Pretty big cleanup

daemonconn/conninit.go

@@ -0,0 +1,34 @@
+package daemonconn
+
+import (
+	"net"
+)
+
+const DefaultUnixSocketPath = "/tmp/liberum.sock"
+
+func UnixSocketListen(socketPath string) (<-chan DaemonConn, error) {
+	listener, err := net.Listen("unix", "/tmp/liberum.sock")
+	if err != nil {
+		return nil, err
+	}
+
+	connChan := make(chan DaemonConn, 32)
+
+	go func() {
+		var conn net.Conn
+		for conn, err = listener.Accept(); err == nil; {
+			connChan <- FromConn(conn)
+		}
+	}()
+
+	return connChan, err
+}
+
+func UnixSocketConnect(socketPath string) (DaemonConn, error) {
+	conn, err := net.Dial("unix", DefaultUnixSocketPath)
+	if err != nil {
+		return DaemonConn{}, err
+	}
+
+	return FromConn(conn), nil
+}

daemonconn/daemonconn.go

@@ -0,0 +1,69 @@
+package daemonconn
+
+import (
+	"encoding/json"
+	"errors"
+	"net"
+)
+
+type Message interface {
+	TypeID() uint32
+}
+
+type DaemonConn struct {
+	FrameReadWriter
+}
+
+func FromConn(conn net.Conn) DaemonConn {
+	return DaemonConn{FrameReadWriter{conn}}
+}
+
+func (dc DaemonConn) ReadMessage() (Message, error) {
+	frame, err := dc.FrameReadWriter.ReadFrame()
+	if err != nil {
+		return nil, err
+	}
+
+	var msg Message
+
+	switch frame.Type() {
+	case MessageTypeEchoRequest:
+		msg, err = frameToMessage[EchoRequest](frame)
+	case MessageTypeEchoResponse:
+		msg, err = frameToMessage[EchoResponse](frame)
+	default:
+		err = errors.New("unknown frame type")
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	return msg, nil
+}
+
+func (dc DaemonConn) WriteMessage(msg Message) error {
+	msgBytes, err := json.Marshal(msg)
+	if err != nil {
+		return err
+	}
+
+	f := frame{typeID: msg.TypeID(), valueBytes: msgBytes}
+	err = dc.WriteFrame(f)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func frameToMessage[M Message](frame Frame) (Message, error) {
+	var msg M
+
+	err := json.Unmarshal(frame.Value(), &msg)
+	if err != nil {
+		return nil, err
+	}
+
+	return msg, nil
+}

daemonconn/framereadwriter.go

@@ -1,4 +1,4 @@
-package main
+package daemonconn
 
 import (
 	"encoding/binary"

daemonconn/messages.go

@@ -0,0 +1,20 @@
+package daemonconn
+
+const (
+	MessageTypeEchoRequest = iota
+	MessageTypeEchoResponse
+)
+
+type EchoRequest struct {
+	EchoByte byte
+}
+
+func (EchoRequest) TypeID() uint32 {
+	return MessageTypeEchoRequest
+}
+
+type EchoResponse EchoRequest
+
+func (EchoResponse) TypeID() uint32 {
+	return MessageTypeEchoResponse
+}

main.go

@@ -1,226 +1,15 @@
 package main
 
 import (
-	"encoding/binary"
+	"daemonSocketExample/daemonconn"
-	"encoding/json"
+	"daemonSocketExample/msghandlers"
-	"errors"
 	"github.com/sevlyar/go-daemon"
-	"io"
 	"log"
 	"log/slog"
-	"net"
 	"os"
 	"time"
 )
 
