MeiliSearch/meilisearch-http/src/helpers/meilisearch.rs
2020-05-28 16:23:46 +02:00

649 lines
24 KiB
Rust

use std::cmp::Ordering;
use std::collections::{HashMap, HashSet};
use std::hash::{Hash, Hasher};
use std::time::Instant;
use indexmap::IndexMap;
use log::error;
use meilisearch_core::{Filter, MainReader};
use meilisearch_core::facets::FacetFilter;
use meilisearch_core::criterion::*;
use meilisearch_core::settings::RankingRule;
use meilisearch_core::{Highlight, Index, RankedMap};
use meilisearch_schema::{FieldId, Schema};
use meilisearch_tokenizer::is_cjk;
use serde::{Deserialize, Serialize};
use serde_json::Value;
use siphasher::sip::SipHasher;
use slice_group_by::GroupBy;
use crate::error::{Error, ResponseError};
pub trait IndexSearchExt {
fn new_search(&self, query: String) -> SearchBuilder;
}
impl IndexSearchExt for Index {
fn new_search(&self, query: String) -> SearchBuilder {
SearchBuilder {
index: self,
query,
offset: 0,
limit: 20,
attributes_to_crop: None,
attributes_to_retrieve: None,
attributes_to_highlight: None,
filters: None,
matches: false,
facet_filters: None,
facets: None,
}
}
}
pub struct SearchBuilder<'a> {
index: &'a Index,
query: String,
offset: usize,
limit: usize,
attributes_to_crop: Option<HashMap<String, usize>>,
attributes_to_retrieve: Option<HashSet<String>>,
attributes_to_highlight: Option<HashSet<String>>,
filters: Option<String>,
matches: bool,
facet_filters: Option<FacetFilter>,
facets: Option<Vec<(FieldId, String)>>
}
impl<'a> SearchBuilder<'a> {
pub fn offset(&mut self, value: usize) -> &SearchBuilder {
self.offset = value;
self
}
pub fn limit(&mut self, value: usize) -> &SearchBuilder {
self.limit = value;
self
}
pub fn attributes_to_crop(&mut self, value: HashMap<String, usize>) -> &SearchBuilder {
self.attributes_to_crop = Some(value);
self
}
pub fn attributes_to_retrieve(&mut self, value: HashSet<String>) -> &SearchBuilder {
self.attributes_to_retrieve = Some(value);
self
}
pub fn add_retrievable_field(&mut self, value: String) -> &SearchBuilder {
let attributes_to_retrieve = self.attributes_to_retrieve.get_or_insert(HashSet::new());
attributes_to_retrieve.insert(value);
self
}
pub fn attributes_to_highlight(&mut self, value: HashSet<String>) -> &SearchBuilder {
self.attributes_to_highlight = Some(value);
self
}
pub fn add_facet_filters(&mut self, filters: FacetFilter) -> &SearchBuilder {
self.facet_filters = Some(filters);
self
}
pub fn filters(&mut self, value: String) -> &SearchBuilder {
self.filters = Some(value);
self
}
pub fn get_matches(&mut self) -> &SearchBuilder {
self.matches = true;
self
}
pub fn add_facets(&mut self, facets: Vec<(FieldId, String)>) -> &SearchBuilder {
self.facets = Some(facets);
self
}
pub fn search(self, reader: &MainReader) -> Result<SearchResult, ResponseError> {
let schema = self
.index
.main
.schema(reader)?
