MeiliSearch/milli/src/search/new/query_term/mod.rs

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mod compute_derivations;
mod ntypo_subset;
mod parse_query;
mod phrase;
use std::collections::BTreeSet;
use std::iter::FromIterator;
use std::ops::RangeInclusive;
use either::Either;
pub use ntypo_subset::NTypoTermSubset;
pub use parse_query::{located_query_terms_from_tokens, make_ngram, number_of_typos_allowed};
pub use phrase::Phrase;
use super::interner::{DedupInterner, Interned};
use super::{limits, SearchContext, Word};
use crate::Result;
/// A set of word derivations attached to a location in the search query.
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct LocatedQueryTermSubset {
pub term_subset: QueryTermSubset,
pub positions: RangeInclusive<u16>,
pub term_ids: RangeInclusive<u8>,
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct QueryTermSubset {
original: Interned<QueryTerm>,
zero_typo_subset: NTypoTermSubset,
one_typo_subset: NTypoTermSubset,
two_typo_subset: NTypoTermSubset,
/// `true` if the term cannot be deleted through the term matching strategy
///
/// Note that there are other reasons for which a term cannot be deleted, such as
/// being a phrase. In that case, this field could be set to `false`, but it
/// still wouldn't be deleteable by the term matching strategy.
mandatory: bool,
}
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct QueryTerm {
original: Interned<String>,
ngram_words: Option<Vec<Interned<String>>>,
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max_levenshtein_distance: u8,
is_prefix: bool,
zero_typo: ZeroTypoTerm,
// May not be computed yet
one_typo: Lazy<OneTypoTerm>,
// May not be computed yet
two_typo: Lazy<TwoTypoTerm>,
}
// SubTerms will be in a dedup interner
#[derive(Default, Clone, PartialEq, Eq, Hash)]
struct ZeroTypoTerm {
/// The original phrase, if any
phrase: Option<Interned<Phrase>>,
/// A single word equivalent to the original term, with zero typos
exact: Option<Interned<String>>,
/// All the words that contain the original word as prefix
prefix_of: BTreeSet<Interned<String>>,
/// All the synonyms of the original word or phrase
synonyms: BTreeSet<Interned<Phrase>>,
/// A prefix in the prefix databases matching the original word
use_prefix_db: Option<Interned<String>>,
}
#[derive(Default, Clone, PartialEq, Eq, Hash)]
struct OneTypoTerm {
/// The original word split into multiple consecutive words
split_words: Option<Interned<Phrase>>,
/// Words that are 1 typo away from the original word
one_typo: BTreeSet<Interned<String>>,
}
#[derive(Default, Clone, PartialEq, Eq, Hash)]
struct TwoTypoTerm {
/// Words that are 2 typos away from the original word
two_typos: BTreeSet<Interned<String>>,
}
#[derive(Clone, PartialEq, Eq, Hash)]
pub enum Lazy<T> {
Uninit,
Init(T),
}
impl<T> Lazy<T> {
pub fn is_init(&self) -> bool {
match self {
Lazy::Uninit => false,
Lazy::Init(_) => true,
}
}
pub fn is_uninit(&self) -> bool {
match self {
Lazy::Uninit => true,
Lazy::Init(_) => false,
}
}
}
#[derive(Clone, Copy)]
pub enum ExactTerm {
Phrase(Interned<Phrase>),
Word(Interned<String>),
}
impl ExactTerm {
pub fn interned_words<'ctx>(
&self,
ctx: &'ctx SearchContext<'ctx>,
) -> impl Iterator<Item = Option<Interned<String>>> + 'ctx {
match *self {
ExactTerm::Phrase(phrase) => {
let phrase = ctx.phrase_interner.get(phrase);
Either::Left(phrase.words.iter().copied())
}
ExactTerm::Word(word) => Either::Right(std::iter::once(Some(word))),
}
}
}
impl QueryTermSubset {
