blockfactory.go

package raftv2

import (
	"bytes"
	"encoding/binary"
	"encoding/json"
	"errors"
	"fmt"
	"runtime"
	"strings"
	"sync"
	"time"

	"github.com/aergoio/aergo-lib/log"
	bc "github.com/aergoio/aergo/chain"
	"github.com/aergoio/aergo/config"
	"github.com/aergoio/aergo/consensus"
	"github.com/aergoio/aergo/consensus/chain"
	"github.com/aergoio/aergo/contract"
	"github.com/aergoio/aergo/contract/system"
	"github.com/aergoio/aergo/internal/enc"
	"github.com/aergoio/aergo/p2p/p2pcommon"
	"github.com/aergoio/aergo/p2p/p2pkey"
	"github.com/aergoio/aergo/pkg/component"
	"github.com/aergoio/aergo/state"
	"github.com/aergoio/aergo/types"
	"github.com/libp2p/go-libp2p-core/crypto"
)

var (
	logger     *log.Logger
	httpLogger *log.Logger
)

var (
	ErrClusterNotReady      = errors.New("cluster is not ready")
	ErrNotRaftLeader        = errors.New("this node is not leader")
	ErrInvalidConsensusName = errors.New("invalid consensus name")
	ErrCancelGenerate       = errors.New("cancel generating block because work becomes stale")
)

func init() {
	logger = log.NewLogger("raft")
	httpLogger = log.NewLogger("rafthttp")
}

type txExec struct {
	execTx bc.TxExecFn
}

func newTxExec(ccc consensus.ChainConsensusCluster, cdb consensus.ChainDB, bi *types.BlockHeaderInfo) chain.TxOp {
	// Block hash not determined yet
	return &txExec{
		execTx: bc.NewTxExecutor(ccc, cdb, bi, contract.BlockFactory),
	}
}

func (te *txExec) Apply(bState *state.BlockState, tx types.Transaction) error {
	err := te.execTx(bState, tx)
	return err
}

type Work struct {
	*types.Block
	term uint64
}

func (work *Work) GetTimeout() time.Duration {
	return BlockIntervalMs
}

func (work *Work) ToString() string {
	return fmt.Sprintf("bestblock=%s, no=%d, term=%d", work.BlockID(), work.BlockNo(), work.term)
}

type leaderReady struct {
	sync.RWMutex

	ce *commitEntry
}

func (ready *leaderReady) set(ce *commitEntry) {
	logger.Debug().Uint64("term", ce.term).Msg("set ready marker")

	ready.Lock()
	defer ready.Unlock()

	ready.ce = ce
}

func (ready *leaderReady) isReady(curTerm uint64) bool {
	ready.RLock()
	defer ready.RUnlock()

	if curTerm <= 0 {
		logger.Fatal().Msg("failed to get status of raft")
		return false
	}

	if ready.ce == nil {
		logger.Debug().Msg("not exist ready marker")
		return false
	}

	if ready.ce.term != curTerm {
		logger.Debug().Uint64("ready-term", ready.ce.term).Uint64("cur-term", curTerm).Msg("not ready for producing")
		return false
	}

	return true
}

// BlockFactory implements a raft block factory which generate block each cfg.Consensus.BlockIntervalMs if this node is leader of raft
//
// This can be used for testing purpose.
type BlockFactory struct {
	*component.ComponentHub
	consensus.ChainWAL

	bpc *Cluster
	rhw consensus.AergoRaftAccessor

	workerQueue chan *Work
	jobQueue    chan interface{}
	bpTimeoutC  chan struct{}
	quit        chan interface{}

	ready leaderReady

	maxBlockBodySize uint32
	ID               string
	privKey          crypto.PrivKey
	txOp             chain.TxOp
	sdb              *state.ChainStateDB
	prevBlock        *types.Block // best block of last job
	jobLock          sync.RWMutex

	raftOp     *RaftOperator
	raftServer *raftServer

	bv types.BlockVersionner
}

// GetName returns the name of the consensus.
func GetName() string {
	return consensus.ConsensusName[consensus.ConsensusRAFT]
}