.ok_or(Error::internal("missing schema"))?;
let ranked_map = self.index.main.ranked_map(reader)?.unwrap_or_default();
// Change criteria
let mut query_builder = match self.get_criteria(reader, &ranked_map, &schema)? {
Some(criteria) => self.index.query_builder_with_criteria(criteria),
None => self.index.query_builder(),
};
if let Some(filter_expression) = &self.filters {
let filter = Filter::parse(filter_expression, &schema)?;
let index = &self.index;
query_builder.with_filter(move |id| {
let reader = &reader;
let filter = &filter;
match filter.test(reader, index, id) {
Ok(res) => res,
Err(e) => {
log::warn!("unexpected error during filtering: {}", e);
false
}
}
});
}
if let Some(field) = self.index.main.distinct_attribute(reader)? {
if let Some(field_id) = schema.id(&field) {
let index = &self.index;
query_builder.with_distinct(1, move |id| {
match index.document_attribute_bytes(reader, id, field_id) {
Ok(Some(bytes)) => {
let mut s = SipHasher::new();
bytes.hash(&mut s);
Some(s.finish())
}
_ => None,
}
});
}
}
query_builder.set_facet_filter(self.facet_filters);
query_builder.set_facets(self.facets);
let start = Instant::now();
let result = query_builder.query(reader, &self.query, self.offset..(self.offset + self.limit));
let search_result = result.map_err(Error::search_documents)?;
let time_ms = start.elapsed().as_millis() as usize;
let mut all_attributes: HashSet<&str> = HashSet::new();
let mut all_formatted: HashSet<&str> = HashSet::new();
match &self.attributes_to_retrieve {
Some(to_retrieve) => {
all_attributes.extend(to_retrieve.iter().map(String::as_str));
if let Some(to_highlight) = &self.attributes_to_highlight {
all_formatted.extend(to_highlight.iter().map(String::as_str));
}
if let Some(to_crop) = &self.attributes_to_crop {
all_formatted.extend(to_crop.keys().map(String::as_str));
}
all_attributes.extend(&all_formatted);
},
None => {
all_attributes.extend(schema.displayed_name());
// If we specified at least one attribute to highlight or crop then
// all available attributes will be returned in the _formatted field.
if self.attributes_to_highlight.is_some() || self.attributes_to_crop.is_some() {
all_formatted.extend(all_attributes.iter().cloned());
}
},
}
let mut hits = Vec::with_capacity(self.limit);
for doc in search_result.documents {
let mut document: IndexMap<String, Value> = self
.index
.document(reader, Some(&all_attributes), doc.id)
.map_err(|e| Error::retrieve_document(doc.id.0, e))?
.ok_or(Error::internal(
"Impossible to retrieve the document; Corrupted data",
))?;
let mut formatted = document.iter()
.filter(|(key, _)| all_formatted.contains(key.as_str()))
.map(|(k, v)| (k.clone(), v.clone()))
.collect();
let mut matches = doc.highlights.clone();
// Crops fields if needed
if let Some(fields) = &self.attributes_to_crop {
crop_document(&mut formatted, &mut matches, &schema, fields);
}
// Transform to readable matches
if let Some(attributes_to_highlight) = &self.attributes_to_highlight {
let matches = calculate_matches(
&matches,
self.attributes_to_highlight.clone(),
&schema,
);
formatted = calculate_highlights(&formatted, &matches, attributes_to_highlight);
}
let matches_info = if self.matches {
Some(calculate_matches(&matches, self.attributes_to_retrieve.clone(), &schema))
} else {
None
};
if let Some(attributes_to_retrieve) = &self.attributes_to_retrieve {
document.retain(|key, _| attributes_to_retrieve.contains(&key.to_string()))
}
let hit = SearchHit {
document,
formatted,
matches_info,
};
hits.push(hit);
}
let results = SearchResult {
hits,
offset: self.offset,
limit: self.limit,
nb_hits: search_result.nb_hits,
exhaustive_nb_hits: search_result.exhaustive_nb_hit,
processing_time_ms: time_ms,
query: self.query.to_string(),
facets_distribution: search_result.facets,
exhaustive_facets_count: search_result.exhaustive_facets_count,
};
Ok(results)
}
pub fn get_criteria(
&self,
reader: &MainReader,
ranked_map: &'a RankedMap,
schema: &Schema,
) -> Result<Option<Criteria<'a>>, ResponseError> {
