101 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			V
		
	
	
			
		
		
	
	
			101 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			V
		
	
	
module net
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import strings
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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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	max_read_line_len = 1048576
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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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// 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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// read_line is a *simple*, *non customizable*, blocking line reader.
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// It will return a line, ending with LF, or just '', on EOF.
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// Note: 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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	return con.read_line_max(net.max_read_line_len)
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}
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// read_line_max is a *simple*, *non customizable*, blocking line reader.
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// It will return a line, ending with LF, '' on EOF.
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// It stops reading, when the result line length exceeds max_line_len.
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[manualfree]
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pub fn (mut con TcpConn) read_line_max(max_line_len int) string {
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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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	mut buf := [net.max_read]u8{} // where C.recv will store the network data
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	mut res := strings.new_builder(net.max_read) // The final result, including the ending \n.
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	defer {
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		unsafe { res.free() }
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	}
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	bstart := unsafe { &buf[0] }
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	for {
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		n := C.recv(con.sock.handle, bstart, net.max_read - 1, net.msg_peek | msg_nosignal)
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		if n <= 0 {
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			return res.str()
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		}
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		buf[n] = `\0`
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		mut eol_idx := -1
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		mut lend := n
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		for i in 0 .. n {
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			if buf[i] == `\n` {
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				eol_idx = i
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				lend = i + 1
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				buf[lend] = `\0`
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				break
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			}
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		}
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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, bstart, lend, msg_nosignal)
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			unsafe { res.write_ptr(bstart, lend) }
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			break
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		}
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		// recv returned a buffer without \n in it, just store it for now:
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		C.recv(con.sock.handle, bstart, n, msg_nosignal)
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		unsafe { res.write_ptr(bstart, lend) }
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		if res.len > max_line_len {
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			break
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		}
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	}
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	return res.str()
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}
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