414: Feature/generic stream r=jordens a=ryan-summers

This PR fixes #385 by improving the semantics by which streams are generated. Specifically, serialization format is now application-defined and data is only copied once.

TODO:
- [x] Add documentation for streaming architecture
- [x] Add format specifiers
- [x] Clean up reception script
- [x] Update lockin serialization

Co-authored-by: Ryan Summers <ryan.summers@vertigo-designs.com>
This commit is contained in:
bors[bot] 2021-07-27 11:52:48 +00:00 committed by GitHub
commit 62d1a16b4a
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8 changed files with 310 additions and 341 deletions

3
Cargo.lock generated
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@ -353,8 +353,7 @@ dependencies = [
[[package]]
name = "heapless"
version = "0.7.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "34e26526e7168021f34243a3c8faac4dc4f938cde75a0f9b8e373cca5eb4e7ce"
source = "git+https://github.com/quartiq/heapless.git?branch=feature/assume-init#0139ab11d55c6924dafd5d99ac9eda92bd0df77b"
dependencies = [
"atomic-polyfill",
"hash32 0.2.1",

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@ -69,6 +69,10 @@ rev = "33aa67d"
git = "https://github.com/rust-embedded/cortex-m-rt.git"
rev = "a2e3ad5"
[patch.crates-io.heapless]
git = "https://github.com/quartiq/heapless.git"
branch = "feature/assume-init"
[patch.crates-io.miniconf]
git = "https://github.com/quartiq/miniconf.git"
rev = "9c826f8"

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@ -4,14 +4,55 @@ Author: Ryan Summers
Description: Provides a mechanism for measuring Stabilizer stream data throughput.
"""
import argparse
import socket
import collections
import struct
import time
import logging
# Representation of a single UDP packet transmitted by Stabilizer.
Packet = collections.namedtuple('Packet', ['index', 'adc', 'dac'])
# Representation of a single data batch transmitted by Stabilizer.
Packet = collections.namedtuple('Packet', ['index', 'data'])
# The magic header half-word at the start of each packet.
MAGIC_HEADER = 0x057B
# The struct format of the header.
HEADER_FORMAT = '<HBBI'
# All supported formats by this reception script.
#
# The items in this dict are functions that will be provided the sample batch size and will return
# the struct deserialization code to unpack a single batch.
FORMAT = {
1: lambda batch_size: f'<{batch_size}H{batch_size}H{batch_size}H{batch_size}H'
}
def parse_packet(buf):
""" Attempt to parse packets from the received buffer. """
# Attempt to parse a block from the buffer.
if len(buf) < struct.calcsize(HEADER_FORMAT):
return
# Parse out the packet header
magic, format_id, batch_size, sequence_number = struct.unpack_from(HEADER_FORMAT, buf)
buf = buf[struct.calcsize(HEADER_FORMAT):]
if magic != MAGIC_HEADER:
logging.warning('Encountered bad magic header: %s', hex(magic))
return
frame_format = FORMAT[format_id](batch_size)
batch_count = int(len(buf) / struct.calcsize(frame_format))
packets = []
for offset in range(batch_count):
data = struct.unpack_from(frame_format, buf)
buf = buf[struct.calcsize(frame_format):]
yield Packet(sequence_number + offset, data)
class Timer:
""" A basic timer for measuring elapsed time periods. """
@ -52,99 +93,35 @@ class Timer:
return now - self.start_time
class PacketParser:
""" Utilize class used for parsing received UDP data. """
def sequence_delta(previous_sequence, next_sequence):
""" Check the number of items between two sequence numbers. """
if previous_sequence is None:
return 0
def __init__(self):
""" Initialize the parser. """
self.buf = b''
self.total_bytes = 0
def ingress(self, data):
""" Ingress received UDP data. """
self.total_bytes += len(data)
self.buf += data
def parse_all_packets(self):
""" Parse all received packets from the receive buffer.
Returns:
A list of received Packets.
