github.com/linapex/ethereum-dpos-chinese@v0.0.0-20190316121959-b78b3a4a1ece/eth/backend.go

//<developer>
//    <name>linapex 曹一峰</name>
//    <email>linapex@163.com</email>
//    <wx>superexc</wx>
//    <qqgroup>128148617</qqgroup>
//    <url>https://jsq.ink</url>
//    <role>pku engineer</role>
//    <date>2019-03-16 12:09:38</date>
//</624342633153564672>


//包ETH实现以太坊协议。
package eth

import (
	"errors"
	"fmt"
	"math/big"
	"runtime"
	"sync"
	"sync/atomic"

	"github.com/ethereum/go-ethereum/accounts"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/consensus"
//“github.com/ethereum/go-ethereum/consension/clique”
	"github.com/ethereum/go-ethereum/consensus/dpos"
	"github.com/ethereum/go-ethereum/core"
	"github.com/ethereum/go-ethereum/core/bloombits"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/core/vm"
	"github.com/ethereum/go-ethereum/eth/downloader"
	"github.com/ethereum/go-ethereum/eth/filters"
	"github.com/ethereum/go-ethereum/eth/gasprice"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/event"
	"github.com/ethereum/go-ethereum/internal/ethapi"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/miner"
	"github.com/ethereum/go-ethereum/node"
	"github.com/ethereum/go-ethereum/p2p"
	"github.com/ethereum/go-ethereum/params"
	"github.com/ethereum/go-ethereum/rlp"
	"github.com/ethereum/go-ethereum/rpc"
)


type LesServer interface {
	Start(srvr *p2p.Server)
	Stop()
	Protocols() []p2p.Protocol
	SetBloomBitsIndexer(bbIndexer *core.ChainIndexer)
}

//以太坊实施以太坊全节点服务。
type Ethereum struct {
	config      *Config
	chainConfig *params.ChainConfig

//关闭服务的通道
shutdownChan chan bool //关闭以太坊的通道

//处理程序
	txPool          *core.TxPool
	blockchain      *core.BlockChain
	protocolManager *ProtocolManager
	lesServer       LesServer

//数据库接口
chainDb ethdb.Database //区块链数据库

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

bloomRequests chan chan *bloombits.Retrieval //接收Bloom数据检索请求的通道
bloomIndexer  *core.ChainIndexer             //块导入期间的Bloom索引器操作

	APIBackend *EthAPIBackend

	miner     *miner.Miner
	gasPrice  *big.Int
	validator common.Address
	coinbase  common.Address

	networkID     uint64
	netRPCService *ethapi.PublicNetAPI

lock sync.RWMutex //保护可变油田（如天然气价格和Coinbase）
}

func (s *Ethereum) AddLesServer(ls LesServer) {
	s.lesServer = ls
	ls.SetBloomBitsIndexer(s.bloomIndexer)
}

//新建创建新的以太坊对象（包括
//公共EythUM对象的初始化
func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
	if config.SyncMode == downloader.LightSync {
		return nil, errors.New("can't run eth.Ethereum in light sync mode, use les.LightEthereum")
	}
	if !config.SyncMode.IsValid() {
		return nil, fmt.Errorf("invalid sync mode %d", config.SyncMode)
	}
	chainDb, err := CreateDB(ctx, config, "chaindata")
	if err != nil {
		return nil, err
	}
	chainConfig, genesisHash, genesisErr := core.SetupGenesisBlock(chainDb, config.Genesis)
	if _, ok := genesisErr.(*params.ConfigCompatError); genesisErr != nil && !ok {
		return nil, genesisErr
	}

	log.Info("Initialised chain configuration", "config", chainConfig)

	eth := &Ethereum{
		config:         config,
		chainDb:        chainDb,
		chainConfig:    chainConfig,
		eventMux:       ctx.EventMux,
		accountManager: ctx.AccountManager,
		engine:         dpos.New(chainConfig.Dpos, chainDb),
		shutdownChan:   make(chan bool),
		networkID:      config.NetworkId,
		gasPrice:       config.MinerGasPrice,
		validator:      config.Validator,
		coinbase:       config.Coinbase,
		bloomRequests:  make(chan chan *bloombits.Retrieval),
		bloomIndexer:   NewBloomIndexer(chainDb, params.BloomBitsBlocks, bloomConfirms),
	}

	log.Info("Initialising Ethereum protocol", "versions", ProtocolVersions, "network", config.NetworkId)
	if !config.SkipBcVersionCheck {
		bcVersion := rawdb.ReadDatabaseVersion(chainDb)
		if bcVersion != core.BlockChainVersion && bcVersion != 0 {
			return nil, fmt.Errorf("Blockchain DB version mismatch (%d / %d).\n", bcVersion, core.BlockChainVersion)
		}
		rawdb.WriteDatabaseVersion(chainDb, core.BlockChainVersion)
	}
	var (
		vmConfig    = vm.Config{EnablePreimageRecording: config.EnablePreimageRecording}
		cacheConfig = &core.CacheConfig{Disabled: config.NoPruning, TrieNodeLimit: config.TrieCache, TrieTimeLimit: config.TrieTimeout}
	)
	eth.blockchain, err = core.NewBlockChain(chainDb, cacheConfig, eth.chainConfig, eth.engine, vmConfig)
	if err != nil {
		return nil, err
	}
//在不兼容的配置升级时倒带链。
	if compat, ok := genesisErr.(*params.ConfigCompatError); ok {
		log.Warn("Rewinding chain to upgrade configuration", "err", compat)
		eth.blockchain.SetHead(compat.RewindTo)
		rawdb.WriteChainConfig(chainDb, genesisHash, chainConfig)
	}
	eth.bloomIndexer.Start(eth.blockchain)

