meilisearch/milli/src/search/query_tree.rs

1444 lines
52 KiB
Rust
Executable File

use std::borrow::Cow;
use std::cmp::max;
use std::collections::hash_map::Entry;
use std::collections::HashMap;
use std::hash::Hash;
use std::rc::Rc;
use std::{fmt, mem};
use charabia::classifier::ClassifiedTokenIter;
use charabia::{SeparatorKind, TokenKind};
use roaring::RoaringBitmap;
use slice_group_by::GroupBy;
use crate::search::matches::matching_words::{MatchingWord, PrimitiveWordId};
use crate::search::TermsMatchingStrategy;
use crate::{CboRoaringBitmapLenCodec, Index, MatchingWords, Result};
type IsOptionalWord = bool;
type IsPrefix = bool;
#[derive(Clone, PartialEq, Eq, Hash)]
pub enum Operation {
And(Vec<Operation>),
// series of consecutive non prefix and exact words
// `None` means a stop word.
Phrase(Vec<Option<String>>),
Or(IsOptionalWord, Vec<Operation>),
Query(Query),
}
impl fmt::Debug for Operation {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fn pprint_tree(f: &mut fmt::Formatter<'_>, op: &Operation, depth: usize) -> fmt::Result {
match op {
Operation::And(children) => {
writeln!(f, "{:1$}AND", "", depth * 2)?;
children.iter().try_for_each(|c| pprint_tree(f, c, depth + 1))
}
Operation::Phrase(children) => {
writeln!(f, "{:2$}PHRASE {:?}", "", children, depth * 2)
}
Operation::Or(true, children) => {
writeln!(f, "{:1$}OR(WORD)", "", depth * 2)?;
children.iter().try_for_each(|c| pprint_tree(f, c, depth + 1))
}
Operation::Or(false, children) => {
writeln!(f, "{:1$}OR", "", depth * 2)?;
children.iter().try_for_each(|c| pprint_tree(f, c, depth + 1))
}
Operation::Query(query) => writeln!(f, "{:2$}{:?}", "", query, depth * 2),
}
}
pprint_tree(f, self, 0)
}
}
impl Operation {
fn and(mut ops: Vec<Self>) -> Self {
if ops.len() == 1 {
ops.pop().unwrap()
} else {
Self::And(ops)
}
}
pub fn or(word_branch: IsOptionalWord, mut ops: Vec<Self>) -> Self {
if ops.len() == 1 {
ops.pop().unwrap()
} else {
let ops = ops
.into_iter()
.flat_map(|o| match o {
Operation::Or(wb, children) if wb == word_branch => children,
op => vec![op],
})
.collect();
Self::Or(word_branch, ops)
}
}
fn phrase(mut words: Vec<Option<String>>) -> Self {
if words.len() == 1 {
if let Some(word) = words.pop().unwrap() {
Self::Query(Query { prefix: false, kind: QueryKind::exact(word) })
} else {
Self::Phrase(words)
}
} else {
Self::Phrase(words)
}
}
pub fn query(&self) -> Option<&Query> {
match self {
Operation::Query(query) => Some(query),
_ => None,
}
}
}
#[derive(Clone, Eq, PartialEq, Hash)]
pub struct Query {
pub prefix: IsPrefix,
pub kind: QueryKind,
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum QueryKind {
Tolerant { typo: u8, word: String },
Exact { original_typo: u8, word: String },
}
impl QueryKind {
pub fn exact(word: String) -> Self {
QueryKind::Exact { original_typo: 0, word }
}
pub fn tolerant(typo: u8, word: String) -> Self {
QueryKind::Tolerant { typo, word }
}
pub fn typo(&self) -> u8 {
match self {
QueryKind::Tolerant { typo, .. } => *typo,
QueryKind::Exact { original_typo, .. } => *original_typo,
}
}
pub fn word(&self) -> &str {
match self {
QueryKind::Tolerant { word, .. } => word,
QueryKind::Exact { word, .. } => word,
}
}
}
impl fmt::Debug for Query {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let Query { prefix, kind } = self;
let prefix = if *prefix { String::from("Prefix") } else { String::default() };
match kind {
QueryKind::Exact { word, .. } => {
f.debug_struct(&(prefix + "Exact")).field("word", &word).finish()
}
QueryKind::Tolerant { typo, word } => f
.debug_struct(&(prefix + "Tolerant"))
.field("word", &word)
.field("max typo", &typo)
.finish(),
}
}
}
trait Context {
fn word_docids(&self, word: &str) -> heed::Result<Option<RoaringBitmap>>;
fn synonyms<S: AsRef<str>>(&self, words: &[S]) -> heed::Result<Option<Vec<Vec<String>>>>;
fn word_documents_count(&self, word: &str) -> heed::Result<Option<u64>> {
match self.word_docids(word)? {
Some(rb) => Ok(Some(rb.len())),
None => Ok(None),
}
}
/// Returns the minimum word len for 1 and 2 typos.
fn min_word_len_for_typo(&self) -> heed::Result<(u8, u8)>;
fn exact_words(&self) -> Option<&fst::Set<Cow<[u8]>>>;
fn word_pair_frequency(
&self,
left_word: &str,
right_word: &str,
proximity: u8,
) -> heed::Result<Option<u64>>;
}
/// The query tree builder is the interface to build a query tree.
