meilisearch/meilisearch-core/src/raw_indexer.rs
2020-02-11 15:28:00 +01:00

273 lines
8.1 KiB
Rust
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

use std::collections::{BTreeMap, HashMap};
use std::convert::TryFrom;
use crate::{DocIndex, DocumentId};
use deunicode::deunicode_with_tofu;
use meilisearch_schema::IndexedPos;
use meilisearch_tokenizer::{is_cjk, SeqTokenizer, Token, Tokenizer};
use sdset::SetBuf;
const WORD_LENGTH_LIMIT: usize = 80;
type Word = Vec<u8>; // TODO make it be a SmallVec
pub struct RawIndexer {
word_limit: usize, // the maximum number of indexed words
stop_words: fst::Set,
words_doc_indexes: BTreeMap<Word, Vec<DocIndex>>,
docs_words: HashMap<DocumentId, Vec<Word>>,
}
pub struct Indexed {
pub words_doc_indexes: BTreeMap<Word, SetBuf<DocIndex>>,
pub docs_words: HashMap<DocumentId, fst::Set>,
}
impl RawIndexer {
pub fn new(stop_words: fst::Set) -> RawIndexer {
RawIndexer::with_word_limit(stop_words, 1000)
}
pub fn with_word_limit(stop_words: fst::Set, limit: usize) -> RawIndexer {
RawIndexer {
word_limit: limit,
stop_words,
words_doc_indexes: BTreeMap::new(),
docs_words: HashMap::new(),
}
}
pub fn index_text(&mut self, id: DocumentId, indexed_pos: IndexedPos, text: &str) -> usize {
let mut number_of_words = 0;
for token in Tokenizer::new(text) {
let must_continue = index_token(
token,
id,
indexed_pos,
self.word_limit,
&self.stop_words,
&mut self.words_doc_indexes,
&mut self.docs_words,
);
number_of_words += 1;
if !must_continue {
break;
}
}
number_of_words
}
pub fn index_text_seq<'a, I>(&mut self, id: DocumentId, indexed_pos: IndexedPos, iter: I)
where
I: IntoIterator<Item = &'a str>,
{
let iter = iter.into_iter();
for token in SeqTokenizer::new(iter) {
let must_continue = index_token(
token,
id,
indexed_pos,
self.word_limit,
&self.stop_words,
&mut self.words_doc_indexes,
&mut self.docs_words,
);
if !must_continue {
break;
}
}
}
pub fn build(self) -> Indexed {
let words_doc_indexes = self
.words_doc_indexes
.into_iter()
.map(|(word, indexes)| (word, SetBuf::from_dirty(indexes)))
.collect();
let docs_words = self
.docs_words
.into_iter()
.map(|(id, mut words)| {
words.sort_unstable();
words.dedup();
(id, fst::Set::from_iter(words).unwrap())
})
.collect();
Indexed {
words_doc_indexes,
docs_words,
}
}
}
fn index_token(
token: Token,
id: DocumentId,
indexed_pos: IndexedPos,
word_limit: usize,
stop_words: &fst::Set,
words_doc_indexes: &mut BTreeMap<Word, Vec<DocIndex>>,
docs_words: &mut HashMap<DocumentId, Vec<Word>>,
) -> bool {
if token.word_index >= word_limit {
return false;
}
let lower = token.word.to_lowercase();
let token = Token {
word: &lower,
..token
};
if !stop_words.contains(&token.word) {
match token_to_docindex(id, indexed_pos, token) {
Some(docindex) => {
let word = Vec::from(token.word);
if word.len() <= WORD_LENGTH_LIMIT {
words_doc_indexes
.entry(word.clone())
.or_insert_with(Vec::new)
.push(docindex);
docs_words.entry(id).or_insert_with(Vec::new).push(word);
if !lower.contains(is_cjk) {
let unidecoded = deunicode_with_tofu(&lower, "");
if unidecoded != lower && !unidecoded.is_empty() {
let word = Vec::from(unidecoded);
if word.len() <= WORD_LENGTH_LIMIT {
words_doc_indexes
.entry(word.clone())
.or_insert_with(Vec::new)
.push(docindex);
docs_words.entry(id).or_insert_with(Vec::new).push(word);
}
}
}
}
}
None => return false,
}
}
true
}
fn token_to_docindex(id: DocumentId, indexed_pos: IndexedPos, token: Token) -> Option<DocIndex> {
let word_index = u16::try_from(token.word_index).ok()?;
let char_index = u16::try_from(token.char_index).ok()?;
let char_length = u16::try_from(token.word.chars().count()).ok()?;
let docindex = DocIndex {
document_id: id,
attribute: indexed_pos.0,
word_index,
char_index,
char_length,
};
Some(docindex)
}
#[cfg(test)]
mod tests {
use super::*;
use meilisearch_schema::IndexedPos;
#[test]
fn strange_apostrophe() {
let mut indexer = RawIndexer::new(fst::Set::default());
let docid = DocumentId(0);
let indexed_pos = IndexedPos(0);
let text = "Zut, laspirateur, jai oublié de léteindre !";
indexer.index_text(docid, indexed_pos, text);
let Indexed {
words_doc_indexes, ..
