MeiliSearch/meilisearch-core/src/bucket_sort.rs

630 lines
22 KiB
Rust

use std::borrow::Cow;
use std::collections::HashMap;
use std::mem;
use std::ops::Deref;
use std::ops::Range;
use std::rc::Rc;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::time::Instant;
use std::fmt;
use compact_arena::{SmallArena, Idx32, mk_arena};
use log::debug;
use meilisearch_types::DocIndex;
use sdset::{Set, SetBuf, exponential_search, SetOperation, Counter, duo::OpBuilder};
use slice_group_by::{GroupBy, GroupByMut};
use crate::error::Error;
use crate::criterion::{Criteria, Context, ContextMut};
use crate::distinct_map::{BufferedDistinctMap, DistinctMap};
use crate::raw_document::RawDocument;
use crate::{database::MainT, reordered_attrs::ReorderedAttrs};
use crate::{store, Document, DocumentId, MResult};
use crate::query_tree::{create_query_tree, traverse_query_tree};
use crate::query_tree::{Operation, QueryResult, QueryKind, QueryId, PostingsKey};
use crate::query_tree::Context as QTContext;
#[derive(Debug, Default)]
pub struct SortResult {
pub documents: Vec<Document>,
pub nb_hits: usize,
pub exhaustive_nb_hit: bool,
pub facets: Option<HashMap<String, HashMap<String, usize>>>,
pub exhaustive_facet_count: Option<bool>,
}
pub fn bucket_sort<'c, FI>(
reader: &heed::RoTxn<MainT>,
query: &str,
range: Range<usize>,
facets_docids: Option<SetBuf<DocumentId>>,
facet_count_docids: Option<HashMap<String, HashMap<String, Cow<Set<DocumentId>>>>>,
filter: Option<FI>,
criteria: Criteria<'c>,
searchable_attrs: Option<ReorderedAttrs>,
main_store: store::Main,
postings_lists_store: store::PostingsLists,
documents_fields_counts_store: store::DocumentsFieldsCounts,
synonyms_store: store::Synonyms,
prefix_documents_cache_store: store::PrefixDocumentsCache,
prefix_postings_lists_cache_store: store::PrefixPostingsListsCache,
) -> MResult<SortResult>
where
FI: Fn(DocumentId) -> bool,
{
// We delegate the filter work to the distinct query builder,
// specifying a distinct rule that has no effect.
if filter.is_some() {
let distinct = |_| None;
let distinct_size = 1;
return bucket_sort_with_distinct(
reader,
query,
range,
facets_docids,
facet_count_docids,
filter,
distinct,
distinct_size,
criteria,
searchable_attrs,
main_store,
postings_lists_store,
documents_fields_counts_store,
synonyms_store,
prefix_documents_cache_store,
prefix_postings_lists_cache_store,
);
}
let mut result = SortResult::default();
let words_set = match unsafe { main_store.static_words_fst(reader)? } {
Some(words) => words,
None => return Ok(SortResult::default()),
};
let stop_words = main_store.stop_words_fst(reader)?.unwrap_or_default();
let context = QTContext {
words_set,
stop_words,
synonyms: synonyms_store,
postings_lists: postings_lists_store,
prefix_postings_lists: prefix_postings_lists_cache_store,
};
let (operation, mapping) = create_query_tree(reader, &context, query)?;
debug!("operation:\n{:?}", operation);
debug!("mapping:\n{:?}", mapping);
fn recurs_operation<'o>(map: &mut HashMap<QueryId, &'o QueryKind>, operation: &'o Operation) {
match operation {
Operation::And(ops) => ops.iter().for_each(|op| recurs_operation(map, op)),
Operation::Or(ops) => ops.iter().for_each(|op| recurs_operation(map, op)),
Operation::Query(query) => { map.insert(query.id, &query.kind); },
}
}
let mut queries_kinds = HashMap::new();
recurs_operation(&mut queries_kinds, &operation);
let QueryResult { mut docids, queries } = traverse_query_tree(reader, &context, &operation)?;
debug!("found {} documents", docids.len());
debug!("number of postings {:?}", queries.len());
