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Code Issues Releases Wiki Activity

Support ngram typos + splitwords and splitwords+synonyms in proximity

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This commit is contained in:
Loïc Lecrenier 2023-03-13 17:21:29 +01:00
parent 14e8d0aaa2
commit 3004e281d7
9 changed files with 701 additions and 411 deletions
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11
milli/src/search/new/logger/detailed.rs
View File

@ -447,6 +447,8 @@ results.{random} {{
use_prefix_db,
synonyms,
split_words,
prefix_of,
is_prefix: _,
} = ctx.derivations_interner.get(*derivations);
let original = ctx.word_interner.get(*original);
@ -460,6 +462,10 @@ shape: class"
let w = ctx.word_interner.get(w);
writeln!(file, "\"{w}\" : 0").unwrap();
}
for w in prefix_of.iter().copied() {
let w = ctx.word_interner.get(w);
writeln!(file, "\"{w}\" : 0P").unwrap();
}
for w in one_typo.iter().copied() {
let w = ctx.word_interner.get(w);
writeln!(file, "\"{w}\" : 1").unwrap();
@ -478,8 +484,9 @@ shape: class"
let phrase_str = phrase.description(&ctx.word_interner);
writeln!(file, "\"{phrase_str}\" : synonym").unwrap();
}
if *use_prefix_db {
writeln!(file, "use prefix DB : true").unwrap();
if let Some(use_prefix_db) = use_prefix_db {
let p = ctx.word_interner.get(*use_prefix_db);
writeln!(file, "use prefix DB : {p}").unwrap();
}
for (d, edges) in distances.iter() {
writeln!(file, "\"distance {d}\" : {:?}", edges.iter().collect::<Vec<_>>())

68
milli/src/search/new/mod.rs
View File

@ -295,45 +295,45 @@ mod tests {
println!("nbr docids: {}", index.documents_ids(&txn).unwrap().len());
loop {
let start = Instant::now();
// loop {
let start = Instant::now();
// let mut logger = crate::search::new::logger::detailed::DetailedSearchLogger::new("log");
let mut ctx = SearchContext::new(&index, &txn);
let results = execute_search(
&mut ctx,
"zero config",
TermsMatchingStrategy::Last,
None,
0,
20,
&mut DefaultSearchLogger,
&mut DefaultSearchLogger,
)
.unwrap();
let mut logger = crate::search::new::logger::detailed::DetailedSearchLogger::new("log");
let mut ctx = SearchContext::new(&index, &txn);
let results = execute_search(
&mut ctx,
"sun flower s are the best",
TermsMatchingStrategy::Last,
None,
0,
20,
&mut DefaultSearchLogger,
&mut logger,
)
.unwrap();
// logger.write_d2_description(&mut ctx);
logger.write_d2_description(&mut ctx);
let elapsed = start.elapsed();
println!("{}us", elapsed.as_micros());
let elapsed = start.elapsed();
println!("{}us", elapsed.as_micros());
let _documents = index
.documents(&txn, results.iter().copied())
.unwrap()
.into_iter()
.map(|(id, obkv)| {
let mut object = serde_json::Map::default();
for (fid, fid_name) in index.fields_ids_map(&txn).unwrap().iter() {
let value = obkv.get(fid).unwrap();
let value: serde_json::Value = serde_json::from_slice(value).unwrap();
object.insert(fid_name.to_owned(), value);
}
(id, serde_json::to_string_pretty(&object).unwrap())
})
.collect::<Vec<_>>();
let _documents = index
.documents(&txn, results.iter().copied())
.unwrap()
.into_iter()
.map(|(id, obkv)| {
let mut object = serde_json::Map::default();
for (fid, fid_name) in index.fields_ids_map(&txn).unwrap().iter() {
let value = obkv.get(fid).unwrap();
let value: serde_json::Value = serde_json::from_slice(value).unwrap();
object.insert(fid_name.to_owned(), value);
}
(id, serde_json::to_string_pretty(&object).unwrap())
})
.collect::<Vec<_>>();
println!("{}us: {:?}", elapsed.as_micros(), results);
}
println!("{}us: {:?}", elapsed.as_micros(), results);
// }
// for (id, _document) in documents {
// println!("{id}:");
// // println!("{document}");

68
milli/src/search/new/query_graph.rs
View File

@ -1,4 +1,4 @@
use super::query_term::{self, LocatedQueryTerm, QueryTerm, WordDerivations};
use super::query_term::{self, number_of_typos_allowed, LocatedQueryTerm};
use super::small_bitmap::SmallBitmap;
use super::SearchContext;
use crate::Result;
@ -132,18 +132,18 @@ impl QueryGraph {
impl QueryGraph {
/// Build the query graph from the parsed user search query.
pub fn from_query(ctx: &mut SearchContext, terms: Vec<LocatedQueryTerm>) -> Result<QueryGraph> {
let nbr_typos = number_of_typos_allowed(ctx)?;
let mut empty_nodes = vec![];
let word_set = ctx.index.words_fst(ctx.txn)?;
let mut graph = QueryGraph::default();
// TODO: we could consider generalizing to 4,5,6,7,etc. ngrams
let (mut prev2, mut prev1, mut prev0): (Vec<u16>, Vec<u16>, Vec<u16>) =
(vec![], vec![], vec![graph.root_node]);
for length in 1..=terms.len() {
let query = &terms[..length];
let term0 = query.last().unwrap();
for term_idx in 0..terms.len() {
let term0 = &terms[term_idx];
let mut new_nodes = vec![];
let new_node_idx = graph.add_node(&prev0, QueryNode::Term(term0.clone()));
@ -153,57 +153,19 @@ impl QueryGraph {
}
if !prev1.is_empty() {
if let Some((ngram2_str, ngram2_pos)) =
query_term::ngram2(ctx, &query[length - 2], &query[length - 1])
if let Some(ngram) =
query_term::make_ngram(ctx, &terms[term_idx - 1..=term_idx], &nbr_typos)?
{
if word_set.contains(ctx.word_interner.get(ngram2_str)) {
let ngram2 = LocatedQueryTerm {
value: QueryTerm::Word {
derivations: ctx.derivations_interner.insert(WordDerivations {
original: ngram2_str,
// TODO: could add a typo if it's an ngram?
zero_typo: Box::new([ngram2_str]),
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: false,
synonyms: Box::new([]), // TODO: ngram synonyms
split_words: None, // TODO: maybe ngram split words?
}),
},
positions: ngram2_pos,
};
let ngram2_idx = graph.add_node(&prev1, QueryNode::Term(ngram2));
new_nodes.push(ngram2_idx);
}
let ngram_idx = graph.add_node(&prev1, QueryNode::Term(ngram));
new_nodes.push(ngram_idx);
}
}
if !prev2.is_empty() {
if let Some((ngram3_str, ngram3_pos)) = query_term::ngram3(
ctx,
&query[length - 3],
&query[length - 2],
&query[length - 1],
) {
if word_set.contains(ctx.word_interner.get(ngram3_str)) {
let ngram3 = LocatedQueryTerm {
value: QueryTerm::Word {
derivations: ctx.derivations_interner.insert(WordDerivations {
original: ngram3_str,
// TODO: could add a typo if it's an ngram?
zero_typo: Box::new([ngram3_str]),
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: false,
synonyms: Box::new([]), // TODO: ngram synonyms
split_words: None, // TODO: maybe ngram split words?
// would be nice for typos like su nflower
}),
},
positions: ngram3_pos,
};
let ngram3_idx = graph.add_node(&prev2, QueryNode::Term(ngram3));
new_nodes.push(ngram3_idx);
}
if let Some(ngram) =
query_term::make_ngram(ctx, &terms[term_idx - 2..=term_idx], &nbr_typos)?
{
let ngram_idx = graph.add_node(&prev2, QueryNode::Term(ngram));
new_nodes.push(ngram_idx);
}
}
(prev0, prev1, prev2) = (new_nodes, prev0, prev1);