let ranking_rules = self.index.main.ranking_rules(reader)?;
if let Some(ranking_rules) = ranking_rules {
let mut builder = CriteriaBuilder::with_capacity(7 + ranking_rules.len());
for rule in ranking_rules {
match rule {
RankingRule::Typo => builder.push(Typo),
RankingRule::Words => builder.push(Words),
RankingRule::Proximity => builder.push(Proximity),
RankingRule::Attribute => builder.push(Attribute),
RankingRule::WordsPosition => builder.push(WordsPosition),
RankingRule::Exactness => builder.push(Exactness),
RankingRule::Asc(field) => {
match SortByAttr::lower_is_better(&ranked_map, &schema, &field) {
Ok(rule) => builder.push(rule),
Err(err) => error!("Error during criteria builder; {:?}", err),
}
}
RankingRule::Desc(field) => {
match SortByAttr::higher_is_better(&ranked_map, &schema, &field) {
Ok(rule) => builder.push(rule),
Err(err) => error!("Error during criteria builder; {:?}", err),
}
}
}
}
builder.push(DocumentId);
return Ok(Some(builder.build()));
}
Ok(None)
}
}
#[derive(Debug, Clone, Eq, PartialEq, PartialOrd, Serialize, Deserialize)]
pub struct MatchPosition {
pub start: usize,
pub length: usize,
}
impl Ord for MatchPosition {
fn cmp(&self, other: &Self) -> Ordering {
match self.start.cmp(&other.start) {
Ordering::Equal => self.length.cmp(&other.length),
_ => self.start.cmp(&other.start),
}
}
}
pub type HighlightInfos = HashMap<String, Value>;
pub type MatchesInfos = HashMap<String, Vec<MatchPosition>>;
// pub type RankingInfos = HashMap<String, u64>;
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SearchHit {
#[serde(flatten)]
pub document: IndexMap<String, Value>,
#[serde(rename = "_formatted", skip_serializing_if = "IndexMap::is_empty")]
pub formatted: IndexMap<String, Value>,
#[serde(rename = "_matchesInfo", skip_serializing_if = "Option::is_none")]
pub matches_info: Option<MatchesInfos>,
}
#[derive(Debug, Clone, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct SearchResult {
pub hits: Vec<SearchHit>,
pub offset: usize,
pub limit: usize,
pub nb_hits: usize,
pub exhaustive_nb_hits: bool,
pub processing_time_ms: usize,
pub query: String,
#[serde(skip_serializing_if = "Option::is_none")]
pub facets_distribution: Option<HashMap<String, HashMap<String, usize>>>,
#[serde(skip_serializing_if = "Option::is_none")]
pub exhaustive_facets_count: Option<bool>,
}
/// returns the start index and the length on the crop.
fn aligned_crop(text: &str, match_index: usize, context: usize) -> (usize, usize) {
let is_word_component = |c: &char| c.is_alphanumeric() && !is_cjk(*c);
let word_end_index = |mut index| {
if text.chars().nth(index - 1).map_or(false, |c| is_word_component(&c)) {
index += text.chars().skip(index).take_while(is_word_component).count();
}
index
};
if context == 0 {
// count need to be at least 1 for cjk queries to return something
return (match_index, 1 + text.chars().skip(match_index).take_while(is_word_component).count());
}
let start = match match_index.saturating_sub(context) {
0 => 0,
n => {
let word_end_index = word_end_index(n);
// skip whitespaces if any
word_end_index + text.chars().skip(word_end_index).take_while(char::is_ascii_whitespace).count()
}
};
let end = word_end_index(match_index + context);
(start, end - start)
}
fn crop_text(
text: &str,
matches: impl IntoIterator<Item = Highlight>,
context: usize,
) -> (String, Vec<Highlight>) {
let mut matches = matches.into_iter().peekable();
let char_index = matches.peek().map(|m| m.char_index as usize).unwrap_or(0);
let (start, count) = aligned_crop(text, char_index, context);
// TODO do something about double allocation
let text = text
.chars()
.skip(start)
.take(count)
.collect::<String>()
.trim()
.to_string();
// update matches index to match the new cropped text
let matches = matches
.take_while(|m| (m.char_index as usize) + (m.char_length as usize) <= start + count)
.map(|m| Highlight {
char_index: m.char_index - start as u16,
..m
})
.collect();
(text, matches)
}
fn crop_document(
document: &mut IndexMap<String, Value>,
matches: &mut Vec<Highlight>,
