add ReadableConnection interface

src/network/Network.hpp

@@ -3,13 +3,12 @@
 #include "commons.hpp"
 
 namespace network {
-    class TcpConnection : public Connection {
+    class TcpConnection : public ReadableConnection {
     public:
         ~TcpConnection() override = default;
 
         virtual void connect(runnable callback) = 0;
-        virtual int recv(char* buffer, size_t length) = 0;
+
-        virtual int available() = 0;
         virtual void setNoDelay(bool noDelay) = 0;
         [[nodiscard]] virtual bool isNoDelay() const = 0;
 

src/network/Sockets.cpp

@@ -231,7 +231,7 @@ public:
             readBatch.clear();
 
             if (state != ConnectionState::CLOSED) {
-                shutdown(descriptor, 2);
+                shutdown(descriptor, SHUT_RDWR);
                 closesocket(descriptor);
             }
         }

src/network/commons.hpp

@@ -75,6 +75,12 @@ namespace network {
         bool isprivate = false;
     };
 
+    class ReadableConnection : public Connection {
+    public:
+        virtual int recv(char* buffer, size_t length) = 0;
+        virtual int available() = 0;
+    };
+
     class Server {
     public:
         virtual ~Server() = default;