pub struct QueryTreeBuilder<'a> {
rtxn: &'a heed::RoTxn<'a>,
index: &'a Index,
terms_matching_strategy: TermsMatchingStrategy,
authorize_typos: bool,
words_limit: Option<usize>,
exact_words: Option<fst::Set<Cow<'a, [u8]>>>,
}
impl<'a> Context for QueryTreeBuilder<'a> {
fn word_docids(&self, word: &str) -> heed::Result<Option<RoaringBitmap>> {
self.index.word_docids.get(self.rtxn, word)
}
fn synonyms<S: AsRef<str>>(&self, words: &[S]) -> heed::Result<Option<Vec<Vec<String>>>> {
self.index.words_synonyms(self.rtxn, words)
}
fn word_documents_count(&self, word: &str) -> heed::Result<Option<u64>> {
self.index.word_documents_count(self.rtxn, word)
}
fn min_word_len_for_typo(&self) -> heed::Result<(u8, u8)> {
let one = self.index.min_word_len_one_typo(self.rtxn)?;
let two = self.index.min_word_len_two_typos(self.rtxn)?;
Ok((one, two))
}
fn exact_words(&self) -> Option<&fst::Set<Cow<[u8]>>> {
self.exact_words.as_ref()
}
fn word_pair_frequency(
&self,
left_word: &str,
right_word: &str,
proximity: u8,
) -> heed::Result<Option<u64>> {
let key = (proximity, left_word, right_word);
self.index
.word_pair_proximity_docids
.remap_data_type::<CboRoaringBitmapLenCodec>()
.get(self.rtxn, &key)
}
}
impl<'a> QueryTreeBuilder<'a> {
/// Create a `QueryTreeBuilder` from a heed ReadOnly transaction `rtxn`
/// and an Index `index`.
pub fn new(rtxn: &'a heed::RoTxn<'a>, index: &'a Index) -> Result<Self> {
Ok(Self {
rtxn,
index,
terms_matching_strategy: TermsMatchingStrategy::default(),
authorize_typos: true,
words_limit: None,
exact_words: index.exact_words(rtxn)?,
})
}
/// if `terms_matching_strategy` is set to `All` the query tree will be
/// generated forcing all query words to be present in each matching documents
/// (the criterion `words` will be ignored).
/// default value if not called: `Last`
pub fn terms_matching_strategy(
&mut self,
terms_matching_strategy: TermsMatchingStrategy,
) -> &mut Self {
self.terms_matching_strategy = terms_matching_strategy;
self
}
/// if `authorize_typos` is set to `false` the query tree will be generated
/// forcing all query words to match documents without any typo
/// (the criterion `typo` will be ignored).
/// default value if not called: `true`
pub fn authorize_typos(&mut self, authorize_typos: bool) -> &mut Self {
self.authorize_typos = authorize_typos;
self
}
/// Limit words and phrases that will be taken for query building.
/// Any beyond `words_limit` will be ignored.
pub fn words_limit(&mut self, words_limit: usize) -> &mut Self {
self.words_limit = Some(words_limit);
self
}
/// Build the query tree:
/// - if `terms_matching_strategy` is set to `All` the query tree will be
/// generated forcing all query words to be present in each matching documents
/// (the criterion `words` will be ignored)
/// - if `authorize_typos` is set to `false` the query tree will be generated
/// forcing all query words to match documents without any typo
/// (the criterion `typo` will be ignored)
pub fn build<A: AsRef<[u8]>>(
&self,
query: ClassifiedTokenIter<A>,
) -> Result<Option<(Operation, PrimitiveQuery, MatchingWords)>> {
let primitive_query = create_primitive_query(query, self.words_limit);
if !primitive_query.is_empty() {
let qt = create_query_tree(
self,
self.terms_matching_strategy,
self.authorize_typos,
&primitive_query,
)?;
let matching_words =
create_matching_words(self, self.authorize_typos, &primitive_query)?;
Ok(Some((qt, primitive_query, matching_words)))
} else {
Ok(None)
}
}
}
/// Split the word depending on the frequency of pairs near together in the database documents.
fn split_best_frequency<'a>(
ctx: &impl Context,
word: &'a str,
) -> heed::Result<Option<(&'a str, &'a str)>> {
let chars = word.char_indices().skip(1);
let mut best = None;
for (i, _) in chars {
let (left, right) = word.split_at(i);
let pair_freq = ctx.word_pair_frequency(left, right, 1)?.unwrap_or(0);
if pair_freq != 0 && best.map_or(true, |(old, _, _)| pair_freq > old) {
best = Some((pair_freq, left, right));
}
}
Ok(best.map(|(_, left, right)| (left, right)))
}
#[derive(Clone)]
pub struct TypoConfig<'a> {
pub max_typos: u8,
pub word_len_one_typo: u8,
pub word_len_two_typo: u8,
pub exact_words: Option<&'a fst::Set<Cow<'a, [u8]>>>,
}
/// Return the `QueryKind` of a word depending on `authorize_typos`
/// and the provided word length.