342
milli/src/search/new/query_term.rs
View File

@ -13,7 +13,7 @@ use super::interner::{Interned, Interner};
use super::SearchContext;
use crate::search::fst_utils::{Complement, Intersection, StartsWith, Union};
use crate::search::{build_dfa, get_first};
use crate::{CboRoaringBitmapLenCodec, Index, Result};
use crate::{CboRoaringBitmapLenCodec, Index, Result, MAX_WORD_LENGTH};
/// A phrase in the user's search query, consisting of several words
/// that must appear side-by-side in the search results.
@ -31,46 +31,70 @@ impl Phrase {
/// a term in the user's search query.
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct WordDerivations {
/// The original word
/// The original terms, for debugging purposes
pub original: Interned<String>,
// TODO: original should only be used for debugging purposes?
// TODO: pub zero_typo: Option<Interned<String>>,
// TODO: pub prefix_of: Box<[Interned<String>]>,
pub is_prefix: bool,
/// A single word equivalent to the original one, with zero typos
pub zero_typo: Option<Interned<String>>,
/// All the words that contain the original word as prefix
pub prefix_of: Box<[Interned<String>]>,
/// All the synonyms of the original word
pub synonyms: Box<[Interned<Phrase>]>,
/// The original word split into multiple consecutive words
pub split_words: Option<Interned<Phrase>>,
/// The original words and words which are prefixed by it
pub zero_typo: Box<[Interned<String>]>,
/// Words that are 1 typo away from the original word
pub one_typo: Box<[Interned<String>]>,
/// Words that are 2 typos away from the original word
pub two_typos: Box<[Interned<String>]>,
/// True if the prefix databases must be used to retrieve
/// the words which are prefixed by the original word.
pub use_prefix_db: bool,
/// A prefix in the prefix databases matching the original word
pub use_prefix_db: Option<Interned<String>>,
}
impl WordDerivations {
pub fn empty(word_interner: &mut Interner<String>, original: &str) -> Self {
Self {
original: word_interner.insert(original.to_owned()),
is_prefix: false,
zero_typo: None,
prefix_of: Box::new([]),
synonyms: Box::new([]),
split_words: None,
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: None,
}
}
/// Return an iterator over all the single words derived from the original word.
///
/// This excludes synonyms, split words, and words stored in the prefix databases.
pub fn all_single_word_derivations_except_prefix_db(
&'_ self,
) -> impl Iterator<Item = Interned<String>> + Clone + '_ {
self.zero_typo.iter().chain(self.one_typo.iter()).chain(self.two_typos.iter()).copied()
self.zero_typo
.iter()
.chain(self.prefix_of.iter())
.chain(self.one_typo.iter())
.chain(self.two_typos.iter())
.copied()
}
/// Return an iterator over all the single words derived from the original word.
///
/// This excludes synonyms, split words, and words stored in the prefix databases.
pub fn all_phrase_derivations(&'_ self) -> impl Iterator<Item = Interned<Phrase>> + Clone + '_ {
self.split_words.iter().chain(self.synonyms.iter()).copied()
}
pub fn is_empty(&self) -> bool {
self.zero_typo.is_empty()
self.zero_typo.is_none()
&& self.one_typo.is_empty()
&& self.two_typos.is_empty()
&& self.prefix_of.is_empty()
&& self.synonyms.is_empty()
&& self.split_words.is_none()
&& !self.use_prefix_db
&& self.use_prefix_db.is_none()
}
}
@ -80,7 +104,11 @@ pub fn word_derivations(
word: &str,
max_typo: u8,
is_prefix: bool,
) -> Result<Interned<WordDerivations>> {
) -> Result<WordDerivations> {
if word.len() > MAX_WORD_LENGTH {
return Ok(WordDerivations::empty(&mut ctx.word_interner, word));
}
let fst = ctx.index.words_fst(ctx.txn)?;
let word_interned = ctx.word_interner.insert(word.to_owned());
@ -91,23 +119,29 @@ pub fn word_derivations(
.remap_data_type::<DecodeIgnore>()
.get(ctx.txn, word)?
.is_some();
let use_prefix_db = if use_prefix_db { Some(word_interned) } else { None };
let mut zero_typo = vec![];
let mut zero_typo = None;
let mut prefix_of = vec![];
let mut one_typo = vec![];
let mut two_typos = vec![];
if fst.contains(word) {
zero_typo = Some(word_interned);
}
if max_typo == 0 {
if is_prefix && !use_prefix_db {
if is_prefix && use_prefix_db.is_none() {
let prefix = Str::new(word).starts_with();
let mut stream = fst.search(prefix).into_stream();
while let Some(derived_word) = stream.next() {
let derived_word = std::str::from_utf8(derived_word)?.to_owned();
let derived_word_interned = ctx.word_interner.insert(derived_word);
zero_typo.push(derived_word_interned);
if derived_word_interned != word_interned {
prefix_of.push(derived_word_interned);
}
}
} else if fst.contains(word) {
zero_typo.push(word_interned);
}
} else if max_typo == 1 {
let dfa = build_dfa(word, 1, is_prefix);
@ -122,7 +156,9 @@ pub fn word_derivations(
let derived_word_interned = ctx.word_interner.insert(derived_word.to_owned());
match d.to_u8() {
0 => {