"""
packets = []
while True:
new_packets = self._parse()
if new_packets:
packets += new_packets
else:
return packets
def _parse(self):
""" Attempt to parse packets from the received buffer. """
# Attempt to parse a block from the buffer.
if len(self.buf) < 4:
return None
start_id, num_blocks, data_size = struct.unpack_from('!HBB', self.buf)
packet_size = 4 + data_size * num_blocks * 8
if len(self.buf) < packet_size:
return None
self.buf = self.buf[4:]
packets = []
for offset in range(num_blocks):
adcs_dacs = struct.unpack_from(f'!{4 * data_size}H', self.buf)
adc = [
adcs_dacs[0:data_size],
adcs_dacs[data_size:2*data_size],
]
dac = [
adcs_dacs[2*data_size: 3*data_size],
adcs_dacs[3*data_size:],
]
self.buf = self.buf[8*data_size:]
packets.append(Packet(start_id + offset, adc, dac))
return packets
def check_index(previous_index, next_index):
""" Check if two indices are sequential. """
if previous_index == -1:
return True
# Handle index roll-over. Indices are only stored in 16-bit numbers.
if next_index < previous_index:
next_index += 65536
expected_index = previous_index + 1
return next_index == expected_index
delta = next_sequence - (previous_sequence + 1)
return delta & 0xFFFFFFFF
def main():
""" Main program. """
parser = argparse.ArgumentParser(description='Measure Stabilizer livestream quality')
parser.add_argument('--port', default=1111, help='The port that stabilizer is streaming to')
args = parser.parse_args()
connection = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
connection.bind(("", 1111))
connection.bind(("", args.port))
logging.basicConfig(level=logging.INFO,
format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s')
last_index = -1
last_index = None
drop_count = 0
good_blocks = 0
total_bytes = 0
timer = Timer()
parser = PacketParser()
while True:
# Receive any data over UDP and parse it.
@ -152,34 +129,24 @@ def main():
if data and not timer.is_started():
timer.start()
parser.ingress(data)
# Handle any received packets.
for packet in parser.parse_all_packets():
total_bytes += len(data)
for packet in parse_packet(data):
# Handle any dropped packets.
if not check_index(last_index, packet.index):
print(hex(last_index), hex(packet.index))
if packet.index < (last_index + 1):
dropped = packet.index + 65536 - (last_index + 1)
else:
dropped = packet.index - (last_index + 1)
drop_count += dropped
drop_count += sequence_delta(last_index, packet.index)
last_index = packet.index
good_blocks += 1
# Report the throughput periodically.
if timer.is_triggered():
drate = parser.total_bytes * 8 / 1e6 / timer.elapsed()
drate = total_bytes * 8 / 1e6 / timer.elapsed()
print(f'''
Data Rate: {drate:.3f} Mbps
Received Blocks: {good_blocks}
Dropped blocks: {drop_count}
Metadata: {parser.total_bytes / 1e6:.3f} MB in {timer.elapsed():.2f} s
Metadata: {total_bytes / 1e6:.3f} MB in {timer.elapsed():.2f} s
----
''')
timer.arm()

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@ -43,6 +43,7 @@ use stabilizer::{
adc::{Adc0Input, Adc1Input, AdcCode},
afe::Gain,
dac::{Dac0Output, Dac1Output, DacCode},
design_parameters::SAMPLE_BUFFER_SIZE,
embedded_hal::digital::v2::InputPin,
hal,
signal_generator::{self, SignalGenerator},
@ -50,7 +51,7 @@ use stabilizer::{
DigitalInput0, DigitalInput1, AFE0, AFE1,
},
net::{
data_stream::{BlockGenerator, StreamTarget},
data_stream::{FrameGenerator, StreamFormat, StreamTarget},
miniconf::Miniconf,
serde::Deserialize,
telemetry::{Telemetry, TelemetryBuffer},
@ -169,7 +170,7 @@ const APP: () = {
adcs: (Adc0Input, Adc1Input),
dacs: (Dac0Output, Dac1Output),
network: NetworkUsers<Settings, Telemetry>,
generator: BlockGenerator,
generator: FrameGenerator,
signal_generator: [SignalGenerator; 2],
settings: Settings,
@ -193,7 +194,10 @@ const APP: () = {
stabilizer.net.mac_address,
);
let generator = network.enable_streaming();
let generator = network.configure_streaming(
StreamFormat::AdcDacData,
SAMPLE_BUFFER_SIZE as u8,
);
// Spawn a settings update for default settings.