fn typos(word: String, authorize_typos: bool, config: TypoConfig) -> QueryKind {
if authorize_typos && !config.exact_words.map_or(false, |s| s.contains(&word)) {
let count = word.chars().count().min(u8::MAX as usize) as u8;
if count < config.word_len_one_typo {
QueryKind::exact(word)
} else if count < config.word_len_two_typo {
QueryKind::tolerant(1.min(config.max_typos), word)
} else {
QueryKind::tolerant(2.min(config.max_typos), word)
}
} else {
QueryKind::exact(word)
}
}
/// Fetch synonyms from the `Context` for the provided word
/// and create the list of operations for the query tree
fn synonyms(ctx: &impl Context, word: &[&str]) -> heed::Result<Option<Vec<Operation>>> {
let synonyms = ctx.synonyms(word)?;
Ok(synonyms.map(|synonyms| {
synonyms
.into_iter()
.map(|synonym| {
let words = synonym
.into_iter()
.map(|word| {
Operation::Query(Query { prefix: false, kind: QueryKind::exact(word) })
})
.collect();
Operation::and(words)
})
.collect()
}))
}
/// Main function that creates the final query tree from the primitive query.
fn create_query_tree(
ctx: &impl Context,
terms_matching_strategy: TermsMatchingStrategy,
authorize_typos: bool,
query: &[PrimitiveQueryPart],
) -> Result<Operation> {
/// Matches on the `PrimitiveQueryPart` and create an operation from it.
fn resolve_primitive_part(
ctx: &impl Context,
authorize_typos: bool,
part: PrimitiveQueryPart,
) -> Result<Operation> {
match part {
// 1. try to split word in 2
// 2. try to fetch synonyms
// 3. create an operation containing the word
// 4. wrap all in an OR operation
PrimitiveQueryPart::Word(word, prefix) => {
let mut children = synonyms(ctx, &[&word])?.unwrap_or_default();
if let Some((left, right)) = split_best_frequency(ctx, &word)? {
children.push(Operation::Phrase(vec![
Some(left.to_string()),
Some(right.to_string()),
]));
}
let (word_len_one_typo, word_len_two_typo) = ctx.min_word_len_for_typo()?;
let exact_words = ctx.exact_words();
let config =
TypoConfig { max_typos: 2, word_len_one_typo, word_len_two_typo, exact_words };
children.push(Operation::Query(Query {
prefix,
kind: typos(word, authorize_typos, config),
}));
Ok(Operation::or(false, children))
}
// create a CONSECUTIVE operation wrapping all word in the phrase
PrimitiveQueryPart::Phrase(words) => Ok(Operation::phrase(words)),
}
}
/// Create all ngrams 1..=3 generating query tree branches.
fn ngrams(
ctx: &impl Context,
authorize_typos: bool,
query: &[PrimitiveQueryPart],
any_words: bool,
) -> Result<Operation> {
const MAX_NGRAM: usize = 3;
let mut op_children = Vec::new();
for sub_query in query.linear_group_by(|a, b| !(a.is_phrase() || b.is_phrase())) {
let mut or_op_children = Vec::new();
for ngram in 1..=MAX_NGRAM.min(sub_query.len()) {
if let Some(group) = sub_query.get(..ngram) {
let mut and_op_children = Vec::new();
let tail = &sub_query[ngram..];
let is_last = tail.is_empty();
match group {
[part] => {
let operation =
resolve_primitive_part(ctx, authorize_typos, part.clone())?;
and_op_children.push(operation);
}
words => {
let is_prefix = words.last().map_or(false, |part| part.is_prefix());
let words: Vec<_> = words
.iter()
.filter_map(|part| {
if let PrimitiveQueryPart::Word(word, _) = part {
Some(word.as_str())
} else {
None
}
})
.collect();
let mut operations = synonyms(ctx, &words)?.unwrap_or_default();
let concat = words.concat();
let (word_len_one_typo, word_len_two_typo) =
ctx.min_word_len_for_typo()?;
let exact_words = ctx.exact_words();
let config = TypoConfig {
max_typos: 1,
word_len_one_typo,
word_len_two_typo,
exact_words,
};
let query = Query {
prefix: is_prefix,
kind: typos(concat, authorize_typos, config),
};
operations.push(Operation::Query(query));
and_op_children.push(Operation::or(false, operations));
}
}
if !is_last {
let ngrams = ngrams(ctx, authorize_typos, tail, any_words)?;
and_op_children.push(ngrams);
}
if any_words {
or_op_children.push(Operation::or(false, and_op_children));
} else {
or_op_children.push(Operation::and(and_op_children));
}
}
}
op_children.push(Operation::or(false, or_op_children));
}
if any_words {
Ok(Operation::or(false, op_children))
} else {
Ok(Operation::and(op_children))
}
}
let number_phrases = query.iter().filter(|p| p.is_phrase()).count();
let remove_count = query.len() - max(number_phrases, 1);
if remove_count == 0 {
return ngrams(ctx, authorize_typos, query, false);
}
let mut operation_children = Vec::new();
let mut query = query.to_vec();
for _ in 0..=remove_count {
let pos = match terms_matching_strategy {
TermsMatchingStrategy::All => return ngrams(ctx, authorize_typos, &query, false),
TermsMatchingStrategy::Any => {
let operation = Operation::Or(
true,
vec![
// branch allowing matching documents to contains any query word.
ngrams(ctx, authorize_typos, &query, true)?,
// branch forcing matching documents to contains all the query words,
// keeping this documents of the top of the resulted list.