zero_typo.push(derived_word_interned);
if derived_word_interned != word_interned {
prefix_of.push(derived_word_interned);
}
}
1 => {
one_typo.push(derived_word_interned);
@ -153,7 +189,9 @@ pub fn word_derivations(
let d = second_dfa.distance((state.1).0);
match d.to_u8() {
0 => {
zero_typo.push(derived_word_interned);
if derived_word_interned != word_interned {
prefix_of.push(derived_word_interned);
}
}
1 => {
one_typo.push(derived_word_interned);
@ -185,17 +223,17 @@ pub fn word_derivations(
})
.collect();
let interned = ctx.derivations_interner.insert(WordDerivations {
original: ctx.word_interner.insert(word.to_owned()),
Ok(WordDerivations {
original: word_interned,
is_prefix,
zero_typo,
prefix_of: prefix_of.into_boxed_slice(),
synonyms,
split_words,
zero_typo: zero_typo.into_boxed_slice(),
one_typo: one_typo.into_boxed_slice(),
two_typos: two_typos.into_boxed_slice(),
use_prefix_db,
});
Ok(interned)
})
}
/// Split the original word into the two words that appear the
@ -236,12 +274,17 @@ pub enum QueryTerm {
}
impl QueryTerm {
pub fn is_prefix(&self, derivations_interner: &Interner<WordDerivations>) -> bool {
match self {
QueryTerm::Phrase { .. } => false,
QueryTerm::Word { derivations } => derivations_interner.get(*derivations).is_prefix,
}
}
/// Return the original word from the given query term
pub fn original_single_word<'interner>(
pub fn original_single_word(
&self,
word_interner: &'interner Interner<String>,
derivations_interner: &'interner Interner<WordDerivations>,
) -> Option<&'interner str> {
derivations_interner: &Interner<WordDerivations>,
) -> Option<Interned<String>> {
match self {
QueryTerm::Phrase { phrase: _ } => None,
QueryTerm::Word { derivations } => {
@ -249,7 +292,7 @@ impl QueryTerm {
if derivations.is_empty() {
None
} else {
Some(word_interner.get(derivations.original))
Some(derivations.original)
}
}
}
@ -281,25 +324,7 @@ pub fn located_query_terms_from_string<'ctx>(
query: NormalizedTokenIter<Vec<u8>>,
words_limit: Option<usize>,
) -> Result<Vec<LocatedQueryTerm>> {
let authorize_typos = ctx.index.authorize_typos(ctx.txn)?;
let min_len_one_typo = ctx.index.min_word_len_one_typo(ctx.txn)?;
let min_len_two_typos = ctx.index.min_word_len_two_typos(ctx.txn)?;
// TODO: should `exact_words` also disable prefix search, ngrams, split words, or synonyms?
let exact_words = ctx.index.exact_words(ctx.txn)?;
let nbr_typos = |word: &str| {
if !authorize_typos
|| word.len() < min_len_one_typo as usize
|| exact_words.as_ref().map_or(false, |fst| fst.contains(word))
{
0
} else if word.len() < min_len_two_typos as usize {
1
} else {
2
}
};
let nbr_typos = number_of_typos_allowed(ctx)?;
let mut located_terms = Vec::new();
@ -344,7 +369,9 @@ pub fn located_query_terms_from_string<'ctx>(
let word = token.lemma();
let derivations = word_derivations(ctx, word, nbr_typos(word), false)?;
let located_term = LocatedQueryTerm {
value: QueryTerm::Word { derivations },
value: QueryTerm::Word {
derivations: ctx.derivations_interner.insert(derivations),
},
positions: position..=position,
};
located_terms.push(located_term);
@ -355,7 +382,9 @@ pub fn located_query_terms_from_string<'ctx>(
let word = token.lemma();
let derivations = word_derivations(ctx, word, nbr_typos(word), true)?;
let located_term = LocatedQueryTerm {
value: QueryTerm::Word { derivations },
value: QueryTerm::Word {
derivations: ctx.derivations_interner.insert(derivations),
},
positions: position..=position,
};
located_terms.push(located_term);
@ -407,54 +436,171 @@ pub fn located_query_terms_from_string<'ctx>(
Ok(located_terms)
}
// TODO: return a word derivations instead?
pub fn ngram2(
ctx: &mut SearchContext,
x: &LocatedQueryTerm,
y: &LocatedQueryTerm,
) -> Option<(Interned<String>, RangeInclusive<i8>)> {
if *x.positions.end() != y.positions.start() - 1 {
return None;
}
match (
&x.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
&y.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
) {
(Some(w1), Some(w2)) => {
let term = (
ctx.word_interner.insert(format!("{w1}{w2}")),
*x.positions.start()..=*y.positions.end(),
);
Some(term)
pub fn number_of_typos_allowed<'ctx>(
ctx: &SearchContext<'ctx>,
) -> Result<impl Fn(&str) -> u8 + 'ctx> {
let authorize_typos = ctx.index.authorize_typos(ctx.txn)?;
let min_len_one_typo = ctx.index.min_word_len_one_typo(ctx.txn)?;
let min_len_two_typos = ctx.index.min_word_len_two_typos(ctx.txn)?;
// TODO: should `exact_words` also disable prefix search, ngrams, split words, or synonyms?
let exact_words = ctx.index.exact_words(ctx.txn)?;
Ok(Box::new(move |word: &str| {
if !authorize_typos
|| word.len() < min_len_one_typo as usize
|| exact_words.as_ref().map_or(false, |fst| fst.contains(word))
{
0
} else if word.len() < min_len_two_typos as usize {
1
} else {
2
}
_ => None,
}
}))
}
// TODO: return a word derivations instead?
pub fn ngram3(
