From 3deb34f613aca9278334bea331d97dabb8d0d8cd Mon Sep 17 00:00:00 2001 From: Christopher Berner Date: Mon, 28 Jan 2019 23:08:22 -0800 Subject: [PATCH] Refactor Symbol to use Octet --- src/decoder.rs | 6 +-- src/encoder.rs | 23 ++++----- src/matrix.rs | 6 +-- src/octet.rs | 7 +++ src/symbol.rs | 135 +++++++++---------------------------------------- 5 files changed, 45 insertions(+), 132 deletions(-) diff --git a/src/decoder.rs b/src/decoder.rs index 42d723e..4b705f2 100644 --- a/src/decoder.rs +++ b/src/decoder.rs @@ -57,7 +57,7 @@ impl SourceBlockDecoder { if self.received_source_symbols == self.source_block_symbols { let mut result = vec![]; for symbol in self.source_symbols.clone() { - result.extend(symbol.unwrap().value.clone()); + result.extend(symbol.unwrap().bytes()); } return Some(result); } @@ -102,11 +102,11 @@ impl SourceBlockDecoder { let mut result = vec![]; for i in 0..self.source_block_symbols as usize { if self.source_symbols[i] != None { - result.extend(self.source_symbols[i].clone().unwrap().value.clone()) + result.extend(self.source_symbols[i].clone().unwrap().bytes()) } else { let rebuilt = self.rebuild_source_symbol(intermediate_symbols.clone(), i as u32); - result.extend(rebuilt.value); + result.extend(rebuilt.bytes()); } } diff --git a/src/encoder.rs b/src/encoder.rs index 5c94764..af3f124 100644 --- a/src/encoder.rs +++ b/src/encoder.rs @@ -24,7 +24,7 @@ impl SourceBlockEncoder { let source_symbols: Vec = data.chunks(symbol_size as usize) .map(|x| Symbol::new(Vec::from(x))) .collect(); - let intermediate_symbols = gen_intermediate_symbols(extend_source_block(source_symbols.clone())); + let intermediate_symbols = gen_intermediate_symbols(extend_source_block(source_symbols.clone(), symbol_size as usize), symbol_size as usize); SourceBlockEncoder { source_block_id, symbol_size, @@ -60,27 +60,24 @@ impl SourceBlockEncoder { } // Extend the source block with padding. See section 5.3.2 -fn extend_source_block(mut source_block: Vec) -> Vec { +fn extend_source_block(mut source_block: Vec, symbol_size: usize) -> Vec { assert_ne!(0, source_block.len()); let symbols = source_block.len() as u32; - let symbol_size = source_block[0].value.len(); let extended_source_symbols = extended_source_block_symbols(source_block.len() as u32); for _ in 0..(extended_source_symbols - symbols) { - source_block.push(Symbol { - value: vec![0; symbol_size] - }); + source_block.push(Symbol::zero(symbol_size)); } source_block } // See section 5.3.3.4 #[allow(non_snake_case)] -fn gen_intermediate_symbols(extended_source_block: Vec) -> Vec { +fn gen_intermediate_symbols(extended_source_block: Vec, symbol_size: usize) -> Vec { let L = num_intermediate_symbols(extended_source_block.len() as u32); let S = num_ldpc_symbols(extended_source_block.len() as u32); let H = num_hdpc_symbols(extended_source_block.len() as u32); - let mut D = vec![Symbol::zero(extended_source_block[0].value.len()); L as usize]; + let mut D = vec![Symbol::zero(symbol_size); L as usize]; for i in 0..extended_source_block.len() { D[(S + H) as usize + i] = extended_source_block[i].clone(); } @@ -151,18 +148,16 @@ mod tests { for i in 0..SYMBOL_SIZE { data[i] = rand::thread_rng().gen(); } - source_block.push(Symbol { - value: data - }); + source_block.push(Symbol::new(data)); } - extend_source_block(source_block) + extend_source_block(source_block, SYMBOL_SIZE) } #[test] fn enc_constraint() { let extended_source_symbols = gen_test_symbols(); - let intermediate_symbols = gen_intermediate_symbols(extended_source_symbols.clone()); + let intermediate_symbols = gen_intermediate_symbols(extended_source_symbols.clone(), SYMBOL_SIZE); // See section 5.3.3.4.1, item 1. for i in 0..extended_source_symbols.len() { @@ -175,7 +170,7 @@ mod tests { #[allow(non_snake_case)] #[test] fn ldpc_constraint() { - let C = gen_intermediate_symbols(gen_test_symbols()); + let C = gen_intermediate_symbols(gen_test_symbols(), SYMBOL_SIZE); let S = num_ldpc_symbols(NUM_SYMBOLS) as usize; let P = num_pi_symbols(NUM_SYMBOLS) as usize; let W = num_lt_symbols(NUM_SYMBOLS) as usize; diff --git a/src/matrix.rs b/src/matrix.rs index 596df5e..d78833c 100644 --- a/src/matrix.rs +++ b/src/matrix.rs @@ -27,7 +27,7 @@ impl OctetMatrix { assert_ne!(0, symbols.len()); let mut result: Vec = vec![]; for i in 0..self.height { - let mut symbol = Symbol::zero(symbols[0].value.len()); + let mut symbol = Symbol::zero(symbols[0].len()); for j in 0..self.width { symbol += symbols[j].mul_scalar(&self.elements[i][j]); } @@ -177,9 +177,7 @@ mod tests { for _ in 0..3 { data.push(rand::thread_rng().gen()); } - symbols.push(Symbol { - value: data - }); + symbols.push(Symbol::new(data)); } assert_eq!(symbols.clone(), identity.mul_symbols(&symbols)); diff --git a/src/octet.rs b/src/octet.rs index 37d97d0..568a6f1 100644 --- a/src/octet.rs +++ b/src/octet.rs @@ -2,6 +2,7 @@ use std::ops::Add; use std::ops::Mul; use std::ops::Div; use std::ops::Sub; +use std::ops::AddAssign; // As defined in section 5.7.3 const OCT_EXP: [u8; 510] = [ @@ -106,6 +107,12 @@ impl Add for Octet { } } +impl AddAssign for Octet { + fn add_assign(&mut self, other: Octet) { + self.value ^= other.value; + } +} + impl Sub for Octet { type Output = Octet; diff --git a/src/symbol.rs b/src/symbol.rs index 14fc2af..a0d3e0a 100644 --- a/src/symbol.rs +++ b/src/symbol.rs @@ -4,87 +4,35 @@ use std::ops::Div; use octet::Octet; use std::ops::AddAssign; -// As defined in section 5.7.3 -const OCT_EXP: [u8; 510] = [ - 1, 2, 4, 8, 16, 32, 64, 128, 29, 58, 116, 232, 205, 135, 19, 38, 76, - 152, 45, 90, 180, 117, 234, 201, 143, 3, 6, 12, 24, 48, 96, 192, 157, - 39, 78, 156, 37, 74, 148, 53, 106, 212, 181, 119, 238, 193, 159, 35, - 70, 140, 5, 10, 20, 40, 80, 160, 93, 186, 105, 210, 185, 111, 222, - 161, 95, 190, 97, 194, 153, 47, 94, 188, 101, 202, 137, 15, 30, 60, - 120, 240, 253, 231, 211, 187, 107, 214, 177, 127, 254, 225, 223, 163, - 91, 182, 113, 226, 217, 175, 67, 134, 17, 34, 68, 136, 13, 26, 52, - 104, 208, 189, 103, 206, 129, 31, 62, 124, 248, 237, 199, 147, 59, - 118, 236, 197, 151, 51, 102, 204, 133, 23, 46, 92, 184, 109, 218, - 169, 79, 158, 33, 66, 132, 21, 42, 84, 168, 77, 154, 41, 82, 164, 85, - 170, 73, 146, 57, 114, 228, 213, 183, 115, 230, 209, 191, 99, 198, - 145, 63, 126, 252, 229, 215, 179, 123, 246, 241, 255, 227, 219, 171, - 75, 150, 49, 98, 196, 149, 55, 110, 220, 165, 87, 174, 65, 130, 25, - 50, 100, 200, 141, 7, 14, 28, 56, 112, 224, 221, 167, 83, 166, 81, - 162, 89, 178, 121, 242, 249, 239, 195, 155, 43, 86, 172, 69, 138, 9, - 