用流来封装SOCKET通信的一种方法

aits::off_type off_type; typedef traits traits_type; streambufadaptor(Rw& rw,ios_base::openmode mode = ios_base::in | ios_base::out | ios_base::binary): _rw(rw),_out(0),_out_len(0),_in(0),_in_len(0){ setg(_in,_in,_in); setp(_out,_out + _out_len); basic_streambuf::mode_ = mode; } ~streambufadaptor() { if(_out) free_out_buf(); if(_in) free_in_buf(); } private: void init_out_buf() { _out_len = 512; _out = new charT[_out_len]; setp(_out,_out + _out_len); } void free_out_buf() { delete [] _out; _out = 0; _out_len = 0; setp(0,0); } void init_in_buf() { _in_len = 512; _in = new charT[_in_len]; setg(_in,_in,_in); } void free_in_buf() { delete [] _in; _in = 0; _in_len = 0; setg(_in,_in,_in); } protected: virtual int_type overflow(int_type c) { if((basic_streambuf::mode_ & ios_base::out) == 0) { return traits::eof(); } sync(); if(traits::eq_int_type(c,traits::eof()) ) return traits::not_eof(c); else { if(pptr() == 0) init_out_buf(); return sputc(c); } } virtual int_type underflow() { if((basic_streambuf::mode_ & ios_base::in) == 0) { return traits::eof(); } if(egptr() == 0) init_in_buf(); if(egptr() == _in + _in_len) setg(_in,_in,_in); int tmp = _rw.read(egptr(),_in + _in_len - egptr()); if(tmp < 1) return traits::eof(); setg(eback(),egptr(),egptr() + tmp); return traits::to_int_type(*gptr()); } virtual int sync() { if(pptr() > pbase()){ int tmp = pptr() - pbase(); int tmp1 = _rw.write(pbase(),tmp); if(tmp1 < 1) return -1; if(tmp1 < tmp) { memcpy(pbase(),pbase() + tmp1, tmp - tmp1); setp(pbase(),epptr()); pbump(tmp1); }else setp(pbase(),epptr()); } return 0; } }; class streamadaptor_base{}; typedef const streamadaptor_base& StreamAdaptor; template class streamadaptor: public streamadaptor_base { public: typedef typename stream::char_type char_type; typedef typename stream::traits_type traits_type; private: basic_ios& _stream ; streambufadaptor _buff; basic_streambuf* _oldbuf; public: streamadaptor(stream& s,Rw& rw):_stream(s),_buff(rw){ _oldbuf = _stream.rdbuf(&_buff); } ~streamadaptor(){ _stream.rdbuf(_oldbuf); } operator stream&(){ return _stream; } stream& get() { return _stream; } }; template streamadaptor MakeStreamAdaptor(Stream& s,Rw& rw) { return streamadaptor(s,rw); } #define CONCATENATE_DIRECT(s1, s2) s1##s2 #define CONCATENATE(s1, s2) CONCATENATE_DIRECT(s1, s2) #define ANONYMOUS_VARIABLE(str) CONCATENATE(str, __LINE__) #define STREAM_ADAPTOR StreamAdaptor ANONYMOUS_VARIABLE(streamAdaptor) = MakeStreamAdaptor }