schema: &Schema,
fields: &HashMap<String, usize>,
) {
matches.sort_unstable_by_key(|m| (m.char_index, m.char_length));
for (field, length) in fields {
let attribute = match schema.id(field) {
Some(attribute) => attribute,
None => continue,
};
let selected_matches = matches
.iter()
.filter(|m| FieldId::new(m.attribute) == attribute)
.cloned();
if let Some(Value::String(ref mut original_text)) = document.get_mut(field) {
let (cropped_text, cropped_matches) =
crop_text(original_text, selected_matches, *length);
*original_text = cropped_text;
matches.retain(|m| FieldId::new(m.attribute) != attribute);
matches.extend_from_slice(&cropped_matches);
}
}
}
fn calculate_matches(
matches: &[Highlight],
attributes_to_retrieve: Option<HashSet<String>>,
schema: &Schema,
) -> MatchesInfos {
let mut matches_result: HashMap<String, Vec<MatchPosition>> = HashMap::new();
for m in matches.iter() {
if let Some(attribute) = schema.name(FieldId::new(m.attribute)) {
if let Some(ref attributes_to_retrieve) = attributes_to_retrieve {
if !attributes_to_retrieve.contains(attribute) {
continue;
}
}
if !schema.displayed_name().contains(attribute) {
continue;
}
if let Some(pos) = matches_result.get_mut(attribute) {
pos.push(MatchPosition {
start: m.char_index as usize,
length: m.char_length as usize,
});
} else {
let mut positions = Vec::new();
positions.push(MatchPosition {
start: m.char_index as usize,
length: m.char_length as usize,
});
matches_result.insert(attribute.to_string(), positions);
}
}
}
for (_, val) in matches_result.iter_mut() {
val.sort_unstable();
val.dedup();
}
matches_result
}
fn calculate_highlights(
document: &IndexMap<String, Value>,
matches: &MatchesInfos,
attributes_to_highlight: &HashSet<String>,
) -> IndexMap<String, Value> {
let mut highlight_result = document.clone();
for (attribute, matches) in matches.iter() {
if attributes_to_highlight.contains(attribute) {
if let Some(Value::String(value)) = document.get(attribute) {
let value: Vec<_> = value.chars().collect();
let mut highlighted_value = String::new();
let mut index = 0;
let longest_matches = matches
.linear_group_by_key(|m| m.start)
.map(|group| group.last().unwrap())
.filter(move |m| m.start >= index);
for m in longest_matches {
let before = value.get(index..m.start);
let highlighted = value.get(m.start..(m.start + m.length));
if let (Some(before), Some(highlighted)) = (before, highlighted) {
highlighted_value.extend(before);
highlighted_value.push_str("<em>");
highlighted_value.extend(highlighted);
highlighted_value.push_str("</em>");
index = m.start + m.length;
} else {
error!("value: {:?}; index: {:?}, match: {:?}", value, index, m);
}
}
highlighted_value.extend(value[index..].iter());
highlight_result.insert(attribute.to_string(), Value::String(highlighted_value));
};
}
}
highlight_result
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn aligned_crops() {
let text = r#"En ce début de trentième millénaire, l'Empire n'a jamais été aussi puissant, aussi étendu à travers toute la galaxie. C'est dans sa capitale, Trantor, que l'éminent savant Hari Seldon invente la psychohistoire, une science toute nouvelle, à base de psychologie et de mathématiques, qui lui permet de prédire l'avenir... C'est-à-dire l'effondrement de l'Empire d'ici cinq siècles et au-delà, trente mille années de chaos et de ténèbres. Pour empêcher cette catastrophe et sauver la civilisation, Seldon crée la Fondation."#;
// simple test
let (start, length) = aligned_crop(&text, 6, 2);
let cropped = text.chars().skip(start).take(length).collect::<String>().trim().to_string();
assert_eq!("début", cropped);
// first word test
let (start, length) = aligned_crop(&text, 0, 1);
let cropped = text.chars().skip(start).take(length).collect::<String>().trim().to_string();
assert_eq!("En", cropped);
// last word test
let (start, length) = aligned_crop(&text, 510, 2);
let cropped = text.chars().skip(start).take(length).collect::<String>().trim().to_string();
assert_eq!("Fondation", cropped);
// CJK tests
