Merge #3834

3834: Define searchable fields at runtime r=Kerollmops a=ManyTheFish

## Summary
This feature allows the end-user to search in one or multiple attributes using the search parameter `attributesToSearchOn`:

```json
{
  "q": "Captain Marvel",
  "attributesToSearchOn": ["title"]
}
```

This feature act like a filter, forcing Meilisearch to only return the documents containing the requested words in the attributes-to-search-on. Note that, with the matching strategy `last`, Meilisearch will only ensure that the first word is in the attributes-to-search-on, but, the retrieved documents will be ordered taking into account the word contained in the attributes-to-search-on. 

## Trying the prototype

A dedicated docker image has been released for this feature:

#### last prototype version:

```bash
docker pull getmeili/meilisearch:prototype-define-searchable-fields-at-search-time-1
```

#### others prototype versions:

```bash
docker pull getmeili/meilisearch:prototype-define-searchable-fields-at-search-time-0
```

## Technical Detail

The attributes-to-search-on list is given to the search context, then, the search context uses the `fid_word_docids`database using only the allowed field ids instead of the global `word_docids` database. This is the same for the prefix databases.
The database cache is updated with the merged values, meaning that the union of the field-id-database values is only made if the requested key is missing from the cache.

### Relevancy limits

Almost all ranking rules behave as expected when ordering the documents.
Only `proximity` could miss-order documents if all the searched words are in the restricted attribute but a better proximity is found in an ignored attribute in a document that should be ranked lower. I put below a failing test showing it:
```rust
#[actix_rt::test]
async fn proximity_ranking_rule_order() {
    let server = Server::new().await;
    let index = index_with_documents(
        &server,
        &json!([
        {
            "title": "Captain super mega cool. A Marvel story",
            // Perfect distance between words in an ignored attribute
            "desc": "Captain Marvel",
            "id": "1",
        },
        {
            "title": "Captain America from Marvel",
            "desc": "a Shazam ersatz",
            "id": "2",
        }]),
    )
    .await;

    // Document 2 should appear before document 1.
    index
        .search(json!({"q": "Captain Marvel", "attributesToSearchOn": ["title"], "attributesToRetrieve": ["id"]}), |response, code| {
            assert_eq!(code, 200, "{}", response);
            assert_eq!(
                response["hits"],
                json!([
                    {"id": "2"},
                    {"id": "1"},
                ])
            );
        })
        .await;
}
```

Fixing this would force us to create a `fid_word_pair_proximity_docids` and a `fid_word_prefix_pair_proximity_docids` databases which may multiply the keys of `word_pair_proximity_docids` and `word_prefix_pair_proximity_docids` by the number of attributes in the searchable_attributes list. If we think we should fix this test, I'll suggest doing it in another PR.

## Related

Fixes #3772

Co-authored-by: Tamo <tamo@meilisearch.com>
Co-authored-by: ManyTheFish <many@meilisearch.com>

meilisearch-types/src/error.rs

@@ -226,6 +226,7 @@ InvalidIndexLimit                     , InvalidRequest       , BAD_REQUEST ;
 InvalidIndexOffset                    , InvalidRequest       , BAD_REQUEST ;
 InvalidIndexPrimaryKey                , InvalidRequest       , BAD_REQUEST ;
 InvalidIndexUid                       , InvalidRequest       , BAD_REQUEST ;
+InvalidAttributesToSearchOn   , InvalidRequest       , BAD_REQUEST ;
 InvalidSearchAttributesToCrop         , InvalidRequest       , BAD_REQUEST ;
 InvalidSearchAttributesToHighlight    , InvalidRequest       , BAD_REQUEST ;
 InvalidSearchAttributesToRetrieve     , InvalidRequest       , BAD_REQUEST ;
@@ -336,6 +337,9 @@ impl ErrorCode for milli::Error {
                     UserError::SortRankingRuleMissing => Code::InvalidSearchSort,
                     UserError::InvalidFacetsDistribution { .. } => Code::InvalidSearchFacets,
                     UserError::InvalidSortableAttribute { .. } => Code::InvalidSearchSort,
+                    UserError::InvalidSearchableAttribute { .. } => {
+                        Code::InvalidAttributesToSearchOn
+                    }
                     UserError::CriterionError(_) => Code::InvalidSettingsRankingRules,
                     UserError::InvalidGeoField { .. } => Code::InvalidDocumentGeoField,
                     UserError::InvalidVectorDimensions { .. } => Code::InvalidVectorDimensions,

meilisearch/src/routes/indexes/search.rs

@@ -72,6 +72,8 @@ pub struct SearchQueryGet {
     crop_marker: String,
     #[deserr(default, error = DeserrQueryParamError<InvalidSearchMatchingStrategy>)]
     matching_strategy: MatchingStrategy,
+    #[deserr(default, error = DeserrQueryParamError<InvalidAttributesToSearchOn>)]
+    pub attributes_to_search_on: Option<CS<String>>,
 }
 
