Files
eskin-player/src/serial_core/codecs/hand_gateway.rs

405 lines
12 KiB
Rust

use crate::serial_core::codec::Codec;
use crate::serial_core::error::CodecError;
use crate::serial_core::utils::{calc_crc8_itu, elapsed_millis};
use std::time::Instant;
const FRAME_HEADER: [u8; 2] = [0x55, 0xAA];
const RESPONSE_DATA_CMD: u8 = 0x81;
const RESPONSE_DATA_LEGACY_FIXED_LENGTH: usize = 16;
const RESPONSE_DATA_LEGACY_PREFIX_LENGTH: usize = 19;
const RESPONSE_DATA_TEMP_FIXED_LENGTH: usize = 20;
const RESPONSE_DATA_TEMP_PREFIX_LENGTH: usize = 23;
const MIN_FRAME_LENGTH: usize = 7;
const DEFAULT_MAX_FRAME_LENGTH: usize = 64 * 1024;
#[derive(Debug, Clone, Copy)]
struct HandGatewayResponseLayout {
fixed_length: usize,
prefix_length: usize,
timestamp_len: usize,
config_offset: usize,
valid_config_offset: usize,
block_count_offset: usize,
}
const TEMP_RESPONSE_LAYOUT: HandGatewayResponseLayout = HandGatewayResponseLayout {
fixed_length: RESPONSE_DATA_TEMP_FIXED_LENGTH,
prefix_length: RESPONSE_DATA_TEMP_PREFIX_LENGTH,
timestamp_len: 8,
config_offset: 14,
valid_config_offset: 18,
block_count_offset: 22,
};
const LEGACY_RESPONSE_LAYOUT: HandGatewayResponseLayout = HandGatewayResponseLayout {
fixed_length: RESPONSE_DATA_LEGACY_FIXED_LENGTH,
prefix_length: RESPONSE_DATA_LEGACY_PREFIX_LENGTH,
timestamp_len: 4,
config_offset: 10,
valid_config_offset: 14,
block_count_offset: 18,
};
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct HandGatewayNodeConfig {
pub config_mask: u32,
pub sample_count: usize,
}
impl HandGatewayNodeConfig {
pub const fn new(config_mask: u32, sample_count: usize) -> Self {
Self {
config_mask,
sample_count,
}
}
fn payload_len(&self, bytes_per_sample: usize) -> Option<usize> {
self.sample_count.checked_mul(bytes_per_sample)
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct HandGatewayConfig {
pub protocol_version: u8,
pub bytes_per_sample: usize,
pub max_frame_length: usize,
pub nodes: Vec<HandGatewayNodeConfig>,
}
impl HandGatewayConfig {
pub fn new(nodes: Vec<HandGatewayNodeConfig>) -> Self {
Self {
protocol_version: 0x01,
bytes_per_sample: 2,
max_frame_length: DEFAULT_MAX_FRAME_LENGTH,
nodes,
}
}
fn validate(&self) -> Result<(), CodecError> {
if self.bytes_per_sample == 0 || self.max_frame_length < MIN_FRAME_LENGTH {
return Err(CodecError::InvalidLength);
}
let mut used_masks = 0u32;
for node in &self.nodes {
if node.config_mask == 0
|| node.config_mask.count_ones() != 1
|| used_masks & node.config_mask != 0
|| node.payload_len(self.bytes_per_sample).is_none()
{
return Err(CodecError::InvalidLength);
}
used_masks |= node.config_mask;
}
Ok(())
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct HandGatewayFrameNode {
pub config_mask: u32,
pub valid: bool,
pub payload: Vec<u8>,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct HandGatewayDataRepFrame {
pub timestamp: u64,
pub config: u32,
pub valid_config: u32,
pub block_count: u8,
pub raw: Vec<u8>,
pub nodes: Vec<HandGatewayFrameNode>,
pub dts_ms: u64,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum HandGatewayFrame {
DataRep(HandGatewayDataRepFrame),
}
pub struct HandGatewayCodec {
buffer: Vec<u8>,
config: HandGatewayConfig,
}
impl HandGatewayCodec {
