Fix platform wrapper

experimental/libbox/log_server.go

@@ -0,0 +1,139 @@
+//go:build ios
+
+package libbox
+
+import (
+	"encoding/binary"
+	"io"
+	"net"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/sagernet/sing-box/log"
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/observable"
+	"github.com/sagernet/sing/common/x/list"
+)
+
+type LogServer struct {
+	sockPath string
+	listener net.Listener
+
+	access     sync.Mutex
+	savedLines *list.List[string]
+	subscriber *observable.Subscriber[string]
+	observer   *observable.Observer[string]
+}
+
+func NewLogServer(sharedDirectory string) *LogServer {
+	server := &LogServer{
+		sockPath:   filepath.Join(sharedDirectory, "log.sock"),
+		savedLines: new(list.List[string]),
+		subscriber: observable.NewSubscriber[string](128),
+	}
+	server.observer = observable.NewObserver[string](server.subscriber, 64)
+	return server
+}
+
+func (s *LogServer) Start() error {
+	os.Remove(s.sockPath)
+	listener, err := net.ListenUnix("unix", &net.UnixAddr{
+		Name: s.sockPath,
+		Net:  "unix",
+	})
+	if err != nil {
+		return err
+	}
+	go s.loopConnection(listener)
+	return nil
+}
+
+func (s *LogServer) Close() error {
+	return s.listener.Close()
+}
+
+func (s *LogServer) WriteMessage(message string) {
+	s.subscriber.Emit(message)
+	s.access.Lock()
+	s.savedLines.PushBack(message)
+	if s.savedLines.Len() > 100 {
+		s.savedLines.Remove(s.savedLines.Front())
+	}
+	s.access.Unlock()
+}
+
+func (s *LogServer) loopConnection(listener net.Listener) {
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			return
+		}
+		go func() {
+			hErr := s.handleConnection(&messageConn{conn})
+			if hErr != nil && !E.IsClosed(err) {
+				log.Warn("log-server: process connection: ", hErr)
+			}
+		}()
+	}
+}
+
+func (s *LogServer) handleConnection(conn *messageConn) error {
+	var savedLines []string
+	s.access.Lock()
+	savedLines = make([]string, 0, s.savedLines.Len())
+	for element := s.savedLines.Front(); element != nil; element = element.Next() {
+		savedLines = append(savedLines, element.Value)
+	}
+	s.access.Unlock()
+	subscription, done, err := s.observer.Subscribe()
+	if err != nil {
+		return err
+	}
+	defer s.observer.UnSubscribe(subscription)
+	for _, line := range savedLines {
+		err = conn.Write([]byte(line))
+		if err != nil {
+			return err
+		}
+	}
+	for {
+		select {
+		case message := <-subscription:
+			err = conn.Write([]byte(message))
+			if err != nil {
+				return err
+			}
+		case <-done:
+			conn.Close()
+			return nil
+		}
+	}
+}
+
+type messageConn struct {
+	net.Conn
+}
+
+func (c *messageConn) Read() ([]byte, error) {
+	var messageLength uint16
+	err := binary.Read(c.Conn, binary.BigEndian, &messageLength)
+	if err != nil {
+		return nil, err
+	}
+	data := make([]byte, messageLength)
+	_, err = io.ReadFull(c.Conn, data)
+	if err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func (c *messageConn) Write(message []byte) error {
+	err := binary.Write(c.Conn, binary.BigEndian, uint16(len(message)))
+	if err != nil {
+		return err
+	}
+	_, err = c.Conn.Write(message)
+	return err
+}