Improve: refactor ssr and fix #995 (#1189)

Co-authored-by: goomada <madao@DESKTOP-IOEBS0C.localdomain>

component/ssr/protocol/packet.go

@@ -1,30 +1,26 @@
 package protocol
 
 import (
+	"bytes"
 	"net"
 
-	"github.com/Dreamacro/clash/common/pool"
+	"github.com/Dreamacro/clash/component/ssr/tools"
 )
 
-// NewPacketConn returns a net.NewPacketConn with protocol decoding/encoding
-func NewPacketConn(pc net.PacketConn, p Protocol) net.PacketConn {
-	return &PacketConn{PacketConn: pc, Protocol: p.initForConn(nil)}
-}
-
-// PacketConn represents a protocol packet connection
 type PacketConn struct {
 	net.PacketConn
 	Protocol
 }
 
 func (c *PacketConn) WriteTo(b []byte, addr net.Addr) (int, error) {
-	buf := pool.Get(pool.RelayBufferSize)
-	defer pool.Put(buf)
-	buf, err := c.EncodePacket(b)
+	buf := tools.BufPool.Get().(*bytes.Buffer)
+	defer tools.BufPool.Put(buf)
+	defer buf.Reset()
+	err := c.EncodePacket(buf, b)
 	if err != nil {
 		return 0, err
 	}
-	_, err = c.PacketConn.WriteTo(buf, addr)
+	_, err = c.PacketConn.WriteTo(buf.Bytes(), addr)
 	return len(b), err
 }
 
@@ -33,10 +29,10 @@ func (c *PacketConn) ReadFrom(b []byte) (int, net.Addr, error) {
 	if err != nil {
 		return n, addr, err
 	}
-	bb, length, err := c.DecodePacket(b[:n])
+	decoded, err := c.DecodePacket(b[:n])
 	if err != nil {
 		return n, addr, err
 	}
-	copy(b, bb)
-	return length, addr, err
+	copy(b, decoded)
+	return len(decoded), addr, nil
 }