if let Some(facets_docids) = facets_docids {
let intersection = sdset::duo::OpBuilder::new(docids.as_ref(), facets_docids.as_set())
.intersection()
.into_set_buf();
docids = Cow::Owned(intersection);
}
if let Some(f) = facet_count_docids {
// hardcoded value, until approximation optimization
result.exhaustive_facet_count = Some(true);
result.facets = Some(facet_count(f, &docids));
}
let before = Instant::now();
mk_arena!(arena);
let mut bare_matches = cleanup_bare_matches(&mut arena, &docids, queries);
debug!("matches cleaned in {:.02?}", before.elapsed());
let before_bucket_sort = Instant::now();
let before_raw_documents_building = Instant::now();
let mut raw_documents = Vec::new();
for bare_matches in bare_matches.linear_group_by_key_mut(|sm| sm.document_id) {
let raw_document = RawDocument::new(bare_matches, &mut arena, searchable_attrs.as_ref());
raw_documents.push(raw_document);
}
debug!("creating {} candidates documents took {:.02?}",
raw_documents.len(),
before_raw_documents_building.elapsed(),
);
let before_criterion_loop = Instant::now();
let proximity_count = AtomicUsize::new(0);
let mut groups = vec![raw_documents.as_mut_slice()];
'criteria: for criterion in criteria.as_ref() {
let tmp_groups = mem::replace(&mut groups, Vec::new());
let mut documents_seen = 0;
for mut group in tmp_groups {
let before_criterion_preparation = Instant::now();
let ctx = ContextMut {
reader,
postings_lists: &mut arena,
query_mapping: &mapping,
documents_fields_counts_store,
};
criterion.prepare(ctx, &mut group)?;
debug!("{:?} preparation took {:.02?}", criterion.name(), before_criterion_preparation.elapsed());
let ctx = Context {
postings_lists: &arena,
query_mapping: &mapping,
};
let before_criterion_sort = Instant::now();
group.sort_unstable_by(|a, b| criterion.evaluate(&ctx, a, b));
debug!("{:?} evaluation took {:.02?}", criterion.name(), before_criterion_sort.elapsed());
for group in group.binary_group_by_mut(|a, b| criterion.eq(&ctx, a, b)) {
debug!("{:?} produced a group of size {}", criterion.name(), group.len());
documents_seen += group.len();
groups.push(group);
// we have sort enough documents if the last document sorted is after
// the end of the requested range, we can continue to the next criterion
if documents_seen >= range.end {
continue 'criteria;
}
}
}
}
debug!("criterion loop took {:.02?}", before_criterion_loop.elapsed());
debug!("proximity evaluation called {} times", proximity_count.load(Ordering::Relaxed));
let schema = main_store.schema(reader)?.ok_or(Error::SchemaMissing)?;
let iter = raw_documents.into_iter().skip(range.start).take(range.len());
let iter = iter.map(|rd| Document::from_raw(rd, &queries_kinds, &arena, searchable_attrs.as_ref(), &schema));
let documents = iter.collect();
debug!("bucket sort took {:.02?}", before_bucket_sort.elapsed());
result.documents = documents;
result.nb_hits = docids.len();
Ok(result)
}
pub fn bucket_sort_with_distinct<'c, FI, FD>(
reader: &heed::RoTxn<MainT>,
query: &str,
range: Range<usize>,
facets_docids: Option<SetBuf<DocumentId>>,
facet_count_docids: Option<HashMap<String, HashMap<String, Cow<Set<DocumentId>>>>>,
filter: Option<FI>,
distinct: FD,
distinct_size: usize,
criteria: Criteria<'c>,
searchable_attrs: Option<ReorderedAttrs>,
main_store: store::Main,
postings_lists_store: store::PostingsLists,
documents_fields_counts_store: store::DocumentsFieldsCounts,
synonyms_store: store::Synonyms,
_prefix_documents_cache_store: store::PrefixDocumentsCache,
prefix_postings_lists_cache_store: store::PrefixPostingsListsCache,
