MeiliSearch/meilisearch-core/src/criterion/exactness.rs
2020-02-25 14:16:55 +01:00

79 lines
2.8 KiB
Rust

use std::cmp::{Ordering, Reverse};
use std::collections::hash_map::{HashMap, Entry};
use meilisearch_schema::IndexedPos;
use slice_group_by::GroupBy;
use crate::{RawDocument, MResult};
use crate::bucket_sort::BareMatch;
use super::{Criterion, Context, ContextMut};
pub struct Exactness;
impl Criterion for Exactness {
fn name(&self) -> &str { "exactness" }
fn prepare<'h, 'p, 'tag, 'txn, 'q, 'r>(
&self,
ctx: ContextMut<'h, 'p, 'tag, 'txn, 'q>,
documents: &mut [RawDocument<'r, 'tag>],
) -> MResult<()>
{
let store = ctx.documents_fields_counts_store;
let reader = ctx.reader;
'documents: for doc in documents {
doc.bare_matches.sort_unstable_by_key(|bm| (bm.query_index, Reverse(bm.is_exact)));
// mark the document if we find a "one word field" that matches
let mut fields_counts = HashMap::new();
for group in doc.bare_matches.linear_group_by_key(|bm| bm.query_index) {
for group in group.linear_group_by_key(|bm| bm.is_exact) {
if !group[0].is_exact { break }
for bm in group {
for di in ctx.postings_lists[bm.postings_list].as_ref() {
let attr = IndexedPos(di.attribute);
let count = match fields_counts.entry(attr) {
Entry::Occupied(entry) => *entry.get(),
Entry::Vacant(entry) => {
let count = store.document_field_count(reader, doc.id, attr)?;
*entry.insert(count)
},
};
if count == Some(1) {
doc.contains_one_word_field = true;
continue 'documents
}
}
}
}
}
}
Ok(())
}
fn evaluate(&self, _ctx: &Context, lhs: &RawDocument, rhs: &RawDocument) -> Ordering {
#[inline]
fn sum_exact_query_words(matches: &[BareMatch]) -> usize {
let mut sum_exact_query_words = 0;
for group in matches.linear_group_by_key(|bm| bm.query_index) {
sum_exact_query_words += group[0].is_exact as usize;
}
sum_exact_query_words
}
// does it contains a "one word field"
lhs.contains_one_word_field.cmp(&rhs.contains_one_word_field).reverse()
// if not, with document contains the more exact words
.then_with(|| {
let lhs = sum_exact_query_words(&lhs.bare_matches);
let rhs = sum_exact_query_words(&rhs.bare_matches);
lhs.cmp(&rhs).reverse()
})
}
}