Display the original facet string value from the linear facet database

milli/src/heed_codec/facet/field_doc_id_facet_string_codec.rs

@@ -9,13 +9,13 @@ impl FieldDocIdFacetStringCodec {
     pub fn serialize_into(
         field_id: FieldId,
         document_id: DocumentId,
-        value: &str,
+        normalized_value: &str,
         out: &mut Vec<u8>,
     ) {
-        out.reserve(2 + 4 + value.len());
+        out.reserve(2 + 4 + normalized_value.len());
         out.extend_from_slice(&field_id.to_be_bytes());
         out.extend_from_slice(&document_id.to_be_bytes());
-        out.extend_from_slice(value.as_bytes());
+        out.extend_from_slice(normalized_value.as_bytes());
     }
 }
 
@@ -29,17 +29,22 @@ impl<'a> heed::BytesDecode<'a> for FieldDocIdFacetStringCodec {
         let (document_id_bytes, bytes) = try_split_array_at(bytes)?;
         let document_id = u32::from_be_bytes(document_id_bytes);
 
-        let value = str::from_utf8(bytes).ok()?;
+        let normalized_value = str::from_utf8(bytes).ok()?;
-        Some((field_id, document_id, value))
+        Some((field_id, document_id, normalized_value))
     }
 }
 
 impl<'a> heed::BytesEncode<'a> for FieldDocIdFacetStringCodec {
     type EItem = (FieldId, DocumentId, &'a str);
 
-    fn bytes_encode((field_id, document_id, value): &Self::EItem) -> Option<Cow<[u8]>> {
+    fn bytes_encode((field_id, document_id, normalized_value): &Self::EItem) -> Option<Cow<[u8]>> {
         let mut bytes = Vec::new();
-        FieldDocIdFacetStringCodec::serialize_into(*field_id, *document_id, value, &mut bytes);
+        FieldDocIdFacetStringCodec::serialize_into(
+            *field_id,
+            *document_id,
+            normalized_value,
+            &mut bytes,
+        );
         Some(Cow::Owned(bytes))
     }
 }

milli/src/index.rs

@@ -96,7 +96,7 @@ pub struct Index {
     /// Maps the document id, the facet field id and the numbers.
     pub field_id_docid_facet_f64s: Database<FieldDocIdFacetF64Codec, Unit>,
     /// Maps the document id, the facet field id and the strings.
-    pub field_id_docid_facet_strings: Database<FieldDocIdFacetStringCodec, Unit>,
+    pub field_id_docid_facet_strings: Database<FieldDocIdFacetStringCodec, Str>,
 
     /// Maps the document id to the document as an obkv store.
     pub documents: Database<OwnedType<BEU32>, ObkvCodec>,

milli/src/search/distinct/facet_distinct.rs

@@ -1,6 +1,6 @@
 use std::mem::size_of;
 
-use heed::types::ByteSlice;
+use heed::types::{ByteSlice, Str, Unit};
 use roaring::RoaringBitmap;
 
 use super::{Distinct, DocIter};
@@ -127,7 +127,7 @@ fn facet_number_values<'a>(
     distinct: FieldId,
     index: &Index,
     txn: &'a heed::RoTxn,
-) -> Result<heed::RoPrefix<'a, FieldDocIdFacetF64Codec, heed::types::Unit>> {
+) -> Result<heed::RoPrefix<'a, FieldDocIdFacetF64Codec, Unit>> {
     let key = facet_values_prefix_key(distinct, id);
 
     let iter = index
@@ -144,14 +144,14 @@ fn facet_string_values<'a>(
     distinct: FieldId,
     index: &Index,
     txn: &'a heed::RoTxn,
-) -> Result<heed::RoPrefix<'a, FieldDocIdFacetStringCodec, heed::types::Unit>> {
+) -> Result<heed::RoPrefix<'a, FieldDocIdFacetStringCodec, Str>> {
     let key = facet_values_prefix_key(distinct, id);
 
     let iter = index
         .field_id_docid_facet_strings
         .remap_key_type::<ByteSlice>()
         .prefix_iter(txn, &key)?
-        .remap_key_type::<FieldDocIdFacetStringCodec>();
+        .remap_types::<FieldDocIdFacetStringCodec, Str>();
 
     Ok(iter)
 }

milli/src/search/facet/facet_distribution.rs

@@ -2,15 +2,16 @@ use std::collections::{BTreeMap, HashSet};
 use std::ops::Bound::Unbounded;
 use std::{cmp, fmt, mem};
 
