x.net: new net module (#6130)

vlib/x/net/udp_test.v

@@ -0,0 +1,74 @@
+import x.net as net
+import time
+
+fn echo_server(_c net.UdpConn) {
+	mut c := _c
+	// arbitrary timeouts to ensure that it doesnt
+	// instantly throw its hands in the air and give up
+	c.set_read_timeout(10 * time.second)
+	c.set_write_timeout(10 * time.second)
+	for {
+		buf := []byte{ len: 100, init: 0 }
+		read, addr := c.read_into(mut buf) or {
+			continue
+		}
+
+		c.write_to(addr, buf[..read]) or {
+			println('Server: connection dropped')
+			return
+		}
+	}
+}
+
+fn echo() ? {
+	mut c := net.dial_udp('127.0.0.1:40003', '127.0.0.1:40001')?
+	defer { c.close() or { } }
+
+	// arbitrary timeouts to ensure that it doesnt
+	// instantly throw its hands in the air and give up
+	c.set_read_timeout(10 * time.second)
+	c.set_write_timeout(10 * time.second)
+
+	data := 'Hello from vlib/net!'
+
+	c.write_string(data)?
+
+	buf := []byte{ len: 100, init: 0 }
+	read, addr := c.read_into(mut buf)?
+
+	assert read == data.len
+	println('Got address $addr')
+	// Can't test this here because loopback addresses
+	// are mapped to other addresses
+	// assert addr.str() == '127.0.0.1:30001'
+
+	for i := 0; i < read; i++ {
+		assert buf[i] == data[i]
+	}
+
+	println('Got "${buf.bytestr()}"')
+
+	c.close()?
+
+	return none
+}
+
+fn test_udp() {
+	l := net.listen_udp(40001) or {
+		println(err)
+		assert false
+		panic('')
+	}
+
+	go echo_server(l)
+	echo() or {
+		println(err)
+		assert false
+	}
+
+	l.close() or { }
+}
+
+fn main() {
+	test_udp()
+}