Golang util.DOut函数代码示例

func (dht *IpfsDHT) handleFindPeer(p *peer.Peer, pmes *PBDHTMessage) {
	resp := Message{
		Type:     pmes.GetType(),
		ID:       pmes.GetId(),
		Response: true,
	}
	defer func() {
		mes := swarm.NewMessage(p, resp.ToProtobuf())
		dht.netChan.Outgoing <- mes
	}()
	level := pmes.GetValue()[0]
	u.DOut("handleFindPeer: searching for '%s'\n", peer.ID(pmes.GetKey()).Pretty())
	closest := dht.routingTables[level].NearestPeer(kb.ConvertKey(u.Key(pmes.GetKey())))
	if closest == nil {
		u.PErr("handleFindPeer: could not find anything.\n")
		return
	}

	if len(closest.Addresses) == 0 {
		u.PErr("handleFindPeer: no addresses for connected peer...\n")
		return
	}

	// If the found peer further away than this peer...
	if kb.Closer(dht.self.ID, closest.ID, u.Key(pmes.GetKey())) {
		return
	}

	u.DOut("handleFindPeer: sending back '%s'\n", closest.ID.Pretty())
	resp.Peers = []*peer.Peer{closest}
	resp.Success = true
}

// peerWantsBlock will check if we have the block in question,
// and then if we do, check the ledger for whether or not we should send it.
func (bs *BitSwap) peerWantsBlock(p *peer.Peer, want string) {
	u.DOut("peer [%s] wants block [%s]\n", p.ID.Pretty(), u.Key(want).Pretty())
	ledger := bs.getLedger(p)

	dsk := ds.NewKey(want)
	blk_i, err := bs.datastore.Get(dsk)
	if err != nil {
		if err == ds.ErrNotFound {
			ledger.Wants(u.Key(want))
		}
		u.PErr("datastore get error: %v\n", err)
		return
	}

	blk, ok := blk_i.([]byte)
	if !ok {
		u.PErr("data conversion error.\n")
		return
	}

	if ledger.ShouldSend() {
		u.DOut("Sending block to peer.\n")
		bblk, err := blocks.NewBlock(blk)
		if err != nil {
			u.PErr("newBlock error: %v\n", err)
			return
		}
		bs.SendBlock(p, bblk)
		ledger.SentBytes(len(blk))
	} else {
		u.DOut("Decided not to send block.")
	}
}

// GetBlock retrieves a particular block from the service,
// Getting it from the datastore using the key (hash).
func (s *BlockService) GetBlock(k u.Key) (*blocks.Block, error) {
	u.DOut("BlockService GetBlock: '%s'\n", k.Pretty())
	dsk := ds.NewKey(string(k))
	datai, err := s.Datastore.Get(dsk)
	if err == nil {
		u.DOut("Blockservice: Got data in datastore.\n")
		bdata, ok := datai.([]byte)
		if !ok {
			return nil, fmt.Errorf("data associated with %s is not a []byte", k)
		}
		return &blocks.Block{
			Multihash: mh.Multihash(k),
			Data:      bdata,
		}, nil
	} else if err == ds.ErrNotFound && s.Remote != nil {
		u.DOut("Blockservice: Searching bitswap.\n")
		blk, err := s.Remote.GetBlock(k, time.Second*5)
		if err != nil {
			return nil, err
		}
		return blk, nil
	} else {
		u.DOut("Blockservice GetBlock: Not found.\n")
		return nil, u.ErrNotFound
	}
}

// ResolvePath fetches the node for given path. It uses the first
// path component as a hash (key) of the first node, then resolves
// all other components walking the links, with ResolveLinks.
func (s *Resolver) ResolvePath(fpath string) (*merkledag.Node, error) {
	u.DOut("Resolve: '%s'\n", fpath)
	fpath = path.Clean(fpath)

	parts := strings.Split(fpath, "/")

	// skip over empty first elem
	if len(parts[0]) == 0 {
		parts = parts[1:]
	}

	// if nothing, bail.
	if len(parts) == 0 {
		return nil, fmt.Errorf("ipfs path must contain at least one component")
	}