c.spawn.settings_update().unwrap();
@ -307,7 +311,23 @@ const APP: () = {
}
// Stream the data.
generator.send(&adc_samples, &dac_samples);
const N: usize = SAMPLE_BUFFER_SIZE * core::mem::size_of::<u16>();
generator.add::<_, { N * 4 }>(|buf| {
for (data, buf) in adc_samples
.iter()
.chain(dac_samples.iter())
.zip(buf.chunks_exact_mut(N))
{
assert_eq!(core::mem::size_of_val(*data), N);
let data = unsafe {
core::slice::from_raw_parts(
data.as_ptr() as *const u8,
N,
)
};
buf.copy_from_slice(data)
}
});
// Update telemetry measurements.
telemetry.adcs =

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@ -43,6 +43,7 @@ use stabilizer::{
adc::{Adc0Input, Adc1Input, AdcCode},
afe::Gain,
dac::{Dac0Output, Dac1Output, DacCode},
design_parameters::SAMPLE_BUFFER_SIZE,
embedded_hal::digital::v2::InputPin,
hal,
input_stamper::InputStamper,
@ -51,7 +52,7 @@ use stabilizer::{
DigitalInput0, DigitalInput1, AFE0, AFE1,
},
net::{
data_stream::{BlockGenerator, StreamTarget},
data_stream::{FrameGenerator, StreamFormat, StreamTarget},
miniconf::Miniconf,
serde::Deserialize,
telemetry::{Telemetry, TelemetryBuffer},
@ -208,7 +209,7 @@ const APP: () = {
settings: Settings,
telemetry: TelemetryBuffer,
digital_inputs: (DigitalInput0, DigitalInput1),
generator: BlockGenerator,
generator: FrameGenerator,
signal_generator: signal_generator::SignalGenerator,
timestamper: InputStamper,
@ -230,7 +231,10 @@ const APP: () = {
stabilizer.net.mac_address,
);
let generator = network.enable_streaming();
let generator = network.configure_streaming(
StreamFormat::AdcDacData,
SAMPLE_BUFFER_SIZE as u8,
);
let settings = Settings::default();
@ -394,8 +398,24 @@ const APP: () = {
}
}
// Stream data
generator.send(&adc_samples, &dac_samples);
// Stream the data.
const N: usize = SAMPLE_BUFFER_SIZE * core::mem::size_of::<u16>();
generator.add::<_, { N * 4 }>(|buf| {
for (data, buf) in adc_samples
.iter()
.chain(dac_samples.iter())
.zip(buf.chunks_exact_mut(N))
{
assert_eq!(core::mem::size_of_val(*data), N);
let data = unsafe {
core::slice::from_raw_parts(
data.as_ptr() as *const u8,
N,
)
};
buf.copy_from_slice(data)
}
});
// Update telemetry measurements.
telemetry.adcs =

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@ -36,11 +36,6 @@ pub struct NetStorage {
[Option<(smoltcp::wire::IpAddress, smoltcp::iface::Neighbor)>; 8],
pub routes_cache:
[Option<(smoltcp::wire::IpCidr, smoltcp::iface::Route)>; 8],
pub dhcp_rx_metadata: [smoltcp::socket::RawPacketMetadata; 1],
pub dhcp_tx_metadata: [smoltcp::socket::RawPacketMetadata; 1],
pub dhcp_tx_storage: [u8; 600],
pub dhcp_rx_storage: [u8; 600],
}
pub struct UdpSocketStorage {
@ -94,10 +89,6 @@ impl Default for NetStorage {
sockets: [None, None, None, None, None, None],
tcp_socket_storage: [TcpSocketStorage::new(); NUM_TCP_SOCKETS],
udp_socket_storage: [UdpSocketStorage::new(); NUM_UDP_SOCKETS],
dhcp_tx_storage: [0; 600],
dhcp_rx_storage: [0; 600],
dhcp_rx_metadata: [smoltcp::socket::RawPacketMetadata::EMPTY; 1],
dhcp_tx_metadata: [smoltcp::socket::RawPacketMetadata::EMPTY; 1],
}
}
}

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@ -2,27 +2,56 @@
//!