-use heed::types::{ByteSlice, Unit};
+use heed::types::ByteSlice;
-use heed::{BytesDecode, Database};
 use roaring::RoaringBitmap;
 
 use crate::error::{FieldIdMapMissingEntry, UserError};
 use crate::facet::FacetType;
-use crate::heed_codec::facet::FacetStringLevelZeroCodec;
+use crate::heed_codec::facet::{
+    FacetStringLevelZeroCodec, FieldDocIdFacetF64Codec, FieldDocIdFacetStringCodec,
+};
 use crate::search::facet::{FacetNumberIter, FacetNumberRange, FacetStringIter};
-use crate::{DocumentId, FieldId, Index, Result};
+use crate::{FieldId, Index, Result};
 
 /// The default number of values by facets that will
 /// be fetched from the key-value store.
@@ -67,46 +68,55 @@ impl<'a> FacetDistribution<'a> {
         candidates: &RoaringBitmap,
         distribution: &mut BTreeMap<String, u64>,
     ) -> heed::Result<()> {
-        fn fetch_facet_values<'t, KC, K: 't>(
+        match facet_type {
-            rtxn: &'t heed::RoTxn,
+            FacetType::Number => {
-            db: Database<KC, Unit>,
-            field_id: FieldId,
-            candidates: &RoaringBitmap,
-            distribution: &mut BTreeMap<String, u64>,
-        ) -> heed::Result<()>
-        where
-            K: fmt::Display,
-            KC: BytesDecode<'t, DItem = (FieldId, DocumentId, K)>,
-        {
                 let mut key_buffer: Vec<_> = field_id.to_be_bytes().iter().copied().collect();
 
+                let db = self.index.field_id_docid_facet_f64s;
                 for docid in candidates.into_iter() {
                     key_buffer.truncate(mem::size_of::<FieldId>());
                     key_buffer.extend_from_slice(&docid.to_be_bytes());
                     let iter = db
                         .remap_key_type::<ByteSlice>()
-                    .prefix_iter(rtxn, &key_buffer)?
+                        .prefix_iter(self.rtxn, &key_buffer)?
-                    .remap_key_type::<KC>();
+                        .remap_key_type::<FieldDocIdFacetF64Codec>();
 
                     for result in iter {
                         let ((_, _, value), ()) = result?;
                         *distribution.entry(value.to_string()).or_insert(0) += 1;
                     }
                 }
-
-            Ok(())
-        }
-
-        match facet_type {
-            FacetType::Number => {
-                let db = self.index.field_id_docid_facet_f64s;
-                fetch_facet_values(self.rtxn, db, field_id, candidates, distribution)
             }
             FacetType::String => {
+                let mut normalized_distribution = BTreeMap::new();
+                let mut key_buffer: Vec<_> = field_id.to_be_bytes().iter().copied().collect();
+
                 let db = self.index.field_id_docid_facet_strings;
-                fetch_facet_values(self.rtxn, db, field_id, candidates, distribution)
+                for docid in candidates.into_iter() {
+                    key_buffer.truncate(mem::size_of::<FieldId>());
+                    key_buffer.extend_from_slice(&docid.to_be_bytes());
+                    let iter = db
+                        .remap_key_type::<ByteSlice>()
+                        .prefix_iter(self.rtxn, &key_buffer)?
+                        .remap_key_type::<FieldDocIdFacetStringCodec>();
+
+                    for result in iter {
+                        let ((_, _, normalized_value), original_value) = result?;
+                        let (_, count) = normalized_distribution
+                            .entry(normalized_value)
+                            .or_insert_with(|| (original_value, 0));
+                        *count += 1;
                     }
                 }
+
+                let iter = normalized_distribution
+                    .into_iter()
+                    .map(|(_normalized, (original, count))| (original.to_string(), count));
+                distribution.extend(iter);
+            }
+        }
+
+        Ok(())
     }
 
     /// There is too much documents, we use the facet levels to move throught
@@ -227,7 +237,6 @@ impl<'a> FacetDistribution<'a> {
                         &mut distribution,
                     )?;
                 }
-
                 Ok(distribution)
             }
             None => self.facet_values_from_raw_facet_database(field_id),

milli/src/update/delete_documents.rs

@@ -3,7 +3,7 @@ use std::collections::HashMap;
 
 use chrono::Utc;
 use fst::IntoStreamer;
-use heed::types::{ByteSlice, Unit};
+use heed::types::ByteSlice;
 use roaring::RoaringBitmap;
 use serde_json::Value;
 
