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