pub fn make_ngram(
ctx: &mut SearchContext,
x: &LocatedQueryTerm,
y: &LocatedQueryTerm,
z: &LocatedQueryTerm,
) -> Option<(Interned<String>, RangeInclusive<i8>)> {
if *x.positions.end() != y.positions.start() - 1
|| *y.positions.end() != z.positions.start() - 1
{
return None;
}
match (
&x.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
&y.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
&z.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
) {
(Some(w1), Some(w2), Some(w3)) => {
let term = (
ctx.word_interner.insert(format!("{w1}{w2}{w3}")),
*x.positions.start()..=*z.positions.end(),
);
Some(term)
terms: &[LocatedQueryTerm],
number_of_typos_allowed: &impl Fn(&str) -> u8,
) -> Result<Option<LocatedQueryTerm>> {
assert!(!terms.is_empty());
for ts in terms.windows(2) {
let [t1, t2] = ts else { panic!() };
if *t1.positions.end() != t2.positions.start() - 1 {
return Ok(None);
}
_ => None,
}
let mut words_interned = vec![];
for term in terms {
if let Some(original_term_word) = term.value.original_single_word(&ctx.derivations_interner)
{
words_interned.push(original_term_word);
} else {
return Ok(None);
}
}
let words =
words_interned.iter().map(|&i| ctx.word_interner.get(i).to_owned()).collect::<Vec<_>>();
let start = *terms.first().as_ref().unwrap().positions.start();
let end = *terms.last().as_ref().unwrap().positions.end();
let is_prefix = terms.last().as_ref().unwrap().value.is_prefix(&ctx.derivations_interner);
let ngram_str = words.join("");
if ngram_str.len() > MAX_WORD_LENGTH {
return Ok(None);
}
let mut derivations = word_derivations(
ctx,
&ngram_str,
number_of_typos_allowed(ngram_str.as_str()).saturating_sub(terms.len() as u8),
is_prefix,
)?;
derivations.original = ctx.word_interner.insert(words.join(" "));
// Now add the synonyms
let index_synonyms = ctx.index.synonyms(ctx.txn)?;
let mut derivations_synonyms = derivations.synonyms.to_vec();
derivations_synonyms.extend(
index_synonyms.get(&words).cloned().unwrap_or_default().into_iter().map(|words| {
let words = words.into_iter().map(|w| Some(ctx.word_interner.insert(w))).collect();
ctx.phrase_interner.insert(Phrase { words })
}),
);
derivations.synonyms = derivations_synonyms.into_boxed_slice();
if let Some(split_words) = derivations.split_words {
let split_words = ctx.phrase_interner.get(split_words);
if split_words.words == words_interned.iter().map(|&i| Some(i)).collect::<Vec<_>>() {
derivations.split_words = None;
}
}
if derivations.is_empty() {
return Ok(None);
}
let term = LocatedQueryTerm {
value: QueryTerm::Word { derivations: ctx.derivations_interner.insert(derivations) },
positions: start..=end,
};
Ok(Some(term))
}
// // TODO: return a word derivations instead?
// pub fn ngram2(
// ctx: &mut SearchContext,
// x: &LocatedQueryTerm,
// y: &LocatedQueryTerm,
// number_of_typos_allowed: impl Fn(&str) -> u8,
// ) -> Result<Option<LocatedQueryTerm>> {
// if *x.positions.end() != y.positions.start() - 1 {
// return Ok(None);
// }
// match (
// x.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
// y.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
// ) {
// (Some(w1), Some(w2)) => {
// let ngram2_str = format!("{w1}{w2}");
// let mut derivations = word_derivations(
// ctx,
// &ngram2_str,
// number_of_typos_allowed(ngram2_str.as_str()).saturating_sub(1),
// y.value.is_prefix(&ctx.derivations_interner),
// )?;
// // Now add the synonyms
// let index_synonyms = ctx.index.synonyms(ctx.txn)?;
// let mut derivations_synonyms = derivations.synonyms.to_vec();
// derivations_synonyms.extend(
// index_synonyms
// .get(&vec![w1.to_owned(), w2.to_owned()])
// .cloned()
// .unwrap_or_default()
// .into_iter()
// .map(|words| {
// let words =
// words.into_iter().map(|w| Some(ctx.word_interner.insert(w))).collect();
// ctx.phrase_interner.insert(Phrase { words })
// }),
// );
// let term = LocatedQueryTerm {
// value: QueryTerm::Word {
// derivations: ctx.derivations_interner.insert(derivations),
// },
// positions: *x.positions.start()..=*y.positions.end(),
// };
// Ok(Some(term))
// }
// _ => Ok(None),
// }
// }
// // TODO: return a word derivations instead?
// pub fn ngram3(
// ctx: &mut SearchContext,
// x: &LocatedQueryTerm,
// y: &LocatedQueryTerm,
// z: &LocatedQueryTerm,
// ) -> Option<(Interned<String>, RangeInclusive<i8>)> {
// if *x.positions.end() != y.positions.start() - 1
// || *y.positions.end() != z.positions.start() - 1
// {
// return None;
// }
// match (
// &x.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
// &y.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
// &z.value.original_single_word(&ctx.word_interner, &ctx.derivations_interner),
// ) {
// (Some(w1), Some(w2), Some(w3)) => {
// let term = (
// ctx.word_interner.insert(format!("{w1}{w2}{w3}")),
// *x.positions.start()..=*z.positions.end(),
// );
// Some(term)
// }
// _ => None,
// }
// }