// GetConstructor build and returns consensus.Constructor from New function.
func GetConstructor(cfg *config.Config, hub *component.ComponentHub, cdb consensus.ChainWAL,
	sdb *state.ChainStateDB, pa p2pcommon.PeerAccessor) consensus.Constructor {
	return func() (consensus.Consensus, error) {
		return New(cfg, hub, cdb, sdb, pa)
	}
}

// New returns a BlockFactory.
func New(cfg *config.Config, hub *component.ComponentHub, cdb consensus.ChainWAL,
	sdb *state.ChainStateDB, pa p2pcommon.PeerAccessor) (*BlockFactory, error) {

	bf := &BlockFactory{
		ComponentHub:     hub,
		ChainWAL:         cdb,
		jobQueue:         make(chan interface{}),
		workerQueue:      make(chan *Work),
		bpTimeoutC:       make(chan struct{}, 1),
		quit:             make(chan interface{}),
		maxBlockBodySize: chain.MaxBlockBodySize(),
		ID:               p2pkey.NodeSID(),
		privKey:          p2pkey.NodePrivKey(),
		sdb:              sdb,
		bv:               cfg.Hardfork,
	}

	if cfg.Consensus.EnableBp {
		Init(cfg.Consensus.Raft)

		if err := bf.newRaftServer(cfg); err != nil {
			logger.Error().Err(err).Msg("failed to init raft server")
			return bf, err
		}

		bf.raftServer.SetPeerAccessor(pa)
		bf.rhw = &raftHttpWrapper{raftServer: bf.raftServer}
	} else {
		bf.rhw = &consensus.DummyRaftAccessor{}
	}

	bf.txOp = chain.NewCompTxOp(
		// timeout check
		chain.TxOpFn(func(bState *state.BlockState, txIn types.Transaction) error {
			return bf.checkBpTimeout()
		}),
	)

	contract.SetBPTimeout(bf.bpTimeoutC)

	return bf, nil
}

func (bf *BlockFactory) newRaftServer(cfg *config.Config) error {
	if err := bf.InitCluster(cfg); err != nil {
		return err
	}

	bf.raftOp = newRaftOperator(bf.raftServer, bf.bpc)

	logger.Info().Str("name", bf.bpc.NodeName()).Msg("create raft server")

	bf.raftServer = newRaftServer(bf.ComponentHub, bf.bpc,
		!cfg.Consensus.Raft.NewCluster, cfg.Consensus.Raft.UseBackup, nil,
		RaftTick, bf.bpc.confChangeC, bf.raftOp.commitC, false, bf.ChainWAL)

	bf.bpc.rs = bf.raftServer
	bf.raftOp.rs = bf.raftServer

	return nil
}

// Ticker returns a time.Ticker for the main consensus loop.
func (bf *BlockFactory) Ticker() *time.Ticker {
	return time.NewTicker(BlockFactoryTickMs)
}

// QueueJob send a block triggering information to jq.
func (bf *BlockFactory) QueueJob(now time.Time, jq chan<- interface{}) {
	bf.jobLock.Lock()
	defer bf.jobLock.Unlock()

	var (
		isReady bool
		term    uint64
	)

	if isReady, term = bf.isLeaderReady(); !isReady {
		//logger.Debug().Msg("skip producing block because this bp is leader but it's not ready to produce new block")
		return
	}

	prevToString := func(prevBlock *types.Block) string {
		if prevBlock == nil {
			return "empty"
		} else {
			return prevBlock.ID()
		}
	}

	if b, _ := bf.GetBestBlock(); b != nil {
		if bf.prevBlock != nil && bf.prevBlock.BlockNo() == b.BlockNo() {
			//logger.Debug().Uint64("bestno", b.BlockNo()).Msg("previous block not connected. skip to generate block")
			return
		}

		// If requested block remains in commit channel, block factory must wait until all requests are completed.
		// otherwise block of same height will be created and a fork will occur.
		if !bf.raftServer.commitProgress.IsReadyToPropose() {
			logger.Debug().Uint64("bestno", b.BlockNo()).Msg("pending request block not connected. skip to generate block")
			return
		}

		prev := bf.prevBlock
		bf.prevBlock = b
		work := &Work{Block: b, term: term}

		logger.Debug().Str("work", work.ToString()).Str("prev", prevToString(prev)).Msg("new work generated")
		jq <- work
	}
}

