fid_rs/fid/chunks.rs
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241
#[cfg(feature = "rayon")]
use rayon::prelude::*;
use super::{Chunk, Chunks};
use crate::internal_data_structure::raw_bit_vector::RawBitVector;
impl super::Chunks {
/// Constructor.
#[cfg(feature = "rayon")]
pub fn new(rbv: &RawBitVector) -> Chunks {
let n = rbv.len();
let chunk_size: u16 = Chunks::calc_chunk_size(n);
let chunks_cnt: usize = Chunks::calc_chunks_cnt(n) as usize;
// In order to use chunks.par_iter_mut(), chunks should have len first.
// So fill meaning less None value.
let mut chunks: Vec<Chunk> = Vec::with_capacity(chunks_cnt);
// Parallel - Each chunk has its popcount.
// Actually, chunk should have total popcount from index 0 but it is calculated later in sequential manner.
(0..chunks_cnt)
.into_par_iter()
.map(|number_of_chunk| {
let this_chunk_size: u16 = if number_of_chunk == chunks_cnt - 1 {
// When `chunk_size == 6`:
//
// 000 111 000 11 : rbv
// | | | : chunks
//
// Here, when `i_chunk == 1` (targeting on last '00011' chunk),
// `this_chunk_size == 5`
let chunk_size_or_0 = (n % chunk_size as u64) as u16;
if chunk_size_or_0 == 0 {
chunk_size
} else {
chunk_size_or_0
}
} else {
chunk_size
};
let chunk_rbv = rbv.clone_sub(
number_of_chunk as u64 * chunk_size as u64,
this_chunk_size as u64,
);
let popcnt_in_chunk = chunk_rbv.popcount();
Chunk::new(
popcnt_in_chunk,
this_chunk_size,
rbv,
number_of_chunk as u64,
)
})
.collect_into_vec(&mut chunks);
// Sequential - Each chunk has total popcount from index 0.
for i_chunk in 0..chunks_cnt {
chunks[i_chunk].value += if i_chunk == 0 {
0
} else {
chunks[i_chunk - 1].value
}
}
Chunks {
chunks,
chunks_cnt: chunks_cnt as u64,
}
}
/// Constructor.
#[cfg(not(feature = "rayon"))]
pub fn new(rbv: &RawBitVector) -> Chunks {
let n = rbv.len();
let chunk_size: u16 = Chunks::calc_chunk_size(n);
let chunks_cnt: u64 = Chunks::calc_chunks_cnt(n);
let mut chunks: Vec<Chunk> = Vec::with_capacity(chunks_cnt as usize);
let mut comulative_popcount = 0;
for i_chunk in 0..chunks_cnt {
let this_chunk_size: u16 = if i_chunk == chunks_cnt - 1 {
// When `chunk_size == 6`:
//
// 000 111 000 11 : rbv
// | | | : chunks
//
// Here, when `i_chunk == 1` (targeting on last '00011' chunk),
// `this_chunk_size == 5`
let chunk_size_or_0 = (n % chunk_size as u64) as u16;
if chunk_size_or_0 == 0 {
chunk_size
} else {
chunk_size_or_0
}
} else {
chunk_size
};
let chunk_rbv = rbv.clone_sub(i_chunk * chunk_size as u64, this_chunk_size as u64);
let popcnt_in_chunk = chunk_rbv.popcount();
comulative_popcount += popcnt_in_chunk;
chunks.push(Chunk::new(
comulative_popcount,
this_chunk_size,
rbv,
i_chunk,
));
}
Chunks { chunks, chunks_cnt }
}
/// Returns size of 1 chunk: _(log N)^2_.
pub fn calc_chunk_size(n: u64) -> u16 {
let lg2 = (n as f64).log2() as u16;
let sz = lg2 * lg2;
if sz == 0 {
1
} else {
sz
}
}
/// Returns count of chunks: _N / (log N)^2_.
