Files
succinct_rs
internal_data_structure
popcount_table.rsraw_bit_vector.rs
louds
louds.rslouds_builder.rslouds_index.rslouds_node_num.rs
succinct_bit_vector
block.rsblocks.rschunk.rschunks.rssuccinct_bit_vector.rssuccinct_bit_vector_builder.rs
bit_string.rsinternal_data_structure.rslib.rslouds.rssuccinct_bit_vector.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

use super::{Chunk, Chunks};
use crate::internal_data_structure::raw_bit_vector::RawBitVector;

impl super::Chunks {
    /// Constructor.
    pub fn new(rbv: &RawBitVector) -> Self {
        let n = rbv.length();
        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);
        for i_chunk in 0..(chunks_cnt as usize) {
            let this_chunk_size: u16 = if i_chunk as u64 == 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.copy_sub(i_chunk as u64 * chunk_size as u64, this_chunk_size as u64);

            let popcnt_in_chunk = chunk_rbv.popcount();
            let chunk = Chunk::new(
                popcnt_in_chunk
                    + if i_chunk == 0 {
                        0
                    } else {
                        chunks[i_chunk - 1].value
                    },
                this_chunk_size,
                rbv,
                i_chunk as u64,
            );
            chunks.push(chunk);
        }
        Self { 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::super::BitString;
    use super::Chunks;
    use crate::internal_data_structure::raw_bit_vector::RawBitVector;

    struct Input<'a> {
        in_s: &'a str,
        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::from_bit_string(&BitString::new(input.in_s));
                let n = rbv.length();
                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 {
            in_s: "0", // N = 1, (log_2(N))^2 = 1
            expected_chunk_size: 1,
            expected_chunks: &vec!(0)
        },
        t2: Input {
            in_s: "1", // N = 1, (log_2(N))^2 = 1
            expected_chunk_size: 1,
            expected_chunks: &vec!(1)
        },
        t3: Input {
            in_s: "0111", // N = 2^2, (log_2(N))^2 = 4
            expected_chunk_size: 4,
            expected_chunks: &vec!(3)
        },
        t4: Input {
            in_s: "0111_1101", // N = 2^3, (log_2(N))^2 = 9
            expected_chunk_size: 9,
            expected_chunks: &vec!(6)
        },
        t5: Input {
            in_s: "0111_1101_1", // N = 2^3 + 1, (log_2(N))^2 = 9
            expected_chunk_size: 9,
            expected_chunks: &vec!(7)
        },
        t6: Input {
            in_s: "0111_1101_11", // N = 2^3 + 2, (log_2(N))^2 = 9
            expected_chunk_size: 9,
            expected_chunks: &vec!(7, 8)
        },

        bugfix_11: Input {
            in_s: "11", // N = 2^1, (log_2(N))^2 = 4
            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 {
            in_s: "11110110_11010101_01000101_11101111_10101011_10100101_0__1100011_00110100_01010101_10010000_01001100_10111111_00__110011_00111110_01110101_11011100", // N = 8 * 16 = 2^7, (log_2(N))^2 = 49
            expected_chunk_size: 49,
            expected_chunks: &vec!(30, 53, 72)
        },
    }
}