// isLeaderReady must be called after bf.jobLock
// check if block factory has finished all blocks of previous term. it can be checked that it has received raft marker of this term.
// TODO) term may be set when raft leader is changed from hardstate
func (bf *BlockFactory) isLeaderReady() (bool, uint64) {
	var (
		status LeaderStatus
	)

	if status = bf.raftServer.GetLeaderStatus(); !status.IsLeader {
		return false, 0
	}

	return bf.ready.isReady(status.Term), status.Term
}

func (bf *BlockFactory) GetType() consensus.ConsensusType {
	return consensus.ConsensusRAFT
}

// IsTransactionValid checks the onsensus level validity of a transaction
func (bf *BlockFactory) IsTransactionValid(tx *types.Tx) bool {
	// BlockFactory has no tx valid check.
	return true
}

// VerifyTimestamp checks the validity of the block timestamp.
func (bf *BlockFactory) VerifyTimestamp(*types.Block) bool {
	// BlockFactory don't need to check timestamp.
	return true
}

// VerifySign checks the consensus level validity of a block.
func (bf *BlockFactory) VerifySign(block *types.Block) error {
	valid, err := block.VerifySign()
	if !valid || err != nil {
		return &consensus.ErrorConsensus{Msg: "bad block signature", Err: err}
	}
	return nil
}

// IsBlockValid checks the consensus level validity of a block.
func (bf *BlockFactory) IsBlockValid(block *types.Block, bestBlock *types.Block) error {
	// BlockFactory has no block valid check.
	_, err := block.BPID()
	if err != nil {
		return &consensus.ErrorConsensus{Msg: "bad public key in block", Err: err}
	}
	return nil
}

// QuitChan returns the channel from which consensus-related goroutines check
// when shutdown is initiated.
func (bf *BlockFactory) QuitChan() chan interface{} {
	return bf.quit
}

// Update has nothging to do.
func (bf *BlockFactory) Update(block *types.Block) {
}

// Save has nothging to do.
func (bf *BlockFactory) Save(tx consensus.TxWriter) error {
	return nil
}

// BlockFactory returns r itself.
func (bf *BlockFactory) BlockFactory() consensus.BlockFactory {
	return bf
}

// NeedReorganization has nothing to do.
func (bf *BlockFactory) NeedReorganization(rootNo types.BlockNo) bool {
	return true
}

// Start run a raft block factory service.
func (bf *BlockFactory) Start() {
	bf.raftServer.Start()

	go bf.worker()
	go bf.controller()
}

func (bf *BlockFactory) controller() {
	defer shutdownMsg("block factory controller")

	beginBlock := func(work *Work) error {
		// This is only for draining an unconsumed message, which means
		// the previous block is generated within timeout. This code
		// is needed since an empty block will be generated without it.
		if err := bf.checkBpTimeout(); err == chain.ErrQuit {
			return err
		}

		select {
		case bf.workerQueue <- work:
		default:
			logger.Error().Msgf(
				"skip block production for %s due to a pending job", work.ToString())
		}
		return nil
	}

	notifyBpTimeout := func(work *Work) {
		timeout := work.GetTimeout()
		time.Sleep(timeout)
		bf.bpTimeoutC <- struct{}{}
		logger.Debug().Int64("timeout(ms)", timeout.Nanoseconds()/int64(time.Millisecond)).Msg("block production timeout signaled")
	}

	for {
		select {
		case info := <-bf.jobQueue:
			work := info.(*Work)

			logger.Debug().Msgf("received work: %s",
				log.DoLazyEval(func() string { return work.ToString() }))

			err := beginBlock(work)
			if err == chain.ErrQuit {
				return
			} else if err != nil {
				logger.Debug().Err(err).Msg("skip block production")
				continue
			}

			notifyBpTimeout(work)

		case <-bf.quit:
			return
		}
	}
}

// worker() is different for each consensus
func (bf *BlockFactory) worker() {
	defer logger.Info().Msg("shutdown initiated. stop the service")

	runtime.LockOSThread()

	for {
		select {
		case work := <-bf.workerQueue:
			var (
				block      *types.Block
				blockState *state.BlockState
				err        error
			)

			if block, blockState, err = bf.generateBlock(work); err != nil {
				logger.Error().Err(err).Msg("failed to generate block")
				if err == chain.ErrQuit {
					logger.Info().Msg("quit worker of block factory")
					return
				}

				bf.reset()
				continue
			}

			if err = bf.raftOp.propose(block, blockState, work.term); err != nil {
				logger.Error().Err(err).Msg("failed to propose block")
				bf.reset()
			}

		case cEntry, ok := <-bf.commitC():
			logger.Debug().Msg("received block to connect from raft")

			if !ok {
				logger.Fatal().Msg("commit channel for raft is closed")
				return
			}