) -> MResult<SortResult>
where
FI: Fn(DocumentId) -> bool,
FD: Fn(DocumentId) -> Option<u64>,
{
let mut result = SortResult::default();
let words_set = match unsafe { main_store.static_words_fst(reader)? } {
Some(words) => words,
None => return Ok(SortResult::default()),
};
let stop_words = main_store.stop_words_fst(reader)?.unwrap_or_default();
let context = QTContext {
words_set,
stop_words,
synonyms: synonyms_store,
postings_lists: postings_lists_store,
prefix_postings_lists: prefix_postings_lists_cache_store,
};
let (operation, mapping) = create_query_tree(reader, &context, query)?;
debug!("operation:\n{:?}", operation);
debug!("mapping:\n{:?}", mapping);
fn recurs_operation<'o>(map: &mut HashMap<QueryId, &'o QueryKind>, operation: &'o Operation) {
match operation {
Operation::And(ops) => ops.iter().for_each(|op| recurs_operation(map, op)),
Operation::Or(ops) => ops.iter().for_each(|op| recurs_operation(map, op)),
Operation::Query(query) => { map.insert(query.id, &query.kind); },
}
}
let mut queries_kinds = HashMap::new();
recurs_operation(&mut queries_kinds, &operation);
let QueryResult { mut docids, queries } = traverse_query_tree(reader, &context, &operation)?;
debug!("found {} documents", docids.len());
debug!("number of postings {:?}", queries.len());
if let Some(facets_docids) = facets_docids {
let intersection = OpBuilder::new(docids.as_ref(), facets_docids.as_set())
.intersection()
.into_set_buf();
docids = Cow::Owned(intersection);
}
if let Some(f) = facet_count_docids {
// hardcoded value, until approximation optimization
result.exhaustive_facet_count = Some(true);
result.facets = Some(facet_count(f, &docids));
}
let before = Instant::now();
mk_arena!(arena);
let mut bare_matches = cleanup_bare_matches(&mut arena, &docids, queries);
debug!("matches cleaned in {:.02?}", before.elapsed());
let before_raw_documents_building = Instant::now();
let mut raw_documents = Vec::new();
for bare_matches in bare_matches.linear_group_by_key_mut(|sm| sm.document_id) {
let raw_document = RawDocument::new(bare_matches, &mut arena, searchable_attrs.as_ref());
raw_documents.push(raw_document);
}
debug!("creating {} candidates documents took {:.02?}",
raw_documents.len(),
before_raw_documents_building.elapsed(),
);
let mut groups = vec![raw_documents.as_mut_slice()];
let mut key_cache = HashMap::new();
let mut filter_map = HashMap::new();
// these two variables informs on the current distinct map and
// on the raw offset of the start of the group where the
// range.start bound is located according to the distinct function
let mut distinct_map = DistinctMap::new(distinct_size);
let mut distinct_raw_offset = 0;
'criteria: for criterion in criteria.as_ref() {
let tmp_groups = mem::replace(&mut groups, Vec::new());
let mut buf_distinct = BufferedDistinctMap::new(&mut distinct_map);
let mut documents_seen = 0;
for mut group in tmp_groups {
// if this group does not overlap with the requested range,
// push it without sorting and splitting it
if documents_seen + group.len() < distinct_raw_offset {
documents_seen += group.len();
groups.push(group);
continue;
}
let ctx = ContextMut {
reader,
postings_lists: &mut arena,
query_mapping: &mapping,
documents_fields_counts_store,
};
let before_criterion_preparation = Instant::now();
criterion.prepare(ctx, &mut group)?;
debug!("{:?} preparation took {:.02?}", criterion.name(), before_criterion_preparation.elapsed());
let ctx = Context {
postings_lists: &arena,
query_mapping: &mapping,
};
let before_criterion_sort = Instant::now();
