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Fix symbol IDs assigned to encoding packets #165

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merged 1 commit into from
Mar 12, 2024
Merged

Fix symbol IDs assigned to encoding packets #165

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112 changes: 58 additions & 54 deletions src/decoder.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -155,10 +155,6 @@ impl SourceBlockDecoder {
) -> SourceBlockDecoder {
let source_symbols = int_div_ceil(block_length, config.symbol_size() as u64);

let mut received_esi = Set::new();
for i in source_symbols..extended_source_block_symbols(source_symbols) {
received_esi.insert(i);
}
SourceBlockDecoder {
source_block_id,
symbol_size: config.symbol_size(),
Expand All @@ -168,7 +164,7 @@ impl SourceBlockDecoder {
source_symbols: vec![None; source_symbols as usize],
repair_packets: vec![],
received_source_symbols: 0,
received_esi,
received_esi: Set::new(),
decoded: false,
sparse_threshold: SPARSE_MATRIX_THRESHOLD,
}
Expand Down Expand Up @@ -253,15 +249,12 @@ impl SourceBlockDecoder {
);

let (payload_id, payload) = packet.split();
let num_extended_symbols = extended_source_block_symbols(self.source_block_symbols);
if self.received_esi.insert(payload_id.encoding_symbol_id()) {
if payload_id.encoding_symbol_id() >= num_extended_symbols {
if payload_id.encoding_symbol_id() >= self.source_block_symbols {
// Repair symbol
self.repair_packets
.push(EncodingPacket::new(payload_id, payload));
} else {
// Check that this is not an extended symbol (which aren't explicitly sent)
assert!(payload_id.encoding_symbol_id() < self.source_block_symbols);
// Source symbol
self.source_symbols[payload_id.encoding_symbol_id() as usize] =
Some(Symbol::new(payload));
Expand All @@ -271,6 +264,14 @@ impl SourceBlockDecoder {
}

let num_extended_symbols = extended_source_block_symbols(self.source_block_symbols);
let num_padding_symbols = num_extended_symbols - self.source_block_symbols;

// Case 1: the number of received packets is insufficient for decoding
if self.received_esi.len() < self.source_block_symbols as usize {
return None;
}

// Case 2: we have all source symbols and can return them without decoding
if self.received_source_symbols == self.source_block_symbols {
let mut result =
vec![0; self.symbol_size as usize * self.source_block_symbols as usize];
Expand All @@ -282,46 +283,46 @@ impl SourceBlockDecoder {
return Some(result);
}

if self.received_esi.len() as u32 >= num_extended_symbols {
let s = num_ldpc_symbols(self.source_block_symbols) as usize;
let h = num_hdpc_symbols(self.source_block_symbols) as usize;

let mut encoded_indices = vec![];
// See section 5.3.3.4.2. There are S + H zero symbols to start the D vector
let mut d = vec![Symbol::zero(self.symbol_size); s + h];
for (i, source) in self.source_symbols.iter().enumerate() {
if let Some(symbol) = source {
encoded_indices.push(i as u32);
d.push(symbol.clone());
}
// Case 3: we may have sufficient symbols to do a standard decoding
let s = num_ldpc_symbols(self.source_block_symbols) as usize;
let h = num_hdpc_symbols(self.source_block_symbols) as usize;

let mut encoded_isis = vec![];
// See section 5.3.3.4.2. There are S + H zero symbols to start the D vector
let mut d = vec![Symbol::zero(self.symbol_size); s + h];
for (i, source) in self.source_symbols.iter().enumerate() {
if let Some(symbol) = source {
encoded_isis.push(i as u32);
d.push(symbol.clone());
}
}

// Append the extended padding symbols
for i in self.source_block_symbols..num_extended_symbols {
encoded_indices.push(i);
d.push(Symbol::zero(self.symbol_size));
}
// Append the extended padding symbols
for i in self.source_block_symbols..num_extended_symbols {
encoded_isis.push(i);
d.push(Symbol::zero(self.symbol_size));
}

for repair_packet in self.repair_packets.iter() {
encoded_indices.push(repair_packet.payload_id.encoding_symbol_id());
d.push(Symbol::new(repair_packet.data.clone()));
}
// Append the received repair symbols
for repair_packet in self.repair_packets.iter() {
// We need to convert from ESI to ISI
encoded_isis.push(repair_packet.payload_id.encoding_symbol_id() + num_padding_symbols);
d.push(Symbol::new(repair_packet.data.clone()));
}