 impl From<SearchQueryGet> for SearchQuery {
@@ -105,6 +107,7 @@ impl From<SearchQueryGet> for SearchQuery {
             highlight_post_tag: other.highlight_post_tag,
             crop_marker: other.crop_marker,
             matching_strategy: other.matching_strategy,
+            attributes_to_search_on: other.attributes_to_search_on.map(|o| o.into_iter().collect()),
         }
     }
 }

meilisearch/src/search.rs

@@ -79,6 +79,8 @@ pub struct SearchQuery {
     pub crop_marker: String,
     #[deserr(default, error = DeserrJsonError<InvalidSearchMatchingStrategy>, default)]
     pub matching_strategy: MatchingStrategy,
+    #[deserr(default, error = DeserrJsonError<InvalidAttributesToSearchOn>, default)]
+    pub attributes_to_search_on: Option<Vec<String>>,
 }
 
 impl SearchQuery {
@@ -136,6 +138,8 @@ pub struct SearchQueryWithIndex {
     pub crop_marker: String,
     #[deserr(default, error = DeserrJsonError<InvalidSearchMatchingStrategy>, default)]
     pub matching_strategy: MatchingStrategy,
+    #[deserr(default, error = DeserrJsonError<InvalidAttributesToSearchOn>, default)]
+    pub attributes_to_search_on: Option<Vec<String>>,
 }
 
 impl SearchQueryWithIndex {
@@ -162,6 +166,7 @@ impl SearchQueryWithIndex {
             highlight_post_tag,
             crop_marker,
             matching_strategy,
+            attributes_to_search_on,
         } = self;
         (
             index_uid,
@@ -186,6 +191,7 @@ impl SearchQueryWithIndex {
                 highlight_post_tag,
                 crop_marker,
                 matching_strategy,
+                attributes_to_search_on,
                 // do not use ..Default::default() here,
                 // rather add any missing field from `SearchQuery` to `SearchQueryWithIndex`
             },
@@ -314,6 +320,10 @@ pub fn perform_search(
         search.query(query);
     }
 
+    if let Some(ref searchable) = query.attributes_to_search_on {
+        search.searchable_attributes(searchable);
+    }
+
     let is_finite_pagination = query.is_finite_pagination();
     search.terms_matching_strategy(query.matching_strategy.into());
 

meilisearch/tests/common/index.rs

@@ -346,17 +346,24 @@ impl Index<'_> {
         query: Value,
         test: impl Fn(Value, StatusCode) + UnwindSafe + Clone,
     ) {
-        let (response, code) = self.search_post(query.clone()).await;
-        let t = test.clone();
-        if let Err(e) = catch_unwind(move || t(response, code)) {
-            eprintln!("Error with post search");
-            resume_unwind(e);
-        }
+        let post = self.search_post(query.clone()).await;
+
         let query = yaup::to_string(&query).unwrap();
-        let (response, code) = self.search_get(&query).await;
-        if let Err(e) = catch_unwind(move || test(response, code)) {
-            eprintln!("Error with get search");
-            resume_unwind(e);
+        let get = self.search_get(&query).await;
+
+        insta::allow_duplicates! {
+            let (response, code) = post;
+            let t = test.clone();
+            if let Err(e) = catch_unwind(move || t(response, code)) {
+                eprintln!("Error with post search");
+                resume_unwind(e);
+            }
+
+            let (response, code) = get;
+            if let Err(e) = catch_unwind(move || test(response, code)) {
+                eprintln!("Error with get search");
+                resume_unwind(e);
+            }
         }
     }
 

meilisearch/tests/search/errors.rs

@@ -963,3 +963,29 @@ async fn sort_unset_ranking_rule() {
         )
         .await;
 }
+
+#[actix_rt::test]
+async fn search_on_unknown_field() {
+    let server = Server::new().await;
+    let index = server.index("test");
+    let documents = DOCUMENTS.clone();
+    index.add_documents(documents, None).await;
+    index.wait_task(0).await;
+
+    index
+        .search(
+            json!({"q": "Captain Marvel", "attributesToSearchOn": ["unknown"]}),
+            |response, code| {
+                snapshot!(code, @"400 Bad Request");
+                snapshot!(json_string!(response), @r###"
+                {
+                  "message": "Attribute `unknown` is not searchable. Available searchable attributes are: `id, title`.",
+                  "code": "invalid_attributes_to_search_on",
+                  "type": "invalid_request",
+                  "link": "https://docs.meilisearch.com/errors#invalid_attributes_to_search_on"
+                }
+                "###);
+            },
+        )
+        .await;
+}

