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use std::fmt;
/// CRTP data packet
#[derive(Debug, Clone)]
pub struct Packet {
header: u8,
port: u8,
channel: u8,
data: Vec<u8>,
}
impl fmt::Display for Packet {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"(ch: {}, port: {}, data: {})",
self.channel, self.port, self.data[0]
)
}
}
impl From<Vec<u8>> for Packet {
fn from(v: Vec<u8>) -> Self {
let header = v[0];
//
// A packet on the wire starts with a header byte, formatted as:
//
// pppp00cc
//
// Where ...
// ... bit 1 and 2 is the channel (c) ...
// ... bit 3 and 4 are reserved for flow-control for the radio link ...
// ... bit 5, 6, 7 and 8 is the port (p).
//
let channel = header & 0x03; // mask out the channel
let port = (header & 0xF0) >> 4; // twiddle out the port
let data = v[1..].to_vec(); // the rest is data!
Packet {
header,
port,
channel,
data,
}
}
}
impl From<Packet> for Vec<u8> {
fn from(packet: Packet) -> Self {
let mut vec = vec![packet.get_header()];
vec.append(&mut packet.get_data().to_vec());
vec
}
}
impl Packet {
pub fn new(port: u8, channel: u8, data: Vec<u8>) -> Self {
let mut header = 0;
// channel is at bit 1 to 2
header |= channel & 0x03; // header => 000000cc
// port is at bit 5 to 8
header |= (port << 4) & 0xF0; // header => pppp00cc
Packet {
header,
port,
channel,
data,
}
}
pub fn get_channel(&self) -> u8 {
self.channel
}
pub fn get_port(&self) -> u8 {
self.port
}
pub fn get_data(&self) -> &Vec<u8> {
&self.data
}
pub fn append_data(&mut self, v: &mut Vec<u8>) {
self.data.append(v);
}
pub fn get_header(&self) -> u8 {
//
// See the From trait implementation above for more details of the
// vector format.
//
self.header
}
}