-type Message interface {
-	ID() uint32
-}
-
-const (
-	EchoRequestID = iota
-)
-
-type EchoRequest struct {
-	EchoByte byte
-}
-
-type MessageHandler func(m Message) error
-
-var Handlers = map[uint32]MessageHandler{
-	EchoRequestID: handleEchoRequest,
-}
-
-func (EchoRequest) ID() uint32 {
-	return EchoRequestID
-}
-
-func unixSocketListen() error {
-	listener, err := net.Listen("unix", "/tmp/liberum.sock")
-	if err != nil {
-		return err
-	}
-
-	for conn, err := listener.Accept(); err == nil; {
-		err = handleConnection(conn)
-		if err != nil {
-			slog.Error("Error handling connection:", err)
-		}
-	}
-
-	return nil
-}
-
-func handleConnection(conn net.Conn) error {
-	msgChan := readSocketMessages(conn)
-
-	for msg := range msgChan {
-		err := handleMessage(msg)
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func readSocketMessages(conn net.Conn) chan Message {
-	msgChan := make(chan Message, 64)
-
-	go func() {
-		for {
-			msgBytes, err := readMessage(conn)
-			if err != nil {
-				slog.Error("Error reading message", "error", err)
-			}
-
-			msg, err := decodeMessage(msgBytes)
-			if err != nil {
-				slog.Error("Error parsing message", "error", err)
-			}
-
-			msgChan <- msg
-		}
-	}()
-
-	return msgChan
-}
-
-func decodeMessage(msgBytes []byte) (Message, error) {
-	if len(msgBytes) < 4 {
-		return nil, errors.New("message too short to have type ID")
-	}
-
-	msgID := binary.LittleEndian.Uint32(msgBytes[0:4])
-	msgRest := msgBytes[4:]
-	var err error
-	var msg Message
-
-	switch msgID {
-	case EchoRequestID:
-		var echoReq EchoRequest
-		err = json.Unmarshal(msgRest, &echoReq)
-		msg = echoReq
-	default:
-		err = errors.New("unknown message type ID")
-	}
-
-	if err != nil {
-		return nil, err
-	}
-
-	return msg, nil
-}
-
-func readMessage(conn net.Conn) ([]byte, error) {
-	msgLenBuf := make([]byte, 4)
-	n, err := io.ReadFull(conn, msgLenBuf)
-	if err != nil {
-		return nil, err
-	}
-
-	if n != 4 {
-		return nil, errors.New("could not read message length")
-	}
-
-	msgLen := binary.LittleEndian.Uint32(msgLenBuf)
-	msgContent := make([]byte, msgLen)
-	n, err = io.ReadFull(conn, msgContent)
-	if err != nil {
-		return nil, err
-	}
-
-	if uint32(n) != msgLen {
-		return nil, errors.New("could not read full message")
-	}
-
-	return msgContent, nil
-}
-
-func handleMessage(msg Message) error {
-	handler, ok := Handlers[msg.ID()]
-	if !ok {
-		return errors.New("message handler not defined for a given ID")
-	}
-
-	err := handler(msg)
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func handleEchoRequest(echoRequestMsg Message) error {
-	echoRequest := echoRequestMsg.(EchoRequest)
-	slog.Info("Got echo request", "EchoByte", echoRequest.EchoByte)
-
-	return nil
-}
-
-func writeMessage(conn net.Conn, msg Message) error {
-	msgBytes, err := encodeMessage(msg)
-	if err != nil {
-		return err
-	}
-
-	n, err := conn.Write(msgBytes)
-	if err != nil {
-		return err
-	}
-
-	if n != len(msgBytes) {
-		return errors.New("could not write full message")
-	}
-
-	return nil
-}
-
-func encodeMessage(msg Message) ([]byte, error) {
-	var msgBytes []byte
-	var msgJsonBytes []byte
-	var err error
-
-	msgJsonBytes, err = json.Marshal(msg)
-	if err != nil {
-		return nil, err
-	}
-
-	// +4 for type field length
-	msgLen := len(msgJsonBytes) + 4
-	msgLenBytes := make([]byte, 4)
-	binary.LittleEndian.PutUint32(msgLenBytes, uint32(msgLen))
-	msgBytes = append(msgBytes, msgLenBytes...)
-
-	msgTypeBytes := make([]byte, 4)
-	binary.LittleEndian.PutUint32(msgTypeBytes, msg.ID())
-	msgBytes = append(msgBytes, msgTypeBytes...)
-
-	msgBytes = append(msgBytes, msgJsonBytes...)
-
-	return msgBytes, nil
-}
-
-func writeSocketMessages(conn net.Conn, msgChan <-chan Message) error {
-	for msg := range msgChan {
-		err := writeMessage(conn, msg)
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func unixSocketConnect() (net.Conn, error) {
-	conn, err := net.Dial("unix", "/tmp/liberum.sock")
-	if err != nil {
-		return nil, err
-	}
-
-	return conn, nil
-}
-
 func main() {
 	ctx := &daemon.Context{
 		PidFileName: "liberum-daemon.pid",
@@ -248,28 +37,29 @@ func main() {
 
 	_ = os.Remove("/tmp/liberum.sock")
 
-	go func() {
+	connChan, err := daemonconn.UnixSocketListen(daemonconn.DefaultUnixSocketPath)
-		err = unixSocketListen()
-		if err != nil {
-			slog.Error("Error listening unix socket", "error", err)
-		}
-	}()
-
-	time.Sleep(1 * time.Second)
-	conn, err := unixSocketConnect()
 	if err != nil {
 		panic(err)
 	}
 
-	msgWriteChan := make(chan Message, 64)
-
 	go func() {
-		err = writeSocketMessages(conn, msgWriteChan)
+		for conn := range connChan {
-		if err != nil {
+			err := msghandlers.HandleDaemonConn(conn)
-			panic(err)
+			if err != nil {
+				panic(err)
+			}
 		}
 	}()
 
-	msgWriteChan <- EchoRequest{123}
+	conn, err := daemonconn.UnixSocketConnect(daemonconn.DefaultUnixSocketPath)
+	if err != nil {
+		panic(err)
+	}
+
+	err = conn.WriteMessage(daemonconn.EchoRequest{EchoByte: 123})
+	if err != nil {
+		panic(err)
+	}
+
 	time.Sleep(time.Second * 5)
 }

msghandlers/echorequesthandler.go

@@ -0,0 +1,13 @@
+package msghandlers
+
+import (
+	"daemonSocketExample/daemonconn"
+	"log/slog"
+)
+
+func handleEchoRequest(msg daemonconn.Message) error {
+	echoRequest := msg.(daemonconn.EchoRequest)
+	slog.Info("Got echo request", "echoByte", echoRequest.EchoByte)
+
+	return nil
+}

msghandlers/msghandlers.go

@@ -0,0 +1,32 @@
+package msghandlers
+
+import (
+	"daemonSocketExample/daemonconn"
+)
+
+type MessageHandler func(daemonconn.Message) error
+
+var Handlers = map[uint32]MessageHandler{
+	daemonconn.MessageTypeEchoRequest: handleEchoRequest,
+}
+
+func HandleDaemonConn(conn daemonconn.DaemonConn) error {
+	msg, err := conn.ReadMessage()
+
+	for err == nil {
+		err := handleMessage(msg)
+		if err != nil {
+			return err
+		}
+
+		msg, err = conn.ReadMessage()
+	}
+
+	return err
+}
+
+func handleMessage(msg daemonconn.Message) error {
+	handlerFunc := Handlers[msg.TypeID()]
+
+	return handlerFunc(msg)
+}