			// RaftEmptyBlockLog: When the leader changes, the new raft leader creates an empty data log with a new term and index.
			// When block factory receives empty block log, the blockfactory that is running as the leader should reset the proposal in progress.
			// since it may have been dropped on the raft. Block factory must produce new block after all blocks of previous term are connected. Empty log can be a marker for that.
			if cEntry.IsReadyMarker() {
				bf.handleReadyMarker(cEntry)
				continue
			}

			// add block that has produced by remote BP
			if err := bf.connect(cEntry.block); err != nil {
				logger.Error().Err(err).Msg("failed to connect block")
				return
			}

			bf.raftServer.commitProgress.UpdateConnect(cEntry)
		case <-bf.quit:
			return
		}
	}
}

// @ReadyMarker: leader can make new block after receiving empty commit entry. It is ready marker.
//               Receiving a marker ensures that all the blocks of previous term has been connected in chain
func (bf *BlockFactory) handleReadyMarker(ce *commitEntry) {
	logger.Debug().Uint64("index", ce.index).Uint64("term", ce.term).Msg("set raft marker(empty block)")

	// set ready to produce block for this term
	bf.ready.set(ce)
	bf.reset()
}

func (bf *BlockFactory) generateBlock(work *Work) (*types.Block, *state.BlockState, error) {
	var (
		bestBlock *types.Block
		err       error
	)

	bestBlock = work.Block

	defer func() {
		if panicMsg := recover(); panicMsg != nil {
			err = fmt.Errorf("panic ocurred during block generation - %v", panicMsg)
		}
	}()

	checkCancel := func() bool {
		if !bf.raftServer.IsLeaderOfTerm(work.term) {
			logger.Debug().Msg("cancel because blockfactory is not leader of term")
			return true
		}

		if b, _ := bf.GetBestBlock(); b != nil && bestBlock.BlockNo() != b.BlockNo() {
			logger.Debug().Uint64("best", b.BlockNo()).Msg("cancel because best block changed")
			if StopDupCommit {
				logger.Fatal().Str("work", work.ToString()).Msg("work duplicate")
			}
			return true
		}

		return false
	}

	if checkCancel() {
		return nil, nil, ErrCancelGenerate
	}

	bi := types.NewBlockHeaderInfoFromPrevBlock(bestBlock, time.Now().UnixNano(), bf.bv)
	txOp := chain.NewCompTxOp(bf.txOp, newTxExec(bf, bf.ChainWAL, bi))
	blockState := bf.sdb.NewBlockState(
		bestBlock.GetHeader().GetBlocksRootHash(),
		state.SetPrevBlockHash(bestBlock.BlockHash()),
		state.SetGasPrice(system.GetGasPrice()),
	)
	blockState.Receipts().SetHardFork(bf.bv, bi.No)

	block, err := chain.GenerateBlock(bf, bi, blockState, txOp, RaftSkipEmptyBlock)
	if err == chain.ErrBlockEmpty {
		//need reset previous work
		return nil, nil, chain.ErrBlockEmpty
	} else if err != nil {
		logger.Info().Err(err).Msg("failed to generate block")
		return nil, nil, err
	}

	if err = block.Sign(bf.privKey); err != nil {
		logger.Error().Err(err).Msg("failed to sign in block")
		return nil, nil, err
	}

	logger.Info().Str("blockProducer", bf.ID).Str("raftID", EtcdIDToString(bf.bpc.NodeID())).
		Str("sroot", enc.ToString(block.GetHeader().GetBlocksRootHash())).
		Uint64("no", block.GetHeader().GetBlockNo()).
		Str("hash", block.ID()).
		Msg("block produced")

	return block, blockState, nil
}

func (bf *BlockFactory) commitC() chan *commitEntry {
	return bf.raftOp.commitC
}

func (bf *BlockFactory) reset() {
	bf.jobLock.Lock()
	defer bf.jobLock.Unlock()