ngrams(ctx, authorize_typos, &query, false)?,
],
);
return Ok(operation);
}
TermsMatchingStrategy::Last => query
.iter()
.enumerate()
.filter(|(_, part)| !part.is_phrase())
.last()
.map(|(pos, _)| pos),
TermsMatchingStrategy::First => {
query.iter().enumerate().find(|(_, part)| !part.is_phrase()).map(|(pos, _)| pos)
}
TermsMatchingStrategy::Size => query
.iter()
.enumerate()
.filter(|(_, part)| !part.is_phrase())
.min_by_key(|(_, part)| match part {
PrimitiveQueryPart::Word(s, _) => s.len(),
_ => unreachable!(),
})
.map(|(pos, _)| pos),
TermsMatchingStrategy::Frequency => query
.iter()
.enumerate()
.filter(|(_, part)| !part.is_phrase())
.max_by_key(|(_, part)| match part {
PrimitiveQueryPart::Word(s, _) => {
ctx.word_documents_count(s).unwrap_or_default().unwrap_or(u64::max_value())
}
_ => unreachable!(),
})
.map(|(pos, _)| pos),
};
// compute and push the current branch on the front
operation_children.insert(0, ngrams(ctx, authorize_typos, &query, false)?);
// remove word from query before creating an new branch
match pos {
Some(pos) => query.remove(pos),
None => break,
};
}
Ok(Operation::or(true, operation_children))
}
#[derive(Default, Debug)]
struct MatchingWordCache {
all: Vec<Rc<MatchingWord>>,
map: HashMap<(String, u8, bool), Rc<MatchingWord>>,
}
impl MatchingWordCache {
fn insert(&mut self, word: String, typo: u8, prefix: bool) -> Option<Rc<MatchingWord>> {
match self.map.entry((word.clone(), typo, prefix)) {
Entry::Occupied(idx) => Some(idx.get().clone()),
Entry::Vacant(vacant) => {
let matching_word = Rc::new(MatchingWord::new(word, typo, prefix)?);
self.all.push(matching_word.clone());
vacant.insert(matching_word.clone());
Some(matching_word)
}
}
// To deactivate the cache, for testing purposes, use the following instead:
// let matching_word = Rc::new(MatchingWord::new(word, typo, prefix)?);
// self.all.push(matching_word.clone());
// Some(matching_word)
}
}
/// Main function that matchings words used for crop and highlight.
fn create_matching_words(
ctx: &impl Context,
authorize_typos: bool,
query: &[PrimitiveQueryPart],
) -> Result<MatchingWords> {
/// Matches on the `PrimitiveQueryPart` and create matchings words from it.
fn resolve_primitive_part(
ctx: &impl Context,
authorize_typos: bool,
part: PrimitiveQueryPart,
matching_words: &mut Vec<(Vec<Rc<MatchingWord>>, Vec<PrimitiveWordId>)>,
matching_word_cache: &mut MatchingWordCache,
id: PrimitiveWordId,
) -> Result<()> {
match part {
// 1. try to split word in 2
// 2. try to fetch synonyms
PrimitiveQueryPart::Word(word, prefix) => {
if let Some(synonyms) = ctx.synonyms(&[word.as_str()])? {
for synonym in synonyms {
let synonym = synonym
.into_iter()
.flat_map(|syn| matching_word_cache.insert(syn, 0, false))
.collect();
matching_words.push((synonym, vec![id]));
}
}
if let Some((left, right)) = split_best_frequency(ctx, &word)? {
if let Some(left) = matching_word_cache.insert(left.to_string(), 0, false) {
if let Some(right) = matching_word_cache.insert(right.to_string(), 0, false)
{
matching_words.push((vec![left, right], vec![id]));
}
}
}
let (word_len_one_typo, word_len_two_typo) = ctx.min_word_len_for_typo()?;
let exact_words = ctx.exact_words();
let config =
TypoConfig { max_typos: 2, word_len_one_typo, word_len_two_typo, exact_words };
let matching_word = match typos(word, authorize_typos, config) {
QueryKind::Exact { word, .. } => matching_word_cache.insert(word, 0, prefix),
QueryKind::Tolerant { typo, word } => {
matching_word_cache.insert(word, typo, prefix)
}
};
if let Some(matching_word) = matching_word {
matching_words.push((vec![matching_word], vec![id]));
}
}
// create a CONSECUTIVE matchings words wrapping all word in the phrase
PrimitiveQueryPart::Phrase(words) => {
let ids: Vec<_> =
(0..words.len()).into_iter().map(|i| id + i as PrimitiveWordId).collect();
let words = words
.into_iter()
.flatten()
.flat_map(|w| matching_word_cache.insert(w, 0, false))
.collect();
matching_words.push((words, ids));
}
}
Ok(())
}
/// Create all ngrams 1..=3 generating query tree branches.
