mqttbytes 0.6.0

MQTT 4/5 serialization and deserialization
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

use crate::*;

mod connack;
mod connect;
mod disconnect;
mod ping;
mod puback;
mod pubcomp;
mod publish;
mod pubrec;
mod pubrel;
mod suback;
mod subscribe;
mod unsuback;
mod unsubscribe;

pub use connack::*;
pub use connect::*;
pub use disconnect::*;
pub use ping::*;
pub use puback::*;
pub use pubcomp::*;
pub use publish::*;
pub use pubrec::*;
pub use pubrel::*;
pub use suback::*;
pub use subscribe::*;
pub use unsuback::*;
pub use unsubscribe::*;

/// Encapsulates all MQTT packet types
#[derive(Debug, Clone, PartialEq)]
pub enum Packet {
    Connect(Connect),
    ConnAck(ConnAck),
    Publish(Publish),
    PubAck(PubAck),
    PubRec(PubRec),
    PubRel(PubRel),
    PubComp(PubComp),
    Subscribe(Subscribe),
    SubAck(SubAck),
    Unsubscribe(Unsubscribe),
    UnsubAck(UnsubAck),
    PingReq,
    PingResp,
    Disconnect(Disconnect),
}

#[repr(u8)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum PropertyType {
    PayloadFormatIndicator = 1,
    MessageExpiryInterval = 2,
    ContentType = 3,
    ResponseTopic = 8,
    CorrelationData = 9,
    SubscriptionIdentifier = 11,
    SessionExpiryInterval = 17,
    AssignedClientIdentifier = 18,
    ServerKeepAlive = 19,
    AuthenticationMethod = 21,
    AuthenticationData = 22,
    RequestProblemInformation = 23,
    WillDelayInterval = 24,
    RequestResponseInformation = 25,
    ResponseInformation = 26,
    ServerReference = 28,
    ReasonString = 31,
    ReceiveMaximum = 33,
    TopicAliasMaximum = 34,
    TopicAlias = 35,
    MaximumQos = 36,
    RetainAvailable = 37,
    UserProperty = 38,
    MaximumPacketSize = 39,
    WildcardSubscriptionAvailable = 40,
    SubscriptionIdentifierAvailable = 41,
    SharedSubscriptionAvailable = 42,
}

fn property(num: u8) -> Result<PropertyType, Error> {
    let property = match num {
        1 => PropertyType::PayloadFormatIndicator,
        2 => PropertyType::MessageExpiryInterval,
        3 => PropertyType::ContentType,
        8 => PropertyType::ResponseTopic,
        9 => PropertyType::CorrelationData,
        11 => PropertyType::SubscriptionIdentifier,
        17 => PropertyType::SessionExpiryInterval,
        18 => PropertyType::AssignedClientIdentifier,
        19 => PropertyType::ServerKeepAlive,
        21 => PropertyType::AuthenticationMethod,
        22 => PropertyType::AuthenticationData,
        23 => PropertyType::RequestProblemInformation,
        24 => PropertyType::WillDelayInterval,
        25 => PropertyType::RequestResponseInformation,
        26 => PropertyType::ResponseInformation,
        28 => PropertyType::ServerReference,
        31 => PropertyType::ReasonString,
        33 => PropertyType::ReceiveMaximum,
        34 => PropertyType::TopicAliasMaximum,
        35 => PropertyType::TopicAlias,
        36 => PropertyType::MaximumQos,
        37 => PropertyType::RetainAvailable,
        38 => PropertyType::UserProperty,
        39 => PropertyType::MaximumPacketSize,
        40 => PropertyType::WildcardSubscriptionAvailable,
        41 => PropertyType::SubscriptionIdentifierAvailable,
        42 => PropertyType::SharedSubscriptionAvailable,
        num => return Err(Error::InvalidPropertyType(num)),
    };

    Ok(property)
}

/// Reads a stream of bytes and extracts next MQTT packet out of it
pub fn read(stream: &mut BytesMut, max_size: usize) -> Result<Packet, Error> {
    let fixed_header = check(stream.iter(), max_size)?;

    // Test with a stream with exactly the size to check border panics
    let packet = stream.split_to(fixed_header.frame_length());
    let packet_type = fixed_header.packet_type()?;

    if fixed_header.remaining_len == 0 {
        // no payload packets
        return match packet_type {
            PacketType::PingReq => Ok(Packet::PingReq),
            PacketType::PingResp => Ok(Packet::PingResp),
            _ => Err(Error::PayloadRequired),
        };
    }

    let packet = packet.freeze();
    let packet = match packet_type {
        PacketType::Connect => Packet::Connect(Connect::read(fixed_header, packet)?),
        PacketType::ConnAck => Packet::ConnAck(ConnAck::read(fixed_header, packet)?),
        PacketType::Publish => Packet::Publish(Publish::read(fixed_header, packet)?),
        PacketType::PubAck => Packet::PubAck(PubAck::read(fixed_header, packet)?),
        PacketType::PubRec => Packet::PubRec(PubRec::read(fixed_header, packet)?),
        PacketType::PubRel => Packet::PubRel(PubRel::read(fixed_header, packet)?),
        PacketType::PubComp => Packet::PubComp(PubComp::read(fixed_header, packet)?),
        PacketType::Subscribe => Packet::Subscribe(Subscribe::read(fixed_header, packet)?),
        PacketType::SubAck => Packet::SubAck(SubAck::read(fixed_header, packet)?),
        PacketType::Unsubscribe => Packet::Unsubscribe(Unsubscribe::read(fixed_header, packet)?),
        PacketType::UnsubAck => Packet::UnsubAck(UnsubAck::read(fixed_header, packet)?),
        PacketType::PingReq => Packet::PingReq,
        PacketType::PingResp => Packet::PingResp,
        PacketType::Disconnect => Packet::Disconnect(Disconnect::read(fixed_header, packet)?),
    };

    Ok(packet)
}