	// empty jobQueue. Pushed works in job queue should be removed before resetting prev work of block factory. Otherwise, it can be possible to make same job since prev work is nil.
	for len(bf.jobQueue) > 0 {
		info := <-bf.jobQueue
		drop := info.(*Work)
		logger.Debug().Str("work", drop.ToString()).Msg("drop work for reset")
	}

	if bf.prevBlock != nil {
		logger.Info().Str("prev proposed", bf.raftOp.toString()).Msg("reset previous work of block factory")
		bf.prevBlock = nil
	}
	bf.bpc.resetSavedConfChangePropose()
}

// save block/block state to connect after commit
func (bf *BlockFactory) connect(block *types.Block) error {
	proposed := bf.raftOp.proposed
	var blockState *state.BlockState

	if proposed != nil {
		if !bytes.Equal(block.BlockHash(), proposed.block.BlockHash()) {
			logger.Warn().Uint64("prop-no", proposed.block.GetHeader().GetBlockNo()).Str("prop", proposed.block.ID()).Uint64("commit-no", block.GetHeader().GetBlockNo()).Str("commit", block.ID()).Msg("commited block is not proposed by me. this node is probably not leader")
			bf.raftOp.resetPropose()
		} else {
			blockState = proposed.blockState
		}
	}

	logger.Info().Uint64("no", block.BlockNo()).
		Str("hash", block.ID()).
		Str("prev", block.PrevID()).
		Bool("proposed", blockState != nil).
		Msg("connect block")

	// if bestblock is changed, connecting block failed. new block is generated in next tick
	// On a slow server, chain service takes too long to add block in blockchain. In this case, raft server waits to send new block to commit channel.
	if err := chain.ConnectBlock(bf, block, blockState, time.Second*300); err != nil {
		logger.Fatal().Msg(err.Error())
		return err
	}

	return nil
}

/*
// waitUntilStartable wait until this chain synchronizes with more than half of all peers
func (bf *BlockFactory) waitSyncWithMajority() error {
	ticker := time.NewTicker(peerCheckInterval)

	for {
		select {
		case <-ticker.C:
			if synced, err := bf.cl.hasSynced(); err != nil {
				logger.Error().Err(err).Msg("failed to check sync with a majority of peers")
				return err
			} else if synced {
				return nil
			}

		case <-bf.QuitChan():
			logger.Info().Msg("quit while wait sync")
			return ErrBFQuit
		default:
		}
	}
}
*/
// JobQueue returns the queue for block production triggering.
func (bf *BlockFactory) JobQueue() chan<- interface{} {
	return bf.jobQueue
}

// Info retuns an empty string.
func (bf *BlockFactory) Info() string {
	// TODO: Returns a appropriate information inx json format like current
	// leader, etc.
	info := consensus.NewInfo(GetName())
	if bf.raftServer == nil {
		return info.AsJSON()
	}

	b, err := json.Marshal(bf.bpc.getRaftInfo(false))
	if err != nil {
		logger.Error().Err(err).Msg("failed to marshalEntryData raft consensus")
	} else {
		m := json.RawMessage(b)
		info.Status = &m
	}

	return info.AsJSON()
}

func (bf *BlockFactory) ConsensusInfo() *types.ConsensusInfo {
	if bf.bpc == nil {
		return &types.ConsensusInfo{Type: GetName()}
	}
	return bf.bpc.toConsensusInfo()
}

func (bf *BlockFactory) NeedNotify() bool {
	return false
}

func (bf *BlockFactory) HasWAL() bool {
	return true
}

func (bf *BlockFactory) IsForkEnable() bool {
	return false
}

// check already connect block
// In raft, block hash may already have been writtern when writing log entry.
func (bf *BlockFactory) IsConnectedBlock(block *types.Block) bool {
	savedBlk, err := bf.GetBlockByNo(block.GetHeader().GetBlockNo())
	if err == nil {
		if bytes.Equal([]byte(savedBlk.BlockHash()), []byte(block.BlockHash())) {
			return true
		}
	}
	return false
}

type ErrorMembershipChange struct {
	Err error
}

func (e ErrorMembershipChange) Error() string {
	return fmt.Sprintf("failed to change membership: %s", e.Err.Error())
}