} = indexer.build();
assert!(words_doc_indexes.get(&b"l"[..]).is_some());
assert!(words_doc_indexes.get(&b"aspirateur"[..]).is_some());
assert!(words_doc_indexes.get(&b"ai"[..]).is_some());
assert!(words_doc_indexes.get(&b"eteindre"[..]).is_some());
assert!(words_doc_indexes
.get(&"éteindre".to_owned().into_bytes())
.is_some());
}
#[test]
fn strange_apostrophe_in_sequence() {
let mut indexer = RawIndexer::new(fst::Set::default());
let docid = DocumentId(0);
let indexed_pos = IndexedPos(0);
let text = vec!["Zut, laspirateur, jai oublié de léteindre !"];
indexer.index_text_seq(docid, indexed_pos, text);
let Indexed {
words_doc_indexes, ..
} = indexer.build();
assert!(words_doc_indexes.get(&b"l"[..]).is_some());
assert!(words_doc_indexes.get(&b"aspirateur"[..]).is_some());
assert!(words_doc_indexes.get(&b"ai"[..]).is_some());
assert!(words_doc_indexes.get(&b"eteindre"[..]).is_some());
assert!(words_doc_indexes
.get(&"éteindre".to_owned().into_bytes())
.is_some());
}
#[test]
fn basic_stop_words() {
let stop_words = sdset::SetBuf::from_dirty(vec!["l", "j", "ai", "de"]);
let stop_words = fst::Set::from_iter(stop_words).unwrap();
let mut indexer = RawIndexer::new(stop_words);
let docid = DocumentId(0);
let indexed_pos = IndexedPos(0);
let text = "Zut, laspirateur, jai oublié de léteindre !";
indexer.index_text(docid, indexed_pos, text);
let Indexed {
words_doc_indexes, ..
} = indexer.build();
assert!(words_doc_indexes.get(&b"l"[..]).is_none());
assert!(words_doc_indexes.get(&b"aspirateur"[..]).is_some());
assert!(words_doc_indexes.get(&b"j"[..]).is_none());
assert!(words_doc_indexes.get(&b"ai"[..]).is_none());
assert!(words_doc_indexes.get(&b"de"[..]).is_none());
assert!(words_doc_indexes.get(&b"eteindre"[..]).is_some());
assert!(words_doc_indexes
.get(&"éteindre".to_owned().into_bytes())
.is_some());
}
#[test]
fn no_empty_unidecode() {
let mut indexer = RawIndexer::new(fst::Set::default());
let docid = DocumentId(0);
let indexed_pos = IndexedPos(0);
let text = "🇯🇵";
indexer.index_text(docid, indexed_pos, text);
let Indexed {
words_doc_indexes, ..
} = indexer.build();
assert!(words_doc_indexes
.get(&"🇯🇵".to_owned().into_bytes())
.is_some());
}
}