91 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			V
		
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			V
		
	
	
| module net
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| 
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| const (
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| 	crlf     = '\r\n'
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| 	msg_peek = 0x02
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| 	max_read = 400
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| )
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| 
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| // get_blocking returns whether the connection is in a blocking state,
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| // that is calls to .read_line, C.recv etc will block till there is new
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| // data arrived, instead of returning immediately.
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| pub fn (mut con TcpConn) get_blocking() bool {
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| 	// flags := C.fcntl(con.sock.handle, C.F_GETFL, 0)
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| 	// return 0 == flags & C.O_NONBLOCK
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| 	return con.is_blocking
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| }
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| 
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| // set_blocking will change the state of the connection to either blocking,
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| // when state is true, or non blocking (false).
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| // The default for `net` tcp connections is the non blocking mode.
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| // Calling .read_line will set the connection to blocking mode.
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| pub fn (mut con TcpConn) set_blocking(state bool) ? {
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| 	con.is_blocking = state
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| 	$if windows {
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| 		mut t := u32(0)
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| 		if !con.is_blocking {
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| 			t = 1
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| 		}
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| 		socket_error(C.ioctlsocket(con.sock.handle, fionbio, &t)) ?
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| 	} $else {
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| 		mut flags := C.fcntl(con.sock.handle, C.F_GETFL, 0)
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| 		if state {
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| 			flags &= ~C.O_NONBLOCK
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| 		} else {
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| 			flags |= C.O_NONBLOCK
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| 		}
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| 		socket_error(C.fcntl(con.sock.handle, C.F_SETFL, flags)) ?
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| 	}
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| }
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| 
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| // read_line is a *simple*, *non customizable*, blocking line reader.
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| // It will *always* return a line, ending with CRLF, or just '', on EOF.
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| // NB: if you want more control over the buffer, please use a buffered IO
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| // reader instead: `io.new_buffered_reader({reader: io.make_reader(con)})`
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| pub fn (mut con TcpConn) read_line() string {
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| 	mut buf := [net.max_read]byte{} // where C.recv will store the network data
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| 	mut res := '' // The final result, including the ending \n.
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| 	if !con.is_blocking {
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| 		con.set_blocking(true) or {}
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| 	}
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| 	for {
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| 		mut line := '' // The current line. Can be a partial without \n in it.
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| 		n := C.recv(con.sock.handle, &buf[0], net.max_read - 1, net.msg_peek | msg_nosignal)
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| 		if n == -1 {
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| 			return res
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| 		}
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| 		if n == 0 {
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| 			return res
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| 		}
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| 		buf[n] = `\0`
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| 		mut eol_idx := -1
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| 		for i in 0 .. n {
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| 			if int(buf[i]) == `\n` {
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| 				eol_idx = i
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| 				// Ensure that tos_clone(buf) later,
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| 				// will return *only* the first line (including \n),
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| 				// and ignore the rest
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| 				buf[i + 1] = `\0`
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| 				break
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| 			}
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| 		}
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| 		line = unsafe { tos_clone(&buf[0]) }
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| 		if eol_idx > 0 {
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| 			// At this point, we are sure that recv returned valid data,
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| 			// that contains *at least* one line.
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| 			// Ensure that the block till the first \n (including it)
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| 			// is removed from the socket's receive queue, so that it does
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| 			// not get read again.
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| 			C.recv(con.sock.handle, &buf[0], eol_idx + 1, msg_nosignal)
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| 			res += line
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| 			break
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| 		}
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| 		// recv returned a buffer without \n in it .
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| 		C.recv(con.sock.handle, &buf[0], n, msg_nosignal)
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| 		res += line
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| 		res += net.crlf
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| 		break
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| 	}
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| 	return res
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| }
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