439
milli/src/search/new/ranking_rule_graph/proximity/build.rs
View File

@ -1,37 +1,43 @@
#![allow(clippy::too_many_arguments)]
use std::collections::BTreeMap;
use itertools::Itertools;
use super::ProximityEdge;
use crate::search::new::interner::Interner;
use crate::search::new::query_term::{LocatedQueryTerm, QueryTerm, WordDerivations};
use crate::search::new::db_cache::DatabaseCache;
use crate::search::new::interner::{Interned, Interner};
use crate::search::new::query_term::{LocatedQueryTerm, Phrase, QueryTerm, WordDerivations};
use crate::search::new::ranking_rule_graph::proximity::WordPair;
use crate::search::new::ranking_rule_graph::EdgeCondition;
use crate::search::new::{QueryNode, SearchContext};
use crate::Result;
use heed::RoTxn;
pub fn visit_from_node(
ctx: &mut SearchContext,
from_node: &QueryNode,
) -> Result<Option<(WordDerivations, i8)>> {
Ok(Some(match from_node {
) -> Result<Option<(Vec<(Option<Interned<Phrase>>, Interned<String>)>, i8)>> {
let SearchContext { derivations_interner, .. } = ctx;
let (left_phrase, left_derivations, left_end_position) = match from_node {
QueryNode::Term(LocatedQueryTerm { value: value1, positions: pos1 }) => {
match value1 {
QueryTerm::Word { derivations } => {
(ctx.derivations_interner.get(*derivations).clone(), *pos1.end())
(None, derivations_interner.get(*derivations).clone(), *pos1.end())
}
QueryTerm::Phrase { phrase: phrase1 } => {
let phrase1 = ctx.phrase_interner.get(*phrase1);
if let Some(original) = *phrase1.words.last().unwrap() {
QueryTerm::Phrase { phrase: phrase_interned } => {
let phrase = ctx.phrase_interner.get(*phrase_interned);
if let Some(original) = *phrase.words.last().unwrap() {
(
Some(*phrase_interned),
WordDerivations {
original,
zero_typo: Box::new([original]),
zero_typo: Some(original),
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: false,
use_prefix_db: None,
synonyms: Box::new([]),
split_words: None,
is_prefix: false,
prefix_of: Box::new([]),
},
*pos1.end(),
)
@ -42,190 +48,175 @@ pub fn visit_from_node(
}
}
}
QueryNode::Start => (
WordDerivations {
original: ctx.word_interner.insert(String::new()),
zero_typo: Box::new([]),
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: false,
synonyms: Box::new([]),
split_words: None,
},
-100,
),
QueryNode::Start => (None, WordDerivations::empty(&mut ctx.word_interner, ""), -1),
_ => return Ok(None),
}))
};
// left term cannot be a prefix
assert!(left_derivations.use_prefix_db.is_none() && !left_derivations.is_prefix);
let last_word_left_phrase = if let Some(left_phrase_interned) = left_phrase {
let left_phrase = ctx.phrase_interner.get(left_phrase_interned);
left_phrase.words.last().copied().unwrap()
} else {
None
};
let left_single_word_iter: Vec<(Option<Interned<Phrase>>, Interned<String>)> = left_derivations
.all_single_word_derivations_except_prefix_db()
.chain(last_word_left_phrase.iter().copied())
.map(|w| (left_phrase, w))
.collect();
let left_phrase_iter: Vec<(Option<Interned<Phrase>>, Interned<String>)> = left_derivations
.all_phrase_derivations()
.map(|left_phrase_interned: Interned<Phrase>| {
let left_phrase = ctx.phrase_interner.get(left_phrase_interned);
let last_word_left_phrase: Interned<String> =
left_phrase.words.last().unwrap().unwrap();
let r: (Option<Interned<Phrase>>, Interned<String>) =
(Some(left_phrase_interned), last_word_left_phrase);
r
})
.collect();
let mut left_word_iter = left_single_word_iter;
left_word_iter.extend(left_phrase_iter);
Ok(Some((left_word_iter, left_end_position)))
}
pub fn visit_to_node<'ctx, 'from_data>(
pub fn build_step_visit_destination_node<'ctx, 'from_data>(
ctx: &mut SearchContext<'ctx>,
conditions_interner: &mut Interner<ProximityEdge>,
from_node_data: &'from_data (Vec<(Option<Interned<Phrase>>, Interned<String>)>, i8),
to_node: &QueryNode,
from_node_data: &'from_data (WordDerivations, i8),
) -> Result<Vec<(u8, EdgeCondition<ProximityEdge>)>> {
let SearchContext { index, txn, db_cache, word_interner, derivations_interner, .. } = ctx;
// IMPORTANT! TODO: split words support
let (derivations1, pos1) = from_node_data;
let term2 = match &to_node {
let SearchContext {
index,
txn,
db_cache,
word_interner,
phrase_interner,
derivations_interner,
query_term_docids: _,
} = ctx;
let right_term = match &to_node {
QueryNode::End => return Ok(vec![(0, EdgeCondition::Unconditional)]),
QueryNode::Deleted | QueryNode::Start => return Ok(vec![]),
QueryNode::Term(term) => term,
};
let LocatedQueryTerm { value: value2, positions: pos2 } = term2;
let LocatedQueryTerm { value: right_value, positions: right_positions } = right_term;
let (derivations2, pos2, ngram_len2) = match value2 {
QueryTerm::Word { derivations } => {
(derivations_interner.get(*derivations).clone(), *pos2.start(), pos2.len())
}
QueryTerm::Phrase { phrase: phrase2 } => {
let phrase2 = ctx.phrase_interner.get(*phrase2);
if let Some(original) = *phrase2.words.first().unwrap() {
(
WordDerivations {
original,
zero_typo: Box::new([original]),
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: false,
synonyms: Box::new([]),
split_words: None,
},
*pos2.start(),
1,
)
} else {
// No word pairs if the phrase does not have a regular word as its first term
return Ok(vec![]);
let (right_phrase, right_derivations, right_start_position, right_ngram_length) =
match right_value {
QueryTerm::Word { derivations } => (
None,
derivations_interner.get(*derivations).clone(),
*right_positions.start(),
right_positions.len(),
),
QueryTerm::Phrase { phrase: right_phrase_interned } => {
let right_phrase = phrase_interner.get(*right_phrase_interned);
if let Some(original) = *right_phrase.words.first().unwrap() {
(
Some(*right_phrase_interned),
WordDerivations {
original,
zero_typo: Some(original),
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: None,
synonyms: Box::new([]),
split_words: None,
is_prefix: false,
prefix_of: Box::new([]),
},
*right_positions.start(),
1,
)
} else {
// No word pairs if the phrase does not have a regular word as its first term
return Ok(vec![]);
}
}
}
};
};
if pos1 + 1 != pos2 {
// TODO: how should this actually be handled?
// We want to effectively ignore this pair of terms
let (left_derivations, left_end_position) = from_node_data;
if left_end_position + 1 != right_start_position {
// We want to ignore this pair of terms
// Unconditionally walk through the edge without computing the docids
// But also what should the cost be?
// This can happen when, in a query like `the sun flowers are beautiful`, the term
// `flowers` is removed by the words ranking rule due to the terms matching strategy.
// The remaining query graph represents `the sun .. are beautiful`
// but `sun` and `are` have no proximity condition between them
return Ok(vec![(0, EdgeCondition::Unconditional)]);
}
let updb1 = derivations1.use_prefix_db;
let updb2 = derivations2.use_prefix_db;
// left term cannot be a prefix
assert!(!updb1);
// TODO: IMPORTANT! split words and synonyms support