meilisearch/tests/search/mod.rs

@@ -5,6 +5,7 @@ mod errors;
 mod formatted;
 mod multi;
 mod pagination;
+mod restrict_searchable;
 
 use once_cell::sync::Lazy;
 use serde_json::{json, Value};

meilisearch/tests/search/restrict_searchable.rs

@@ -0,0 +1,267 @@
+use meili_snap::{json_string, snapshot};
+use once_cell::sync::Lazy;
+use serde_json::{json, Value};
+
+use crate::common::index::Index;
+use crate::common::Server;
+
+async fn index_with_documents<'a>(server: &'a Server, documents: &Value) -> Index<'a> {
+    let index = server.index("test");
+
+    index.add_documents(documents.clone(), None).await;
+    index.wait_task(0).await;
+    index
+}
+
+static SIMPLE_SEARCH_DOCUMENTS: Lazy<Value> = Lazy::new(|| {
+    json!([
+    {
+        "title": "Shazam!",
+        "desc": "a Captain Marvel ersatz",
+        "id": "1",
+    },
+    {
+        "title": "Captain Planet",
+        "desc": "He's not part of the Marvel Cinematic Universe",
+        "id": "2",
+    },
+    {
+        "title": "Captain Marvel",
+        "desc": "a Shazam ersatz",
+        "id": "3",
+    }])
+});
+
+#[actix_rt::test]
+async fn simple_search_on_title() {
+    let server = Server::new().await;
+    let index = index_with_documents(&server, &SIMPLE_SEARCH_DOCUMENTS).await;
+
+    // simple search should return 2 documents (ids: 2 and 3).
+    index
+        .search(
+            json!({"q": "Captain Marvel", "attributesToSearchOn": ["title"]}),
+            |response, code| {
+                snapshot!(code, @"200 OK");
+                snapshot!(response["hits"].as_array().unwrap().len(), @"2");
+            },
+        )
+        .await;
+}
+
+#[actix_rt::test]
+async fn simple_prefix_search_on_title() {
+    let server = Server::new().await;
+    let index = index_with_documents(&server, &SIMPLE_SEARCH_DOCUMENTS).await;
+
+    // simple search should return 2 documents (ids: 2 and 3).
+    index
+        .search(json!({"q": "Captain Mar", "attributesToSearchOn": ["title"]}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(response["hits"].as_array().unwrap().len(), @"2");
+        })
+        .await;
+}
+
+#[actix_rt::test]
+async fn simple_search_on_title_matching_strategy_all() {
+    let server = Server::new().await;
+    let index = index_with_documents(&server, &SIMPLE_SEARCH_DOCUMENTS).await;
+    // simple search matching strategy all should only return 1 document (ids: 2).
+    index
+        .search(json!({"q": "Captain Marvel", "attributesToSearchOn": ["title"], "matchingStrategy": "all"}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(response["hits"].as_array().unwrap().len(), @"1");
+        })
+        .await;
+}
+
+#[actix_rt::test]
+async fn simple_search_on_no_field() {
+    let server = Server::new().await;
+    let index = index_with_documents(&server, &SIMPLE_SEARCH_DOCUMENTS).await;
+    // simple search on no field shouldn't return any document.
+    index
+        .search(json!({"q": "Captain Marvel", "attributesToSearchOn": []}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(response["hits"].as_array().unwrap().len(), @"0");
+        })
+        .await;
+}
+
+#[actix_rt::test]
+async fn word_ranking_rule_order() {
+    let server = Server::new().await;
+    let index = index_with_documents(&server, &SIMPLE_SEARCH_DOCUMENTS).await;
+
+    // Document 3 should appear before document 2.
+    index
+        .search(
+            json!({"q": "Captain Marvel", "attributesToSearchOn": ["title"], "attributesToRetrieve": ["id"]}),
+            |response, code| {
+                snapshot!(code, @"200 OK");
+                snapshot!(json_string!(response["hits"]),
+                    @r###"
+                [
+                  {
+                    "id": "3"
+                  },
+                  {
+                    "id": "2"
+                  }
+                ]
+                "###
+                );
+            },
+        )
+        .await;
+}
+
+#[actix_rt::test]
+async fn word_ranking_rule_order_exact_words() {
+    let server = Server::new().await;
+    let index = index_with_documents(&server, &SIMPLE_SEARCH_DOCUMENTS).await;
+    index.update_settings_typo_tolerance(json!({"disableOnWords": ["Captain", "Marvel"]})).await;
+    index.wait_task(1).await;
+
+    // simple search should return 2 documents (ids: 2 and 3).
+    index
+        .search(
+            json!({"q": "Captain Marvel", "attributesToSearchOn": ["title"], "attributesToRetrieve": ["id"]}),
+            |response, code| {
+                snapshot!(code, @"200 OK");
+                snapshot!(json_string!(response["hits"]),
+                    @r###"
+                [
+                  {
+                    "id": "3"
+                  },
+                  {
+                    "id": "2"
+                  }
+                ]
+                "###
+                );
+            },
+        )
+        .await;
+}
+
+#[actix_rt::test]
+async fn typo_ranking_rule_order() {
+    let server = Server::new().await;
+    let index = index_with_documents(
+        &server,
+        &json!([
+        {
+            "title": "Capitain Marivel",
+            "desc": "Captain Marvel",
+            "id": "1",
+        },
+        {
+            "title": "Captain Marivel",
+            "desc": "a Shazam ersatz",
+            "id": "2",
+        }]),
+    )
+    .await;
+
+    // Document 2 should appear before document 1.
+    index
+        .search(json!({"q": "Captain Marvel", "attributesToSearchOn": ["title"], "attributesToRetrieve": ["id"]}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(json_string!(response["hits"]),
+                @r###"
+            [
+              {
+                "id": "2"
+              },
+              {
+                "id": "1"
+              }
+            ]
+            "###
+            );
+        })
+        .await;
+}
+
+#[actix_rt::test]
+async fn attributes_ranking_rule_order() {
+    let server = Server::new().await;
+    let index = index_with_documents(
+        &server,
+        &json!([
+        {
+            "title": "Captain Marvel",
+            "desc": "a Shazam ersatz",
+            "footer": "The story of Captain Marvel",
+            "id": "1",
+        },
+        {
+            "title": "The Avengers",
+            "desc": "Captain Marvel is far from the earth",
+            "footer": "A super hero team",
+            "id": "2",
+        }]),
+    )
+    .await;
+
+    // Document 2 should appear before document 1.
+    index
+        .search(json!({"q": "Captain Marvel", "attributesToSearchOn": ["desc", "footer"], "attributesToRetrieve": ["id"]}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(json_string!(response["hits"]),
+                @r###"
+            [
+              {
+                "id": "2"
+              },
+              {
+                "id": "1"
+              }
+            ]
+            "###
+            );
+        })
+        .await;
+}
+
+#[actix_rt::test]
+async fn exactness_ranking_rule_order() {
+    let server = Server::new().await;
+    let index = index_with_documents(
+        &server,
+        &json!([
+        {
+            "title": "Captain Marvel",
+            "desc": "Captain Marivel",
+            "id": "1",
+        },
+        {
+            "title": "Captain Marvel",
+            "desc": "CaptainMarvel",
+            "id": "2",
+        }]),
+    )
+    .await;
+
+    // Document 2 should appear before document 1.
+    index
+        .search(json!({"q": "Captain Marvel", "attributesToRetrieve": ["id"], "attributesToSearchOn": ["desc"]}), |response, code| {
+            snapshot!(code, @"200 OK");
+            snapshot!(json_string!(response["hits"]),
+                @r###"
+            [
+              {
+                "id": "2"
+              },
+              {
+                "id": "1"
+              }
+            ]
+            "###
+            );
+        })
+        .await;
+}