@@ -419,15 +419,16 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
     }
 }
 
-fn remove_docids_from_field_id_docid_facet_value<'a, C, K, F>(
+fn remove_docids_from_field_id_docid_facet_value<'a, C, K, F, DC, V>(
     wtxn: &'a mut heed::RwTxn,
-    db: &heed::Database<C, Unit>,
+    db: &heed::Database<C, DC>,
     field_id: FieldId,
     to_remove: &RoaringBitmap,
     convert: F,
 ) -> heed::Result<()>
 where
-    C: heed::BytesDecode<'a, DItem = K> + heed::BytesEncode<'a, EItem = K>,
+    C: heed::BytesDecode<'a, DItem = K>,
+    DC: heed::BytesDecode<'a, DItem = V>,
     F: Fn(K) -> DocumentId,
 {
     let mut iter = db
@@ -436,7 +437,7 @@ where
         .remap_key_type::<C>();
 
     while let Some(result) = iter.next() {
-        let (key, ()) = result?;
+        let (key, _) = result?;
         if to_remove.contains(convert(key)) {
             // safety: we don't keep references from inside the LMDB database.
             unsafe { iter.del_current()? };

milli/src/update/index_documents/store.rs

@@ -65,7 +65,7 @@ pub struct Store<'s, A> {
         LinkedHashMap<(SmallVec32<u8>, SmallVec32<u8>, u8), RoaringBitmap>,
     words_pairs_proximities_docids_limit: usize,
     facet_field_number_docids: LinkedHashMap<(FieldId, OrderedFloat<f64>), RoaringBitmap>,
-    facet_field_string_docids: LinkedHashMap<(FieldId, String), RoaringBitmap>,
+    facet_field_string_docids: LinkedHashMap<(FieldId, String), (String, RoaringBitmap)>,
     facet_field_value_docids_limit: usize,
     // MTBL parameters
     chunk_compression_type: CompressionType,
@@ -283,25 +283,33 @@ impl<'s, A: AsRef<[u8]>> Store<'s, A> {
     fn insert_facet_string_values_docid(
         &mut self,
         field_id: FieldId,
-        value: String,
+        normalized_value: String,
+        original_value: String,
         id: DocumentId,
     ) -> Result<()> {
-        if value.is_empty() {
+        if normalized_value.is_empty() {
             return Ok(());
         }
 
         let sorter = &mut self.field_id_docid_facet_strings_sorter;
-        Self::write_field_id_docid_facet_string_value(sorter, field_id, id, &value)?;
+        Self::write_field_id_docid_facet_string_value(
+            sorter,
+            field_id,
+            id,
+            &normalized_value,
+            &original_value,
+        )?;
 
-        let key = (field_id, value);
+        let key = (field_id, normalized_value);
         // if get_refresh finds the element it is assured to be at the end of the linked hash map.
         match self.facet_field_string_docids.get_refresh(&key) {
-            Some(old) => {
+            Some((_original_value, old)) => {
                 old.insert(id);
             }
             None => {
                 // A newly inserted element is append at the end of the linked hash map.
-                self.facet_field_string_docids.insert(key, RoaringBitmap::from_iter(Some(id)));
+                self.facet_field_string_docids
+                    .insert(key, (original_value, RoaringBitmap::from_iter(Some(id))));
                 // If the word docids just reached it's capacity we must make sure to remove
                 // one element, this way next time we insert we doesn't grow the capacity.
                 if self.facet_field_string_docids.len() == self.facet_field_value_docids_limit {
@@ -363,7 +371,7 @@ impl<'s, A: AsRef<[u8]>> Store<'s, A> {
         document_id: DocumentId,
         words_positions: &mut HashMap<String, SmallVec32<Position>>,
         facet_numbers_values: &mut HashMap<FieldId, Vec<f64>>,
-        facet_strings_values: &mut HashMap<FieldId, Vec<String>>,
+        facet_strings_values: &mut HashMap<FieldId, Vec<(String, String)>>,
         record: &[u8],
     ) -> Result<()> {
         // We compute the list of words pairs proximities (self-join) and write it directly to disk.
@@ -399,8 +407,8 @@ impl<'s, A: AsRef<[u8]>> Store<'s, A> {
 
