package blockchain import ( "bytes" "errors" "reflect" "time" wire "github.com/tendermint/go-wire" "github.com/tendermint/tendermint/p2p" "github.com/tendermint/tendermint/proxy" sm "github.com/tendermint/tendermint/state" "github.com/tendermint/tendermint/types" cmn "github.com/tendermint/tmlibs/common" ) const ( // BlockchainChannel is a channel for blocks and status updates (`BlockStore` height) BlockchainChannel = byte(0x40) defaultChannelCapacity = 100 trySyncIntervalMS = 100 // stop syncing when last block's time is // within this much of the system time. // stopSyncingDurationMinutes = 10 // ask for best height every 10s statusUpdateIntervalSeconds = 10 // check if we should switch to consensus reactor switchToConsensusIntervalSeconds = 1 ) type consensusReactor interface { // for when we switch from blockchain reactor and fast sync to // the consensus machine SwitchToConsensus(*sm.State) } // BlockchainReactor handles long-term catchup syncing. type BlockchainReactor struct { p2p.BaseReactor state *sm.State proxyAppConn proxy.AppConnConsensus // same as consensus.proxyAppConn store *BlockStore pool *BlockPool fastSync bool requestsCh chan BlockRequest timeoutsCh chan string evsw types.EventSwitch } // NewBlockchainReactor returns new reactor instance. func NewBlockchainReactor(state *sm.State, proxyAppConn proxy.AppConnConsensus, store *BlockStore, fastSync bool) *BlockchainReactor { if state.LastBlockHeight == store.Height()-1 { store.height-- // XXX HACK, make this better } if state.LastBlockHeight != store.Height() { cmn.PanicSanity(cmn.Fmt("state (%v) and store (%v) height mismatch", state.LastBlockHeight, store.Height())) } requestsCh := make(chan BlockRequest, defaultChannelCapacity) timeoutsCh := make(chan string, defaultChannelCapacity) pool := NewBlockPool( store.Height()+1, requestsCh, timeoutsCh, ) bcR := &BlockchainReactor{ state: state, proxyAppConn: proxyAppConn, store: store, pool: pool, fastSync: fastSync, requestsCh: requestsCh, timeoutsCh: timeoutsCh, } bcR.BaseReactor = *p2p.NewBaseReactor("BlockchainReactor", bcR) return bcR } // OnStart implements BaseService func (bcR *BlockchainReactor) OnStart() error { bcR.BaseReactor.OnStart() if bcR.fastSync { _, err := bcR.pool.Start() if err != nil { return err } go bcR.poolRoutine() } return nil } // OnStop implements BaseService func (bcR *BlockchainReactor) OnStop() { bcR.BaseReactor.OnStop() bcR.pool.Stop() } // GetChannels implements Reactor func (bcR *BlockchainReactor) GetChannels() []*p2p.ChannelDescriptor { return []*p2p.ChannelDescriptor{ &p2p.ChannelDescriptor{ ID: BlockchainChannel, Priority: 5, SendQueueCapacity: 100, }, } } // AddPeer implements Reactor by sending our state to peer. func (bcR *BlockchainReactor) AddPeer(peer p2p.Peer) { if !peer.Send(BlockchainChannel, struct{ BlockchainMessage }{&bcStatusResponseMessage{bcR.store.Height()}}) { // doing nothing, will try later in `poolRoutine` } } // RemovePeer implements Reactor by removing peer from the pool. func (bcR *BlockchainReactor) RemovePeer(peer p2p.Peer, reason interface{}) { bcR.pool.RemovePeer(peer.Key()) } // respondToPeer loads a block and sends it to the requesting peer, // if we have it. Otherwise, we'll respond saying we don't have it. // According to the Tendermint spec, if all nodes are honest, // no node should be requesting for a block that's non-existent. func (bcR *BlockchainReactor) respondToPeer(msg *bcBlockRequestMessage, src p2p.Peer) (queued bool) { block := bcR.store.LoadBlock(msg.Height) if block != nil { msg := &bcBlockResponseMessage{Block: block} return src.TrySend(BlockchainChannel, struct{ BlockchainMessage }{msg}) } bcR.Logger.Info("Peer asking for a block we don't