MeiliSearch/milli/src/search/mod.rs

316 lines
9.6 KiB
Rust

use std::fmt;
use levenshtein_automata::{LevenshteinAutomatonBuilder as LevBuilder, DFA};
use once_cell::sync::Lazy;
use roaring::bitmap::RoaringBitmap;
pub use self::facet::{FacetDistribution, Filter, DEFAULT_VALUES_PER_FACET};
pub use self::matches::{
FormatOptions, MatchBounds, Matcher, MatcherBuilder, MatchingWord, MatchingWords,
};
use crate::{
execute_search, AscDesc, DefaultSearchLogger, DocumentId, Index, Result, SearchContext,
};
// Building these factories is not free.
static LEVDIST0: Lazy<LevBuilder> = Lazy::new(|| LevBuilder::new(0, true));
static LEVDIST1: Lazy<LevBuilder> = Lazy::new(|| LevBuilder::new(1, true));
static LEVDIST2: Lazy<LevBuilder> = Lazy::new(|| LevBuilder::new(2, true));
pub mod facet;
mod fst_utils;
mod matches;
pub mod new;
pub struct Search<'a> {
query: Option<String>,
// this should be linked to the String in the query
filter: Option<Filter<'a>>,
offset: usize,
limit: usize,
sort_criteria: Option<Vec<AscDesc>>,
terms_matching_strategy: TermsMatchingStrategy,
authorize_typos: bool,
words_limit: usize,
exhaustive_number_hits: bool,
rtxn: &'a heed::RoTxn<'a>,
index: &'a Index,
}
impl<'a> Search<'a> {
pub fn new(rtxn: &'a heed::RoTxn, index: &'a Index) -> Search<'a> {
Search {
query: None,
filter: None,
offset: 0,
limit: 20,
sort_criteria: None,
terms_matching_strategy: TermsMatchingStrategy::default(),
authorize_typos: true,
exhaustive_number_hits: false,
words_limit: 10,
rtxn,
index,
}
}
pub fn query(&mut self, query: impl Into<String>) -> &mut Search<'a> {
self.query = Some(query.into());
self
}
pub fn offset(&mut self, offset: usize) -> &mut Search<'a> {
self.offset = offset;
self
}
pub fn limit(&mut self, limit: usize) -> &mut Search<'a> {
self.limit = limit;
self
}
pub fn sort_criteria(&mut self, criteria: Vec<AscDesc>) -> &mut Search<'a> {
self.sort_criteria = Some(criteria);
self
}
pub fn terms_matching_strategy(&mut self, value: TermsMatchingStrategy) -> &mut Search<'a> {
self.terms_matching_strategy = value;
self
}
pub fn authorize_typos(&mut self, value: bool) -> &mut Search<'a> {
self.authorize_typos = value;
self
}
pub fn words_limit(&mut self, value: usize) -> &mut Search<'a> {
self.words_limit = value;
self
}
pub fn filter(&mut self, condition: Filter<'a>) -> &mut Search<'a> {
self.filter = Some(condition);
self
}
/// Force the search to exhastivelly compute the number of candidates,
/// this will increase the search time but allows finite pagination.
pub fn exhaustive_number_hits(&mut self, exhaustive_number_hits: bool) -> &mut Search<'a> {
self.exhaustive_number_hits = exhaustive_number_hits;
self
}
// TODO!
fn _is_typo_authorized(&self) -> Result<bool> {
let index_authorizes_typos = self.index.authorize_typos(self.rtxn)?;
// only authorize typos if both the index and the query allow it.
Ok(self.authorize_typos && index_authorizes_typos)
}
pub fn execute(&self) -> Result<SearchResult> {
let mut ctx = SearchContext::new(self.index, self.rtxn);
execute_search(
&mut ctx,
&self.query,
self.terms_matching_strategy,
self.exhaustive_number_hits,
&self.filter,
&self.sort_criteria,
self.offset,
self.limit,
Some(self.words_limit),
&mut DefaultSearchLogger,
&mut DefaultSearchLogger,
)
}
}
impl fmt::Debug for Search<'_> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let Search {
query,
filter,
offset,
limit,
sort_criteria,
terms_matching_strategy,
authorize_typos,
words_limit,
exhaustive_number_hits,
rtxn: _,
index: _,
} = self;
f.debug_struct("Search")
.field("query", query)
.field("filter", filter)
.field("offset", offset)
.field("limit", limit)
.field("sort_criteria", sort_criteria)
.field("terms_matching_strategy", terms_matching_strategy)
.field("authorize_typos", authorize_typos)
.field("exhaustive_number_hits", exhaustive_number_hits)
.field("words_limit", words_limit)
.finish()
}
}
#[derive(Default, Debug)]
pub struct SearchResult {
pub matching_words: MatchingWords,
pub candidates: RoaringBitmap,
// TODO those documents ids should be associated with their criteria scores.
