work on framework for dht message handling

routing/dht/dht.go

@@ -2,6 +2,8 @@ package dht
 
 import (
 	swarm "github.com/jbenet/go-ipfs/swarm"
+	u "github.com/jbenet/go-ipfs/util"
+	"code.google.com/p/goprotobuf/proto"
 	"sync"
 )
 
@@ -14,36 +16,56 @@ type IpfsDHT struct {
 
 	network *swarm.Swarm
 
-	listeners  map[uint64]chan swarm.Message
+	// map of channels waiting for reply messages
+	listeners  map[uint64]chan *swarm.Message
 	listenLock sync.RWMutex
+
+	// Signal to shutdown dht
+	shutdown chan struct{}
 }
 
 // Read in all messages from swarm and handle them appropriately
 // NOTE: this function is just a quick sketch
 func (dht *IpfsDHT) handleMessages() {
-	for mes := range dht.network.Chan.Incoming {
-		for {
-			select {
-			case mes := <-dht.network.Chan.Incoming:
-				// Unmarshal message
-				dht.listenLock.RLock()
-				ch, ok := dht.listeners[id]
-				dht.listenLock.RUnlock()
-				if ok {
-					// Send message to waiting goroutine
-					ch <- mes
-				}
-
-				//case closeChan: or something
+	for {
+		select {
+		case mes := <-dht.network.Chan.Incoming:
+			pmes := new(DHTMessage)
+			err := proto.Unmarshal(mes.Data, pmes)
+			if err != nil {
+				u.PErr("Failed to decode protobuf message: %s", err)
+				continue
 			}
+
+			// Note: not sure if this is the correct place for this
+			dht.listenLock.RLock()
+			ch, ok := dht.listeners[pmes.GetId()]
+			dht.listenLock.RUnlock()
+			if ok {
+				ch <- mes
+			}
+			//
+
+			// Do something else with the messages?
+			switch pmes.GetType() {
+			case DHTMessage_ADD_PROVIDER:
+			case DHTMessage_FIND_NODE:
+			case DHTMessage_GET_PROVIDERS:
+			case DHTMessage_GET_VALUE:
+			case DHTMessage_PING:
+			case DHTMessage_PUT_VALUE:
+			}
+
+		case <-dht.shutdown:
+			return
 		}
 	}
 }
 
 // Register a handler for a specific message ID, used for getting replies
 // to certain messages (i.e. response to a GET_VALUE message)
-func (dht *IpfsDHT) ListenFor(mesid uint64) <-chan swarm.Message {
-	lchan := make(chan swarm.Message)
+func (dht *IpfsDHT) ListenFor(mesid uint64) <-chan *swarm.Message {
+	lchan := make(chan *swarm.Message)
 	dht.listenLock.Lock()
 	dht.listeners[mesid] = lchan
 	dht.listenLock.Unlock()

routing/dht/messages.pb.go

@@ -23,23 +23,29 @@ var _ = math.Inf
 type DHTMessage_MessageType int32
 
 const (
-	DHTMessage_PUT_VALUE DHTMessage_MessageType = 0
-	DHTMessage_GET_VALUE DHTMessage_MessageType = 1
-	DHTMessage_PING      DHTMessage_MessageType = 2
-	DHTMessage_FIND_NODE DHTMessage_MessageType = 3
+	DHTMessage_PUT_VALUE     DHTMessage_MessageType = 0
+	DHTMessage_GET_VALUE     DHTMessage_MessageType = 1
+	DHTMessage_ADD_PROVIDER  DHTMessage_MessageType = 2
+	DHTMessage_GET_PROVIDERS DHTMessage_MessageType = 3
+	DHTMessage_FIND_NODE     DHTMessage_MessageType = 4
+	DHTMessage_PING          DHTMessage_MessageType = 5
 )
 
 var DHTMessage_MessageType_name = map[int32]string{
 	0: "PUT_VALUE",
 	1: "GET_VALUE",
-	2: "PING",
-	3: "FIND_NODE",
+	2: "ADD_PROVIDER",
+	3: "GET_PROVIDERS",
+	4: "FIND_NODE",
+	5: "PING",
 }
 var DHTMessage_MessageType_value = map[string]int32{
-	"PUT_VALUE": 0,
-	"GET_VALUE": 1,
-	"PING":      2,
-	"FIND_NODE": 3,
+	"PUT_VALUE":     0,
+	"GET_VALUE":     1,
+	"ADD_PROVIDER":  2,
+	"GET_PROVIDERS": 3,
+	"FIND_NODE":     4,
+	"PING":          5,
 }
 
 func (x DHTMessage_MessageType) Enum() *DHTMessage_MessageType {
@@ -63,6 +69,7 @@ type DHTMessage struct {
 	Type             *DHTMessage_MessageType `protobuf:"varint,1,req,name=type,enum=dht.DHTMessage_MessageType" json:"type,omitempty"`
 	Key              *string                 `protobuf:"bytes,2,opt,name=key" json:"key,omitempty"`
 	Value            []byte                  `protobuf:"bytes,3,opt,name=value" json:"value,omitempty"`
+	Id               *uint64                 `protobuf:"varint,4,req,name=id" json:"id,omitempty"`
 	XXX_unrecognized []byte                  `json:"-"`
 }
 