// ConfChange change membership of raft cluster and returns new membership
func (bf *BlockFactory) ConfChange(req *types.MembershipChange) (*consensus.Member, error) {
	if bf.bpc == nil {
		return nil, ErrorMembershipChange{ErrClusterNotReady}
	}

	if !bf.raftServer.IsLeader() {
		return nil, ErrorMembershipChange{ErrNotRaftLeader}
	}

	var member *consensus.Member
	var err error

	// set reqID by blockHash
	var best *types.Block
	if best, err = bf.GetBestBlock(); err != nil {
		return nil, err
	}

	req.RequestID = binary.LittleEndian.Uint64(best.GetHash()[0:8])

	if member, err = bf.bpc.ChangeMembership(req, false); err != nil {
		return nil, ErrorMembershipChange{err}
	}

	return member, nil
}

func (bf *BlockFactory) RaftAccessor() consensus.AergoRaftAccessor {
	return bf.rhw
}

func (bf *BlockFactory) MakeConfChangeProposal(req *types.MembershipChange) (*consensus.ConfChangePropose, error) {
	var (
		proposal *consensus.ConfChangePropose
		err      error
	)

	if bf.bpc == nil {
		return nil, ErrorMembershipChange{ErrClusterNotReady}
	}

	cl := bf.bpc

	cl.Lock()
	defer cl.Unlock()

	if !bf.raftServer.IsLeader() {
		logger.Info().Msg("skipped conf change request since node is not leader")
		return nil, consensus.ErrorMembershipChangeSkip
	}

	logger.Info().Str("request", req.ToString()).Msg("make proposal of cluster conf change")

	if proposal, err = cl.makeProposal(req, true); err != nil {
		logger.Error().Uint64("requestID", req.GetRequestID()).Msg("failed to make proposal for conf change")
		return nil, err
	}

	// To make cluster_test easier, this check called not in makeProposal() but here
	if err = cl.isEnableChangeMembership(proposal.Cc); err != nil {
		logger.Error().Err(err).Msg("failed cluster availability check to change membership")
		return nil, err
	}

	return proposal, nil
}

// getHardStateOfBlock returns (term/commit) corresponding to best block hash.
// To get hardstateinfo, it needs to search all raft indexes.
func (bf *BlockFactory) getHardStateOfBlock(bestBlockHash []byte) (*types.HardStateInfo, error) {
	var (
		bestBlock *types.Block
		err       error
		hash      []byte
	)
	if bestBlock, err = bf.GetBlock(bestBlockHash); err != nil {
		return nil, fmt.Errorf("block does not exist in chain")
	}

	entry, err := bf.ChainWAL.GetRaftEntryOfBlock(bestBlockHash)
	if err == nil {
		logger.Debug().Uint64("term", entry.Term).Uint64("comit", entry.Index).Msg("get hardstate of block")

		return &types.HardStateInfo{Term: entry.Term, Commit: entry.Index}, nil
	}

	logger.Warn().Uint64("request no", bestBlock.BlockNo()).Msg("can't find raft entry for requested hash. so try to find closest raft entry.")

	// find best hash mapping (no < bestBlock no)
	for i := bestBlock.BlockNo() - 1; i >= 1; i-- {
		if hash, err = bf.GetHashByNo(i); err == nil {
			if entry, err = bf.ChainWAL.GetRaftEntryOfBlock(hash); err == nil {
				logger.Debug().Str("entry", entry.ToString()).Msg("find best closest entry")
				return &types.HardStateInfo{Term: entry.Term, Commit: entry.Index}, nil
			}
		}
	}

	return nil, fmt.Errorf("not exist proper raft entry for requested hash")
}

// ClusterInfo returns members of cluster and hardstate info corresponding to best block hash
func (bf *BlockFactory) ClusterInfo(bestBlockHash []byte) *types.GetClusterInfoResponse {
	var (
		hardStateInfo *types.HardStateInfo
		mbrAttrs      []*types.MemberAttr
		bestBlock     *types.Block
		err           error
	)