have", "src", src, "height", msg.Height) return src.TrySend(BlockchainChannel, struct{ BlockchainMessage }{ &bcNoBlockResponseMessage{Height: msg.Height}, }) } // Receive implements Reactor by handling 4 types of messages (look below). func (bcR *BlockchainReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) { _, msg, err := DecodeMessage(msgBytes, bcR.maxMsgSize()) if err != nil { bcR.Logger.Error("Error decoding message", "err", err) return } bcR.Logger.Debug("Receive", "src", src, "chID", chID, "msg", msg) // TODO: improve logic to satisfy megacheck switch msg := msg.(type) { case *bcBlockRequestMessage: if queued := bcR.respondToPeer(msg, src); !queued { // Unfortunately not queued since the queue is full. } case *bcBlockResponseMessage: // Got a block. bcR.pool.AddBlock(src.Key(), msg.Block, len(msgBytes)) case *bcStatusRequestMessage: // Send peer our state. queued := src.TrySend(BlockchainChannel, struct{ BlockchainMessage }{&bcStatusResponseMessage{bcR.store.Height()}}) if !queued { // sorry } case *bcStatusResponseMessage: // Got a peer status. Unverified. bcR.pool.SetPeerHeight(src.Key(), msg.Height) default: bcR.Logger.Error(cmn.Fmt("Unknown message type %v", reflect.TypeOf(msg))) } } // maxMsgSize returns the maximum allowable size of a // message on the blockchain reactor. func (bcR *BlockchainReactor) maxMsgSize() int { return bcR.state.Params().BlockSizeParams.MaxBytes + 2 } // Handle messages from the poolReactor telling the reactor what to do. // NOTE: Don't sleep in the FOR_LOOP or otherwise slow it down! // (Except for the SYNC_LOOP, which is the primary purpose and must be synchronous.) func (bcR *BlockchainReactor) poolRoutine() { trySyncTicker := time.NewTicker(trySyncIntervalMS * time.Millisecond) statusUpdateTicker := time.NewTicker(statusUpdateIntervalSeconds * time.Second) switchToConsensusTicker := time.NewTicker(switchToConsensusIntervalSeconds * time.Second) FOR_LOOP: for { select { case request := <-bcR.requestsCh: // chan BlockRequest peer := bcR.Switch.Peers().Get(request.PeerID) if peer == nil { continue FOR_LOOP // Peer has since been disconnected. } msg := &bcBlockRequestMessage{request.Height} queued := peer.TrySend(BlockchainChannel, struct{ BlockchainMessage }{msg}) if !queued { // We couldn't make the request, send-queue full. // The pool handles timeouts, just let it go. continue FOR_LOOP } case peerID := <-bcR.timeoutsCh: // chan string // Peer timed out. peer := bcR.Switch.Peers().Get(peerID) if peer != nil { bcR.Switch.StopPeerForError(peer, errors.New("BlockchainReactor Timeout")) } case <-statusUpdateTicker.C: // ask for status updates go bcR.BroadcastStatusRequest() case <-switchToConsensusTicker.C: height, numPending, _ := bcR.pool.GetStatus() outbound, inbound, _ := bcR.Switch.NumPeers() bcR.Logger.Info("Consensus ticker", "numPending", numPending, "total", len(bcR.pool.requesters), "outbound", outbound, "inbound", inbound) if bcR.pool.IsCaughtUp() { bcR.Logger.Info("Time to switch to consensus reactor!", "height", height) bcR.pool.Stop() conR := bcR.Switch.Reactor("CONSENSUS").(consensusReactor) conR.SwitchToConsensus(bcR.state) break FOR_LOOP } case <-trySyncTicker.C: // chan time // This loop can be slow as long as it's doing syncing work. SYNC_LOOP: for i := 0; i < 10; i++ { // See if there are any blocks to sync. first, second := bcR.pool.PeekTwoBlocks() //bcR.Logger.Info("TrySync peeked", "first", first, "second", second) if first == nil || second == nil { // We need both to sync the first block. break SYNC_LOOP } firstParts := first.MakePartSet(bcR.state.Params().BlockPartSizeBytes) firstPartsHeader := firstParts.Header() // Finally, verify the first block using the second's commit // NOTE: we