osdp 0.3.0

Pure-Rust, no_std-friendly implementation of the SIA Open Supervised Device Protocol (OSDP) v2.2
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

//! `osdp_COM` (`0x54`) — communications configuration report.
//!
//! # Spec: §7.13
//!
//! Body is 5 bytes: `address (1) + baud (4 LE)` — same layout as
//! `osdp_COMSET`.

use crate::error::Error;
use crate::payload_util::require_exact_len;
use alloc::vec::Vec;

/// `osdp_COM` body.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Com {
    /// PD's address.
    pub address: u8,
    /// PD's baud rate.
    pub baud: u32,
}

impl Com {
    /// Encode.
    pub fn encode(&self) -> Result<Vec<u8>, Error> {
        let mut out = Vec::with_capacity(5);
        out.push(self.address);
        out.extend_from_slice(&self.baud.to_le_bytes());
        Ok(out)
    }

    /// Decode.
    pub fn decode(data: &[u8]) -> Result<Self, Error> {
        require_exact_len(data, 5, 0x54)?;
        Ok(Self {
            address: data[0],
            baud: u32::from_le_bytes([data[1], data[2], data[3], data[4]]),
        })
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn roundtrip() {
        let body = Com {
            address: 0x05,
            baud: 9600,
        };
        let bytes = body.encode().unwrap();
        assert_eq!(bytes, [0x05, 0x80, 0x25, 0x00, 0x00]);
        assert_eq!(Com::decode(&bytes).unwrap(), body);
    }

    #[test]
    fn decode_rejects_wrong_length() {
        assert!(matches!(
            Com::decode(&[0; 4]),
            Err(Error::PayloadLength { code: 0x54, .. })
        ));
    }
}