fn ngrams(
ctx: &impl Context,
authorize_typos: bool,
query: &[PrimitiveQueryPart],
matching_words: &mut Vec<(Vec<Rc<MatchingWord>>, Vec<PrimitiveWordId>)>,
matching_word_cache: &mut MatchingWordCache,
mut id: PrimitiveWordId,
) -> Result<()> {
const MAX_NGRAM: usize = 3;
for sub_query in query.linear_group_by(|a, b| !(a.is_phrase() || b.is_phrase())) {
for ngram in 1..=MAX_NGRAM.min(sub_query.len()) {
if let Some(group) = sub_query.get(..ngram) {
let tail = &sub_query[ngram..];
let is_last = tail.is_empty();
match group {
[part] => {
resolve_primitive_part(
ctx,
authorize_typos,
part.clone(),
matching_words,
matching_word_cache,
id,
)?;
}
words => {
let is_prefix = words.last().map_or(false, |part| part.is_prefix());
let words: Vec<_> = words
.iter()
.filter_map(|part| {
if let PrimitiveQueryPart::Word(word, _) = part {
Some(word.as_str())
} else {
None
}
})
.collect();
let ids: Vec<_> = (0..words.len())
.into_iter()
.map(|i| id + i as PrimitiveWordId)
.collect();
if let Some(synonyms) = ctx.synonyms(&words)? {
for synonym in synonyms {
let synonym = synonym
.into_iter()
.flat_map(|syn| matching_word_cache.insert(syn, 0, false))
.collect();
matching_words.push((synonym, ids.clone()));
}
}
let word = words.concat();
let (word_len_one_typo, word_len_two_typo) =
ctx.min_word_len_for_typo()?;
let exact_words = ctx.exact_words();
let config = TypoConfig {
max_typos: 1,
word_len_one_typo,
word_len_two_typo,
exact_words,
};
let matching_word = match typos(word, authorize_typos, config) {
QueryKind::Exact { word, .. } => {
matching_word_cache.insert(word, 0, is_prefix)
}
QueryKind::Tolerant { typo, word } => {
matching_word_cache.insert(word, typo, is_prefix)
}
};
if let Some(matching_word) = matching_word {
matching_words.push((vec![matching_word], ids));
}
}
}
if !is_last {
ngrams(
ctx,
authorize_typos,
tail,
matching_words,
matching_word_cache,
id + 1,
)?;
}
}
}
id += sub_query.iter().map(|x| x.len() as PrimitiveWordId).sum::<PrimitiveWordId>();
}
Ok(())
}
let mut matching_word_cache = MatchingWordCache::default();
let mut matching_words = Vec::new();
ngrams(ctx, authorize_typos, query, &mut matching_words, &mut matching_word_cache, 0)?;
Ok(MatchingWords::new(matching_words))
}
pub type PrimitiveQuery = Vec<PrimitiveQueryPart>;
#[derive(Debug, Clone)]
pub enum PrimitiveQueryPart {
Phrase(Vec<Option<String>>),
Word(String, IsPrefix),
}
impl PrimitiveQueryPart {
fn is_phrase(&self) -> bool {
matches!(self, Self::Phrase(_))
}
fn is_prefix(&self) -> bool {
matches!(self, Self::Word(_, is_prefix) if *is_prefix)
}
fn len(&self) -> usize {
match self {
Self::Phrase(words) => words.len(),
Self::Word(_, _) => 1,
}
}
}
/// Create primitive query from tokenized query string,
/// the primitive query is an intermediate state to build the query tree.
fn create_primitive_query<A>(
query: ClassifiedTokenIter<A>,
words_limit: Option<usize>,
) -> PrimitiveQuery
where
A: AsRef<[u8]>,
{
let mut primitive_query = Vec::new();
let mut phrase = Vec::new();
let mut quoted = false;
let parts_limit = words_limit.unwrap_or(usize::MAX);
let mut peekable = query.peekable();
while let Some(token) = peekable.next() {
// early return if word limit is exceeded
if primitive_query.len() >= parts_limit {
return primitive_query;
}
match token.kind {
TokenKind::Word | TokenKind::StopWord => {
// 1. if the word is quoted we push it in a phrase-buffer waiting for the ending quote,
// 2. if the word is not the last token of the query and is not a stop_word we push it as a non-prefix word,
// 3. if the word is the last token of the query we push it as a prefix word.
if quoted {
if let TokenKind::StopWord = token.kind {
phrase.push(None)
} else {
phrase.push(Some(token.lemma().to_string()));
}
} else if peekable.peek().is_some() {
if let TokenKind::StopWord = token.kind {
} else {
primitive_query
.push(PrimitiveQueryPart::Word(token.lemma().to_string(), false));
}
} else {
primitive_query.push(PrimitiveQueryPart::Word(token.lemma().to_string(), true));
}
}
TokenKind::Separator(separator_kind) => {
let quote_count = token.lemma().chars().filter(|&s| s == '"').count();
// swap quoted state if we encounter a double quote
if quote_count % 2 != 0 {
quoted = !quoted;
}
// if there is a quote or a hard separator we close the phrase.
if !phrase.is_empty() && (quote_count > 0 || separator_kind == SeparatorKind::Hard)
{
primitive_query.push(PrimitiveQueryPart::Phrase(mem::take(&mut phrase)));
}
}
_ => (),
}
}
// If a quote is never closed, we consider all of the end of the query as a phrase.
if !phrase.is_empty() {
primitive_query.push(PrimitiveQueryPart::Phrase(mem::take(&mut phrase)));
}
primitive_query
}
/// Returns the maximum number of typos that this Operation allows.