group.sort_unstable_by(|a, b| criterion.evaluate(&ctx, a, b));
debug!("{:?} evaluation took {:.02?}", criterion.name(), before_criterion_sort.elapsed());
for group in group.binary_group_by_mut(|a, b| criterion.eq(&ctx, a, b)) {
// we must compute the real distinguished len of this sub-group
for document in group.iter() {
let filter_accepted = match &filter {
Some(filter) => {
let entry = filter_map.entry(document.id);
*entry.or_insert_with(|| (filter)(document.id))
}
None => true,
};
if filter_accepted {
let entry = key_cache.entry(document.id);
let key = entry.or_insert_with(|| (distinct)(document.id).map(Rc::new));
match key.clone() {
Some(key) => buf_distinct.register(key),
None => buf_distinct.register_without_key(),
};
}
// the requested range end is reached: stop computing distinct
if buf_distinct.len() >= range.end {
break;
}
}
documents_seen += group.len();
groups.push(group);
// if this sub-group does not overlap with the requested range
// we must update the distinct map and its start index
if buf_distinct.len() < range.start {
buf_distinct.transfert_to_internal();
distinct_raw_offset = documents_seen;
}
// we have sort enough documents if the last document sorted is after
// the end of the requested range, we can continue to the next criterion
if buf_distinct.len() >= range.end {
continue 'criteria;
}
}
}
}
// once we classified the documents related to the current
// automatons we save that as the next valid result
let mut seen = BufferedDistinctMap::new(&mut distinct_map);
let schema = main_store.schema(reader)?.ok_or(Error::SchemaMissing)?;
let mut documents = Vec::with_capacity(range.len());
for raw_document in raw_documents.into_iter().skip(distinct_raw_offset) {
let filter_accepted = match &filter {
Some(_) => filter_map.remove(&raw_document.id).unwrap(),
None => true,
};
if filter_accepted {
let key = key_cache.remove(&raw_document.id).unwrap();
let distinct_accepted = match key {
Some(key) => seen.register(key),
None => seen.register_without_key(),
};
if distinct_accepted && seen.len() > range.start {
documents.push(Document::from_raw(raw_document, &queries_kinds, &arena, searchable_attrs.as_ref(), &schema));
if documents.len() == range.len() {
break;
}
}
}
}
result.documents = documents;
result.nb_hits = docids.len();
Ok(result)
}
fn cleanup_bare_matches<'tag, 'txn>(
arena: &mut SmallArena<'tag, PostingsListView<'txn>>,
docids: &Set<DocumentId>,
queries: HashMap<PostingsKey, Cow<'txn, Set<DocIndex>>>,
) -> Vec<BareMatch<'tag>>
{
let docidslen = docids.len() as f32;
let mut bare_matches = Vec::new();
for (PostingsKey { query, input, distance, is_exact }, matches) in queries {
let postings_list_view = PostingsListView::original(Rc::from(input), Rc::new(matches));
let pllen = postings_list_view.len() as f32;
if docidslen / pllen >= 0.8 {
let mut offset = 0;
for matches in postings_list_view.linear_group_by_key(|m| m.document_id) {
let document_id = matches[0].document_id;
if docids.contains(&document_id) {
let range = postings_list_view.range(offset, matches.len());
let posting_list_index = arena.add(range);
let bare_match = BareMatch {
document_id,
query_index: query.id,
distance,
is_exact,
postings_list: posting_list_index,
};
bare_matches.push(bare_match);
}
offset += matches.len();
}
} else {
let mut offset = 0;
for id in docids.as_slice() {
let di = DocIndex { document_id: *id, ..DocIndex::default() };
let pos = exponential_search(&postings_list_view[offset..], &di).unwrap_or_else(|x| x);
offset += pos;
let group = postings_list_view[offset..]