pub fn is_mandatory(&self) -> bool {
self.mandatory
}
pub fn make_mandatory(&mut self) {
self.mandatory = true;
}
pub fn exact_term(&self, ctx: &SearchContext) -> Option<ExactTerm> {
let full_query_term = ctx.term_interner.get(self.original);
if full_query_term.ngram_words.is_some() {
return None;
}
if let Some(phrase) = full_query_term.zero_typo.phrase {
self.zero_typo_subset.contains_phrase(phrase).then_some(ExactTerm::Phrase(phrase))
} else if let Some(word) = full_query_term.zero_typo.exact {
self.zero_typo_subset.contains_word(word).then_some(ExactTerm::Word(word))
} else {
None
}
}
pub fn empty(for_term: Interned<QueryTerm>) -> Self {
Self {
original: for_term,
zero_typo_subset: NTypoTermSubset::Nothing,
one_typo_subset: NTypoTermSubset::Nothing,
two_typo_subset: NTypoTermSubset::Nothing,
mandatory: false,
}
}
pub fn full(for_term: Interned<QueryTerm>) -> Self {
Self {
original: for_term,
zero_typo_subset: NTypoTermSubset::All,
one_typo_subset: NTypoTermSubset::All,
two_typo_subset: NTypoTermSubset::All,
mandatory: false,
}
}
pub fn union(&mut self, other: &Self) {
assert!(self.original == other.original);
self.zero_typo_subset.union(&other.zero_typo_subset);
self.one_typo_subset.union(&other.one_typo_subset);
self.two_typo_subset.union(&other.two_typo_subset);
}
pub fn intersect(&mut self, other: &Self) {
assert!(self.original == other.original);
self.zero_typo_subset.intersect(&other.zero_typo_subset);
self.one_typo_subset.intersect(&other.one_typo_subset);
self.two_typo_subset.intersect(&other.two_typo_subset);
}
pub fn use_prefix_db(&self, ctx: &SearchContext) -> Option<Word> {
let original = ctx.term_interner.get(self.original);
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let use_prefix_db = original.zero_typo.use_prefix_db?;
let word = match &self.zero_typo_subset {
NTypoTermSubset::All => Some(use_prefix_db),
NTypoTermSubset::Subset { words, phrases: _ } => {
if words.contains(&use_prefix_db) {
Some(use_prefix_db)
} else {
None
}
}
NTypoTermSubset::Nothing => None,
};
word.map(|word| {
if original.ngram_words.is_some() {
Word::Derived(word)
} else {
Word::Original(word)
}
})
}
pub fn all_single_words_except_prefix_db(
&self,
ctx: &mut SearchContext,
) -> Result<BTreeSet<Word>> {
let mut result = BTreeSet::default();
if !self.one_typo_subset.is_empty() || !self.two_typo_subset.is_empty() {
self.original.compute_fully_if_needed(ctx)?;
}
let original = ctx.term_interner.get_mut(self.original);
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match &self.zero_typo_subset {
NTypoTermSubset::All => {
let ZeroTypoTerm {
phrase: _,
exact: zero_typo,
prefix_of,
synonyms: _,
use_prefix_db: _,
} = &original.zero_typo;
result.extend(zero_typo.iter().copied().map(|w| {
if original.ngram_words.is_some() {
Word::Derived(w)
} else {
Word::Original(w)
}
}));
result.extend(prefix_of.iter().copied().map(|w| {
if original.ngram_words.is_some() {
Word::Derived(w)
} else {
Word::Original(w)
}
}));
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}
NTypoTermSubset::Subset { words, phrases: _ } => {
let ZeroTypoTerm {
phrase: _,
exact: zero_typo,
prefix_of,
synonyms: _,
use_prefix_db: _,
} = &original.zero_typo;
if let Some(zero_typo) = zero_typo {
if words.contains(zero_typo) {
if original.ngram_words.is_some() {
result.insert(Word::Derived(*zero_typo));
} else {
result.insert(Word::Original(*zero_typo));
}
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}
}
result.extend(prefix_of.intersection(words).copied().map(|w| {