18, 36, 72, 144, 61, 122, 244, 245, 247, 243, 251, 235, 203, 139, 11, - 22, 44, 88, 176, 125, 250, 233, 207, 131, 27, 54, 108, 216, 173, 71, - 142, 1, 2, 4, 8, 16, 32, 64, 128, 29, 58, 116, 232, 205, 135, 19, 38, - 76, 152, 45, 90, 180, 117, 234, 201, 143, 3, 6, 12, 24, 48, 96, 192, - 157, 39, 78, 156, 37, 74, 148, 53, 106, 212, 181, 119, 238, 193, 159, - 35, 70, 140, 5, 10, 20, 40, 80, 160, 93, 186, 105, 210, 185, 111, - 222, 161, 95, 190, 97, 194, 153, 47, 94, 188, 101, 202, 137, 15, 30, - 60, 120, 240, 253, 231, 211, 187, 107, 214, 177, 127, 254, 225, 223, - 163, 91, 182, 113, 226, 217, 175, 67, 134, 17, 34, 68, 136, 13, 26, - 52, 104, 208, 189, 103, 206, 129, 31, 62, 124, 248, 237, 199, 147, - 59, 118, 236, 197, 151, 51, 102, 204, 133, 23, 46, 92, 184, 109, 218, - 169, 79, 158, 33, 66, 132, 21, 42, 84, 168, 77, 154, 41, 82, 164, 85, - 170, 73, 146, 57, 114, 228, 213, 183, 115, 230, 209, 191, 99, 198, - 145, 63, 126, 252, 229, 215, 179, 123, 246, 241, 255, 227, 219, 171, - 75, 150, 49, 98, 196, 149, 55, 110, 220, 165, 87, 174, 65, 130, 25, - 50, 100, 200, 141, 7, 14, 28, 56, 112, 224, 221, 167, 83, 166, 81, - 162, 89, 178, 121, 242, 249, 239, 195, 155, 43, 86, 172, 69, 138, 9, - 18, 36, 72, 144, 61, 122, 244, 245, 247, 243, 251, 235, 203, 139, 11, - 22, 44, 88, 176, 125, 250, 233, 207, 131, 27, 54, 108, 216, 173, 71, - 142]; - -// As defined in section 5.7.4, but with a prepended zero to make this zero indexed -const OCT_LOG: [u8; 256] = [ - 0, 0, 1, 25, 2, 50, 26, 198, 3, 223, 51, 238, 27, 104, 199, 75, 4, 100, - 224, 14, 52, 141, 239, 129, 28, 193, 105, 248, 200, 8, 76, 113, 5, - 138, 101, 47, 225, 36, 15, 33, 53, 147, 142, 218, 240, 18, 130, 69, - 29, 181, 194, 125, 106, 39, 249, 185, 201, 154, 9, 120, 77, 228, 114, - 166, 6, 191, 139, 98, 102, 221, 48, 253, 226, 152, 37, 179, 16, 145, - 34, 136, 54, 208, 148, 206, 143, 150, 219, 189, 241, 210, 19, 92, - 131, 56, 70, 64, 30, 66, 182, 163, 195, 72, 126, 110, 107, 58, 40, - 84, 250, 133, 186, 61, 202, 94, 155, 159, 10, 21, 121, 43, 78, 212, - 229, 172, 115, 243, 167, 87, 7, 112, 192, 247, 140, 128, 99, 13, 103, - 74, 222, 237, 49, 197, 254, 24, 227, 165, 153, 119, 38, 184, 180, - 124, 17, 68, 146, 217, 35, 32, 137, 46, 55, 63, 209, 91, 149, 188, - 207, 205, 144, 135, 151, 178, 220, 252, 190, 97, 242, 86, 211, 171, - 20, 42, 93, 158, 132, 60, 57, 83, 71, 109, 65, 162, 31, 45, 67, 216, - 183, 123, 164, 118, 196, 23, 73, 236, 127, 12, 111, 246, 108, 161, - 59, 82, 41, 157, 85, 170, 251, 96, 134, 177, 187, 204, 62, 90, 203, - 89, 95, 176, 156, 169, 160, 81, 11, 245, 22, 235, 122, 117, 44, 215, - 79, 174, 213, 233, 230, 231, 173, 232, 116, 214, 244, 234, 168, 80, - 88, 175]; - -// TODO: rewrite to use Octet #[derive(Clone, Debug, PartialEq)] pub struct Symbol { - pub value: Vec + value: Vec } impl Symbol { pub fn new(value: Vec) -> Symbol { Symbol { - value + value: value.iter().map(|&x| Octet::from(x)).collect() } } pub fn zero(size: usize) -> Symbol { Symbol { - value: vec![0; size] + value: vec![Octet::zero(); size] } } + pub fn len(&self) -> usize { + self.value.len() + } + + pub fn bytes(&self) -> Vec { + self.value.iter().map(|octet| octet.clone().into()).collect() + } + pub fn mul_scalar(&self, scalar: &Octet) -> Symbol { self.clone() * Symbol { - value: vec![scalar.clone().into(); self.value.len()] + value: vec![scalar.clone(); self.value.len()] } } } @@ -95,8 +43,7 @@ impl Add for Symbol { fn add(self, other: Symbol) -> Symbol { let mut result = Vec::with_capacity(self.value.len()); for i in 0..self.value.len() { - // As defined in section 5.7.2, addition on octets is implemented as bitxor - result.push(self.value[i] ^ other.value[i]); + result.push(self.value[i].clone() + other.value[i].clone()); } Symbol { value: result @@ -107,7 +54,7 @@ impl Add for Symbol { impl AddAssign for Symbol { fn add_assign(&mut self, other: Symbol) { for i in 0..self.value.len() { - self.value[i] ^= other.value[i]; + self.value[i] += other.value[i].clone(); } } } @@ -118,15 +65,7 @@ impl Mul for Symbol { fn mul(self, other: Symbol) -> Symbol { let mut result = Vec::with_capacity(self.value.len()); for i in 0..self.value.len() { - // As defined in section 5.7.2, multiplication is implemented via the tables above - if self.value[i] == 0 || other.value[i] == 0 { - result.push(0); - } - else { - let log_u = OCT_LOG[self.value[i] as usize] as usize; - let log_v = OCT_LOG[other.value[i] as usize] as usize; - result.push(OCT_EXP[log_u + log_v]); - } + result.push(self.value[i].clone() * other.value[i].clone()) } Symbol { value: result @@ -140,16 +79,7 @@ impl Div for Symbol { fn div(self, rhs: Symbol) -> Symbol { let mut result = Vec::with_capacity(self.value.len()); for i in 0..self.value.len() { - assert_ne!(0, rhs.value[i]); - // As defined in section 5.7.2, division is implemented via the tables above - if self.value[i] == 0 { - result.push(0); - } - else { - let log_u = OCT_LOG[self.value[i] as usize] as usize; - let log_v = OCT_LOG[rhs.value[i] as usize] as usize; - result.push(OCT_EXP[255 + log_u - log_v]); - } + result.push(self.value[i].clone() / rhs.value[i].clone()) } Symbol { value: result @@ -171,15 +101,10 @@ mod tests { for i in 0..elements { data[i] = rand::thread_rng().gen(); } - let symbol = Symbol { - value: data - }; + let symbol = Symbol::new(data); let symbol2 = symbol.clone(); - let zero = Symbol { - value: vec![0, 0, 0, 0] - }; // See section 5.7.2. u is its own additive inverse - assert_eq!(zero, symbol + symbol2); + assert_eq!(Symbol::zero(elements), symbol + symbol2); } #[test] @@ -189,12 +114,8 @@ mod tests { for i in 0..elements { data[i] = rand::thread_rng().gen(); } - let symbol = Symbol { - value: data - }; - let one = Symbol { - value: vec![1, 1, 1, 1] - }; + let symbol = Symbol::new(data); + let one = Symbol::new(vec![1, 1, 1, 1]); assert_eq!(symbol, symbol.clone() * one); } @@ -205,12 +126,8 @@ mod tests { for i in 0..elements { data[i] = rand::thread_rng().gen(); } - let symbol = Symbol { - value: data - }; - let one = Symbol { - value: vec![1, 1, 1, 1] - }; + let symbol = Symbol::new(data); + let one = Symbol::new(vec![1, 1, 1, 1]); assert_eq!(one.clone(), symbol.clone() * (one.clone() / symbol.clone())); } @@ -221,13 +138,9 @@ mod tests { for i in 0..elements { data[i] = rand::thread_rng().gen(); } - let symbol = Symbol { - value: data - }; + let symbol = Symbol::new(data); let symbol2 = symbol.clone(); - let one = Symbol { - value: vec![1, 1, 1, 1] - }; + let one = Symbol::new(vec![1, 1, 1, 1]); assert_eq!(one, symbol / symbol2); } }