MeiliSearch/milli/src/search/mod.rs

323 lines
10 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, OrderBy, DEFAULT_VALUES_PER_FACET};
pub use self::new::matches::{FormatOptions, MatchBounds, MatcherBuilder, MatchingWords};
use self::new::{execute_vector_search, PartialSearchResult};
use crate::score_details::{ScoreDetails, ScoringStrategy};
use crate::vector::DistributionShift;
use crate::{
execute_search, filtered_universe, 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;
pub mod hybrid;
pub mod new;
pub struct Search<'a> {
query: Option<String>,
vector: Option<Vec<f32>>,
// this should be linked to the String in the query
filter: Option<Filter<'a>>,
offset: usize,
limit: usize,
sort_criteria: Option<Vec<AscDesc>>,
searchable_attributes: Option<&'a [String]>,
geo_strategy: new::GeoSortStrategy,
terms_matching_strategy: TermsMatchingStrategy,
scoring_strategy: ScoringStrategy,
words_limit: usize,
exhaustive_number_hits: bool,
/// TODO: Add semantic ratio or pass it directly to execute_hybrid()
rtxn: &'a heed::RoTxn<'a>,
index: &'a Index,
distribution_shift: Option<DistributionShift>,
embedder_name: Option<String>,
}
impl<'a> Search<'a> {
pub fn new(rtxn: &'a heed::RoTxn, index: &'a Index) -> Search<'a> {
Search {
query: None,
vector: None,
filter: None,
offset: 0,
limit: 20,
sort_criteria: None,
searchable_attributes: None,
geo_strategy: new::GeoSortStrategy::default(),
terms_matching_strategy: TermsMatchingStrategy::default(),
scoring_strategy: Default::default(),
exhaustive_number_hits: false,
words_limit: 10,
rtxn,
index,
distribution_shift: None,
embedder_name: None,
}
}
pub fn query(&mut self, query: impl Into<String>) -> &mut Search<'a> {
self.query = Some(query.into());
self
}
pub fn vector(&mut self, vector: Vec<f32>) -> &mut Search<'a> {
self.vector = Some(vector);
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 searchable_attributes(&mut self, searchable: &'a [String]) -> &mut Search<'a> {
self.searchable_attributes = Some(searchable);
self
}
pub fn terms_matching_strategy(&mut self, value: TermsMatchingStrategy) -> &mut Search<'a> {
self.terms_matching_strategy = value;
self
}
pub fn scoring_strategy(&mut self, value: ScoringStrategy) -> &mut Search<'a> {
self.scoring_strategy = 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
}
#[cfg(test)]
pub fn geo_sort_strategy(&mut self, strategy: new::GeoSortStrategy) -> &mut Search<'a> {
self.geo_strategy = strategy;
self
}
/// Forces the search to exhaustively 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
}
pub fn distribution_shift(
&mut self,
distribution_shift: Option<DistributionShift>,
) -> &mut Search<'a> {
self.distribution_shift = distribution_shift;
self
}
pub fn embedder_name(&mut self, embedder_name: impl Into<String>) -> &mut Search<'a> {
self.embedder_name = Some(embedder_name.into());
self
}
pub fn execute_for_candidates(&self, has_vector_search: bool) -> Result<RoaringBitmap> {
if has_vector_search {
let ctx = SearchContext::new(self.index, self.rtxn);
filtered_universe(&ctx, &self.filter)
} else {
Ok(self.execute()?.candidates)
}
}
pub fn execute(&self) -> Result<SearchResult> {
let embedder_name;
let embedder_name = match &self.embedder_name {
Some(embedder_name) => embedder_name,
None => {
embedder_name = self.index.default_embedding_name(self.rtxn)?;
&embedder_name
}
};
let mut ctx = SearchContext::new(self.index, self.rtxn);
if let Some(searchable_attributes) = self.searchable_attributes {
ctx.searchable_attributes(searchable_attributes)?;
}
let universe = filtered_universe(&ctx, &self.filter)?;
let PartialSearchResult { located_query_terms, candidates, documents_ids, document_scores } =
match self.vector.as_ref() {
Some(vector) => execute_vector_search(
&mut ctx,
vector,
self.scoring_strategy,
universe,
&self.sort_criteria,
self.geo_strategy,
self.offset,
self.limit,
self.distribution_shift,
embedder_name,
)?,
None => execute_search(
&mut ctx,
self.query.as_deref(),
self.terms_matching_strategy,
self.scoring_strategy,
self.exhaustive_number_hits,
universe,
&self.sort_criteria,
self.geo_strategy,
self.offset,
self.limit,
Some(self.words_limit),
&mut DefaultSearchLogger,
&mut DefaultSearchLogger,
)?,
};
// consume context and located_query_terms to build MatchingWords.
let matching_words = match located_query_terms {
Some(located_query_terms) => MatchingWords::new(ctx, located_query_terms),
None => MatchingWords::default(),
};
Ok(SearchResult { matching_words, candidates, document_scores, documents_ids })
}
}
impl fmt::Debug for Search<'_> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let Search {
query,
vector: _,
filter,
offset,
limit,
sort_criteria,
searchable_attributes,
geo_strategy: _,
terms_matching_strategy,
scoring_strategy,
words_limit,
exhaustive_number_hits,
rtxn: _,
index: _,
distribution_shift,
embedder_name,
} = self;
f.debug_struct("Search")
.field("query", query)
.field("vector", &"[...]")
.field("filter", filter)
.field("offset", offset)
.field("limit", limit)
.field("sort_criteria", sort_criteria)
.field("searchable_attributes", searchable_attributes)
.field("terms_matching_strategy", terms_matching_strategy)
.field("scoring_strategy", scoring_strategy)
.field("exhaustive_number_hits", exhaustive_number_hits)
.field("words_limit", words_limit)
.field("distribution_shift", distribution_shift)
.field("embedder_name", embedder_name)
.finish()
}
}
#[derive(Default, Debug)]
pub struct SearchResult {
pub matching_words: MatchingWords,
pub candidates: RoaringBitmap,
pub documents_ids: Vec<DocumentId>,
pub document_scores: Vec<Vec<ScoreDetails>>,
}
#[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 {
#[allow(unused_imports)]
use super::*;
#[cfg(feature = "japanese")]
#[test]
fn test_kanji_language_detection() {
use crate::index::tests::TempIndex;
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]);
}
}