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v/vlib/net/tcp_read_line.v

57 lines
1.6 KiB
V

module net
const (
crlf = '\r\n'
msg_peek = 0x02
max_read = 400
)
// 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 := [max_read]byte{} // where C.recv will store the network data
mut res := '' // The final result, including the ending \n.
for {
mut line := '' // The current line. Can be a partial without \n in it.
n := C.recv(con.sock.handle, buf, max_read - 1, 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
}
}
bufbp := byteptr(buf)
line = unsafe { tos_clone(bufbp) }
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, eol_idx + 1, msg_nosignal)
res += line
break
}
// recv returned a buffer without \n in it .
C.recv(con.sock.handle, buf, n, msg_nosignal)
res += line
res += crlf
break
}
return res
}