tcp mux and stuff

tcp-mux-server.go

@@ -0,0 +1,133 @@
+package main
+
+import (
+	"encoding/binary"
+	"io"
+	"log"
+	"net"
+	"sync"
+)
+
+type Server struct {
+	*TCPServerMux
+}
+
+func Listen(address string) (*Server, error) {
+	listener, err := net.Listen("tcp", address)
+	server := &Server{
+		NewTCPServerMux(100),
+	}
+
+	if err != nil {
+		return nil, err
+	}
+	go func() {
+		for {
+			conn, err := listener.Accept()
+			if err != nil {
+				log.Printf("Error accepting connection: %v\n", err)
+				continue
+			}
+			go server.HandleConnection(conn)
+		}
+	}()
+	return server, nil
+}
+
+type TCPServerMux struct {
+	mu          sync.RWMutex
+	listeners   map[uint16]func(data []byte) error
+	functions   map[uint16]func(data []byte) (uint16, []byte, error)
+	connections []net.Conn
+}
+
+func NewTCPServerMux(maxClients int) *TCPServerMux {
+	m := &TCPServerMux{
+		connections: make([]net.Conn, 0, maxClients),
+		mu:          sync.RWMutex{},
+		listeners:   make(map[uint16]func(data []byte) error),
+		functions:   make(map[uint16]func(data []byte) (uint16, []byte, error)),
+	}
+
+	return m
+}
+
+func (m *TCPServerMux) handleListener(messageType uint16, data []byte) (bool, error) {
+	m.mu.RLock()
+	handler, ok := m.listeners[messageType]
+	m.mu.RUnlock()
+	if ok {
+		err := handler(data)
+		if err != nil {
+			return true, err
+		}
+	}
+	return false, nil
+}
+
+func (m *TCPServerMux) handleFunction(connection net.Conn, messageType uint16, data []byte) (bool, error) {
+	m.mu.RLock()
+	function, ok := m.functions[messageType]
+	m.mu.RUnlock()
+	if ok {
+		responseType, responseData, err := function(data)
+		if err != nil {
+			return true, err
+		}
+		err = binary.Write(connection, binary.LittleEndian, Packet{
+			Version:     1,
+			MessageType: responseType,
+			DataLength:  uint16(len(responseData)),
+		})
+		if err != nil {
+			return true, err
+		}
+		packetsSent.Inc()
+		_, err = connection.Write(responseData)
+		return true, err
+	}
+	return false, nil
+}
+
+func (m *TCPServerMux) HandleConnection(connection net.Conn) error {
+	m.mu.Lock()
+	m.connections = append(m.connections, connection)
+	m.mu.Unlock()
+	defer connection.Close()
+	for {
+		messageType, data, err := ReceivePacket(connection)
+		if err != nil {
+			if err == io.EOF {
+				return nil
+			}
+			log.Printf("Error receiving packet: %v\n", err)
+			return err
+		}
+
+		status, err := m.handleListener(messageType, data)
+		if err != nil {
+			log.Printf("Error handling listener: %v\n", err)
+		}
+		if !status {
+			status, err = m.handleFunction(connection, messageType, data)
+			if err != nil {
+				log.Printf("Error handling function: %v\n", err)
+			}
+			if !status {
+				log.Printf("Unknown message type: %d\n", messageType)
+			}
+		}
+	}
+}
+
+func (m *TCPServerMux) ListenFor(messageType uint16, handler func(data []byte) error) {
+	m.mu.Lock()
+	m.listeners[messageType] = handler
+	m.mu.Unlock()
+}
+
+func (m *TCPServerMux) HandleCall(messageType uint16, handler func(data []byte) (uint16, []byte, error)) {
+	m.mu.Lock()
+	m.functions[messageType] = handler
+	m.mu.Unlock()
+}