#ifndef BTSTREAM_H#define BTSTREAM_H#include "./def.h"#include "./bufio.h"#ifdef WINDOWS#include "Winsock2.h"#else#include "unistd.h"#endifclass btStream{private:  SOCKET sock;public:  BufIo in_buffer;  BufIo out_buffer;  btStream() { sock = INVALID_SOCKET ;}  ~btStream() {if( INVALID_SOCKET != sock) CLOSE_SOCKET(sock);}  SOCKET GetSocket() {return sock;}  void SetSocket(SOCKET sk){ sock = sk; }  void Close(){    if( INVALID_SOCKET != sock ){ CLOSE_SOCKET(sock); sock = INVALID_SOCKET;}    in_buffer.Close();    out_buffer.Close();  }  ssize_t PickMessage(); //移除接收緩存中的一條消息  ssize_t Feed();  int HaveMessage();  // 返回值 1: 緩存中有消息 0: 暫無消息 -1: 失敗  ssize_t Send_Keepalive();  ssize_t Send_State(unsigned char state);  ssize_t Send_Have(size_t idx);  ssize_t Send_Piece(size_t idx,size_t off,char *piece_buf,size_t len);  ssize_t Send_Bitfield(char *bit_buf,size_t len);  ssize_t Send_Request(size_t idx,size_t off,size_t len);  ssize_t Send_Cancel(size_t idx,size_t off,size_t len);  ssize_t Send_Buffer(char *buf,size_t len);  ssize_t Flush();};#endif