pub fn new(node_sample_counts: &[u16]) -> Self {
let nodes = node_sample_counts
.iter()
.enumerate()
.map(|(index, &sample_count)| {
HandGatewayNodeConfig::new(
1u32.checked_shl(index as u32).unwrap_or(0),
sample_count as usize,
)
})
.collect();
Self {
buffer: Vec::new(),
config: HandGatewayConfig::new(nodes),
}
}
pub fn parse_node_payload(data: &[u8]) -> Result<Vec<u16>, CodecError> {
if data.len() % 2 != 0 {
return Err(CodecError::InvalidLength);
}
Ok(data
.chunks_exact(2)
.map(|chunk| u16::from_le_bytes([chunk[0], chunk[1]]))
.collect())
}
fn retain_possible_header_prefix(&mut self) {
if self.buffer.last() == Some(&FRAME_HEADER[0]) {
self.buffer.drain(..self.buffer.len() - 1);
} else {
self.buffer.clear();
}
}
fn parse_data_response_with_layout(
&self,
frame: &[u8],
length: u16,
session_started_at: Instant,
layout: HandGatewayResponseLayout,
) -> Result<HandGatewayFrame, CodecError> {
let payload_len = usize::from(length)
.checked_sub(layout.fixed_length)
.ok_or(CodecError::InvalidLength)?;
let payload_end = layout
.prefix_length
.checked_add(payload_len)
.ok_or(CodecError::PayloadTooLarge)?;
if payload_end + 1 != frame.len() {
return Err(CodecError::InvalidLength);
}
let version = frame[5];
if version != self.config.protocol_version {
return Err(CodecError::InvalidFrameType);
}
let timestamp = match layout.timestamp_len {
4 => u32::from_le_bytes(frame[6..10].try_into().unwrap()) as u64,
8 => u64::from_le_bytes(frame[6..14].try_into().unwrap()),
_ => return Err(CodecError::InvalidLength),
};
let config = u32::from_le_bytes(
frame[layout.config_offset..layout.config_offset + 4]
.try_into()
.unwrap(),
);
let valid_config = u32::from_le_bytes(
frame[layout.valid_config_offset..layout.valid_config_offset + 4]
.try_into()
.unwrap(),
);
let block_count = frame[layout.block_count_offset];
let active_nodes = self
.config
.nodes
.iter()
.filter(|node| config & node.config_mask != 0)
.collect::<Vec<_>>();
if active_nodes.len() != usize::from(block_count) {
return Err(CodecError::InvalidLength);
}
let expected_payload_len = active_nodes.iter().try_fold(0usize, |total, node| {
let node_len = node
.payload_len(self.config.bytes_per_sample)
.ok_or(CodecError::PayloadTooLarge)?;
total
.checked_add(node_len)
.ok_or(CodecError::PayloadTooLarge)
})?;
if expected_payload_len != payload_len {
return Err(CodecError::InvalidLength);
}
let mut cursor = layout.prefix_length;
let mut nodes = Vec::with_capacity(active_nodes.len());
for node in active_nodes {
let node_len = node
.payload_len(self.config.bytes_per_sample)
.ok_or(CodecError::PayloadTooLarge)?;
let next = cursor + node_len;
nodes.push(HandGatewayFrameNode {
config_mask: node.config_mask,
valid: valid_config & node.config_mask != 0,
payload: frame[cursor..next].to_vec(),
});
cursor = next;
}
Ok(HandGatewayFrame::DataRep(HandGatewayDataRepFrame {
timestamp,
config,
valid_config,
block_count,
raw: frame.to_vec(),
nodes,
dts_ms: elapsed_millis(session_started_at),
}))
}
fn parse_data_response(
&self,
frame: &[u8],
length: u16,
session_started_at: Instant,
) -> Result<HandGatewayFrame, CodecError> {
self.parse_data_response_with_layout(
frame,
length,
session_started_at,