can probably make this more efficient, but note that calling // first.Hash() doesn't verify the tx contents, so MakePartSet() is // currently necessary. err := bcR.state.Validators.VerifyCommit( bcR.state.ChainID, types.BlockID{first.Hash(), firstPartsHeader}, first.Height, second.LastCommit) if err != nil { bcR.Logger.Error("Error in validation", "err", err) bcR.pool.RedoRequest(first.Height) break SYNC_LOOP } else { bcR.pool.PopRequest() bcR.store.SaveBlock(first, firstParts, second.LastCommit) // TODO: should we be firing events? need to fire NewBlock events manually ... // NOTE: we could improve performance if we // didn't make the app commit to disk every block // ... but we would need a way to get the hash without it persisting err := bcR.state.ApplyBlock(bcR.evsw, bcR.proxyAppConn, first, firstPartsHeader, types.MockMempool{}) if err != nil { // TODO This is bad, are we zombie? cmn.PanicQ(cmn.Fmt("Failed to process committed block (%d:%X): %v", first.Height, first.Hash(), err)) } } } continue FOR_LOOP case <-bcR.Quit: break FOR_LOOP } } } // BroadcastStatusRequest broadcasts `BlockStore` height. func (bcR *BlockchainReactor) BroadcastStatusRequest() error { bcR.Switch.Broadcast(BlockchainChannel, struct{ BlockchainMessage }{&bcStatusRequestMessage{bcR.store.Height()}}) return nil } // SetEventSwitch implements events.Eventable func (bcR *BlockchainReactor) SetEventSwitch(evsw types.EventSwitch) { bcR.evsw = evsw } //----------------------------------------------------------------------------- // Messages const ( msgTypeBlockRequest = byte(0x10) msgTypeBlockResponse = byte(0x11) msgTypeNoBlockResponse = byte(0x12) msgTypeStatusResponse = byte(0x20) msgTypeStatusRequest = byte(0x21) ) // BlockchainMessage is a generic message for this reactor. type BlockchainMessage interface{} var _ = wire.RegisterInterface( struct{ BlockchainMessage }{}, wire.ConcreteType{&bcBlockRequestMessage{}, msgTypeBlockRequest}, wire.ConcreteType{&bcBlockResponseMessage{}, msgTypeBlockResponse}, wire.ConcreteType{&bcNoBlockResponseMessage{}, msgTypeNoBlockResponse}, wire.ConcreteType{&bcStatusResponseMessage{}, msgTypeStatusResponse}, wire.ConcreteType{&bcStatusRequestMessage{}, msgTypeStatusRequest}, ) // DecodeMessage decodes BlockchainMessage. // TODO: ensure that bz is completely read. func DecodeMessage(bz []byte, maxSize int) (msgType byte, msg BlockchainMessage, err error) { msgType = bz[0] n := int(0) r := bytes.NewReader(bz) msg = wire.ReadBinary(struct{ BlockchainMessage }{}, r, maxSize, &n, &err).(struct{ BlockchainMessage }).BlockchainMessage if err != nil && n != len(bz) { err = errors.New("DecodeMessage() had bytes left over") } return } //------------------------------------- type bcBlockRequestMessage struct { Height int } func (m *bcBlockRequestMessage) String() string { return cmn.Fmt("[bcBlockRequestMessage %v]", m.Height) } type bcNoBlockResponseMessage struct { Height int } func (brm *bcNoBlockResponseMessage) String() string { return cmn.Fmt("[bcNoBlockResponseMessage %d]", brm.Height) } //------------------------------------- // NOTE: keep up-to-date with maxBlockchainResponseSize type bcBlockResponseMessage struct { Block *types.Block } func (m *bcBlockResponseMessage) String() string { return cmn.Fmt("[bcBlockResponseMessage %v]", m.Block.Height) } //------------------------------------- type bcStatusRequestMessage struct { Height int } func (m *bcStatusRequestMessage) String() string { return cmn.Fmt("[bcStatusRequestMessage %v]", m.Height) } //------------------------------------- type bcStatusResponseMessage struct { Height int } func (m *bcStatusResponseMessage) String() string { return cmn.Fmt("[bcStatusResponseMessage %v]", m.Height) }