	// first element in the path is a b58 hash (for now)
	h, err := mh.FromB58String(parts[0])
	if err != nil {
		return nil, err
	}

	u.DOut("Resolve dag get.\n")
	nd, err := s.DAG.Get(u.Key(h))
	if err != nil {
		return nil, err
	}

	return s.ResolveLinks(nd, parts[1:])
}

// Ping a peer, log the time it took
func (dht *IpfsDHT) Ping(p *peer.Peer, timeout time.Duration) error {
	// Thoughts: maybe this should accept an ID and do a peer lookup?
	u.DOut("Enter Ping.\n")

	pmes := Message{ID: swarm.GenerateMessageID(), Type: PBDHTMessage_PING}
	mes := swarm.NewMessage(p, pmes.ToProtobuf())

	before := time.Now()
	responseChan := dht.listener.Listen(pmes.ID, 1, time.Minute)
	dht.netChan.Outgoing <- mes

	tout := time.After(timeout)
	select {
	case <-responseChan:
		roundtrip := time.Since(before)
		p.SetLatency(roundtrip)
		u.DOut("Ping took %s.\n", roundtrip.String())
		return nil
	case <-tout:
		// Timed out, think about removing peer from network
		u.DOut("[%s] Ping peer [%s] timed out.", dht.self.ID.Pretty(), p.ID.Pretty())
		dht.listener.Unlisten(pmes.ID)
		return u.ErrTimeout
	}
}

func (l *logDhtRPC) Print() {
	b, err := json.Marshal(l)
	if err != nil {
		u.DOut(err.Error())
	} else {
		u.DOut(string(b))
	}
}

// Read in all messages from swarm and handle them appropriately
// NOTE: this function is just a quick sketch
func (dht *IpfsDHT) handleMessages() {
	u.DOut("Begin message handling routine\n")

	errs := dht.network.GetErrChan()
	for {
		select {
		case mes, ok := <-dht.netChan.Incoming:
			if !ok {
				u.DOut("handleMessages closing, bad recv on incoming\n")
				return
			}
			pmes := new(PBDHTMessage)
			err := proto.Unmarshal(mes.Data, pmes)
			if err != nil {
				u.PErr("Failed to decode protobuf message: %s\n", err)
				continue
			}

			dht.Update(mes.Peer)

			// Note: not sure if this is the correct place for this
			if pmes.GetResponse() {
				dht.listener.Respond(pmes.GetId(), mes)
				continue
			}
			//

			u.DOut("[peer: %s]\nGot message type: '%s' [id = %x, from = %s]\n",
				dht.self.ID.Pretty(),
				PBDHTMessage_MessageType_name[int32(pmes.GetType())],
				pmes.GetId(), mes.Peer.ID.Pretty())
			switch pmes.GetType() {
			case PBDHTMessage_GET_VALUE:
				go dht.handleGetValue(mes.Peer, pmes)
			case PBDHTMessage_PUT_VALUE:
				go dht.handlePutValue(mes.Peer, pmes)
			case PBDHTMessage_FIND_NODE:
				go dht.handleFindPeer(mes.Peer, pmes)
			case PBDHTMessage_ADD_PROVIDER:
				go dht.handleAddProvider(mes.Peer, pmes)
			case PBDHTMessage_GET_PROVIDERS:
				go dht.handleGetProviders(mes.Peer, pmes)
			case PBDHTMessage_PING:
				go dht.handlePing(mes.Peer, pmes)
			case PBDHTMessage_DIAGNOSTIC:
				go dht.handleDiagnostic(mes.Peer, pmes)
			default:
				u.PErr("Recieved invalid message type")
			}

		case err := <-errs:
			u.PErr("dht err: %s\n", err)
		case <-dht.shutdown:
			return
		}
	}
}

// FindProviders searches for peers who can provide the value for given key.
func (dht *IpfsDHT) FindProviders(key u.Key, timeout time.Duration) ([]*peer.Peer, error) {
	ll := startNewRPC("FindProviders")
	defer func() {
		ll.EndLog()
		ll.Print()
	}()
	u.DOut("Find providers for: '%s'\n", key)
	p := dht.routingTables[0].NearestPeer(kb.ConvertKey(key))
	if p == nil {
		return nil, kb.ErrLookupFailure
	}

	for level := 0; level < len(dht.routingTables); {
		pmes, err := dht.findProvidersSingle(p, key, level, timeout)
		if err != nil {
			return nil, err
		}
		if pmes.GetSuccess() {
			u.DOut("Got providers back from findProviders call!\n")
			provs := dht.addPeerList(key, pmes.GetPeers())
			ll.Success = true
			return provs, nil
		}

