConfig, leth.retriever)
    leth.chtIndexer = light.NewChtIndexer(chainDb, leth.odr, params.CHTFrequencyClient, params.HelperTrieConfirmations)
    leth.bloomTrieIndexer = light.NewBloomTrieIndexer(chainDb, leth.odr, params.BloomBitsBlocksClient, params.BloomTrieFrequency)
    leth.odr.SetIndexers(leth.chtIndexer, leth.bloomTrieIndexer, leth.bloomIndexer)

    // Note: NewLightChain adds the trusted checkpoint so it needs an ODR with
    // indexers already set but not started yet
    if leth.blockchain, err = light.NewLightChain(leth.odr, leth.chainConfig, leth.engine); err != nil {
        return nil, err
    }
    // Note: AddChildIndexer starts the update process for the child
    leth.bloomIndexer.AddChildIndexer(leth.bloomTrieIndexer)
    leth.chtIndexer.Start(leth.blockchain)
    leth.bloomIndexer.Start(leth.blockchain)

    // Rewind the chain in case of an incompatible config upgrade.
    if compat, ok := genesisErr.(*params.ConfigCompatError); ok {
        log.Warn("Rewinding chain to upgrade configuration", "err", compat)
        leth.blockchain.SetHead(compat.RewindTo)
        rawdb.WriteChainConfig(chainDb, genesisHash, chainConfig)
    }

    leth.txPool = light.NewTxPool(leth.chainConfig, leth.blockchain, leth.relay)
    if leth.protocolManager, err = NewProtocolManager(leth.chainConfig, light.DefaultClientIndexerConfig, true, config.NetworkId, leth.eventMux, leth.engine, leth.peers, leth.blockchain, nil, chainDb, leth.odr, leth.relay, leth.serverPool, quitSync, &leth.wg); err != nil {
        return nil, err
    }
    leth.ApiBackend = &LesApiBackend{leth, nil}
    gpoParams := config.GPO
    if gpoParams.Default == nil {
        gpoParams.Default = config.MinerGasPrice
    }
    leth.ApiBackend.gpo = gasprice.NewOracle(leth.ApiBackend, gpoParams)
    return leth, nil
}

func lesTopic(genesisHash common.Hash, protocolVersion uint) discv5.Topic {
    var name string
    switch protocolVersion {
    case lpv1:
        name = "LES"
    case lpv2:
        name = "LES2"
    default:
        panic(nil)
    }
    return discv5.Topic(name + "@" + common.Bytes2Hex(genesisHash.Bytes()[0:8]))
}

type LightDummyAPI struct{}

// Etherbase is the address that mining rewards will be send to
func (s *LightDummyAPI) Etherbase() (common.Address, error) {
    return common.Address{}, fmt.Errorf("not supported")
}

// Coinbase is the address that mining rewards will be send to (alias for Etherbase)
func (s *LightDummyAPI) Coinbase() (common.Address, error) {
    return common.Address{}, fmt.Errorf("not supported")
}

// Hashrate returns the POW hashrate
func (s *LightDummyAPI) Hashrate() hexutil.Uint {
    return 0
}

// Mining returns an indication if this node is currently mining.
func (s *LightDummyAPI) Mining() bool {
    return false
}

// APIs returns the collection of RPC services the ethereum package offers.
// NOTE, some of these services probably need to be moved to somewhere else.
func (s *LightEthereum) APIs() []rpc.API {
    return append(ethapi.GetAPIs(s.ApiBackend), []rpc.API{
        {
            Namespace: "eth",
            Version:   "1.0",
            Service:   &LightDummyAPI{},
            Public:    true,
        }, {
            Namespace: "eth",
            Version:   "1.0",
            Service:   downloader.NewPublicDownloaderAPI(s.protocolManager.downloader, s.eventMux),
            Public:    true,
        }, {
            Namespace: "eth",
            Version:   "1.0",
            Service:   filters.NewPublicFilterAPI(s.ApiBackend, true),
            Public:    true,
        }, {
            Namespace: "net",
            Version:   "1.0",
            Service:   s.netRPCService,
            Public:    true,
        },
    }...)
}

func (s *LightEthereum) ResetWithGenesisBlock(gb *types.Block) {
    s.blockchain.ResetWithGenesisBlock(gb)
}

func (s *LightEthereum) BlockChain() *light.LightChain { return s.blockchain }
func (s *LightEthereum) TxPool() *light.TxPool         { return s.txPool }
func (s *LightEthereum) Engine() consensus.Engine      { return s.engine }
func (s *LightEthereum) LesVersion() int               { return int(ClientProtocolVersions[0]) }
func (s *LightEthereum) Downloader() ethapi.Downloader { return s.protocolManager.downloader }
func (s *LightEthereum) EventMux() *event.TypeMux      { return s.eventMux }

// Protocols implements node.Service, returning all the currently configured
// network protocols to start.
func (s *LightEthereum) Protocols() []p2p.Protocol {
    return s.makeProtocols(ClientProtocolVersions)
}

// Start implements node.Service, starting all internal goroutines needed by the
// Ethereum protocol implementation.
func (s *LightEthereum) Start(srvr *p2p.Server) error {
    log.Warn("Light client mode is an experimental feature")
    s.startBloomHandlers(params.BloomBitsBlocksClient)
    s.netRPCService = ethapi.NewPublicNetAPI(srvr, s.networkId)
    // clients are searching for the first advertised protocol in the list
    protocolVersion := AdvertiseProtocolVersions[0]
    s.serverPool.start(srvr, lesTopic(s.blockchain.Genesis().Hash(), protocolVersion))
    s.protocolManager.Start(s.config.LightPeers)
    return nil
}

// Stop implements node.Service, terminating all internal goroutines used by the
// Ethereum protocol.
func (s *LightEthereum) Stop() error {
    s.odr.Stop()
    s.bloomIndexer.Close()
    s.chtIndexer.Close()
    s.blockchain.Stop()
    s.protocolManager.Stop()
    s.txPool.Stop()
    s.engine.Close()

    s.eventMux.Stop()

    time.Sleep(time.Millisecond * 200)
    s.chainDb.Close()
    close(s.shutdownChan)

    return nil
}