增加部分的注释和说明

backend.go

@@ -80,10 +80,12 @@ func (b *Backend) httpProxyClient() (*http.Client, error) {
 	}, nil
 }
 
+// socks5Client to create http client with socks5 proxy
 func (b *Backend) socks5Client(timeout int) (*socks5.Client, error) {
 	return socks5.NewClient(b.Addr, b.Socks5UserName, b.Socks5Password, timeout, timeout)
 }
 
+// Socks5Conn to create a connection by specific params
 func (b *Backend) Socks5Conn(network, addr string, timeout int) (cc net.Conn, err error) {
 	client, err := b.socks5Client(timeout)
 	if err != nil {
@@ -93,6 +95,7 @@ func (b *Backend) Socks5Conn(network, addr string, timeout int) (cc net.Conn, er
 	return client.Dial(network, addr)
 }
 
+// NewBackend creates a new Backend instance
 func NewBackend(addr string, config BackendCheckConfig) (backend *Backend) {
 	backend = &Backend{
 		Addr:        addr,

pool.go

@@ -28,23 +28,30 @@ func (b *Pool) NextIndex() int {
 	return int(atomic.AddUint64(&b.current, uint64(1)) % uint64(len(b.backends)))
 }
 
+// Next returns the next index in the pool if there is one available
+// Only supports round-robin operations by default
 func (b *Pool) Next() *Backend {
 	// loop entire backends to find out an Alive backend
 	next := b.NextIndex()
-	l := len(b.backends) + next // start from next and move a full cycle
+	// start from next and move a full cycle
+	l := len(b.backends) + next
 	for i := next; i < l; i++ {
-		idx := i % len(b.backends)   // take an index by modding
-		if b.backends[idx].Alive() { // if we have an alive backend, use it and store if its not the original one
+		// take an index by modding
+		idx := i % len(b.backends)
+		// if we have an alive backend, use it and store if its not the original one
+		if b.backends[idx].Alive() {
 			if i != next {
 				atomic.StoreUint64(&b.current, uint64(idx))
 			}
+
 			return b.backends[idx]
 		}
 	}
 
 	return nil
 }
 
+// Check if we have an alive backend
 func (b *Pool) Check() {
 	for _, b := range b.backends {
 		err := b.Check()
@@ -56,6 +63,7 @@ func (b *Pool) Check() {
 	}
 }
 
+// NewPool instance for a new Pools instance
 func NewPool() *Pool {
 	return &Pool{
 		backends: []*Backend{},

redirect.go

@@ -12,11 +12,7 @@
 
 package socks5lb
 
-import (
-	"fmt"
-)
-
-func (s *Server) ListenTProxy(_ string) (err error) {
-	err = fmt.Errorf("sorry transparent proxy is ONLY supports Linux platform")
-	return
+// ListenProxy is not implemented by default
+func (s *Server) ListenTProxy(_ string) error {
+	return error.New("sorry transparent proxy is ONLY supports Linux platform")
 }

redirect_linux.go

@@ -25,6 +25,8 @@ import (
 )
 
 // getOriginalDstAddr to get the original address from the socket
+// this function is referenced from
+// https://github.com/ginuerzh/gost/blob/0247b941ac31344f0d7b3c547941a051188ba202/redirect.go#L72
 func getOriginalDstAddr(conn *net.TCPConn) (addr net.Addr, c *net.TCPConn, err error) {
 	defer conn.Close()
 
@@ -65,6 +67,7 @@ var (
 	clientLock    sync.Mutex
 )
 
+// socks5Client to connect to a proxy server
 func (s *Server) socks5Client() (client *socks5.Client, err error) {
 	clientLock.Lock()
 
@@ -80,16 +83,16 @@ func (s *Server) socks5Client() (client *socks5.Client, err error) {
 		socks5Clients = client
 	}()
 
-	backend := s.Pool.Next()
-	if backend == nil {
-		log.Error("sorry, we don't have healthy backend, so close the connection")
-		socks5Clients = nil
-		return
+	// found a available backend
+	if backend := s.Pool.Next(); backend != nil {
+		return backend.socks5Client(0)
 	}
 
-	return backend.socks5Client(0)
+	err = errors.New("sorry, we don't have healthy backend, so close the connection")
+	return
 }
 
+// ListenTProxy is listening the local tcp port on the given address
 func (s *Server) ListenTProxy(addr string) (err error) {
 	tcpAddr, err := net.ResolveTCPAddr("tcp", addr)
 	if err != nil {

server.go

@@ -72,6 +72,7 @@ func (s *Server) Stop() (e error) {
 	return
 }
 
+// Transport is used to connect to the server and client each	other
 func (s *Server) Transport(dst, src io.ReadWriter) (err error) {
 	// @see https://github.com/ginuerzh/gost/blob/0247b941ac31344f0d7b3c547941a051188ba202/server.go#L105
 	errs := make(chan error, 1)

socks5.go

@@ -48,6 +48,7 @@ func (s *Server) ListenSocks5(addr string) (err error) {
 			}
 			defer backendConn.Close()
 
+			// transport the socket connection directly to the backend
 			s.Transport(socks5Conn, backendConn)
 		}()
 	}