///
/// At max: N / (log N)^2 = 2^64 / 64^2 = 2^(64-12)
pub fn calc_chunks_cnt(n: u64) -> u64 {
let chunk_size = Chunks::calc_chunk_size(n);
n / (chunk_size as u64) + if n % (chunk_size as u64) == 0 { 0 } else { 1 }
}
/// Returns i-th chunk.
///
/// # Panics
/// When _`i` >= `self.chunks_cnt()`_.
pub fn access(&self, i: u64) -> &Chunk {
assert!(
i <= self.chunks_cnt,
"i = {} must be smaller then {} (self.chunks_cnt())",
i,
self.chunks_cnt
);
&self.chunks[i as usize]
}
}
#[cfg(test)]
mod new_success_tests {
use super::Chunks;
use crate::internal_data_structure::raw_bit_vector::RawBitVector;
struct Input<'a> {
byte_slice: &'a [u8],
last_byte_len: u8,
expected_chunk_size: u16,
expected_chunks: &'a Vec<u64>,
}
macro_rules! parameterized_tests {
($($name:ident: $value:expr,)*) => {
$(
#[test]
fn $name() {
let input: Input = $value;
let rbv = RawBitVector::new(input.byte_slice, 0, input.last_byte_len);
let n = rbv.len();
let chunks = Chunks::new(&rbv);
assert_eq!(Chunks::calc_chunk_size(n), input.expected_chunk_size);
assert_eq!(Chunks::calc_chunks_cnt(n), input.expected_chunks.len() as u64);
for (i, expected_chunk) in input.expected_chunks.iter().enumerate() {
let chunk = chunks.access(i as u64);
assert_eq!(chunk.value(), *expected_chunk);
}
}
)*
}
}
parameterized_tests! {
t1: Input {
// N = 1, (log_2(N))^2 = 1
byte_slice: &[0b0000_0000],
last_byte_len: 1,
expected_chunk_size: 1,
expected_chunks: &vec!(0)
},
t2: Input {
// N = 1, (log_2(N))^2 = 1
byte_slice: &[0b1000_0000],
last_byte_len: 1,
expected_chunk_size: 1,
expected_chunks: &vec!(1)
},
t3: Input {
// N = 2^2, (log_2(N))^2 = 4
byte_slice: &[0b0111_0000],
last_byte_len: 4,
expected_chunk_size: 4,
expected_chunks: &vec!(3)
},
t4: Input {
// N = 2^3, (log_2(N))^2 = 9
byte_slice: &[0b0111_1101],
last_byte_len: 8,
expected_chunk_size: 9,
expected_chunks: &vec!(6)
},
t5: Input {
// N = 2^3 + 1, (log_2(N))^2 = 9
byte_slice: &[0b0111_1101, 0b1000_0000],
last_byte_len: 1,
expected_chunk_size: 9,
expected_chunks: &vec!(7)
},
t6: Input {
// N = 2^3 + 2, (log_2(N))^2 = 9
byte_slice: &[0b0111_1101, 0b1100_0000],
last_byte_len: 2,
expected_chunk_size: 9,
expected_chunks: &vec!(7, 8)
},
bugfix_11: Input {
// N = 2^1, (log_2(N))^2 = 4
byte_slice: &[0b1100_0000],
last_byte_len: 2,
expected_chunk_size: 1,
expected_chunks: &vec!(1, 2)
},
bugfix_11110110_11010101_01000101_11101111_10101011_10100101_01100011_00110100_01010101_10010000_01001100_10111111_00110011_00111110_01110101_11011100: Input {
// N = 8 * 16 = 2^7, (log_2(N))^2 = 49
byte_slice: &[0b11110110, 0b11010101, 0b01000101, 0b11101111, 0b10101011, 0b10100101, 0b0_1100011, 0b00110100, 0b01010101, 0b10010000, 0b01001100, 0b10111111, 0b00_110011, 0b00111110, 0b01110101, 0b11011100],
last_byte_len: 8,
expected_chunk_size: 49,
expected_chunks: &vec!(30, 53, 72)
},
}
}