let derivations1 = derivations1.all_single_word_derivations_except_prefix_db();
// TODO: eventually, we want to get rid of the uses from `orginal`
let mut cost_proximity_word_pairs = BTreeMap::<u8, BTreeMap<u8, Vec<WordPair>>>::new();
if updb2 {
for word1 in derivations1.clone() {
for proximity in 1..=(8 - ngram_len2) {
let cost = (proximity + ngram_len2 - 1) as u8;
// TODO: if we had access to the universe here, we could already check whether
// the bitmap corresponding to this word pair is disjoint with the universe or not
if db_cache
.get_word_prefix_pair_proximity_docids(
index,
txn,
word_interner,
word1,
derivations2.original,
proximity as u8,
)?
.is_some()
{
cost_proximity_word_pairs
.entry(cost)
.or_default()
.entry(proximity as u8)
.or_default()
.push(WordPair::WordPrefix {
left: word1,
right_prefix: derivations2.original,
});
}
if db_cache
.get_prefix_word_pair_proximity_docids(
index,
txn,
word_interner,
derivations2.original,
word1,
proximity as u8 - 1,
)?
.is_some()
{
cost_proximity_word_pairs
.entry(cost)
.or_default()
.entry(proximity as u8)
.or_default()
.push(WordPair::WordPrefixSwapped {
left_prefix: derivations2.original,
right: word1,
});
}
}
if let Some(right_prefix) = right_derivations.use_prefix_db {
for (left_phrase, left_word) in left_derivations.iter().copied() {
add_prefix_edges(
index,
txn,
db_cache,
word_interner,
right_ngram_length,
left_word,
right_prefix,
&mut cost_proximity_word_pairs,
left_phrase,
)?;
}
}
// TODO: important! support split words and synonyms as well
let derivations2 = derivations2.all_single_word_derivations_except_prefix_db();
// TODO: add safeguard in case the cartesian product is too large!
// even if we restrict the word derivations to a maximum of 100, the size of the
// caterisan product could reach a maximum of 10_000 derivations, which is way too much.
// mMaybe prioritise the product of zero typo derivations, then the product of zero-typo/one-typo
// + one-typo/zero-typo, then one-typo/one-typo, then ... until an arbitrary limit has been
// reached
let product_derivations = derivations1.cartesian_product(derivations2);
let first_word_right_phrase = if let Some(right_phrase_interned) = right_phrase {
let right_phrase = phrase_interner.get(right_phrase_interned);
right_phrase.words.first().copied().unwrap()
} else {
None
};
let right_single_word_iter: Vec<(Option<Interned<Phrase>>, Interned<String>)> =
right_derivations
.all_single_word_derivations_except_prefix_db()
.chain(first_word_right_phrase.iter().copied())
.map(|w| (right_phrase, w))
.collect();
let right_phrase_iter: Vec<(Option<Interned<Phrase>>, Interned<String>)> = right_derivations
.all_phrase_derivations()
.map(|right_phrase_interned: Interned<Phrase>| {
let right_phrase = phrase_interner.get(right_phrase_interned);
let first_word_right_phrase: Interned<String> =
right_phrase.words.first().unwrap().unwrap();
let r: (Option<Interned<Phrase>>, Interned<String>) =
(Some(right_phrase_interned), first_word_right_phrase);
r
})
.collect();
let mut right_word_iter = right_single_word_iter;
right_word_iter.extend(right_phrase_iter);
for (word1, word2) in product_derivations {
for proximity in 1..=(8 - ngram_len2) {
let cost = (proximity + ngram_len2 - 1) as u8;
if db_cache
.get_word_pair_proximity_docids(
index,
txn,
word_interner,
word1,
word2,
proximity as u8,
)?
.is_some()
{
cost_proximity_word_pairs
.entry(cost)
.or_default()
.entry(proximity as u8)
.or_default()
.push(WordPair::Words { left: word1, right: word2 });
}
if proximity > 1
&& db_cache
.get_word_pair_proximity_docids(
index,
txn,
word_interner,
word2,
word1,
proximity as u8 - 1,
)?
.is_some()
{
cost_proximity_word_pairs
.entry(cost)
.or_default()
.entry(proximity as u8 - 1)
.or_default()
.push(WordPair::Words { left: word2, right: word1 });
}
for (left_phrase, left_word) in left_derivations.iter().copied() {
for (right_phrase, right_word) in right_word_iter.iter().copied() {
add_non_prefix_edges(
index,
txn,
db_cache,
word_interner,
right_ngram_length,
left_word,
right_word,
&mut cost_proximity_word_pairs,
&[left_phrase, right_phrase].iter().copied().flatten().collect::<Vec<_>>(),
)?;
}
}
let mut new_edges =
cost_proximity_word_pairs
.into_iter()
@ -243,6 +234,124 @@ pub fn visit_to_node<'ctx, 'from_data>(
edges
})
.collect::<Vec<_>>();
new_edges.push((8 + (ngram_len2 - 1) as u8, EdgeCondition::Unconditional));
new_edges.push((8 + (right_ngram_length - 1) as u8, EdgeCondition::Unconditional));
Ok(new_edges)
}
fn add_prefix_edges<'ctx>(
index: &mut &crate::Index,
txn: &'ctx RoTxn,
db_cache: &mut DatabaseCache<'ctx>,
word_interner: &mut Interner<String>,
right_ngram_length: usize,
left_word: Interned<String>,
right_prefix: Interned<String>,
cost_proximity_word_pairs: &mut BTreeMap<u8, BTreeMap<u8, Vec<WordPair>>>,
left_phrase: Option<Interned<Phrase>>,
) -> Result<()> {
for proximity in 1..=(8 - right_ngram_length) {
let cost = (proximity + right_ngram_length - 1) as u8;
// TODO: if we had access to the universe here, we could already check whether
// the bitmap corresponding to this word pair is disjoint with the universe or not
if db_cache
.get_word_prefix_pair_proximity_docids(
index,
txn,
word_interner,
left_word,
right_prefix,
proximity as u8,
)?
.is_some()
{
cost_proximity_word_pairs
.entry(cost)
.or_default()
.entry(proximity as u8)
.or_default()
.push(WordPair::WordPrefix {
phrases: left_phrase.into_iter().collect(),
left: left_word,
right_prefix,
});
}
// No swapping when computing the proximity between a phrase and a word
if left_phrase.is_none()
&& db_cache
.get_prefix_word_pair_proximity_docids(
index,
txn,
word_interner,
right_prefix,
left_word,
proximity as u8 - 1,
)?
.is_some()
{
cost_proximity_word_pairs
.entry(cost)
.or_default()
.entry(proximity as u8)
.or_default()
.push(WordPair::WordPrefixSwapped { left_prefix: right_prefix, right: left_word });
}
}
Ok(())
}
fn add_non_prefix_edges<'ctx>(
index: &mut &crate::Index,
txn: &'ctx RoTxn,
db_cache: &mut DatabaseCache<'ctx>,
word_interner: &mut Interner<String>,
right_ngram_length: usize,
word1: Interned<String>,
word2: Interned<String>,
cost_proximity_word_pairs: &mut BTreeMap<u8, BTreeMap<u8, Vec<WordPair>>>,
phrases: &[Interned<Phrase>],
) -> Result<()> {
for proximity in 1..=(8 - right_ngram_length) {
let cost = (proximity + right_ngram_length - 1) as u8;
if db_cache
.get_word_pair_proximity_docids(
index,
txn,
word_interner,
word1,
word2,
proximity as u8,
)?
.is_some()
{
cost_proximity_word_pairs
.entry(cost)
.or_default()
.entry(proximity as u8)
.or_default()
.push(WordPair::Words { phrases: phrases.to_vec(), left: word1, right: word2 });
}
if proximity > 1
// no swapping when either term is a phrase
&& phrases.is_empty()
&& db_cache
.get_word_pair_proximity_docids(
index,
txn,
word_interner,
word2,
word1,
proximity as u8 - 1,
)?
.is_some()
{
cost_proximity_word_pairs
.entry(cost)
.or_default()
.entry(proximity as u8 - 1)
.or_default()
.push(WordPair::Words { phrases: vec![], left: word2, right: word1 });
}
}
Ok(())
}