if original.ngram_words.is_some() {
Word::Derived(w)
} else {
Word::Original(w)
}
}));
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}
NTypoTermSubset::Nothing => {}
}
match &self.one_typo_subset {
NTypoTermSubset::All => {
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let Lazy::Init(OneTypoTerm { split_words: _, one_typo }) = &original.one_typo
else {
panic!()
};
result.extend(one_typo.iter().copied().map(Word::Derived))
}
NTypoTermSubset::Subset { words, phrases: _ } => {
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let Lazy::Init(OneTypoTerm { split_words: _, one_typo }) = &original.one_typo
else {
panic!()
};
result.extend(one_typo.intersection(words).copied().map(Word::Derived));
}
NTypoTermSubset::Nothing => {}
};
match &self.two_typo_subset {
NTypoTermSubset::All => {
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let Lazy::Init(TwoTypoTerm { two_typos }) = &original.two_typo else { panic!() };
result.extend(two_typos.iter().copied().map(Word::Derived));
}
NTypoTermSubset::Subset { words, phrases: _ } => {
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let Lazy::Init(TwoTypoTerm { two_typos }) = &original.two_typo else { panic!() };
result.extend(two_typos.intersection(words).copied().map(Word::Derived));
}
NTypoTermSubset::Nothing => {}
};
Ok(result)
}
pub fn all_phrases(&self, ctx: &mut SearchContext) -> Result<BTreeSet<Interned<Phrase>>> {
let mut result = BTreeSet::default();
if !self.one_typo_subset.is_empty() {
self.original.compute_fully_if_needed(ctx)?;
}
let original = ctx.term_interner.get_mut(self.original);
let ZeroTypoTerm { phrase, exact: _, prefix_of: _, synonyms, use_prefix_db: _ } =
&original.zero_typo;
result.extend(phrase.iter().copied());
result.extend(synonyms.iter().copied());
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match &self.one_typo_subset {
NTypoTermSubset::All => {
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let Lazy::Init(OneTypoTerm { split_words, one_typo: _ }) = &original.one_typo
else {
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panic!();
};
result.extend(split_words.iter().copied());
}
NTypoTermSubset::Subset { phrases, .. } => {
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let Lazy::Init(OneTypoTerm { split_words, one_typo: _ }) = &original.one_typo
else {
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panic!();
};
if let Some(split_words) = split_words {
if phrases.contains(split_words) {
result.insert(*split_words);
}
}
}
NTypoTermSubset::Nothing => {}
}
Ok(result)
}
pub fn original_phrase(&self, ctx: &SearchContext) -> Option<Interned<Phrase>> {
let t = ctx.term_interner.get(self.original);
if let Some(p) = t.zero_typo.phrase {
if self.zero_typo_subset.contains_phrase(p) {
return Some(p);
}
}
None
}
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pub fn max_typo_cost(&self, ctx: &SearchContext) -> u8 {
let t = ctx.term_interner.get(self.original);
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match t.max_levenshtein_distance {
0 => {
if t.allows_split_words() {
1
} else {
0
}
}
1 => {
if self.one_typo_subset.is_empty() {
0
} else {
1
}
}
2 => {
if self.two_typo_subset.is_empty() {
if self.one_typo_subset.is_empty() {
0
} else {
1
}
} else {
2
}
}
_ => panic!(),
}
}
pub fn keep_only_exact_term(&mut self, ctx: &SearchContext) {
if let Some(term) = self.exact_term(ctx) {
match term {
ExactTerm::Phrase(p) => {
self.zero_typo_subset = NTypoTermSubset::Subset {
