strings.rs

  1use crate::{
  2    matcher::{Match, MatchCandidate, Matcher},
  3    CharBag,
  4};
  5use gpui::BackgroundExecutor;
  6use std::{
  7    borrow::Cow,
  8    cmp::{self, Ordering},
  9    iter,
 10    ops::Range,
 11    sync::atomic::AtomicBool,
 12};
 13
 14#[derive(Clone, Debug)]
 15pub struct StringMatchCandidate {
 16    pub id: usize,
 17    pub string: String,
 18    pub char_bag: CharBag,
 19}
 20
 21impl Match for StringMatch {
 22    fn score(&self) -> f64 {
 23        self.score
 24    }
 25
 26    fn set_positions(&mut self, positions: Vec<usize>) {
 27        self.positions = positions;
 28    }
 29}
 30
 31impl StringMatchCandidate {
 32    pub fn new(id: usize, string: String) -> Self {
 33        Self {
 34            id,
 35            char_bag: CharBag::from(string.as_str()),
 36            string,
 37        }
 38    }
 39}
 40
 41impl<'a> MatchCandidate for &'a StringMatchCandidate {
 42    fn has_chars(&self, bag: CharBag) -> bool {
 43        self.char_bag.is_superset(bag)
 44    }
 45
 46    fn to_string(&self) -> Cow<'a, str> {
 47        self.string.as_str().into()
 48    }
 49}
 50
 51#[derive(Clone, Debug)]
 52pub struct StringMatch {
 53    pub candidate_id: usize,
 54    pub score: f64,
 55    pub positions: Vec<usize>,
 56    pub string: String,
 57}
 58
 59impl StringMatch {
 60    pub fn ranges(&self) -> impl '_ + Iterator<Item = Range<usize>> {
 61        let mut positions = self.positions.iter().peekable();
 62        iter::from_fn(move || {
 63            if let Some(start) = positions.next().copied() {
 64                if start >= self.string.len() {
 65                    log::error!(
 66                        "Invariant violation: Index {start} out of range in string {:?}",
 67                        self.string
 68                    );
 69                    return None;
 70                }
 71                let mut end = start + self.char_len_at_index(start);
 72                while let Some(next_start) = positions.peek() {
 73                    if end == **next_start {
 74                        if end >= self.string.len() {
 75                            log::error!(
 76                                "Invariant violation: Index {end} out of range in string {:?}",
 77                                self.string
 78                            );
 79                            return None;
 80                        }
 81                        end += self.char_len_at_index(end);
 82                        positions.next();
 83                    } else {
 84                        break;
 85                    }
 86                }
 87
 88                return Some(start..end);
 89            }
 90            None
 91        })
 92    }
 93
 94    fn char_len_at_index(&self, ix: usize) -> usize {
 95        self.string[ix..].chars().next().unwrap().len_utf8()
 96    }
 97}
 98
 99impl PartialEq for StringMatch {
100    fn eq(&self, other: &Self) -> bool {
101        self.cmp(other).is_eq()
102    }
103}
104
105impl Eq for StringMatch {}
106
107impl PartialOrd for StringMatch {
108    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
109        Some(self.cmp(other))
110    }
111}
112
113impl Ord for StringMatch {
114    fn cmp(&self, other: &Self) -> Ordering {
115        self.score
116            .partial_cmp(&other.score)
117            .unwrap_or(Ordering::Equal)
118            .then_with(|| self.candidate_id.cmp(&other.candidate_id))
119    }
120}
121
122pub async fn match_strings(
123    candidates: &[StringMatchCandidate],
124    query: &str,
125    smart_case: bool,
126    max_results: usize,
127    cancel_flag: &AtomicBool,
128    executor: BackgroundExecutor,
129) -> Vec<StringMatch> {
130    if candidates.is_empty() || max_results == 0 {
131        return Default::default();
132    }
133
134    if query.is_empty() {
135        return candidates
136            .iter()
137            .map(|candidate| StringMatch {
138                candidate_id: candidate.id,
139                score: 0.,
140                positions: Default::default(),
141                string: candidate.string.clone(),
142            })
143            .collect();
144    }
145
146    let lowercase_query = query.to_lowercase().chars().collect::<Vec<_>>();
147    let query = query.chars().collect::<Vec<_>>();
148
149    let lowercase_query = &lowercase_query;
150    let query = &query;
151    let query_char_bag = CharBag::from(&lowercase_query[..]);
152
153    let num_cpus = executor.num_cpus().min(candidates.len());
154    let segment_size = (candidates.len() + num_cpus - 1) / num_cpus;
155    let mut segment_results = (0..num_cpus)
156        .map(|_| Vec::with_capacity(max_results.min(candidates.len())))
157        .collect::<Vec<_>>();
158
159    executor
160        .scoped(|scope| {
161            for (segment_idx, results) in segment_results.iter_mut().enumerate() {
162                let cancel_flag = &cancel_flag;
163                scope.spawn(async move {
164                    let segment_start = cmp::min(segment_idx * segment_size, candidates.len());
165                    let segment_end = cmp::min(segment_start + segment_size, candidates.len());
166                    let mut matcher = Matcher::new(
167                        query,
168                        lowercase_query,
169                        query_char_bag,
170                        smart_case,
171                        max_results,
172                    );
173
174                    matcher.match_candidates(
175                        &[],
176                        &[],
177                        candidates[segment_start..segment_end].iter(),
178                        results,
179                        cancel_flag,
180                        |candidate, score| StringMatch {
181                            candidate_id: candidate.id,
182                            score,
183                            positions: Vec::new(),
184                            string: candidate.string.to_string(),
185                        },
186                    );
187                });
188            }
189        })
190        .await;
191
192    let mut results = Vec::new();
193    for segment_result in segment_results {
194        if results.is_empty() {
195            results = segment_result;
196        } else {
197            util::extend_sorted(&mut results, segment_result, max_results, |a, b| b.cmp(a));
198        }
199    }
200    results
201}