csocket.cc

Unix 下的多线程下载程序 支持断点续传功能

#include "CSocket.h" 
 
Sock_instance::Sock_instance(string hostname, unsigned port, s_type type) 
	: _hostname( hostname ), 
	 _port( port ), 
	 _fd( 0 ), 
	 _state( CONN_ERROR ), 
	 _type( type ) 
{ 
	_datalen = 0; 
	_data = new unsigned char[1024*1024]; 
} 
 
Sock_instance::~Sock_instance() 
{ 
	delete[] _data; 
} 
 
bool Sock_instance::Connect() 
{ 
	if( _type == SERVER_TYPE ) 
	{ 
		cout << "The socket is a server, don't use conncet!" << endl; 
		return false; 
	} 
	 
	struct sockaddr_in peer; 
	int fd; 
 
	bzero( &peer, sizeof(peer) ); 
	peer.sin_family = AF_INET; 
	struct hostent *hp = gethostbyname( _hostname.c_str() );	 
	if ( hp == NULL ) 
	{ 
		cout << "unknow host: " << _hostname << endl; 
		return false; 
	} 
	peer.sin_addr = *( ( struct in_addr * )hp->h_addr ); 
	peer.sin_port	= htons(_port); 
 
	cout << "conncet to " << inet_ntoa(peer.sin_addr)  << ": " << ntohs( peer.sin_port ) << endl; 
	 
	fd = socket( AF_INET, SOCK_STREAM, 0 ); 
	if ( fd < 0 ) 
	{ 
		cout <<  "socket call failed" << endl; 
		return false; 
	} 
 
	if( connect( fd, (struct sockaddr *)&peer, sizeof( peer ) ) ) 
	{ 
		cout << errno << "connect failed" << endl; 
		_state = CONN_ERROR; 
		close( fd ); 
		return false; 
	} 
 
	_state = CONN_OK; 
	_fd = fd; 
	 
	return true; 
} 
 
s_state Sock_instance::state() 
{ 
	return _state; 
} 
 
int Sock_instance::fd() 
{ 
	return _fd; 
} 
 
bool Sock_instance::Send(string msg) 
{ 
	if( state() != CONN_OK ) 
	{ 
		cout << "the socket is not ok" << endl; 
		return false; 
	} 
 
	int rc; 
 
	if((rc = send(_fd, msg.c_str(), msg.size(), 0)) == -1) 
	{ 
		if((errno != EWOULDBLOCK) && (errno != EAGAIN)) 
		{ 
			_state = CONN_ERROR; 
			return false; 
		} 
	} 
	return true; 
} 
 
int Sock_instance::Receive() 
{ 
	int rc; 
	char buf[BUFSIZ]; 
	char *p_buf = buf; 
 
	static bool b_readhead = true; 
 
	bzero(buf, BUFSIZ); 
 
	if((rc = recv( _fd, buf, BUFSIZ - 1, 0 )) < 0 ) 
	{ 
		cout << "recive error" << endl; 
		_state = CONN_WAIT; 
		Close(); 
	} 
	else if( rc == 0 ) 
	{ 
		cout << "server teminated" << endl; 
		_state = CONN_WAIT; 
		Close(); 
	} 
	else 
	{ 
		//read HTTP head 
		int ix = 0; 
		while( b_readhead ) 
		{ 
			// 2 0D 0A just for head end 
			if( ix >= rc ) 
				break; 
			if( buf[ix] == 13 && buf[ix+1] == 10 && buf[ix+2] == 13 && buf[ix+3] == 10 ) 
			{ 
				b_readhead = false; 
				char *p = new char[ix+5]; 
				memset( p, 0, ix+5 ); 
				memcpy( p, buf, ix+5 ); 
				p_buf += ix + 5; 
				_http_head = p; 
				delete[] p; 
				cout << _http_head << endl; 
				break; 
			} 
			ix ++; 
		} 
 
		//copy data to _data 
		if( ix != 0 && ix < rc ) 
		{ 
			//this buf has head so data begin with buf+ix+4 
			memcpy( _data+_datalen, buf+ix+4, rc-ix-4 ); 
			_datalen += rc-ix-4; 
		} 
		else 
		{ 
			memcpy( _data+_datalen, buf, rc ); 
			_datalen += rc;	 
		} 
	} 
 
	return rc; 
} 
 
inline void Sock_instance::Close() 
{ 
	close( _fd ); 
} 
 
//string Sock_instance::data() const 
unsigned char * Sock_instance::data() const 
{ 
	return _data; 
} 
 
int Sock_instance::datalen() const 
{ 
	return _datalen; 
} 
 
string Sock_instance::http_head() const 
{ 
	return _http_head; 
}