.linear_group_by_key(|m| m.document_id)
.next()
.filter(|matches| matches[0].document_id == *id);
if let Some(matches) = group {
let range = postings_list_view.range(offset, matches.len());
let posting_list_index = arena.add(range);
let bare_match = BareMatch {
document_id: *id,
query_index: query.id,
distance,
is_exact,
postings_list: posting_list_index,
};
bare_matches.push(bare_match);
}
}
}
}
let before_raw_documents_presort = Instant::now();
bare_matches.sort_unstable_by_key(|sm| sm.document_id);
debug!("sort by documents ids took {:.02?}", before_raw_documents_presort.elapsed());
bare_matches
}
pub struct BareMatch<'tag> {
pub document_id: DocumentId,
pub query_index: usize,
pub distance: u8,
pub is_exact: bool,
pub postings_list: Idx32<'tag>,
}
impl fmt::Debug for BareMatch<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("BareMatch")
.field("document_id", &self.document_id)
.field("query_index", &self.query_index)
.field("distance", &self.distance)
.field("is_exact", &self.is_exact)
.finish()
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub struct SimpleMatch {
pub query_index: usize,
pub distance: u8,
pub attribute: u16,
pub word_index: u16,
pub is_exact: bool,
}
#[derive(Clone)]
pub enum PostingsListView<'txn> {
Original {
input: Rc<[u8]>,
postings_list: Rc<Cow<'txn, Set<DocIndex>>>,
offset: usize,
len: usize,
},
Rewritten {
input: Rc<[u8]>,
postings_list: SetBuf<DocIndex>,
},
}
impl fmt::Debug for PostingsListView<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("PostingsListView")
.field("input", &std::str::from_utf8(&self.input()).unwrap())
.field("postings_list", &self.as_ref())
.finish()
}
}
impl<'txn> PostingsListView<'txn> {
pub fn original(input: Rc<[u8]>, postings_list: Rc<Cow<'txn, Set<DocIndex>>>) -> PostingsListView<'txn> {
let len = postings_list.len();
PostingsListView::Original { input, postings_list, offset: 0, len }
}
pub fn rewritten(input: Rc<[u8]>, postings_list: SetBuf<DocIndex>) -> PostingsListView<'txn> {
PostingsListView::Rewritten { input, postings_list }
}
pub fn rewrite_with(&mut self, postings_list: SetBuf<DocIndex>) {
let input = match self {
PostingsListView::Original { input, .. } => input.clone(),
PostingsListView::Rewritten { input, .. } => input.clone(),
};
*self = PostingsListView::rewritten(input, postings_list);
}
pub fn len(&self) -> usize {
match self {
PostingsListView::Original { len, .. } => *len,
PostingsListView::Rewritten { postings_list, .. } => postings_list.len(),
}
}
pub fn input(&self) -> &[u8] {
match self {
PostingsListView::Original { ref input, .. } => input,
PostingsListView::Rewritten { ref input, .. } => input,
}
}
pub fn range(&self, range_offset: usize, range_len: usize) -> PostingsListView<'txn> {
match self {
PostingsListView::Original { input, postings_list, offset, len } => {
assert!(range_offset + range_len <= *len);
PostingsListView::Original {
input: input.clone(),
postings_list: postings_list.clone(),
offset: offset + range_offset,
len: range_len,
}
},
PostingsListView::Rewritten { .. } => {
panic!("Cannot create a range on a rewritten postings list view");
}
}
}
}
impl AsRef<Set<DocIndex>> for PostingsListView<'_> {
fn as_ref(&self) -> &Set<DocIndex> {
self
}
}
impl Deref for PostingsListView<'_> {
type Target = Set<DocIndex>;
fn deref(&self) -> &Set<DocIndex> {
match *self {
PostingsListView::Original { ref postings_list, offset, len, .. } => {
Set::new_unchecked(&postings_list[offset..offset + len])
},
PostingsListView::Rewritten { ref postings_list, .. } => postings_list,
}
}
}
/// For each entry in facet_docids, calculates the number of documents in the intersection with candidate_docids.
fn facet_count(
facet_docids: HashMap<String, HashMap<String, Cow<Set<DocumentId>>>>,
candidate_docids: &Set<DocumentId>,
) -> HashMap<String, HashMap<String, usize>> {
let mut facets_counts = HashMap::with_capacity(facet_docids.len());
for (key, doc_map) in facet_docids {
let mut count_map = HashMap::with_capacity(doc_map.len());
for (value, docids) in doc_map {
let mut counter = Counter::new();
let op = OpBuilder::new(docids.as_ref(), candidate_docids).intersection();
SetOperation::<DocumentId>::extend_collection(op, &mut counter);
count_map.insert(value, counter.0);
}
facets_counts.insert(key, count_map);
}
facets_counts
}