words: BTreeSet::new(),
phrases: BTreeSet::from_iter([p]),
};
self.clear_one_typo_subset();
self.clear_two_typo_subset();
}
ExactTerm::Word(w) => {
self.zero_typo_subset = NTypoTermSubset::Subset {
words: BTreeSet::from_iter([w]),
phrases: BTreeSet::new(),
};
self.clear_one_typo_subset();
self.clear_two_typo_subset();
}
}
}
}
pub fn clear_zero_typo_subset(&mut self) {
self.zero_typo_subset = NTypoTermSubset::Nothing;
}
pub fn clear_one_typo_subset(&mut self) {
self.one_typo_subset = NTypoTermSubset::Nothing;
}
pub fn clear_two_typo_subset(&mut self) {
self.two_typo_subset = NTypoTermSubset::Nothing;
}
pub fn description(&self, ctx: &SearchContext) -> String {
let t = ctx.term_interner.get(self.original);
ctx.word_interner.get(t.original).to_owned()
}
}
impl ZeroTypoTerm {
fn is_empty(&self) -> bool {
let ZeroTypoTerm { phrase, exact: zero_typo, prefix_of, synonyms, use_prefix_db } = self;
phrase.is_none()
&& zero_typo.is_none()
&& prefix_of.is_empty()
&& synonyms.is_empty()
&& use_prefix_db.is_none()
}
}
impl OneTypoTerm {
fn is_empty(&self) -> bool {
let OneTypoTerm { split_words, one_typo } = self;
one_typo.is_empty() && split_words.is_none()
}
}
impl TwoTypoTerm {
fn is_empty(&self) -> bool {
let TwoTypoTerm { two_typos } = self;
two_typos.is_empty()
}
}
impl QueryTerm {
fn is_empty(&self) -> bool {
let Lazy::Init(one_typo) = &self.one_typo else {
return false;
};
let Lazy::Init(two_typo) = &self.two_typo else {
return false;
};
self.zero_typo.is_empty() && one_typo.is_empty() && two_typo.is_empty()
}
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fn allows_split_words(&self) -> bool {
self.zero_typo.phrase.is_none()
}
}
impl Interned<QueryTerm> {
/// Return the original word from the given query term
fn original_single_word(self, ctx: &SearchContext) -> Option<Interned<String>> {
let self_ = ctx.term_interner.get(self);
if self_.ngram_words.is_some() {
None
} else {
Some(self_.original)
}
}
}
/// A query term coupled with its position in the user's search query.
#[derive(Clone)]
pub struct LocatedQueryTerm {
pub value: Interned<QueryTerm>,
pub positions: RangeInclusive<u16>,
}
impl LocatedQueryTerm {
/// Return `true` iff the term is empty
pub fn is_empty(&self, interner: &DedupInterner<QueryTerm>) -> bool {
interner.get(self.value).is_empty()
}
}
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impl QueryTerm {
pub fn is_cached_prefix(&self) -> bool {
self.zero_typo.use_prefix_db.is_some()
}
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pub fn is_prefix(&self) -> bool {
self.is_prefix
}
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pub fn original_word(&self, ctx: &SearchContext) -> String {
ctx.word_interner.get(self.original).clone()
}
pub fn all_computed_derivations(&self) -> (Vec<Interned<String>>, Vec<Interned<Phrase>>) {
let mut words = BTreeSet::new();
let mut phrases = BTreeSet::new();
let ZeroTypoTerm { phrase, exact: zero_typo, prefix_of, synonyms, use_prefix_db: _ } =
&self.zero_typo;
words.extend(zero_typo.iter().copied());
words.extend(prefix_of.iter().copied());
phrases.extend(phrase.iter().copied());
phrases.extend(synonyms.iter().copied());
if let Lazy::Init(OneTypoTerm { split_words, one_typo }) = &self.one_typo {
words.extend(one_typo.iter().copied());
phrases.extend(split_words.iter().copied());
};
if let Lazy::Init(TwoTypoTerm { two_typos }) = &self.two_typo {
words.extend(two_typos.iter().copied());
};
(words.into_iter().collect(), phrases.into_iter().collect())
}
}