TEMP_RESPONSE_LAYOUT,
)
.or_else(|_| {
self.parse_data_response_with_layout(
frame,
length,
session_started_at,
LEGACY_RESPONSE_LAYOUT,
)
})
}
}
impl Codec<HandGatewayFrame> for HandGatewayCodec {
fn decode(
&mut self,
input: &[u8],
session_started_at: Instant,
) -> Result<Vec<HandGatewayFrame>, CodecError> {
self.config.validate()?;
self.buffer.extend_from_slice(input);
let mut frames = Vec::new();
loop {
let Some(header_pos) = self
.buffer
.windows(FRAME_HEADER.len())
.position(|window| window == FRAME_HEADER)
else {
self.retain_possible_header_prefix();
break;
};
if header_pos > 0 {
self.buffer.drain(..header_pos);
}
if self.buffer.len() < 4 {
break;
}
let length = u16::from_le_bytes([self.buffer[2], self.buffer[3]]);
let frame_len = usize::from(length)
.checked_add(4)
.ok_or(CodecError::PayloadTooLarge)?;
if frame_len < MIN_FRAME_LENGTH || frame_len > self.config.max_frame_length {
log::debug!("invalid hand gateway frame length: {frame_len}");
self.buffer.drain(..1);
continue;
}
if self.buffer.len() < frame_len {
break;
}
let expected_checksum = calc_crc8_itu(&self.buffer[..frame_len - 1]);
let received_checksum = self.buffer[frame_len - 1];
if expected_checksum != received_checksum {
log::debug!(
"hand gateway checksum mismatch: expected {expected_checksum:02X}, got {received_checksum:02X}"
);
self.buffer.drain(..1);
continue;
}
if self.buffer[4] == RESPONSE_DATA_CMD {
match self.parse_data_response(
&self.buffer[..frame_len],
length,
session_started_at,
) {
Ok(frame) => frames.push(frame),
Err(error) => log::debug!("invalid hand gateway data response: {error}"),
}
}
self.buffer.drain(..frame_len);
}
Ok(frames)
}
fn encode(&self, frame: &HandGatewayFrame) -> Result<Vec<u8>, CodecError> {
let _ = frame;
Err(CodecError::InvalidFrameType)
}
}
#[cfg(test)]
mod tests {
use super::*;
fn data_response(config: u32, valid_config: u32, payload: &[u8]) -> Vec<u8> {
let block_count = config.count_ones() as u8;
let length = (RESPONSE_DATA_LEGACY_FIXED_LENGTH + payload.len()) as u16;
let mut frame = Vec::new();
frame.extend_from_slice(&FRAME_HEADER);
frame.extend_from_slice(&length.to_le_bytes());
frame.push(RESPONSE_DATA_CMD);
frame.push(0x01);
frame.extend_from_slice(&0x0102_0304u32.to_le_bytes());
frame.extend_from_slice(&config.to_le_bytes());
frame.extend_from_slice(&valid_config.to_le_bytes());
frame.push(block_count);
frame.extend_from_slice(payload);
let checksum = calc_crc8_itu(&frame);
frame.push(checksum);
frame
}
#[test]
fn decodes_data_response_frame() {
let payload = [0x10, 0x00, 0x34, 0x12, 0x08, 0x00];
let bytes = data_response(0b11, 0b01, &payload);
let frames = HandGatewayCodec::new(&[2, 1])
.decode(&bytes, Instant::now())
.unwrap();
assert_eq!(frames.len(), 1);
let HandGatewayFrame::DataRep(frame) = &frames[0];
assert_eq!(frame.timestamp, 0x0102_0304);
assert_eq!(frame.config, 0b11);
assert_eq!(frame.valid_config, 0b01);
assert_eq!(frame.block_count, 2);
assert_eq!(frame.raw, bytes);
assert_eq!(frame.nodes.len(), 2);
assert_eq!(
HandGatewayCodec::parse_node_payload(&frame.nodes[0].payload).unwrap(),
vec![16, 0x1234]
);
assert_eq!(
HandGatewayCodec::parse_node_payload(&frame.nodes[1].payload).unwrap(),
vec![8]
);
}
}