//! # Design
//! Data streamining utilizes UDP packets to send live data streams at high throughput.
//! Packets are always sent in a best-effort fashion, and data may be dropped. Each packet contains
//! an identifier that can be used to detect dropped data.
//! Packets are always sent in a best-effort fashion, and data may be dropped.
//!
//! Refer to [DataPacket] for information about the serialization format of each UDP packet.
//! Stabilizer organizes livestreamed data into batches within a "Frame" that will be sent as a UDP
//! packet. Each frame consits of a header followed by sequential batch serializations. The packet
//! header is constant for all streaming capabilities, but the serialization format after the header
//! is application-defined.
//!
//! ## Frame Header
//! The header consists of the following, all in little-endian.
//!
//! * **Magic word 0x057B** <u16>: a constant to identify Stabilizer streaming data.
//! * **Format Code** <u8>: a unique ID that indicates the serialization format of each batch of data
//! in the frame. Refer to [StreamFormat] for further information.
//! * **Batch Size** <u8>: the number of samples in each batch of data.
//! * **Sequence Number** <u32>: an the sequence number of the first batch in the frame.
//! This can be used to determine if and how many stream batches are lost.
//!
//! # Example
//! A sample Python script is available in `scripts/stream_throughput.py` to demonstrate reception
//! of livestreamed data.
use heapless::spsc::{Consumer, Producer, Queue};
use miniconf::MiniconfAtomic;
use num_enum::IntoPrimitive;
use serde::Deserialize;
use smoltcp_nal::embedded_nal::{IpAddr, Ipv4Addr, SocketAddr, UdpClientStack};
use heapless::pool::{Box, Init, Pool, Uninit};
use super::NetworkReference;
use crate::hardware::design_parameters::SAMPLE_BUFFER_SIZE;
// The number of data blocks that we will buffer in the queue.
const BLOCK_BUFFER_SIZE: usize = 30;
const MAGIC_WORD: u16 = 0x057B;
// A factor that data may be subsampled at.
const SUBSAMPLE_RATE: usize = 1;
// The size of the header, calculated in bytes.
// The header has a 16-bit magic word, an 8-bit format, 8-bit batch-size, and 32-bit sequence
// number, which corresponds to 8 bytes total.
const HEADER_SIZE: usize = 8;
// The number of frames that can be buffered.
const FRAME_COUNT: usize = 4;
// The size of each livestream frame in bytes.
const FRAME_SIZE: usize = 1024 + HEADER_SIZE;
// The size of the frame queue must be at least as large as the number of frame buffers. Every
// allocated frame buffer should fit in the queue.
const FRAME_QUEUE_SIZE: usize = FRAME_COUNT * 2;
// Static storage used for a heapless::Pool of frame buffers.
static mut FRAME_DATA: [u8; FRAME_SIZE * FRAME_COUNT] =
[0; FRAME_SIZE * FRAME_COUNT];
/// Represents the destination for the UDP stream to send data to.
///
@ -40,6 +69,23 @@ pub struct StreamTarget {
pub port: u16,
}
/// Specifies the format of streamed data
#[repr(u8)]
#[derive(Debug, Copy, Clone, PartialEq, IntoPrimitive)]
pub enum StreamFormat {
/// Reserved, unused format specifier.
Unknown = 0,
/// Streamed data contains ADC0, ADC1, DAC0, and DAC1 sequentially in little-endian format.