if extended_source_block_symbols(self.source_block_symbols) >= self.sparse_threshold {
let (constraint_matrix, hdpc) = generate_constraint_matrix::<SparseBinaryMatrix>(
self.source_block_symbols,
&encoded_indices,
);
return self.try_pi_decode(constraint_matrix, hdpc, d);
} else {
let (constraint_matrix, hdpc) = generate_constraint_matrix::<DenseBinaryMatrix>(
self.source_block_symbols,
&encoded_indices,
);
return self.try_pi_decode(constraint_matrix, hdpc, d);
}
if num_extended_symbols >= self.sparse_threshold {
let (constraint_matrix, hdpc) = generate_constraint_matrix::<SparseBinaryMatrix>(
self.source_block_symbols,
&encoded_isis,
);
self.try_pi_decode(constraint_matrix, hdpc, d)
} else {
let (constraint_matrix, hdpc) = generate_constraint_matrix::<DenseBinaryMatrix>(
self.source_block_symbols,
&encoded_isis,
);
self.try_pi_decode(constraint_matrix, hdpc, d)
}
None
}

fn rebuild_source_symbol(
Expand All @@ -346,16 +347,6 @@ impl SourceBlockDecoder {
#[cfg(feature = "std")]
#[cfg(test)]
mod codec_tests {
#[cfg(not(feature = "python"))]
use crate::Decoder;
use crate::SourceBlockEncoder;
use crate::SourceBlockEncodingPlan;
#[cfg(not(feature = "python"))]
use crate::{Encoder, EncoderBuilder};
use crate::{ObjectTransmissionInformation, SourceBlockDecoder};
#[cfg(not(feature = "python"))]
use rand::seq::SliceRandom;
use rand::Rng;
use std::{
iter,
sync::{
Expand All @@ -365,6 +356,19 @@ mod codec_tests {
vec::Vec,
};

#[cfg(not(feature = "python"))]
use rand::seq::SliceRandom;
use rand::Rng;

#[cfg(not(feature = "python"))]
use crate::Decoder;
#[cfg(not(feature = "python"))]
use crate::{Encoder, EncoderBuilder};
use crate::{
ObjectTransmissionInformation, SourceBlockDecoder, SourceBlockEncoder,
SourceBlockEncodingPlan,
};

#[cfg(not(feature = "python"))]
#[test]
fn random_erasure_dense() {
Expand Down
37 changes: 34 additions & 3 deletions src/encoder.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -321,7 +321,10 @@ impl SourceBlockEncoder {
for i in 0..packets {
let tuple = intermediate_tuple(start_encoding_symbol_id + i, lt_symbols, sys_index, p1);
result.push(EncodingPacket::new(
PayloadId::new(self.source_block_id, start_encoding_symbol_id + i),
PayloadId::new(
self.source_block_id,
self.source_symbols.len() as u32 + start_repair_symbol_id + i,
),
enc(
self.source_symbols.len() as u32,
&self.intermediate_symbols,
Expand Down Expand Up @@ -443,15 +446,16 @@ mod tests {
use rand::Rng;
use std::vec::Vec;

use super::*;

use crate::base::intermediate_tuple;
use crate::encoder::enc;
use crate::encoder::gen_intermediate_symbols;
use crate::symbol::Symbol;
use crate::systematic_constants::num_lt_symbols;
use crate::systematic_constants::num_pi_symbols;
use crate::systematic_constants::{
calculate_p1, num_ldpc_symbols, systematic_index, MAX_SOURCE_SYMBOLS_PER_BLOCK,
};
use crate::PayloadId;
#[cfg(not(feature = "python"))]
use crate::{Encoder, EncoderBuilder, EncodingPacket, ObjectTransmissionInformation};
#[cfg(not(feature = "python"))]
Expand Down Expand Up @@ -555,6 +559,33 @@ mod tests {
}
}

#[test]
fn encoding_creates_expected_packets() {
let symbol_size = 2;
let data: [u8; 6] = [0, 1, 2, 3, 4, 5];
let encoder = SourceBlockEncoder::new2(
0,
&ObjectTransmissionInformation::new(0, symbol_size, 1, 1, 1),
&data,
);
assert_eq!(
encoder.source_packets(),
[[0, 1], [2, 3], [4, 5]]
.into_iter()
.enumerate()
.map(|(i, d)| EncodingPacket::new(PayloadId::new(0, i as u32), d.into()))
.collect::<Vec<_>>()
);
assert_eq!(
encoder
.repair_packets(2, 4)
.into_iter()
.map(|p| p.payload_id.encoding_symbol_id())
.collect::<Vec<_>>(),
&[5, 6, 7, 8]
);
}

#[cfg(not(feature = "python"))]
#[test]
fn test_builder() {
Expand Down
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