pub fn maximum_typo(operation: &Operation) -> usize {
use Operation::{And, Or, Phrase, Query};
match operation {
Or(_, ops) => ops.iter().map(maximum_typo).max().unwrap_or(0),
And(ops) => ops.iter().map(maximum_typo).sum::<usize>(),
Query(q) => q.kind.typo() as usize,
// no typo allowed in phrases
Phrase(_) => 0,
}
}
/// Returns the maximum proximity that this Operation allows.
pub fn maximum_proximity(operation: &Operation) -> usize {
use Operation::{And, Or, Phrase, Query};
match operation {
Or(_, ops) => ops.iter().map(maximum_proximity).max().unwrap_or(0),
And(ops) => {
ops.iter().map(maximum_proximity).sum::<usize>() + ops.len().saturating_sub(1) * 7
}
Query(_) | Phrase(_) => 0,
}
}
#[cfg(test)]
mod test {
use std::alloc::{GlobalAlloc, System};
use std::collections::HashMap;
use std::sync::atomic::{self, AtomicI64};
use charabia::Tokenize;
use maplit::hashmap;
use rand::rngs::StdRng;
use rand::{Rng, SeedableRng};
use super::*;
use crate::index::tests::TempIndex;
use crate::index::{DEFAULT_MIN_WORD_LEN_ONE_TYPO, DEFAULT_MIN_WORD_LEN_TWO_TYPOS};
#[derive(Debug)]
struct TestContext {
synonyms: HashMap<Vec<String>, Vec<Vec<String>>>,
postings: HashMap<String, RoaringBitmap>,
exact_words: Option<fst::Set<Cow<'static, [u8]>>>,
}
impl TestContext {
fn build<A: AsRef<[u8]>>(
&self,
terms_matching_strategy: TermsMatchingStrategy,
authorize_typos: bool,
words_limit: Option<usize>,
query: ClassifiedTokenIter<A>,
) -> Result<Option<(Operation, PrimitiveQuery)>> {
let primitive_query = create_primitive_query(query, words_limit);
if !primitive_query.is_empty() {
let qt = create_query_tree(
self,
terms_matching_strategy,
authorize_typos,
&primitive_query,
)?;
Ok(Some((qt, primitive_query)))
} else {
Ok(None)
}
}
}
impl Context for TestContext {
fn word_docids(&self, word: &str) -> heed::Result<Option<RoaringBitmap>> {
Ok(self.postings.get(word).cloned())
}
fn synonyms<S: AsRef<str>>(&self, words: &[S]) -> heed::Result<Option<Vec<Vec<String>>>> {
let words: Vec<_> = words.iter().map(|s| s.as_ref().to_owned()).collect();
Ok(self.synonyms.get(&words).cloned())
}
fn min_word_len_for_typo(&self) -> heed::Result<(u8, u8)> {
Ok((DEFAULT_MIN_WORD_LEN_ONE_TYPO, DEFAULT_MIN_WORD_LEN_TWO_TYPOS))
}
fn exact_words(&self) -> Option<&fst::Set<Cow<[u8]>>> {
self.exact_words.as_ref()
}
fn word_pair_frequency(
&self,
left_word: &str,
right_word: &str,
_proximity: u8,
) -> heed::Result<Option<u64>> {
match self.word_docids(&format!("{} {}", left_word, right_word))? {
Some(rb) => Ok(Some(rb.len())),
None => Ok(None),
}
}
}
impl Default for TestContext {
fn default() -> TestContext {
let mut rng = StdRng::seed_from_u64(102);
let rng = &mut rng;
fn random_postings<R: Rng>(rng: &mut R, len: usize) -> RoaringBitmap {
let mut values = Vec::<u32>::with_capacity(len);
while values.len() != len {
values.push(rng.gen());
}
values.sort_unstable();
RoaringBitmap::from_sorted_iter(values.into_iter()).unwrap()
}
let exact_words = fst::SetBuilder::new(Vec::new()).unwrap().into_inner().unwrap();
let exact_words =
Some(fst::Set::new(exact_words).unwrap().map_data(Cow::Owned).unwrap());
TestContext {
synonyms: hashmap! {
vec![String::from("hello")] => vec![
vec![String::from("hi")],
vec![String::from("good"), String::from("morning")],
],
vec![String::from("world")] => vec![
vec![String::from("earth")],
vec![String::from("nature")],
],
// new york city
vec![String::from("nyc")] => vec![
vec![String::from("new"), String::from("york")],
vec![String::from("new"), String::from("york"), String::from("city")],
],
vec![String::from("new"), String::from("york")] => vec![
vec![String::from("nyc")],
vec![String::from("new"), String::from("york"), String::from("city")],
],
vec![String::from("new"), String::from("york"), String::from("city")] => vec![
vec![String::from("nyc")],
vec![String::from("new"), String::from("york")],
],
},
postings: hashmap! {
String::from("hello") => random_postings(rng, 1500),
String::from("hi") => random_postings(rng, 4000),
String::from("word") => random_postings(rng, 2500),
String::from("split") => random_postings(rng, 400),
String::from("ngrams") => random_postings(rng, 1400),
String::from("world") => random_postings(rng, 15_000),
String::from("earth") => random_postings(rng, 8000),
String::from("2021") => random_postings(rng, 100),
String::from("2020") => random_postings(rng, 500),
String::from("is") => random_postings(rng, 50_000),
String::from("this") => random_postings(rng, 50_000),
String::from("good") => random_postings(rng, 1250),
String::from("morning") => random_postings(rng, 125),
String::from("word split") => random_postings(rng, 5000),
String::from("quick brownfox") => random_postings(rng, 7000),
