mqtt_codec/
proto.rs

1#[macro_export]
2macro_rules! const_enum {
3    ($name:ty : $repr:ty) => {
4        impl ::std::convert::From<$repr> for $name {
5            fn from(u: $repr) -> Self {
6                unsafe { ::std::mem::transmute(u) }
7            }
8        }
9
10        impl ::std::convert::Into<$repr> for $name {
11            fn into(self) -> $repr {
12                unsafe { ::std::mem::transmute(self) }
13            }
14        }
15    };
16}
17
18pub const DEFAULT_MQTT_LEVEL: u8 = 4;
19
20#[repr(u8)]
21#[derive(Debug, Clone, Copy, PartialEq, Eq)]
22pub enum Protocol {
23    MQTT(u8),
24}
25
26impl Protocol {
27    pub fn name(self) -> &'static str {
28        match self {
29            Protocol::MQTT(_) => "MQTT",
30        }
31    }
32
33    pub fn level(self) -> u8 {
34        match self {
35            Protocol::MQTT(level) => level,
36        }
37    }
38}
39
40impl Default for Protocol {
41    fn default() -> Self {
42        Protocol::MQTT(DEFAULT_MQTT_LEVEL)
43    }
44}
45
46#[repr(u8)]
47#[derive(Debug, Clone, Copy, PartialEq, Eq)]
48/// Quality of Service levels
49pub enum QoS {
50    /// At most once delivery
51    ///
52    /// The message is delivered according to the capabilities of the underlying network.
53    /// No response is sent by the receiver and no retry is performed by the sender.
54    /// The message arrives at the receiver either once or not at all.
55    AtMostOnce = 0,
56    /// At least once delivery
57    ///
58    /// This quality of service ensures that the message arrives at the receiver at least once.
59    /// A QoS 1 PUBLISH Packet has a Packet Identifier in its variable header
60    /// and is acknowledged by a PUBACK Packet.
61    AtLeastOnce = 1,
62    /// Exactly once delivery
63    ///
64    /// This is the highest quality of service,
65    /// for use when neither loss nor duplication of messages are acceptable.
66    /// There is an increased overhead associated with this quality of service.
67    ExactlyOnce = 2,
68}
69
70const_enum!(QoS: u8);
mqtt_codec/proto.rs

mqtt_codec/
proto.rs
