ld-lucivy 0.26.1

BM25 search engine with cross-token fuzzy matching, substring search, regex, and highlights
Documentation 
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

use std::cell::RefCell;

use crate::docset::DocSet;
use crate::postings::Postings;
use crate::query::BitSetDocSet;
use crate::DocId;

/// Creates a `Posting` that uses the bitset for hits and the docsets for PostingLists.
///
/// It is used for the regex phrase query, where we need the union of a large amount of
/// terms, but need to keep the docsets for the postings.
pub struct BitSetPostingUnion<TDocSet> {
    /// The docsets are required to load positions
    ///
    /// RefCell because we mutate in term_freq
    docsets: RefCell<Vec<TDocSet>>,
    /// The already unionized BitSet of the docsets
    bitset: BitSetDocSet,
}

impl<TDocSet: DocSet> BitSetPostingUnion<TDocSet> {
    pub(crate) fn build(
        docsets: Vec<TDocSet>,
        bitset: BitSetDocSet,
    ) -> BitSetPostingUnion<TDocSet> {
        BitSetPostingUnion {
            docsets: RefCell::new(docsets),
            bitset,
        }
    }
}

impl<TDocSet: Postings> Postings for BitSetPostingUnion<TDocSet> {
    fn term_freq(&self) -> u32 {
        let curr_doc = self.bitset.doc();
        let mut term_freq = 0;
        let mut docsets = self.docsets.borrow_mut();
        for docset in docsets.iter_mut() {
            if docset.doc() < curr_doc {
                docset.seek(curr_doc);
            }
            if docset.doc() == curr_doc {
                term_freq += docset.term_freq();
            }
        }
        term_freq
    }

    fn append_positions_with_offset(&mut self, offset: u32, output: &mut Vec<u32>) {
        let curr_doc = self.bitset.doc();
        let mut docsets = self.docsets.borrow_mut();
        for docset in docsets.iter_mut() {
            if docset.doc() < curr_doc {
                docset.seek(curr_doc);
            }
            if docset.doc() == curr_doc {
                docset.append_positions_with_offset(offset, output);
            }
        }
        debug_assert!(
            !output.is_empty(),
            "this method should only be called if positions are available"
        );
        output.sort_unstable();
        output.dedup();
    }

    fn append_offsets(&mut self, output: &mut Vec<(u32, u32)>) {
        let curr_doc = self.bitset.doc();
        let mut docsets = self.docsets.borrow_mut();
        for docset in docsets.iter_mut() {
            if docset.doc() < curr_doc {
                docset.seek(curr_doc);
            }
            if docset.doc() == curr_doc {
                docset.append_offsets(output);
            }
        }
        output.sort_unstable_by_key(|&(from, _)| from);
        output.dedup();
    }

    fn append_positions_and_offsets(&mut self, offset: u32, output: &mut Vec<(u32, u32, u32)>) {
        let base = output.len();
        let curr_doc = self.bitset.doc();
        let mut docsets = self.docsets.borrow_mut();
        for docset in docsets.iter_mut() {
            if docset.doc() < curr_doc {
                docset.seek(curr_doc);
            }
            if docset.doc() == curr_doc {
                docset.append_positions_and_offsets(offset, output);
            }
        }
        output[base..].sort_unstable_by_key(|&(pos, _, _)| pos);
        // Dedup by position (slice doesn't have dedup_by_key)
        let mut write = base;
        for read in base..output.len() {
            if write == base || output[read].0 != output[write - 1].0 {
                output[write] = output[read];
                write += 1;
            }
        }
        output.truncate(write);
    }
}

impl<TDocSet: DocSet> DocSet for BitSetPostingUnion<TDocSet> {
    fn advance(&mut self) -> DocId {
        self.bitset.advance()
    }

    fn seek(&mut self, target: DocId) -> DocId {
        self.bitset.seek(target)
    }

    fn doc(&self) -> DocId {
        self.bitset.doc()
    }

    fn size_hint(&self) -> u32 {
        self.bitset.size_hint()
    }

    fn count_including_deleted(&mut self) -> u32 {
        self.bitset.count_including_deleted()
    }
}