String::from("quickbrown fox") => random_postings(rng, 8000),
},
exact_words,
}
}
}
#[test]
fn prefix() {
let query = "hey friends";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR
AND
Exact { word: "hey" }
PrefixTolerant { word: "friends", max typo: 1 }
PrefixTolerant { word: "heyfriends", max typo: 1 }
"###);
}
#[test]
fn no_prefix() {
let query = "hey friends ";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR
AND
Exact { word: "hey" }
Tolerant { word: "friends", max typo: 1 }
Tolerant { word: "heyfriends", max typo: 1 }
"###);
}
#[test]
fn synonyms() {
let query = "hello world ";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR
AND
OR
Exact { word: "hi" }
AND
Exact { word: "good" }
Exact { word: "morning" }
Tolerant { word: "hello", max typo: 1 }
OR
Exact { word: "earth" }
Exact { word: "nature" }
Tolerant { word: "world", max typo: 1 }
Tolerant { word: "helloworld", max typo: 1 }
"###);
}
#[test]
fn complex_synonyms() {
let query = "new york city ";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR
AND
Exact { word: "new" }
OR
AND
Exact { word: "york" }
Exact { word: "city" }
Tolerant { word: "yorkcity", max typo: 1 }
AND
OR
Exact { word: "nyc" }
AND
Exact { word: "new" }
Exact { word: "york" }
Exact { word: "city" }
Tolerant { word: "newyork", max typo: 1 }
Exact { word: "city" }
Exact { word: "nyc" }
AND
Exact { word: "new" }
Exact { word: "york" }
Tolerant { word: "newyorkcity", max typo: 1 }
"###);
}
#[test]
fn ngrams() {
let query = "n grams ";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR
AND
Exact { word: "n" }
Tolerant { word: "grams", max typo: 1 }
Tolerant { word: "ngrams", max typo: 1 }
"###);
}
#[test]
fn word_split() {
let query = "wordsplit fish ";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR
AND
OR
PHRASE [Some("word"), Some("split")]
Tolerant { word: "wordsplit", max typo: 2 }
Exact { word: "fish" }
Tolerant { word: "wordsplitfish", max typo: 1 }
"###);
}
#[test]
fn word_split_choose_pair_with_max_freq() {
let query = "quickbrownfox";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR
PHRASE [Some("quickbrown"), Some("fox")]
PrefixTolerant { word: "quickbrownfox", max typo: 2 }
"###);
}
#[test]
fn phrase() {
let query = "\"hey friends\" \" \" \"wooop";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
AND
PHRASE [Some("hey"), Some("friends")]
Exact { word: "wooop" }
"###);
}
#[test]
fn phrase_2() {
// https://github.com/meilisearch/meilisearch/issues/2722
let query = "coco \"harry\"";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::default(), true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR(WORD)
Exact { word: "harry" }
AND
Exact { word: "coco" }
Exact { word: "harry" }
"###);
}
#[test]
fn phrase_with_hard_separator() {
let query = "\"hey friends. wooop wooop\"";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
AND
PHRASE [Some("hey"), Some("friends")]
PHRASE [Some("wooop"), Some("wooop")]
"###);
}
#[test]
fn optional_word() {
let query = "hey my friend ";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::default(), true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR(WORD)
Exact { word: "hey" }
OR
AND
Exact { word: "hey" }
Exact { word: "my" }
Tolerant { word: "heymy", max typo: 1 }
OR
AND
Exact { word: "hey" }
OR
AND
Exact { word: "my" }
Tolerant { word: "friend", max typo: 1 }
Tolerant { word: "myfriend", max typo: 1 }
AND
Tolerant { word: "heymy", max typo: 1 }
Tolerant { word: "friend", max typo: 1 }
Tolerant { word: "heymyfriend", max typo: 1 }
"###);
}
#[test]
fn optional_word_phrase() {
let query = "\"hey my\"";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::default(), true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
PHRASE [Some("hey"), Some("my")]
"###);
}
#[test]
fn optional_word_multiple_phrases() {
let query = r#""hey" my good "friend""#;
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::default(), true, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR(WORD)
AND
Exact { word: "hey" }
Exact { word: "friend" }
AND
Exact { word: "hey" }
Exact { word: "my" }
Exact { word: "friend" }
AND
Exact { word: "hey" }
OR
AND
Exact { word: "my" }
Exact { word: "good" }
Tolerant { word: "mygood", max typo: 1 }
Exact { word: "friend" }
"###);
}
#[test]
fn no_typo() {
let query = "hey friends ";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, false, None, tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
OR
AND
Exact { word: "hey" }
Exact { word: "friends" }
Exact { word: "heyfriends" }
"###);
}
#[test]
fn words_limit() {
let query = "\"hey my\" good friend";
let tokens = query.tokenize();
let (query_tree, _) = TestContext::default()
