store one callback instead of many, needed to prevent search failures if there are multiple outstanding packets

src/yggdrasil/dht.go

@@ -59,9 +59,9 @@ type dhtReqKey struct {
 type dht struct {
 	core      *Core
 	nodeID    NodeID
-	peers     chan *dhtInfo                 // other goroutines put incoming dht updates here
-	reqs      map[dhtReqKey]time.Time       // Keeps track of recent outstanding requests
-	callbacks map[dhtReqKey][]func(*dhtRes) // Search and admin lookup callbacks
+	peers     chan *dhtInfo                  // other goroutines put incoming dht updates here
+	reqs      map[dhtReqKey]time.Time        // Keeps track of recent outstanding requests
+	callbacks map[dhtReqKey]dht_callbackInfo // Search and admin lookup callbacks
 	// These next two could be replaced by a single linked list or similar...
 	table map[NodeID]*dhtInfo
 	imp   []*dhtInfo
@@ -72,7 +72,7 @@ func (t *dht) init(c *Core) {
 	t.core = c
 	t.nodeID = *t.core.GetNodeID()
 	t.peers = make(chan *dhtInfo, 1024)
-	t.callbacks = make(map[dhtReqKey][]func(*dhtRes))
+	t.callbacks = make(map[dhtReqKey]dht_callbackInfo)
 	t.reset()
 }
 
@@ -202,26 +202,25 @@ func (t *dht) sendRes(res *dhtRes, req *dhtReq) {
 	t.core.router.out(packet)
 }
 
+type dht_callbackInfo struct {
+	f    func(*dhtRes)
+	time time.Time
+}
+
 // Adds a callback and removes it after some timeout.
 func (t *dht) addCallback(rq *dhtReqKey, callback func(*dhtRes)) {
-	t.callbacks[*rq] = append(t.callbacks[*rq], callback)
-	go func() {
-		time.Sleep(6 * time.Second)
-		t.core.router.admin <- func() {
-			delete(t.callbacks, *rq)
-		}
-	}()
+	info := dht_callbackInfo{callback, time.Now().Add(6 * time.Second)}
+	t.callbacks[*rq] = info
 }
 
 // Reads a lookup response, checks that we had sent a matching request, and processes the response info.
 // This mainly consists of updating the node we asked in our DHT (they responded, so we know they're still alive), and deciding if we want to do anything with their responses
 func (t *dht) handleRes(res *dhtRes) {
 	rq := dhtReqKey{res.Key, res.Dest}
-	for _, callback := range t.callbacks[rq] {
-		callback(res)
+	if callback, isIn := t.callbacks[rq]; isIn {
+		callback.f(res)
+		delete(t.callbacks, rq)
 	}
-	delete(t.callbacks, rq)
-	t.core.searches.handleDHTRes(res)
 	_, isIn := t.reqs[rq]
 	if !isIn {
 		return
@@ -263,7 +262,7 @@ func (t *dht) sendReq(req *dhtReq, dest *dhtInfo) {
 	}
 	packet := p.encode()
 	t.core.router.out(packet)
-	rq := dhtReqKey{req.Key, req.Dest}
+	rq := dhtReqKey{dest.key, req.Dest}
 	t.reqs[rq] = time.Now()
 }
 
@@ -293,9 +292,11 @@ func (t *dht) doMaintenance() {
 		}
 	}
 	t.reqs = newReqs
-	newCallbacks := make(map[dhtReqKey][]func(*dhtRes), len(t.callbacks))
+	newCallbacks := make(map[dhtReqKey]dht_callbackInfo, len(t.callbacks))
 	for key, callback := range t.callbacks {
-		newCallbacks[key] = callback
+		if now.Before(callback.time) {
+			newCallbacks[key] = callback
+		}
 	}
 	t.callbacks = newCallbacks
 	for infoID, info := range t.table {