holy refactor

started out as me making a service abstraction..

- db.Player exists again, and entity.Player uses it as an embedded struct
- chunk.ForEachEntity() lets you add/remove entities during iteration now
- removed account related fields from CNPeer
- protocol/pool has been merged with protocol.
use protocol.GetBuffer() and protocol.PutBuffer().
- new protocol/internal/service!
service.Service is an abstraction layer to handle multiple CNPeer*
connections and allows you to associate each with an interface{} uData.
In the future it might also handle a task queue for jobs that
modify/interact with the player's uData, called from service.handleEvents()
- PacketHandler callback type has a new param! uData is passed as well now
- much of loginserver/shardserver is now handled by the shared service
abstraction
- SHARD: NPC_ENTER packets are now sent on player loading complete
rather than on enter.

internal/service/service.go

@@ -0,0 +1,138 @@
+package service
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"sync"
+
+	"github.com/CPunch/gopenfusion/config"
+	"github.com/CPunch/gopenfusion/internal/protocol"
+)
+
+type PacketHandler func(peer *protocol.CNPeer, uData interface{}, pkt protocol.Packet) error
+
+func StubbedPacket(_ *protocol.CNPeer, _ interface{}, _ protocol.Packet) error {
+	return nil
+}
+
+type Service struct {
+	listener       net.Listener
+	port           int
+	Name           string
+	eRecv          chan *protocol.Event
+	packetHandlers map[uint32]PacketHandler
+	peers          *sync.Map
+
+	// OnDisconnect is called when a peer disconnects from the service.
+	// uData is the stored value of the key/value pair in the peer map.
+	// It may not be set while the service is running. (eg. srvc.Start() has been called)
+	OnDisconnect func(peer *protocol.CNPeer, uData interface{})
+
+	// OnConnect is called when a peer connects to the service.
+	// return value is used as the value in the peer map.
+	// It may not be set while the service is running. (eg. srvc.Start() has been called)
+	OnConnect func(peer *protocol.CNPeer) (uData interface{})
+}
+
+func NewService(name string, port int) (*Service, error) {
+	listener, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
+	if err != nil {
+		return nil, err
+	}
+
+	service := &Service{
+		listener:       listener,
+		port:           port,
+		Name:           name,
+		eRecv:          make(chan *protocol.Event),
+		packetHandlers: make(map[uint32]PacketHandler),
+		peers:          &sync.Map{},
+	}
+
+	return service, nil
+}
+
+// may not be called while the service is running (eg. srvc.Start() has been called)
+func (service *Service) AddPacketHandler(pktID uint32, handler PacketHandler) {
+	service.packetHandlers[pktID] = handler
+}
+
+func (service *Service) Start() {
+	log.Printf("%s service hosted on %s:%d\n", service.Name, config.GetAnnounceIP(), service.port)
+
+	go service.handleEvents()
+	for {
+		conn, err := service.listener.Accept()
+		if err != nil {
+			log.Println("Connection error: ", err)
+			return
+		}
+
+		peer := protocol.NewCNPeer(service.eRecv, conn)
+		service.connect(peer)
+	}
+}
+
+func (service *Service) handleEvents() {
+	for event := range service.eRecv {
+		switch event.Type {
+		case protocol.EVENT_CLIENT_DISCONNECT:
+			service.disconnect(event.Peer)
+		case protocol.EVENT_CLIENT_PACKET:
+			if err := service.handlePacket(event.Peer, event.PktID, protocol.NewPacket(event.Pkt)); err != nil {
+				log.Printf("Error handling packet: %v", err)
+				event.Peer.Kill()
+			}
+
+			// the packet buffer is given to us by the event, so we'll need to make sure to return it to the pool
+			protocol.PutBuffer(event.Pkt)
+		}
+	}
+}
+
+func (service *Service) handlePacket(peer *protocol.CNPeer, typeID uint32, pkt protocol.Packet) error {
+	uData, _ := service.peers.Load(peer)
+	if hndlr, ok := service.packetHandlers[typeID]; ok {
+		if err := hndlr(peer, uData, pkt); err != nil {
+			return err
+		}
+	} else {
+		log.Printf("[WARN] unknown packet ID: %x\n", typeID)
+	}
+
+	return nil
+}
+
+func (service *Service) disconnect(peer *protocol.CNPeer) {
+	if service.OnDisconnect != nil {
+		uData, _ := service.peers.Load(peer)
+		service.OnDisconnect(peer, uData)
+	}
+
+	log.Printf("Peer %p disconnected from %s\n", peer, service.Name)
+	service.peers.Delete(peer)
+}
+
+func (service *Service) connect(peer *protocol.CNPeer) {
+	// default uData to nil, but if the service has an OnConnect
+	// handler, use the result from that
+	uData := interface{}(nil)
+	if service.OnConnect != nil {
+		uData = service.OnConnect(peer)
+	}
+
+	log.Printf("New peer %p connected to %s\n", peer, service.Name)
+	service.peers.Store(peer, uData)
+	go peer.Handler()
+}
+
+func (service *Service) SetPeerData(peer *protocol.CNPeer, uData interface{}) {
+	service.peers.Store(peer, uData)
+}
+
+func (service *Service) RangePeers(f func(peer *protocol.CNPeer, uData interface{}) bool) {
+	service.peers.Range(func(key, value any) bool {
+		return f(key.(*protocol.CNPeer), value)
+	})
+}