net: add read_ptr/2 (from read/1) to UdpConn for consistency with TcpConn (#24000)

Author: larpon

vlib/net/udp.c.v

@@ -94,25 +94,25 @@ pub fn (mut c UdpConn) write_to_string(addr Addr, s string) !int {
 	return c.write_to_ptr(addr, s.str, s.len)
 }
 
-// read reads from the socket into buf up to buf.len returning the number of bytes read
-pub fn (mut c UdpConn) read(mut buf []u8) !(int, Addr) {
+// read_ptr reads from the socket into `buf_ptr` up to `len` bytes, returning the number of bytes read and the `Addr` read from.
+pub fn (c &UdpConn) read_ptr(buf_ptr &u8, len int) !(int, Addr) {
 	mut addr := Addr{
 		addr: AddrData{
 			Ip6: Ip6{}
 		}
 	}
-	len := sizeof(Addr)
-	mut res := wrap_read_result(C.recvfrom(c.sock.handle, voidptr(buf.data), buf.len,
-		0, voidptr(&addr), &len))!
+	addr_len := sizeof(Addr)
+	mut res := wrap_read_result(C.recvfrom(c.sock.handle, voidptr(buf_ptr), len, 0, voidptr(&addr),
+		&addr_len))!
 	if res > 0 {
 		return res, addr
 	}
 	code := error_code()
 	if code == int(error_ewouldblock) {
 		c.wait_for_read()!
 		// same setup as in tcp
-		res = wrap_read_result(C.recvfrom(c.sock.handle, voidptr(buf.data), buf.len, 0,
-			voidptr(&addr), &len))!
+		res = wrap_read_result(C.recvfrom(c.sock.handle, voidptr(buf_ptr), len, 0, voidptr(&addr),
+			&addr_len))!
 		res2 := socket_error(res)!
 		return res2, addr
 	} else {
@@ -121,6 +121,11 @@ pub fn (mut c UdpConn) read(mut buf []u8) !(int, Addr) {
 	return error('none')
 }
 
+// read reads from the socket into buf up to buf.len returning the number of bytes read
+pub fn (mut c UdpConn) read(mut buf []u8) !(int, Addr) {
+	return c.read_ptr(buf.data, buf.len)!
+}
+
 pub fn (c &UdpConn) read_deadline() !time.Time {
 	if c.read_deadline.unix() == 0 {
 		return c.read_deadline
@@ -160,7 +165,7 @@ pub fn (mut c UdpConn) set_write_timeout(t time.Duration) {
 }
 
 @[inline]
-pub fn (mut c UdpConn) wait_for_read() ! {
+pub fn (c &UdpConn) wait_for_read() ! {
 	return wait_for_read(c.sock.handle, c.read_deadline, c.read_timeout)
 }