		u.DOut("Didnt get providers, just closer peers.\n")

		closer := pmes.GetPeers()
		if len(closer) == 0 {
			level++
			continue
		}
		if peer.ID(closer[0].GetId()).Equal(dht.self.ID) {
			u.DOut("Got myself back as a closer peer.")
			return nil, u.ErrNotFound
		}
		maddr, err := ma.NewMultiaddr(closer[0].GetAddr())
		if err != nil {
			// ??? Move up route level???
			panic("not yet implemented")
		}

		np, err := dht.network.GetConnection(peer.ID(closer[0].GetId()), maddr)
		if err != nil {
			u.PErr("[%s] Failed to connect to: %s\n", dht.self.ID.Pretty(), closer[0].GetAddr())
			level++
			continue
		}
		p = np
	}
	return nil, u.ErrNotFound
}

func (dht *IpfsDHT) getDiagnostic(timeout time.Duration) ([]*diagInfo, error) {
	u.DOut("Begin Diagnostic")
	//Send to N closest peers
	targets := dht.routingTables[0].NearestPeers(kb.ConvertPeerID(dht.self.ID), 10)

	// TODO: Add timeout to this struct so nodes know when to return
	pmes := Message{
		Type: PBDHTMessage_DIAGNOSTIC,
		ID:   swarm.GenerateMessageID(),
	}

	listenChan := dht.listener.Listen(pmes.ID, len(targets), time.Minute*2)

	pbmes := pmes.ToProtobuf()
	for _, p := range targets {
		mes := swarm.NewMessage(p, pbmes)
		dht.netChan.Outgoing <- mes
	}

	var out []*diagInfo
	after := time.After(timeout)
	for count := len(targets); count > 0; {
		select {
		case <-after:
			u.DOut("Diagnostic request timed out.")
			return out, u.ErrTimeout
		case resp := <-listenChan:
			pmesOut := new(PBDHTMessage)
			err := proto.Unmarshal(resp.Data, pmesOut)
			if err != nil {
				// NOTE: here and elsewhere, need to audit error handling,
				//		some errors should be continued on from
				return out, err
			}

			dec := json.NewDecoder(bytes.NewBuffer(pmesOut.GetValue()))
			for {
				di := new(diagInfo)
				err := dec.Decode(di)
				if err != nil {
					break
				}

				out = append(out, di)
			}
		}
	}

	return nil, nil
}

func (dl *DaemonListener) handleConnection(conn net.Conn) {
	defer conn.Close()

	dec := json.NewDecoder(conn)

	var command Command
	err := dec.Decode(&command)
	if err != nil {
		fmt.Fprintln(conn, err)
		return
	}

	u.DOut("Got command: %v\n", command)
	switch command.Command {
	case "add":
		err = commands.Add(dl.node, command.Args, command.Opts, conn)
	case "cat":
		err = commands.Cat(dl.node, command.Args, command.Opts, conn)
	case "ls":
		err = commands.Ls(dl.node, command.Args, command.Opts, conn)
	case "pin":
		err = commands.Pin(dl.node, command.Args, command.Opts, conn)
	case "peers":
		err = commands.Peers(dl.node, command.Args, command.Opts, conn)
	default:
		err = fmt.Errorf("Invalid Command: '%s'", command.Command)
	}
	if err != nil {
		fmt.Fprintln(conn, err)
	}
}

// GetBlock attempts to retrieve a particular block from peers, within timeout.
func (bs *BitSwap) GetBlock(k u.Key, timeout time.Duration) (
	*blocks.Block, error) {
	u.DOut("Bitswap GetBlock: '%s'\n", k.Pretty())
	begin := time.Now()
	tleft := timeout - time.Now().Sub(begin)
	provs_ch := bs.routing.FindProvidersAsync(k, 20, timeout)

	valchan := make(chan []byte)
	after := time.After(tleft)