.build(TermsMatchingStrategy::All, false, Some(2), tokens)
.unwrap()
.unwrap();
insta::assert_debug_snapshot!(query_tree, @r###"
AND
PHRASE [Some("hey"), Some("my")]
Exact { word: "good" }
"###);
}
#[test]
fn test_min_word_len_typo() {
let exact_words = fst::Set::from_iter([b""]).unwrap().map_data(Cow::Owned).unwrap();
let config = TypoConfig {
max_typos: 2,
word_len_one_typo: 5,
word_len_two_typo: 7,
exact_words: Some(&exact_words),
};
assert_eq!(
typos("hello".to_string(), true, config.clone()),
QueryKind::Tolerant { typo: 1, word: "hello".to_string() }
);
assert_eq!(
typos("hell".to_string(), true, config.clone()),
QueryKind::exact("hell".to_string())
);
assert_eq!(
typos("verylongword".to_string(), true, config.clone()),
QueryKind::Tolerant { typo: 2, word: "verylongword".to_string() }
);
}
#[test]
fn test_dont_create_matching_word_for_long_words() {
let index = TempIndex::new();
let rtxn = index.read_txn().unwrap();
let query = "what a supercalifragilisticexpialidocioussupercalifragilisticexpialidocioussupercalifragilisticexpialidocioussupercalifragilisticexpialidocioussupercalifragilisticexpialidocioussupercalifragilisticexpialidocioussupercalifragilisticexpialidocioussupercalifragilisticexpialidocious house";
let mut builder = QueryTreeBuilder::new(&rtxn, &index).unwrap();
builder.words_limit(10);
let (_, _, matching_words) = builder.build(query.tokenize()).unwrap().unwrap();
insta::assert_snapshot!(format!("{matching_words:?}"), @r###"
[
([MatchingWord { word: "house", typo: 1, prefix: true }], [3])
([MatchingWord { word: "house", typo: 1, prefix: true }], [2])
([MatchingWord { word: "whata", typo: 1, prefix: false }], [0, 1])
([MatchingWord { word: "house", typo: 1, prefix: true }], [2])
([MatchingWord { word: "house", typo: 1, prefix: true }], [1])
([MatchingWord { word: "what", typo: 0, prefix: false }], [0])
([MatchingWord { word: "a", typo: 0, prefix: false }], [1])
]
"###);
}
#[test]
fn disable_typo_on_word() {
let query = "goodbye";
let tokens = query.tokenize();
let exact_words = fst::Set::from_iter(Some("goodbye")).unwrap().into_fst().into_inner();
let exact_words = Some(fst::Set::new(exact_words).unwrap().map_data(Cow::Owned).unwrap());
let context = TestContext { exact_words, ..Default::default() };
let (query_tree, _) =
context.build(TermsMatchingStrategy::All, true, Some(2), tokens).unwrap().unwrap();
assert!(matches!(
query_tree,
Operation::Query(Query { prefix: true, kind: QueryKind::Exact { .. } })
));
}
#[global_allocator]
static ALLOC: CountingAlloc =
CountingAlloc { resident: AtomicI64::new(0), allocated: AtomicI64::new(0) };
pub struct CountingAlloc {
pub resident: AtomicI64,
pub allocated: AtomicI64,
}
unsafe impl GlobalAlloc for CountingAlloc {
unsafe fn alloc(&self, layout: std::alloc::Layout) -> *mut u8 {
self.allocated.fetch_add(layout.size() as i64, atomic::Ordering::Relaxed);
self.resident.fetch_add(layout.size() as i64, atomic::Ordering::Relaxed);
System.alloc(layout)
}
unsafe fn dealloc(&self, ptr: *mut u8, layout: std::alloc::Layout) {
self.resident.fetch_sub(layout.size() as i64, atomic::Ordering::Relaxed);
System.dealloc(ptr, layout)
}
}
#[test]
fn memory_usage_of_ten_word_query() {
let resident_before = ALLOC.resident.load(atomic::Ordering::SeqCst);
let allocated_before = ALLOC.allocated.load(atomic::Ordering::SeqCst);
let index = TempIndex::new();
let rtxn = index.read_txn().unwrap();
let query = "a beautiful summer house by the beach overlooking what seems";
let mut builder = QueryTreeBuilder::new(&rtxn, &index).unwrap();
builder.words_limit(10);
let x = builder.build(query.tokenize()).unwrap().unwrap();
let resident_after = ALLOC.resident.load(atomic::Ordering::SeqCst);
let allocated_after = ALLOC.allocated.load(atomic::Ordering::SeqCst);
// Weak check on the memory usage
// Don't keep more than 5MB. (Arguably 5MB is already too high)
assert!(resident_after - resident_before < 5_000_000);
// Don't allocate more than 10MB.
assert!(allocated_after - allocated_before < 10_000_000);
// Use these snapshots to measure the exact memory usage.
// The values below were correct at the time I wrote them.
// insta::assert_snapshot!(format!("{}", resident_after - resident_before), @"4486950");
// insta::assert_snapshot!(format!("{}", allocated_after - allocated_before), @"7107502");
// Note, with the matching word cache deactivated, the memory usage was:
// insta::assert_snapshot!(format!("{}", resident_after - resident_before), @"91248697");
// insta::assert_snapshot!(format!("{}", allocated_after - allocated_before), @"125697588");
// or about 20x more resident memory (90MB vs 4.5MB)
// Use x
let _x = x;
}
}