///
/// # Example
/// With a batch size of 2, the serialization would take the following form:
/// ```
/// <ADC0[0]> <ADC0[1]> <ADC1[0]> <ADC1[1]> <DAC0[0]> <DAC0[1]> <DAC1[0]> <DAC1[1]>
/// ```
AdcDacData = 1,
}
impl From<StreamTarget> for SocketAddr {
fn from(target: StreamTarget) -> SocketAddr {
SocketAddr::new(
@ -54,15 +100,6 @@ impl From<StreamTarget> for SocketAddr {
}
}
/// A basic "batch" of data.
// Note: In the future, the stream may be generic over this type.
#[derive(Debug, Copy, Clone)]
pub struct AdcDacData {
block_id: u16,
adcs: [[u16; SAMPLE_BUFFER_SIZE]; 2],
dacs: [[u16; SAMPLE_BUFFER_SIZE]; 2],
}
/// Configure streaming on a device.
///
/// # Args
@ -73,216 +110,147 @@ pub struct AdcDacData {
/// `stream` is the logically consumer (UDP transmitter) of the enqueued data.
pub fn setup_streaming(
stack: NetworkReference,
) -> (BlockGenerator, DataStream) {
let queue = cortex_m::singleton!(: Queue<AdcDacData, BLOCK_BUFFER_SIZE> = Queue::new()).unwrap();
) -> (FrameGenerator, DataStream) {
// The queue needs to be at least as large as the frame count to ensure that every allocated
// frame can potentially be enqueued for transmission.
let queue =
cortex_m::singleton!(: Queue<StreamFrame, FRAME_QUEUE_SIZE> = Queue::new())
.unwrap();
let (producer, consumer) = queue.split();
let generator = BlockGenerator::new(producer);
let frame_pool =
cortex_m::singleton!(: Pool<[u8; FRAME_SIZE]>= Pool::new()).unwrap();
let stream = DataStream::new(stack, consumer);
// Note(unsafe): We guarantee that FRAME_DATA is only accessed once in this function.
let memory = unsafe { &mut FRAME_DATA };
frame_pool.grow(memory);
let generator = FrameGenerator::new(producer, frame_pool);
let stream = DataStream::new(stack, consumer, frame_pool);
(generator, stream)
}
/// The data generator for a stream.
pub struct BlockGenerator {
queue: Producer<'static, AdcDacData, BLOCK_BUFFER_SIZE>,
current_id: u16,
#[derive(Debug)]
struct StreamFrame {
buffer: Box<[u8; FRAME_SIZE], Init>,
offset: usize,
}
impl BlockGenerator {
/// Construct a new generator.
/// # Args
/// * `queue` - The producer portion of the SPSC queue to enqueue data into.
///
/// # Returns
/// The generator to use.
fn new(queue: Producer<'static, AdcDacData, BLOCK_BUFFER_SIZE>) -> Self {
impl StreamFrame {
pub fn new(
buffer: Box<[u8; FRAME_SIZE], Uninit>,
format: u8,
buffer_size: u8,
sequence_number: u32,
) -> Self {
let mut buffer = unsafe { buffer.assume_init() };
buffer[0..2].copy_from_slice(&MAGIC_WORD.to_ne_bytes());
buffer[2] = format;
buffer[3] = buffer_size;
buffer[4..8].copy_from_slice(&sequence_number.to_ne_bytes());
Self {
buffer,
offset: HEADER_SIZE,
}
}
pub fn add_batch<F, const T: usize>(&mut self, mut f: F)
where
F: FnMut(&mut [u8]),
{
f(&mut self.buffer[self.offset..self.offset + T]);
self.offset += T;
}
pub fn is_full<const T: usize>(&self) -> bool {
self.offset + T > self.buffer.len()
}
pub fn finish(&mut self) -> &[u8] {
&self.buffer[..self.offset]
}
}
/// The data generator for a stream.