	// TODO: when the data is received, shut down this for loop ASAP
	go func() {
		for p := range provs_ch {
			go func(pr *peer.Peer) {
				blk, err := bs.getBlock(k, pr, tleft)
				if err != nil {
					u.PErr("getBlock returned: %v\n", err)
					return
				}
				select {
				case valchan <- blk:
				default:
				}
			}(p)
		}
	}()

	select {
	case blkdata := <-valchan:
		close(valchan)
		return blocks.NewBlock(blkdata)
	case <-after:
		return nil, u.ErrTimeout
	}
}

func (dht *IpfsDHT) findProvidersSingle(p *peer.Peer, key u.Key, level int, timeout time.Duration) (*PBDHTMessage, error) {
	pmes := Message{
		Type:  PBDHTMessage_GET_PROVIDERS,
		Key:   string(key),
		ID:    swarm.GenerateMessageID(),
		Value: []byte{byte(level)},
	}

	mes := swarm.NewMessage(p, pmes.ToProtobuf())

	listenChan := dht.listener.Listen(pmes.ID, 1, time.Minute)
	dht.netChan.Outgoing <- mes
	after := time.After(timeout)
	select {
	case <-after:
		dht.listener.Unlisten(pmes.ID)
		return nil, u.ErrTimeout
	case resp := <-listenChan:
		u.DOut("FindProviders: got response.\n")
		pmesOut := new(PBDHTMessage)
		err := proto.Unmarshal(resp.Data, pmesOut)
		if err != nil {
			return nil, err
		}

		return pmesOut, nil
	}
}

// Attr returns the attributes of a given node.
func (s *Node) Attr() fuse.Attr {
	u.DOut("Node attr.\n")
	if len(s.Nd.Links) > 0 {
		return fuse.Attr{Mode: os.ModeDir | 0555}
	}

	size, _ := s.Nd.Size()
	return fuse.Attr{Mode: 0444, Size: uint64(size)}
}

func (dht *IpfsDHT) handleGetValue(p *peer.Peer, pmes *PBDHTMessage) {
	u.DOut("handleGetValue for key: %s\n", pmes.GetKey())
	dskey := ds.NewKey(pmes.GetKey())
	resp := &Message{
		Response: true,
		ID:       pmes.GetId(),
		Key:      pmes.GetKey(),
	}
	iVal, err := dht.datastore.Get(dskey)
	if err == nil {
		u.DOut("handleGetValue success!\n")
		resp.Success = true
		resp.Value = iVal.([]byte)
	} else if err == ds.ErrNotFound {
		// Check if we know any providers for the requested value
		provs := dht.providers.GetProviders(u.Key(pmes.GetKey()))
		if len(provs) > 0 {
			u.DOut("handleGetValue returning %d provider[s]\n", len(provs))
			resp.Peers = provs
			resp.Success = true
		} else {
			// No providers?
			// Find closest peer on given cluster to desired key and reply with that info

			level := 0
			if len(pmes.GetValue()) < 1 {
				// TODO: maybe return an error? Defaulting isnt a good idea IMO
				u.PErr("handleGetValue: no routing level specified, assuming 0\n")
			} else {
				level = int(pmes.GetValue()[0]) // Using value field to specify cluster level
			}
			u.DOut("handleGetValue searching level %d clusters\n", level)

			closer := dht.routingTables[level].NearestPeer(kb.ConvertKey(u.Key(pmes.GetKey())))

			if closer.ID.Equal(dht.self.ID) {
				u.DOut("Attempted to return self! this shouldnt happen...\n")
				resp.Peers = nil
				goto out
			}
			// If this peer is closer than the one from the table, return nil
			if kb.Closer(dht.self.ID, closer.ID, u.Key(pmes.GetKey())) {
				resp.Peers = nil
				u.DOut("handleGetValue could not find a closer node than myself.\n")
			} else {
				u.DOut("handleGetValue returning a closer peer: '%s'\n", closer.ID.Pretty())
				resp.Peers = []*peer.Peer{closer}
			}
		}
	} else {
		//temp: what other errors can a datastore return?
		panic(err)
	}

out:
	mes := swarm.NewMessage(p, resp.ToProtobuf())
	dht.netChan.Outgoing <- mes
}

// Lookup performs a lookup under this node.
func (s *Node) Lookup(name string, intr fs.Intr) (fs.Node, fuse.Error) {
	u.DOut("Lookup '%s'\n", name)
	nd, err := s.Ipfs.Resolver.ResolveLinks(s.Nd, []string{name})
	if err != nil {
		// todo: make this error more versatile.
		return nil, fuse.ENOENT
	}

	return &Node{Ipfs: s.Ipfs, Nd: nd}, nil
}