spvirit-py 0.1.12

Python bindings for spvirit PVAccess client and server.
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
154
155
156
157
158

//! Raw-frame `Packet` wrapper exposed via `Channel.read_packet` /
//! `Channel.read_until`.

use pyo3::prelude::*;
use pyo3::types::{PyBytes, PyDict};

use spvirit_codec::epics_decode::{PvaPacket, command_name};

/// Owned PVA frame with header accessors and on-demand detail decoding.
#[pyclass(name = "Packet", module = "spvirit.lowlevel", frozen)]
pub struct PyPacket {
    bytes: Vec<u8>,
    magic: u8,
    version: u8,
    command: u8,
    flags_raw: u8,
    is_application: bool,
    is_control: bool,
    is_segmented: u8,
    is_client: bool,
    is_server: bool,
    is_msb: bool,
    payload_length: u32,
}

impl PyPacket {
    pub(crate) fn raw(&self) -> &[u8] {
        &self.bytes
    }

    pub fn from_bytes(bytes: Vec<u8>) -> Self {
        if bytes.len() >= 8 {
            let pkt = PvaPacket::new(&bytes);
            return Self {
                magic: pkt.header.magic,
                version: pkt.header.version,
                command: pkt.header.command,
                flags_raw: pkt.header.flags.raw,
                is_application: pkt.header.flags.is_application,
                is_control: pkt.header.flags.is_control,
                is_segmented: pkt.header.flags.is_segmented,
                is_client: pkt.header.flags.is_client,
                is_server: pkt.header.flags.is_server,
                is_msb: pkt.header.flags.is_msb,
                payload_length: pkt.header.payload_length,
                bytes,
            };
        }
        Self {
            magic: 0,
            version: 0,
            command: 0,
            flags_raw: 0,
            is_application: false,
            is_control: false,
            is_segmented: 0,
            is_client: false,
            is_server: false,
            is_msb: false,
            payload_length: 0,
            bytes,
        }
    }
}

#[pymethods]
impl PyPacket {
    #[getter]
    fn magic(&self) -> u8 {
        self.magic
    }
    #[getter]
    fn version(&self) -> u8 {
        self.version
    }
    #[getter]
    fn command(&self) -> u8 {
        self.command
    }
    #[getter]
    fn command_name(&self) -> &'static str {
        command_name(self.command)
    }
    #[getter]
    fn flags(&self) -> u8 {
        self.flags_raw
    }
    #[getter]
    fn is_application(&self) -> bool {
        self.is_application
    }
    #[getter]
    fn is_control(&self) -> bool {
        self.is_control
    }
    #[getter]
    fn is_segmented(&self) -> u8 {
        self.is_segmented
    }
    #[getter]
    fn is_client(&self) -> bool {
        self.is_client
    }
    #[getter]
    fn is_server(&self) -> bool {
        self.is_server
    }
    #[getter]
    fn is_msb(&self) -> bool {
        self.is_msb
    }
    #[getter]
    fn payload_length(&self) -> u32 {
        self.payload_length
    }

    #[getter]
    fn bytes<'py>(&self, py: Python<'py>) -> Bound<'py, PyBytes> {
        PyBytes::new(py, &self.bytes)
    }

    #[getter]
    fn payload<'py>(&self, py: Python<'py>) -> Bound<'py, PyBytes> {
        let start = 8.min(self.bytes.len());
        PyBytes::new(py, &self.bytes[start..])
    }

    fn __len__(&self) -> usize {
        self.bytes.len()
    }

    /// Decode command-specific payload details.  Delegates to the
    /// standalone codec module.
    fn details<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyDict>> {
        let mut pkt = PvaPacket::new(&self.bytes);
        let d = PyDict::new(py);
        if let Some(cmd) = pkt.decode_payload() {
            crate::codec::fill_command_details(py, &cmd, &d)?;
        }
        Ok(d)
    }

    /// Alias for the free `spvirit.codec.decode_packet` function
    /// applied to this packet's bytes.
    fn decode<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, PyDict>> {
        crate::codec::decode_packet(py, &self.bytes)
    }

    fn __repr__(&self) -> String {
        format!(
            "Packet(command={} ({}), flags=0x{:02x}, payload_length={})",
            self.command,
            self.command_name(),
            self.flags_raw,
            self.payload_length
        )
    }
}