         // We store document_id associated with all the facet strings fields ids and values.
         for (field, values) in facet_strings_values.drain() {
-            for value in values {
+            for (normalized, original) in values {
-                self.insert_facet_string_values_docid(field, value, document_id)?;
+                self.insert_facet_string_values_docid(field, normalized, original, document_id)?;
             }
         }
 
@@ -516,23 +524,23 @@ impl<'s, A: AsRef<[u8]>> Store<'s, A> {
 
     fn write_facet_field_string_docids<I, E>(sorter: &mut Sorter<MergeFn<E>>, iter: I) -> Result<()>
     where
-        I: IntoIterator<Item = ((FieldId, String), RoaringBitmap)>,
+        I: IntoIterator<Item = ((FieldId, String), (String, RoaringBitmap))>,
         Error: From<E>,
     {
         let mut key_buffer = Vec::new();
         let mut data_buffer = Vec::new();
 
-        for ((field_id, value), docids) in iter {
+        for ((field_id, normalized_value), (original_value, docids)) in iter {
             key_buffer.clear();
             data_buffer.clear();
 
-            FacetStringLevelZeroCodec::serialize_into(field_id, &value, &mut key_buffer);
+            FacetStringLevelZeroCodec::serialize_into(field_id, &normalized_value, &mut key_buffer);
             CboRoaringBitmapCodec::serialize_into(&docids, &mut data_buffer);
 
             if lmdb_key_valid_size(&key_buffer) {
                 sorter.insert(&key_buffer, &data_buffer)?;
             } else {
-                warn!("facet value {:?} is too large to be saved", value);
+                warn!("facet value {:?} is too large to be saved", original_value);
             }
         }
 
@@ -587,19 +595,24 @@ impl<'s, A: AsRef<[u8]>> Store<'s, A> {
         sorter: &mut Sorter<MergeFn<E>>,
         field_id: FieldId,
         document_id: DocumentId,
-        value: &str,
+        normalized_value: &str,
+        original_value: &str,
     ) -> Result<()>
     where
         Error: From<E>,
     {
         let mut buffer = Vec::new();
-
+        FieldDocIdFacetStringCodec::serialize_into(
-        FieldDocIdFacetStringCodec::serialize_into(field_id, document_id, value, &mut buffer);
+            field_id,
+            document_id,
+            normalized_value,
+            &mut buffer,
+        );
 
         if lmdb_key_valid_size(&buffer) {
-            sorter.insert(&buffer, &[])?;
+            sorter.insert(&buffer, original_value.as_bytes())?;
         } else {
-            warn!("facet value {:?} is too large to be saved", value);
+            warn!("facet value {:?} is too large to be saved", original_value);
         }
 
         Ok(())
@@ -929,24 +942,24 @@ fn process_tokens<'a>(
         .filter(|(_, t)| t.is_word())
 }
 
-fn extract_facet_values(value: &Value) -> (Vec<f64>, Vec<String>) {
+fn extract_facet_values(value: &Value) -> (Vec<f64>, Vec<(String, String)>) {
     fn inner_extract_facet_values(
         value: &Value,
         can_recurse: bool,
         output_numbers: &mut Vec<f64>,
-        output_strings: &mut Vec<String>,
+        output_strings: &mut Vec<(String, String)>,
     ) {
         match value {
             Value::Null => (),
-            Value::Bool(b) => output_strings.push(b.to_string()),
+            Value::Bool(b) => output_strings.push((b.to_string(), b.to_string())),
             Value::Number(number) => {
                 if let Some(float) = number.as_f64() {
                     output_numbers.push(float);
                 }
             }
-            Value::String(string) => {
+            Value::String(original) => {
-                let string = string.trim().to_lowercase();
+                let normalized = original.trim().to_lowercase();
-                output_strings.push(string);
+                output_strings.push((normalized, original.clone()));
             }
             Value::Array(values) => {
                 if can_recurse {

milli/src/update/settings.rs

@@ -276,8 +276,7 @@ impl<'a, 't, 'u, 'i> Settings<'a, 't, 'u, 'i> {
         match self.searchable_fields {
             Setting::Set(ref fields) => {
                 // every time the searchable attributes are updated, we need to update the
-                // ids for any settings that uses the facets. (displayed_fields,
+                // ids for any settings that uses the facets. (distinct_fields, filterable_fields).
-                // filterable_fields)
                 let old_fields_ids_map = self.index.fields_ids_map(self.wtxn)?;
 
                 let mut new_fields_ids_map = FieldsIdsMap::new();