pub documents_ids: Vec<DocumentId>,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum TermsMatchingStrategy {
// remove last word first
Last,
// all words are mandatory
All,
}
impl Default for TermsMatchingStrategy {
fn default() -> Self {
Self::Last
}
}
fn get_first(s: &str) -> &str {
match s.chars().next() {
Some(c) => &s[..c.len_utf8()],
None => panic!("unexpected empty query"),
}
}
pub fn build_dfa(word: &str, typos: u8, is_prefix: bool) -> DFA {
let lev = match typos {
0 => &LEVDIST0,
1 => &LEVDIST1,
_ => &LEVDIST2,
};
if is_prefix {
lev.build_prefix_dfa(word)
} else {
lev.build_dfa(word)
}
}
#[cfg(test)]
mod test {
use super::*;
use crate::index::tests::TempIndex;
#[cfg(feature = "default")]
#[test]
fn test_kanji_language_detection() {
let index = TempIndex::new();
index
.add_documents(documents!([
{ "id": 0, "title": "The quick (\"brown\") fox can't jump 32.3 feet, right? Brr, it's 29.3°F!" },
{ "id": 1, "title": "東京のお寿司。" },
{ "id": 2, "title": "הַשּׁוּעָל הַמָּהִיר (״הַחוּם״) לֹא יָכוֹל לִקְפֹּץ 9.94 מֶטְרִים, נָכוֹן? ברר, 1.5°C- בַּחוּץ!" }
]))
.unwrap();
let txn = index.write_txn().unwrap();
let mut search = Search::new(&txn, &index);
search.query("東京");
let SearchResult { documents_ids, .. } = search.execute().unwrap();
assert_eq!(documents_ids, vec![1]);
}
// #[test]
// fn test_is_authorized_typos() {
// let index = TempIndex::new();
// let mut txn = index.write_txn().unwrap();
// let mut search = Search::new(&txn, &index);
// // default is authorized
// assert!(search.is_typo_authorized().unwrap());
// search.authorize_typos(false);
// assert!(!search.is_typo_authorized().unwrap());
// index.put_authorize_typos(&mut txn, false).unwrap();
// txn.commit().unwrap();
// let txn = index.read_txn().unwrap();
// let mut search = Search::new(&txn, &index);
// assert!(!search.is_typo_authorized().unwrap());
// search.authorize_typos(true);
// assert!(!search.is_typo_authorized().unwrap());
// }
// #[test]
// fn test_one_typos_tolerance() {
// let fst = fst::Set::from_iter(["zealand"].iter()).unwrap().map_data(Cow::Owned).unwrap();
// let mut cache = HashMap::new();
// let found = word_derivations("zealend", false, 1, &fst, &mut cache).unwrap();
// assert_eq!(found, &[("zealand".to_string(), 1)]);
// }
// #[test]
// fn test_one_typos_first_letter() {
// let fst = fst::Set::from_iter(["zealand"].iter()).unwrap().map_data(Cow::Owned).unwrap();
// let mut cache = HashMap::new();
// let found = word_derivations("sealand", false, 1, &fst, &mut cache).unwrap();
// assert_eq!(found, &[]);
// }
// #[test]
// fn test_two_typos_tolerance() {
// let fst = fst::Set::from_iter(["zealand"].iter()).unwrap().map_data(Cow::Owned).unwrap();
// let mut cache = HashMap::new();
// let found = word_derivations("zealemd", false, 2, &fst, &mut cache).unwrap();
// assert_eq!(found, &[("zealand".to_string(), 2)]);
// }
// #[test]
// fn test_two_typos_first_letter() {
// let fst = fst::Set::from_iter(["zealand"].iter()).unwrap().map_data(Cow::Owned).unwrap();
// let mut cache = HashMap::new();
// let found = word_derivations("sealand", false, 2, &fst, &mut cache).unwrap();
// assert_eq!(found, &[("zealand".to_string(), 2)]);
// }
// #[test]
// fn test_prefix() {
// let fst = fst::Set::from_iter(["zealand"].iter()).unwrap().map_data(Cow::Owned).unwrap();
// let mut cache = HashMap::new();
// let found = word_derivations("ze", true, 0, &fst, &mut cache).unwrap();
// assert_eq!(found, &[("zealand".to_string(), 0)]);
// }
// #[test]
// fn test_bad_prefix() {
// let fst = fst::Set::from_iter(["zealand"].iter()).unwrap().map_data(Cow::Owned).unwrap();
// let mut cache = HashMap::new();
// let found = word_derivations("se", true, 0, &fst, &mut cache).unwrap();
// assert_eq!(found, &[]);
// }
// #[test]
// fn test_prefix_with_typo() {
// let fst = fst::Set::from_iter(["zealand"].iter()).unwrap().map_data(Cow::Owned).unwrap();
// let mut cache = HashMap::new();
// let found = word_derivations("zae", true, 1, &fst, &mut cache).unwrap();
// assert_eq!(found, &[("zealand".to_string(), 1)]);
// }
}