85
milli/src/search/new/ranking_rule_graph/proximity/compute_docids.rs
View File

@ -13,24 +13,61 @@ pub fn compute_docids<'ctx>(
let ProximityEdge { pairs, proximity } = edge;
let mut pair_docids = RoaringBitmap::new();
for pair in pairs.iter() {
let bytes = match pair {
WordPair::Words { left, right } => db_cache.get_word_pair_proximity_docids(
index,
txn,
word_interner,
*left,
*right,
*proximity,
),
WordPair::WordPrefix { left, right_prefix } => db_cache
.get_word_prefix_pair_proximity_docids(
index,
txn,
word_interner,
*left,
*right_prefix,
*proximity,
),
let pair = match pair {
WordPair::Words { phrases, left, right } => {
let mut docids = db_cache
.get_word_pair_proximity_docids(
index,
txn,
word_interner,
*left,
*right,
*proximity,
)?
.map(CboRoaringBitmapCodec::deserialize_from)
.transpose()?
.unwrap_or_default();
if !docids.is_empty() {
for phrase in phrases {
docids &= ctx.query_term_docids.get_phrase_docids(
index,
txn,
db_cache,
word_interner,
&ctx.phrase_interner,
*phrase,
)?;
}
}
docids
}
WordPair::WordPrefix { phrases, left, right_prefix } => {
let mut docids = db_cache
.get_word_prefix_pair_proximity_docids(
index,
txn,
word_interner,
*left,
*right_prefix,
*proximity,
)?
.map(CboRoaringBitmapCodec::deserialize_from)
.transpose()?
.unwrap_or_default();
if !docids.is_empty() {
for phrase in phrases {
docids &= ctx.query_term_docids.get_phrase_docids(
index,
txn,
db_cache,
word_interner,
&ctx.phrase_interner,
*phrase,
)?;
}
}
docids
}
WordPair::WordPrefixSwapped { left_prefix, right } => db_cache
.get_prefix_word_pair_proximity_docids(
index,
@ -39,11 +76,13 @@ pub fn compute_docids<'ctx>(
*left_prefix,
*right,
*proximity,
),
}?;
// TODO: deserialize bitmap within a universe, and (maybe) using a bump allocator?
let bitmap = universe
& bytes.map(CboRoaringBitmapCodec::deserialize_from).transpose()?.unwrap_or_default();
)?
.map(CboRoaringBitmapCodec::deserialize_from)
.transpose()?
.unwrap_or_default(),
};
// TODO: deserialize bitmap within a universe
let bitmap = universe & pair;
pair_docids |= bitmap;
}

