mqute_codec/protocol/
version.rs

1//! # MQTT Protocol Version
2//!
3//! This module provides an enum to represent the MQTT protocol versions and utilities
4//! for converting between protocol versions and their corresponding numeric values.
5//!
6//! The `Protocol` enum represents the supported MQTT protocol versions:
7//! - `V3`: MQTT v3.1 (also known as MQIsdp)
8//! - `V4`: MQTT v3.1.1
9//! - `V5`: MQTT v5.0
10//!
11//! The enum also provides methods to convert between protocol versions and their
12//! numeric representations, as well as to retrieve the protocol name.
13
14use crate::Error;
15
16/// Represents the MQTT protocol version.
17#[derive(Debug, Clone, Copy, PartialEq, Eq)]
18pub enum Protocol {
19    /// MQTT v3.1
20    V3,
21    /// MQTT v3.1.1
22    V4,
23    /// MQTT v5.0
24    V5,
25}
26
27impl From<Protocol> for u8 {
28    /// Converts the `Protocol` enum into its corresponding numeric value.
29    ///
30    /// # Examples
31    ///
32    /// ```rust
33    /// use mqute_codec::protocol::Protocol;
34    ///
35    /// let protocol = Protocol::V5;
36    /// let value: u8 = protocol.into();
37    /// assert_eq!(value, 0x05);
38    /// ```
39    fn from(value: Protocol) -> Self {
40        match value {
41            Protocol::V3 => 0x03,
42            Protocol::V4 => 0x04,
43            Protocol::V5 => 0x05,
44        }
45    }
46}
47
48impl TryFrom<u8> for Protocol {
49    type Error = Error;
50
51    /// Attempts to convert a numeric value into a `Protocol` enum.
52    ///
53    /// # Errors
54    /// Returns an `Error::InvalidProtocolLevel` if the value is not a valid protocol version.
55    ///
56    /// # Examples
57    ///
58    /// ```rust
59    /// use mqute_codec::protocol::Protocol;
60    /// use mqute_codec::Error;
61    ///
62    /// let protocol = Protocol::try_from(0x04).unwrap();
63    /// assert_eq!(protocol, Protocol::V4);
64    ///
65    /// let result = Protocol::try_from(0x06);
66    /// assert!(result.is_err());
67    /// ```
68    fn try_from(value: u8) -> Result<Self, Self::Error> {
69        match value {
70            0x03 => Ok(Protocol::V3),
71            0x04 => Ok(Protocol::V4),
72            0x05 => Ok(Protocol::V5),
73            _ => Err(Error::InvalidProtocolLevel(value)),
74        }
75    }
76}
77
78impl Protocol {
79    /// Returns the protocol name as a static string.
80    ///
81    /// - For `Protocol::V3`, the name is `"MQIsdp"`.
82    /// - For `Protocol::V4` and `Protocol::V5`, the name is `"MQTT"`.
83    ///
84    /// # Examples
85    ///
86    /// ```rust
87    /// use mqute_codec::protocol::Protocol;
88    ///
89    /// let protocol = Protocol::V3;
90    /// assert_eq!(protocol.name(), "MQIsdp");
91    ///
92    /// let protocol = Protocol::V5;
93    /// assert_eq!(protocol.name(), "MQTT");
94    /// ```
95    pub fn name(self) -> &'static str {
96        match self {
97            Protocol::V3 => "MQIsdp",
98            // Same for V4 and V5
99            _ => "MQTT",
100        }
101    }
102}
mqute_codec/protocol/version.rs

mqute_codec/protocol/
version.rs