@@ -91,6 +98,13 @@ func (m *DHTMessage) GetValue() []byte {
 	return nil
 }
 
+func (m *DHTMessage) GetId() uint64 {
+	if m != nil && m.Id != nil {
+		return *m.Id
+	}
+	return 0
+}
+
 func init() {
 	proto.RegisterEnum("dht.DHTMessage_MessageType", DHTMessage_MessageType_name, DHTMessage_MessageType_value)
 }

routing/dht/messages.proto

@@ -15,5 +15,5 @@ message DHTMessage {
 	required MessageType type = 1;
 	optional string key = 2;
 	optional bytes value = 3;
-	required int64 id = 4;
+	required uint64 id = 4;
 }

routing/dht/routing.go

@@ -7,6 +7,11 @@ import (
 	"time"
 )
 
+// TODO: determine a way of creating and managing message IDs
+func GenerateMessageID() uint64 {
+	return 4
+}
+
 // This file implements the Routing interface for the IpfsDHT struct.
 
 // Basic Put/Get
@@ -16,9 +21,15 @@ func (s *IpfsDHT) PutValue(key u.Key, value []byte) error {
 	var p *peer.Peer
 	p = s.routes.NearestNode(key)
 
-	pmes := new(PutValue)
-	pmes.Key = &key
+	pmes_type := DHTMessage_PUT_VALUE
+	str_key := string(key)
+	mes_id := GenerateMessageID()
+
+	pmes := new(DHTMessage)
+	pmes.Type = &pmes_type
+	pmes.Key = &str_key
 	pmes.Value = value
+	pmes.Id = &mes_id
 
 	mes := new(swarm.Message)
 	mes.Data = []byte(pmes.String())
@@ -33,23 +44,27 @@ func (s *IpfsDHT) GetValue(key u.Key, timeout time.Duration) ([]byte, error) {
 	var p *peer.Peer
 	p = s.routes.NearestNode(key)
 
+	str_key := string(key)
+	mes_type := DHTMessage_GET_VALUE
+	mes_id := GenerateMessageID()
 	// protobuf structure
-	pmes := new(GetValue)
-	pmes.Key = &key
-	pmes.Id = GenerateMessageID()
+	pmes := new(DHTMessage)
+	pmes.Type = &mes_type
+	pmes.Key = &str_key
+	pmes.Id = &mes_id
 
 	mes := new(swarm.Message)
 	mes.Data = []byte(pmes.String())
 	mes.Peer = p
 
-	response_chan := s.ListenFor(pmes.Id)
+	response_chan := s.ListenFor(*pmes.Id)
 
 	// Wait for either the response or a timeout
 	timeup := time.After(timeout)
 	select {
 	case <-timeup:
 		// TODO: unregister listener
-		return nil, timeoutError
+		return nil, u.ErrTimeout
 	case resp := <-response_chan:
 		return resp.Data, nil
 	}

routing/dht/table.go

@@ -3,6 +3,9 @@ package dht
 import (
 	"bytes"
 	"container/list"
+
+	peer "github.com/jbenet/go-ipfs/peer"
+	u "github.com/jbenet/go-ipfs/util"
 )
 
 // ID for IpfsDHT should be a byte slice, to allow for simpler operations
@@ -22,6 +25,11 @@ type RoutingTable struct {
 	Buckets []Bucket
 }
 
+//TODO: make this accept an ID, requires method of converting keys to IDs
+func (rt *RoutingTable) NearestNode(key u.Key) *peer.Peer {
+	panic("Function not implemented.")
+}
+
 func (id ID) Equal(other ID) bool {
 	return bytes.Equal(id, other)
 }

swarm/swarm.go

@@ -21,8 +21,8 @@ type Message struct {
 
 // Chan is a swam channel, which provides duplex communication and errors.
 type Chan struct {
-	Outgoing chan Message
-	Incoming chan Message
+	Outgoing chan *Message
+	Incoming chan *Message
 	Errors   chan error
 	Close    chan bool
 }
@@ -30,8 +30,8 @@ type Chan struct {
 // NewChan constructs a Chan instance, with given buffer size bufsize.
 func NewChan(bufsize int) *Chan {
 	return &Chan{
-		Outgoing: make(chan Message, bufsize),
-		Incoming: make(chan Message, bufsize),
+		Outgoing: make(chan *Message, bufsize),
+		Incoming: make(chan *Message, bufsize),
 		Errors:   make(chan error),
 		Close:    make(chan bool, bufsize),
 	}
@@ -197,7 +197,7 @@ Loop:
 			}
 
 			// wrap it for consumers.
-			msg := Message{Peer: conn.Peer, Data: data}
+			msg := &Message{Peer: conn.Peer, Data: data}
 			s.Chan.Incoming <- msg
 		}
 	}

util/util.go

@@ -14,6 +14,9 @@ var Debug bool
 // ErrNotImplemented signifies a function has not been implemented yet.
 var ErrNotImplemented = fmt.Errorf("Error: not implemented yet.")
 
+// ErrTimeout implies that a timeout has been triggered
+var ErrTimeout = fmt.Errorf("Error: Call timed out.")
+
 // Key is a string representation of multihash for use with maps.
 type Key string