pub struct FrameGenerator {
queue: Producer<'static, StreamFrame, FRAME_QUEUE_SIZE>,
pool: &'static Pool<[u8; FRAME_SIZE]>,
current_frame: Option<StreamFrame>,
sequence_number: u32,
format: u8,
batch_size: u8,
}
impl FrameGenerator {
fn new(
queue: Producer<'static, StreamFrame, FRAME_QUEUE_SIZE>,
pool: &'static Pool<[u8; FRAME_SIZE]>,
) -> Self {
Self {
queue,
current_id: 0,
pool,
batch_size: 0,
format: StreamFormat::Unknown.into(),
current_frame: None,
sequence_number: 0,
}
}
/// Schedule data to be sent by the generator.
/// Configure the format of the stream.
///
/// # Note
/// If no space is available, the data batch may be silently dropped.
/// # Note:
/// This function shall only be called once upon initializing streaming
///
/// # Args
/// * `adcs` - The ADC data to transmit.
/// * `dacs` - The DAC data to transmit.
pub fn send(
&mut self,
adcs: &[&mut [u16; SAMPLE_BUFFER_SIZE]; 2],
dacs: &[&mut [u16; SAMPLE_BUFFER_SIZE]; 2],
) {
let block = AdcDacData {
block_id: self.current_id,
adcs: [*adcs[0], *adcs[1]],
dacs: [*dacs[0], *dacs[1]],
};
self.current_id = self.current_id.wrapping_add(1);
self.queue.enqueue(block).ok();
}
}
/// # Stream Packet
/// Represents a single UDP packet sent by the stream.
///
/// A "batch" of data is defined to be the data collected for a single invocation of the DSP
/// routine. A packet is composed of as many sequential batches as can fit.
///
/// The packet is given a header indicating the starting batch sequence number and the number of
/// batches present. If the UDP transmitter encounters a non-sequential batch, it does not enqueue
/// it into the packet and instead transmits any staged data. The non-sequential batch is then
/// transmitted in a new UDP packet. This method allows a receiver to detect dropped batches (e.g.
/// due to processing overhead).
///
/// ## Data Format
///
/// Data sent via UDP is sent in "blocks". Each block is a single batch of ADC/DAC codes from an
/// individual DSP processing routine. Each block is assigned a unique 16-bit identifier. The identifier
/// increments by one for each block and rolls over. All blocks in a single packet are guaranteed to
/// contain sequential identifiers.
///
/// All data is transmitted in network-endian (big-endian) format.
///
/// ### Quick Reference
///
/// In the reference below, any values enclosed in parentheses represents the number of bytes used for
/// that value. E.g. "Batch size (1)" indicates 1 byte is used to represent the batch size.
/// ```
/// # UDP packets take the following form
/// <Header>,<Batch 1>,[<Batch 2>, ...<Batch N>]
///
/// # The header takes the following form
/// <Header> = <Starting ID (2)>,<Number blocks [N] (1)>,<Batch size [BS] (1)>
///
/// # Each batch takes the following form
/// <Batch N> = <ADC0>,<ADC1>,<DAC0>,<DAC1>
///
/// # Where
/// <ADCx/DACx> = <Sample 1 (2)>, ...<Sample BS (2)>
/// ```
///
/// ### Packet Format
/// Multiple blocks are sent in a single UDP packet simultaneously. Each UDP packet transmitted
/// contains a header followed by the serialized data blocks.
/// ```
/// <Header>,<Batch 1>,[<Batch 2>, ...<Batch N>]
/// ```
///
/// ### Header
/// A header takes the following form:
/// * The starting block ID (2 bytes)
/// * The number of blocks present in the packet (1 byte)
/// * The size of each bach in samples (1 byte)
///
/// ```
/// <Starting ID (2)>,<N blocks (1)>,<Batch size (1)>
/// ```
///
/// ### Data Blocks
/// Following the header, each block is sequentially serialized. Each block takes the following form:
/// ```
/// <ADC0 samples>,<ADC1 samples>,<DAC0 samples>,<DAC1 samples>
/// ```
///
/// Where `<XXX samples>` is an array of N 16-bit ADC/DAC samples. The number of samples is provided in the
/// header.