	if config.TxPool.Journal != "" {
		config.TxPool.Journal = ctx.ResolvePath(config.TxPool.Journal)
	}
	eth.txPool = core.NewTxPool(config.TxPool, eth.chainConfig, eth.blockchain)

	if eth.protocolManager, err = NewProtocolManager(eth.chainConfig, config.SyncMode, config.NetworkId, eth.eventMux, eth.txPool, eth.engine, eth.blockchain, chainDb); err != nil {
		return nil, err
	}

	eth.miner = miner.New(eth, eth.chainConfig, eth.EventMux(), eth.engine, config.MinerRecommit)
	eth.miner.SetExtra(makeExtraData(config.MinerExtraData))

	eth.APIBackend = &EthAPIBackend{eth, nil}
	gpoParams := config.GPO
	if gpoParams.Default == nil {
		gpoParams.Default = config.MinerGasPrice
	}
	eth.APIBackend.gpo = gasprice.NewOracle(eth.APIBackend, gpoParams)

	return eth, nil
}

func makeExtraData(extra []byte) []byte {
	if len(extra) == 0 {
//创建默认额外数据
		extra, _ = rlp.EncodeToBytes([]interface{}{
			uint(params.VersionMajor<<16 | params.VersionMinor<<8 | params.VersionPatch),
			"geth",
			runtime.Version(),
			runtime.GOOS,
		})
	}
	if uint64(len(extra)) > params.MaximumExtraDataSize {
		log.Warn("Miner extra data exceed limit", "extra", hexutil.Bytes(extra), "limit", params.MaximumExtraDataSize)
		extra = nil
	}
	return extra
}

//createdb创建链数据库。
func CreateDB(ctx *node.ServiceContext, config *Config, name string) (ethdb.Database, error) {
	db, err := ctx.OpenDatabase(name, config.DatabaseCache, config.DatabaseHandles)
	if err != nil {
		return nil, err
	}
	if db, ok := db.(*ethdb.LDBDatabase); ok {
		db.Meter("eth/db/chaindata/")
	}
	return db, nil
}

//API返回以太坊包提供的RPC服务集合。
//注意，其中一些服务可能需要转移到其他地方。
func (s *Ethereum) APIs() []rpc.API {
	apis := ethapi.GetAPIs(s.APIBackend)

//附加由共识引擎显式公开的任何API
	apis = append(apis, s.engine.APIs(s.BlockChain())...)

//附加所有本地API并返回
	return append(apis, []rpc.API{
		{
			Namespace: "eth",
			Version:   "1.0",
			Service:   NewPublicEthereumAPI(s),
			Public:    true,
		}, {
			Namespace: "eth",
			Version:   "1.0",
			Service:   NewPublicMinerAPI(s),
			Public:    true,
		}, {
			Namespace: "eth",
			Version:   "1.0",
			Service:   downloader.NewPublicDownloaderAPI(s.protocolManager.downloader, s.eventMux),
			Public:    true,
		}, {
			Namespace: "miner",
			Version:   "1.0",
			Service:   NewPrivateMinerAPI(s),
			Public:    false,
		}, {
			Namespace: "eth",
			Version:   "1.0",
			Service:   filters.NewPublicFilterAPI(s.APIBackend, false),
			Public:    true,
		}, {
			Namespace: "admin",
			Version:   "1.0",
			Service:   NewPrivateAdminAPI(s),
		}, {
			Namespace: "debug",
			Version:   "1.0",
			Service:   NewPublicDebugAPI(s),
			Public:    true,
		}, {
			Namespace: "debug",
			Version:   "1.0",
			Service:   NewPrivateDebugAPI(s.chainConfig, s),
		}, {
			Namespace: "net",
			Version:   "1.0",
			Service:   s.netRPCService,
			Public:    true,
		},
	}...)
}

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

func (s *Ethereum) Validator() (validator common.Address, err error) {
	s.lock.RLock()
	validator = s.validator
	s.lock.RUnlock()

	if validator != (common.Address{}) {
		return validator, nil
	}
	if wallets := s.AccountManager().Wallets(); len(wallets) > 0 {
		if accounts := wallets[0].Accounts(); len(accounts) > 0 {
			return accounts[0].Address, nil
		}
	}
	return common.Address{}, fmt.Errorf("validator address must be explicitly specified")
}