let text = "this isのス foo myタイリ test";
// mixed charset
let (start, length) = aligned_crop(&text, 5, 3);
let cropped = text.chars().skip(start).take(length).collect::<String>().trim().to_string();
assert_eq!("isの", cropped);
// split regular word / CJK word, no space
let (start, length) = aligned_crop(&text, 7, 1);
let cropped = text.chars().skip(start).take(length).collect::<String>().trim().to_string();
assert_eq!("", cropped);
}
#[test]
fn calculate_matches() {
let mut matches = Vec::new();
matches.push(Highlight { attribute: 0, char_index: 0, char_length: 3});
matches.push(Highlight { attribute: 0, char_index: 0, char_length: 2});
let mut attributes_to_retrieve: HashSet<String> = HashSet::new();
attributes_to_retrieve.insert("title".to_string());
let schema = Schema::with_primary_key("title");
let matches_result = super::calculate_matches(&matches, Some(attributes_to_retrieve), &schema);
let mut matches_result_expected: HashMap<String, Vec<MatchPosition>> = HashMap::new();
let mut positions = Vec::new();
positions.push(MatchPosition {
start: 0,
length: 2,
});
positions.push(MatchPosition {
start: 0,
length: 3,
});
matches_result_expected.insert("title".to_string(), positions);
assert_eq!(matches_result, matches_result_expected);
}
#[test]
fn calculate_highlights() {
let data = r#"{
"title": "Fondation (Isaac ASIMOV)",
"description": "En ce début de trentième millénaire, l'Empire n'a jamais été aussi puissant, aussi étendu à travers toute la galaxie. C'est dans sa capitale, Trantor, que l'éminent savant Hari Seldon invente la psychohistoire, une science toute nouvelle, à base de psychologie et de mathématiques, qui lui permet de prédire l'avenir... C'est-à-dire l'effondrement de l'Empire d'ici cinq siècles et au-delà, trente mille années de chaos et de ténèbres. Pour empêcher cette catastrophe et sauver la civilisation, Seldon crée la Fondation."
}"#;
let document: IndexMap<String, Value> = serde_json::from_str(data).unwrap();
let mut attributes_to_highlight = HashSet::new();
attributes_to_highlight.insert("title".to_string());
attributes_to_highlight.insert("description".to_string());
let mut matches = HashMap::new();
let mut m = Vec::new();
m.push(MatchPosition {
start: 0,
length: 9,
});
matches.insert("title".to_string(), m);
let mut m = Vec::new();
m.push(MatchPosition {
start: 510,
length: 9,
});
matches.insert("description".to_string(), m);
let result = super::calculate_highlights(&document, &matches, &attributes_to_highlight);
let mut result_expected = IndexMap::new();
result_expected.insert(
"title".to_string(),
Value::String("<em>Fondation</em> (Isaac ASIMOV)".to_string()),
);
result_expected.insert("description".to_string(), Value::String("En ce début de trentième millénaire, l'Empire n'a jamais été aussi puissant, aussi étendu à travers toute la galaxie. C'est dans sa capitale, Trantor, que l'éminent savant Hari Seldon invente la psychohistoire, une science toute nouvelle, à base de psychologie et de mathématiques, qui lui permet de prédire l'avenir... C'est-à-dire l'effondrement de l'Empire d'ici cinq siècles et au-delà, trente mille années de chaos et de ténèbres. Pour empêcher cette catastrophe et sauver la civilisation, Seldon crée la <em>Fondation</em>.".to_string()));
assert_eq!(result, result_expected);
}
#[test]
fn highlight_longest_match() {
let data = r#"{
"title": "Ice"
}"#;
let document: IndexMap<String, Value> = serde_json::from_str(data).unwrap();
let mut attributes_to_highlight = HashSet::new();
attributes_to_highlight.insert("title".to_string());
let mut matches = HashMap::new();
let mut m = Vec::new();
m.push(MatchPosition {
start: 0,
length: 2,
});
m.push(MatchPosition {
start: 0,
length: 3,
});
matches.insert("title".to_string(), m);
let result = super::calculate_highlights(&document, &matches, &attributes_to_highlight);
let mut result_expected = IndexMap::new();
result_expected.insert(
"title".to_string(),
Value::String("<em>Ice</em>".to_string()),
);
assert_eq!(result, result_expected);
}
}