///
/// ADC and DAC codes are transmitted in raw machine-code format. Please refer to the datasheet for the
/// ADC and DAC if you need to convert these to voltages.
pub struct DataPacket<'a> {
buf: &'a mut [u8],
subsample_rate: usize,
start_id: Option<u16>,
num_blocks: u8,
write_index: usize,
}
impl<'a> DataPacket<'a> {
/// Construct a new packet.
///
/// # Args
/// * `buf` - The location to serialize the data packet into.
/// * `subsample_rate` - The factor at which to subsample data from batches.
pub fn new(buf: &'a mut [u8], subsample_rate: usize) -> Self {
Self {
buf,
start_id: None,
num_blocks: 0,
subsample_rate,
write_index: 4,
}
/// * `format` - The desired format of the stream.
/// * `batch_size` - The number of samples in each data batch. See
/// [crate::hardware::design_parameters::SAMPLE_BUFFER_SIZE]
#[doc(hidden)]
pub(crate) fn configure(&mut self, format: impl Into<u8>, batch_size: u8) {
self.format = format.into();
self.batch_size = batch_size;
}
/// Add a batch of data to the packet.
///
/// # Note
/// Serialization occurs as the packet is added.
/// Add a batch to the current stream frame.
///
/// # Args
/// * `batch` - The batch to add to the packet.
pub fn add_batch(&mut self, batch: &AdcDacData) -> Result<(), ()> {
// Check that the block is sequential.
if let Some(id) = &self.start_id {
if batch.block_id != id.wrapping_add(self.num_blocks.into()) {
return Err(());
}
} else {
// Otherwise, this is the first block. Record the strt ID.
self.start_id = Some(batch.block_id);
}
/// * `f` - A closure that will be provided the buffer to write batch data into. The buffer will
/// be the size of the `T` template argument.
pub fn add<F, const T: usize>(&mut self, f: F)
where
F: FnMut(&mut [u8]),
{
let sequence_number = self.sequence_number;
self.sequence_number = self.sequence_number.wrapping_add(1);
// Check that there is space for the block.
let block_size_bytes = SAMPLE_BUFFER_SIZE / self.subsample_rate * 4 * 2;
if self.buf.len() - self.get_packet_size() < block_size_bytes {
return Err(());
}
// Copy the samples into the buffer.
for device in &[batch.adcs, batch.dacs] {
for channel in device {
for sample in channel.iter().step_by(self.subsample_rate) {
self.buf[self.write_index..self.write_index + 2]
.copy_from_slice(&sample.to_be_bytes());
self.write_index += 2;
}
if self.current_frame.is_none() {
if let Some(buffer) = self.pool.alloc() {
self.current_frame.replace(StreamFrame::new(
buffer,
self.format as u8,
self.batch_size,
sequence_number,
));
} else {
return;
}
}
self.num_blocks += 1;
// Note(unwrap): We ensure the frame is present above.
let current_frame = self.current_frame.as_mut().unwrap();
Ok(())
}
current_frame.add_batch::<_, T>(f);
fn get_packet_size(&self) -> usize {
let header_length = 4;
let block_sample_size = SAMPLE_BUFFER_SIZE / self.subsample_rate;
let block_size_bytes = block_sample_size * 2 * 4;
block_size_bytes * self.num_blocks as usize + header_length
}
/// Complete the packet and prepare it for transmission.