//通过管理接口或来自cli标志的包装器在js控制台中设置
func (self *Ethereum) SetValidator(validator common.Address) {
	self.lock.Lock()
	self.validator = validator
	self.lock.Unlock()
}

func (s *Ethereum) Coinbase() (eb common.Address, err error) {
	s.lock.RLock()
	coinbase := s.coinbase
	s.lock.RUnlock()

	if coinbase != (common.Address{}) {
		return coinbase, nil
	}
	if wallets := s.AccountManager().Wallets(); len(wallets) > 0 {
		if accounts := wallets[0].Accounts(); len(accounts) > 0 {
			return accounts[0].Address, nil
		}
	}
	return common.Address{}, fmt.Errorf("coinbase address must be explicitly specified")
}


//通过管理接口或来自cli标志的包装器在js控制台中设置
func (self *Ethereum) SetCoinbase(coinbase common.Address) {
	self.lock.Lock()
	self.coinbase = coinbase
	self.lock.Unlock()

	self.miner.SetCoinbase(coinbase)
}

func (s *Ethereum) StartMining(local bool) error {
	validator, err := s.Validator()
	if err != nil {
		log.Error("Cannot start mining without validator", "err", err)
		return fmt.Errorf("validator missing: %v", err)
	}
	cb, err := s.Coinbase()
	if err != nil {
		log.Error("Cannot start mining without coinbase", "err", err)
		return fmt.Errorf("coinbase missing: %v", err)
	}

	if dpos, ok := s.engine.(*dpos.Dpos); ok {
		wallet, err := s.accountManager.Find(accounts.Account{Address: validator})
		if wallet == nil || err != nil {
			log.Error("Coinbase account unavailable locally", "err", err)
			return fmt.Errorf("signer missing: %v", err)
		}
		dpos.Authorize(validator, wallet.SignHash)
	}
	if local {
//如果启动了本地（CPU）挖掘，我们可以禁用事务拒绝
//用于加快同步时间的机制。在Mainnet上的CPU挖掘是荒谬的
//所以没有人会碰到这个路径，而在CPU挖掘上标记同步完成。
//也将确保私有网络以单矿工模式工作。
		atomic.StoreUint32(&s.protocolManager.acceptTxs, 1)
	}
	bi := s.chainConfig.Dpos.BlockInterval
	fmt.Println(bi)
	go s.miner.Start(cb,bi)

	return nil
}

func (s *Ethereum) StopMining()         { s.miner.Stop() }
func (s *Ethereum) IsMining() bool      { return s.miner.Mining() }
func (s *Ethereum) Miner() *miner.Miner { return s.miner }

func (s *Ethereum) AccountManager() *accounts.Manager  { return s.accountManager }
func (s *Ethereum) BlockChain() *core.BlockChain       { return s.blockchain }
func (s *Ethereum) TxPool() *core.TxPool               { return s.txPool }
func (s *Ethereum) EventMux() *event.TypeMux           { return s.eventMux }
func (s *Ethereum) Engine() consensus.Engine           { return s.engine }
func (s *Ethereum) ChainDb() ethdb.Database            { return s.chainDb }
func (s *Ethereum) IsListening() bool                  { return true } //总是倾听
func (s *Ethereum) EthVersion() int                    { return int(s.protocolManager.SubProtocols[0].Version) }
func (s *Ethereum) NetVersion() uint64                 { return s.networkID }
func (s *Ethereum) Downloader() *downloader.Downloader { return s.protocolManager.downloader }

//协议实现node.service，返回所有当前配置的
//要启动的网络协议。
func (s *Ethereum) Protocols() []p2p.Protocol {
	if s.lesServer == nil {
		return s.protocolManager.SubProtocols
	}
	return append(s.protocolManager.SubProtocols, s.lesServer.Protocols()...)
}

//start实现node.service，启动
//以太坊协议实现。
func (s *Ethereum) Start(srvr *p2p.Server) error {
//启动为Goroutines提供服务的Bloom钻头
	s.startBloomHandlers()

//启动RPC服务
	s.netRPCService = ethapi.NewPublicNetAPI(srvr, s.NetVersion())

//根据服务器限制计算最大对等数
	maxPeers := srvr.MaxPeers
	if s.config.LightServ > 0 {
		if s.config.LightPeers >= srvr.MaxPeers {
			return fmt.Errorf("invalid peer config: light peer count (%d) >= total peer count (%d)", s.config.LightPeers, srvr.MaxPeers)
		}
		maxPeers -= s.config.LightPeers
	}
//如果需要，启动网络层和轻型服务器
	s.protocolManager.Start(maxPeers)
	if s.lesServer != nil {
		s.lesServer.Start(srvr)
	}
	return nil
}

//停止实现node.service，终止由
//以太坊协议。
func (s *Ethereum) Stop() error {
	s.bloomIndexer.Close()
	s.blockchain.Stop()
	s.engine.Close()
	s.protocolManager.Stop()
	if s.lesServer != nil {
		s.lesServer.Stop()
	}
	s.txPool.Stop()
	s.miner.Stop()
	s.eventMux.Stop()

	s.chainDb.Close()
	close(s.shutdownChan)
	return nil
}