32
milli/src/search/new/ranking_rule_graph/proximity/mod.rs
View File

@ -7,16 +7,27 @@ use super::empty_paths_cache::EmptyPathsCache;
use super::{EdgeCondition, RankingRuleGraphTrait};
use crate::search::new::interner::{Interned, Interner};
use crate::search::new::logger::SearchLogger;
use crate::search::new::query_term::WordDerivations;
use crate::search::new::query_term::Phrase;
use crate::search::new::small_bitmap::SmallBitmap;
use crate::search::new::{QueryGraph, QueryNode, SearchContext};
use crate::Result;
#[derive(Clone, PartialEq, Eq, Hash)]
pub enum WordPair {
Words { left: Interned<String>, right: Interned<String> },
WordPrefix { left: Interned<String>, right_prefix: Interned<String> },
WordPrefixSwapped { left_prefix: Interned<String>, right: Interned<String> },
Words {
phrases: Vec<Interned<Phrase>>,
left: Interned<String>,
right: Interned<String>,
},
WordPrefix {
phrases: Vec<Interned<Phrase>>,
left: Interned<String>,
right_prefix: Interned<String>,
},
WordPrefixSwapped {
left_prefix: Interned<String>,
right: Interned<String>,
},
}
#[derive(Clone, PartialEq, Eq, Hash)]
@ -29,7 +40,7 @@ pub enum ProximityGraph {}
impl RankingRuleGraphTrait for ProximityGraph {
type EdgeCondition = ProximityEdge;
type BuildVisitedFromNode = (WordDerivations, i8);
type BuildVisitedFromNode = (Vec<(Option<Interned<Phrase>>, Interned<String>)>, i8);
fn label_for_edge_condition(edge: &Self::EdgeCondition) -> String {
let ProximityEdge { pairs, proximity } = edge;
@ -54,10 +65,15 @@ impl RankingRuleGraphTrait for ProximityGraph {
fn build_step_visit_destination_node<'from_data, 'ctx: 'from_data>(
ctx: &mut SearchContext<'ctx>,
conditions_interner: &mut Interner<Self::EdgeCondition>,
to_node: &QueryNode,
from_node_data: &'from_data Self::BuildVisitedFromNode,
dest_node: &QueryNode,
source_node_data: &'from_data Self::BuildVisitedFromNode,
) -> Result<Vec<(u8, EdgeCondition<Self::EdgeCondition>)>> {
build::visit_to_node(ctx, conditions_interner, to_node, from_node_data)
build::build_step_visit_destination_node(
ctx,
conditions_interner,
source_node_data,
dest_node,
)
}
fn log_state(

47
milli/src/search/new/ranking_rule_graph/typo/mod.rs
View File

@ -84,7 +84,7 @@ impl RankingRuleGraphTrait for TypoGraph {
) -> Result<Vec<(u8, EdgeCondition<Self::EdgeCondition>)>> {
let SearchContext { derivations_interner, .. } = ctx;
match to_node {
QueryNode::Term(LocatedQueryTerm { value, .. }) => match *value {
QueryNode::Term(LocatedQueryTerm { value, positions }) => match *value {
QueryTerm::Phrase { phrase } => Ok(vec![(
0,
EdgeCondition::Conditional(
@ -93,57 +93,62 @@ impl RankingRuleGraphTrait for TypoGraph {
)]),
QueryTerm::Word { derivations } => {
let mut edges = vec![];
// Ngrams have a base typo cost
// 2-gram -> equivalent to 1 typo
// 3-gram -> equivalent to 2 typos
let base_cost = positions.len().max(2) as u8;
for nbr_typos in 0..=2 {
let derivations = derivations_interner.get(derivations).clone();
let new_derivations = match nbr_typos {
0 => {
// TODO: think about how split words and synonyms should be handled here
// TODO: what about ngrams?
// Maybe 2grams should have one typo by default and 3grams 2 typos by default
WordDerivations {
original: derivations.original,
synonyms: derivations.synonyms,
split_words: None,
zero_typo: derivations.zero_typo,
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: derivations.use_prefix_db,
}
}
0 => WordDerivations {
original: derivations.original,
is_prefix: derivations.is_prefix,
zero_typo: derivations.zero_typo,
prefix_of: derivations.prefix_of,
synonyms: derivations.synonyms,
split_words: None,
one_typo: Box::new([]),
two_typos: Box::new([]),
use_prefix_db: derivations.use_prefix_db,
},
1 => {
// What about split words and synonyms here?
WordDerivations {
original: derivations.original,
is_prefix: false,
zero_typo: None,
prefix_of: Box::new([]),
synonyms: Box::new([]),
split_words: derivations.split_words,
zero_typo: Box::new([]),
one_typo: derivations.one_typo,
two_typos: Box::new([]),
use_prefix_db: false, // false because all items from use_prefix_db haev 0 typos
use_prefix_db: None, // false because all items from use_prefix_db have 0 typos
}
}
2 => {
// What about split words and synonyms here?
WordDerivations {
original: derivations.original,
zero_typo: None,
is_prefix: false,
prefix_of: Box::new([]),
synonyms: Box::new([]),
split_words: None,
zero_typo: Box::new([]),
one_typo: Box::new([]),
two_typos: derivations.two_typos,
use_prefix_db: false, // false because all items from use_prefix_db haev 0 typos
use_prefix_db: None, // false because all items from use_prefix_db have 0 typos
}
}
_ => panic!(),
};
if !new_derivations.is_empty() {
edges.push((
nbr_typos,
nbr_typos as u8 + base_cost,
EdgeCondition::Conditional(conditions_interner.insert(
TypoEdge::Word {
derivations: derivations_interner.insert(new_derivations),
nbr_typos,
nbr_typos: nbr_typos as u8,
},
)),
))

20
milli/src/search/new/resolve_query_graph.rs
View File

@ -54,25 +54,31 @@ impl QueryTermDocIdsCache {
return Ok(&self.derivations[&derivations]);
};
let WordDerivations {
original,
original: _,
is_prefix: _,
zero_typo,
prefix_of,
synonyms,
split_words,
zero_typo,
one_typo,
two_typos,
use_prefix_db,
} = derivations_interner.get(derivations);
let mut or_docids = vec![];
for word in zero_typo.iter().chain(one_typo.iter()).chain(two_typos.iter()).copied() {
for word in zero_typo
.iter()
.chain(prefix_of.iter())
.chain(one_typo.iter())
.chain(two_typos.iter())
.copied()
{
if let Some(word_docids) = db_cache.get_word_docids(index, txn, word_interner, word)? {
or_docids.push(word_docids);
}
}
if *use_prefix_db {
// TODO: this will change if we decide to change from (original, zero_typo) to:
// (debug_original, prefix_of, zero_typo)
if let Some(prefix) = use_prefix_db {
if let Some(prefix_docids) =
db_cache.get_word_prefix_docids(index, txn, word_interner, *original)?
db_cache.get_word_prefix_docids(index, txn, word_interner, *prefix)?
{
or_docids.push(prefix_docids);
}