///
/// # Returns
/// The size of the packet. The user should utilize the original buffer provided for packet
/// construction to access the packet.
pub fn finish(self) -> usize {
let block_sample_size = SAMPLE_BUFFER_SIZE / self.subsample_rate;
// Write the header into the block.
self.buf[0..2].copy_from_slice(&self.start_id.unwrap().to_be_bytes());
self.buf[2] = self.num_blocks;
self.buf[3] = block_sample_size as u8;
// Return the length of the packet to transmit.
self.get_packet_size()
if current_frame.is_full::<T>() {
// Note(unwrap): The queue is designed to be at least as large as the frame buffer
// count, so this enqueue should always succeed.
self.queue
.enqueue(self.current_frame.take().unwrap())
.unwrap();
}
}
}
@ -293,9 +261,9 @@ impl<'a> DataPacket<'a> {
pub struct DataStream {
stack: NetworkReference,
socket: Option<<NetworkReference as UdpClientStack>::UdpSocket>,
queue: Consumer<'static, AdcDacData, BLOCK_BUFFER_SIZE>,
queue: Consumer<'static, StreamFrame, FRAME_QUEUE_SIZE>,
frame_pool: &'static Pool<[u8; FRAME_SIZE]>,
remote: SocketAddr,
buffer: [u8; 1024],
}
impl DataStream {
@ -304,16 +272,18 @@ impl DataStream {
/// # Args
/// * `stack` - A reference to the shared network stack.
/// * `consumer` - The read side of the queue containing data to transmit.
/// * `frame_pool` - The Pool to return stream frame objects into.
fn new(
stack: NetworkReference,
consumer: Consumer<'static, AdcDacData, BLOCK_BUFFER_SIZE>,
consumer: Consumer<'static, StreamFrame, FRAME_QUEUE_SIZE>,
frame_pool: &'static Pool<[u8; FRAME_SIZE]>,
) -> Self {
Self {
stack,
socket: None,
remote: StreamTarget::default().into(),
queue: consumer,
buffer: [0; 1024],
frame_pool,
}
}
@ -365,27 +335,16 @@ impl DataStream {
// If there's no socket available, try to connect to our remote.
if self.open().is_ok() {
// If we just successfully opened the socket, flush old data from queue.
while self.queue.dequeue().is_some() {}
while let Some(frame) = self.queue.dequeue() {
self.frame_pool.free(frame.buffer);
}
}
}
Some(handle) => {
if self.queue.ready() {
// Dequeue data from the queue into a larger block structure.
let mut packet =
DataPacket::new(&mut self.buffer, SUBSAMPLE_RATE);
while self
.queue
.peek()
.and_then(|batch| packet.add_batch(batch).ok())
.is_some()
{
// Dequeue the batch that we just added to the packet.
self.queue.dequeue();
}
// Transmit the data packet.
let size = packet.finish();
self.stack.send(handle, &self.buffer[..size]).ok();
if let Some(mut frame) = self.queue.dequeue() {
// Transmit the frame and return it to the pool.
self.stack.send(handle, frame.finish()).ok();
self.frame_pool.free(frame.buffer)
}
}
}

View File

@ -17,7 +17,7 @@ pub mod shared;
pub mod telemetry;
use crate::hardware::{cycle_counter::CycleCounter, EthernetPhy, NetworkStack};
use data_stream::{BlockGenerator, DataStream};
use data_stream::{DataStream, FrameGenerator};
use messages::{MqttMessage, SettingsResponse};
use miniconf_client::MiniconfClient;
use network_processor::NetworkProcessor;
@ -49,7 +49,7 @@ pub struct NetworkUsers<S: Default + Clone + Miniconf, T: Serialize> {
pub miniconf: MiniconfClient<S>,
pub processor: NetworkProcessor,
stream: DataStream,
generator: Option<BlockGenerator>,
generator: Option<FrameGenerator>,
pub telemetry: TelemetryClient<T>,
}
@ -113,8 +113,17 @@ where
}
/// Enable live data streaming.
pub fn enable_streaming(&mut self) -> BlockGenerator {
self.generator.take().unwrap()
///
/// # Args
/// * `format` - A unique u8 code indicating the format of the data.
pub fn configure_streaming(
&mut self,
format: impl Into<u8>,
batch_size: u8,
) -> FrameGenerator {
let mut generator = self.generator.take().unwrap();
generator.configure(format, batch_size);
generator
}
/// Direct the stream to the provided remote target.