reworked hub

hub/hub.go

@@ -1,48 +1,60 @@
 package hub
 
 import (
-	"errors"
+	"encoding/binary"
+	"fmt"
+	"strings"
 	"sync"
 
 	"github.com/9seconds/mtg/conntypes"
 	"github.com/9seconds/mtg/protocol"
 )
 
-type Concentrator struct {
-	hubs sync.Map
+type hub struct {
+	subs  map[string]*connectionHub
+	mutex sync.RWMutex
 }
 
-func (c *Concentrator) Write(packet conntypes.Packet, req *protocol.TelegramRequest) error {
-	hub := c.getHub(req)
-	connectionChan := make(chan *connection)
-	hub.connectionRequestsChan <- &connectionHubRequest{
-		req:          req,
-		responseChan: connectionChan,
+func (h *hub) Write(packet conntypes.Packet, req *protocol.TelegramRequest) error {
+	sub := h.getHub(req)
+	connections := make(chan *connection)
+	sub.channelConnectionRequests <- &connectionHubRequest{
+		request:  req,
+		response: connections,
 	}
 
-	conn, ok := <-connectionChan
+	conn, ok := <-connections
 	if !ok {
-		return errors.New("cannot establish connection to telegram")
+		return ErrCannotCreateConnection
 	}
+
+	if err := conn.write(packet); err != nil {
+		return fmt.Errorf("cannot send packet: %w", err)
+	}
+	return nil
 }
 
-func (c *Concentrator) getHub(req *protocol.TelegramRequest) *connectionHub {
-	dcMapRaw, ok := c.hubs.Load(req.ClientProtocol.DC())
-	if !ok {
-		dcMapRaw, _ = c.hubs.LoadOrStore(req.ClientProtocol.DC(), &sync.Map{})
-	}
-	dcMap := dcMapRaw.(*sync.Map)
+func (h *hub) getHub(req *protocol.TelegramRequest) *connectionHub {
+	keyBuilder := strings.Builder{}
+	binary.Write(&keyBuilder, binary.LittleEndian, int16(req.ClientProtocol.DC()))
+	keyBuilder.WriteRune('_')
+	binary.Write(&keyBuilder, binary.LittleEndian, uint8(req.ClientProtocol.ConnectionProtocol()))
+	key := keyBuilder.String()
+
+	h.mutex.RLock()
+	rv, ok := h.subs[key]
+	h.mutex.RUnlock()
 
-	loaded := true
-	hubRaw, ok := dcMap.Load(req.ClientProtocol.ConnectionProtocol())
 	if !ok {
-		hubRaw, loaded = dcMap.LoadOrStore(req.ClientProtocol.ConnectionProtocol(),
-			newConnectionHub())
-	}
-	hub := hubRaw.(*connectionHub)
-	if !loaded {
-		go hub.run()
+		h.mutex.Lock()
+		defer h.mutex.Unlock()
+
+		rv, ok = h.subs[key]
+		if !ok {
+			rv = newConnectionHub()
+			h.subs[key] = rv
+		}
 	}
 
-	return hub
+	return rv
 }