	if bf.bpc.ClusterID() == InvalidClusterID {
		return &types.GetClusterInfoResponse{Error: ErrClusterNotReady.Error()}
	}

	if bestBlockHash != nil {
		if hardStateInfo, err = bf.getHardStateOfBlock(bestBlockHash); err != nil {
			return &types.GetClusterInfoResponse{Error: err.Error()}
		}
	}

	if mbrAttrs, err = bf.bpc.getMemberAttrs(); err != nil {
		return &types.GetClusterInfoResponse{Error: err.Error()}
	}

	if bestBlock, err = bf.GetBestBlock(); err != nil {
		return &types.GetClusterInfoResponse{Error: err.Error()}
	}

	return &types.GetClusterInfoResponse{ChainID: bf.bpc.chainID, ClusterID: bf.bpc.ClusterID(), MbrAttrs: mbrAttrs, BestBlockNo: bestBlock.BlockNo(), HardStateInfo: hardStateInfo}
}

// ConfChangeInfo returns ConfChangeProgress queries by request ID of ConfChange
func (bf *BlockFactory) ConfChangeInfo(requestID uint64) (*types.ConfChangeProgress, error) {
	return bf.GetConfChangeProgress(requestID)
}

func (bf *BlockFactory) checkBpTimeout() error {
	select {
	case <-bf.bpTimeoutC:
		return chain.ErrTimeout{Kind: "block"}
	case <-bf.quit:
		return chain.ErrQuit
	default:
		return nil
	}
}

type Proposed struct {
	block      *types.Block
	blockState *state.BlockState
}

type RaftOperator struct {
	commitC chan *commitEntry

	cl *Cluster
	rs *raftServer

	proposed *Proposed
}

func newRaftOperator(rs *raftServer, cl *Cluster) *RaftOperator {
	//commitC := make(chan *commitEntry, MaxCommitQueueLen)
	commitC := make(chan *commitEntry)

	return &RaftOperator{commitC: commitC, rs: rs, cl: cl}
}

func (rop *RaftOperator) propose(block *types.Block, blockState *state.BlockState, term uint64) error {
	if !rop.rs.IsLeaderOfTerm(term) {
		logger.Info().Msg("dropped produced block because this bp became no longer leader")
		return ErrNotRaftLeader
	}

	debugRaftProposeSleep()

	rop.proposed = &Proposed{block: block, blockState: blockState}

	if err := rop.rs.Propose(block); err != nil {
		return err
	}

	logger.Info().Msg("block proposed by blockfactory")

	if blockState.CCProposal != nil {
		if err := rop.ProposeConfChange(blockState.CCProposal); err != nil {
			logger.Error().Err(err).Msg("failed to change membership")
			return ErrorMembershipChange{err}
		}
	}

	return nil
}

func (rop *RaftOperator) ProposeConfChange(proposal *consensus.ConfChangePropose) error {
	var err error

	if rop.cl == nil {
		return ErrClusterNotReady
	}

	if err = rop.cl.submitProposal(proposal, true); err != nil {
		return err
	}

	return nil
}

func (rop *RaftOperator) resetPropose() {
	rop.proposed = nil
	logger.Debug().Msg("reset proposed block")
}

func (rop *RaftOperator) toString() string {
	buf := "proposed:"
	if rop.proposed != nil && rop.proposed.block != nil {
		buf = buf + fmt.Sprintf("[no=%d, hash=%s]", rop.proposed.block.BlockNo(), rop.proposed.block.BlockID().String())
	} else {
		buf = buf + "empty"
	}
	return buf
}

func shutdownMsg(m string) {
	logger.Info().Msgf("shutdown initiated. stop the %s", m)
}

func ValidateGenesis(genesis *types.Genesis) error {
	if strings.ToLower(genesis.ID.Consensus) != consensus.ConsensusName[consensus.ConsensusRAFT] {
		return ErrInvalidConsensusName
	}

	// validate BPS
	if _, err := parseBpsToMembers(genesis.EnterpriseBPs); err != nil {
		logger.Error().Err(err).Msg("failed to parse bp list of Genesis block")
		return err
	}

	return nil
}