milli/src/error.rs

@@ -128,6 +128,16 @@ only composed of alphanumeric characters (a-z A-Z 0-9), hyphens (-) and undersco
         }
     )]
     InvalidSortableAttribute { field: String, valid_fields: BTreeSet<String> },
+    #[error("Attribute `{}` is not searchable. Available searchable attributes are: `{}{}`.",
+        .field,
+        .valid_fields.iter().map(AsRef::as_ref).collect::<Vec<&str>>().join(", "),
+        .hidden_fields.then_some(", <..hidden-attributes>").unwrap_or(""),
+    )]
+    InvalidSearchableAttribute {
+        field: String,
+        valid_fields: BTreeSet<String>,
+        hidden_fields: bool,
+    },
     #[error("{}", HeedError::BadOpenOptions)]
     InvalidLmdbOpenOptions,
     #[error("You must specify where `sort` is listed in the rankingRules setting to use the sort parameter at search time.")]

milli/src/heed_codec/mod.rs

@@ -23,3 +23,9 @@ pub use self::roaring_bitmap_length::{
 pub use self::script_language_codec::ScriptLanguageCodec;
 pub use self::str_beu32_codec::{StrBEU16Codec, StrBEU32Codec};
 pub use self::str_str_u8_codec::{U8StrStrCodec, UncheckedU8StrStrCodec};
+
+pub trait BytesDecodeOwned {
+    type DItem;
+
+    fn bytes_decode_owned(bytes: &[u8]) -> Option<Self::DItem>;
+}

milli/src/heed_codec/roaring_bitmap/bo_roaring_bitmap_codec.rs

@@ -2,8 +2,11 @@ use std::borrow::Cow;
 use std::convert::TryInto;
 use std::mem::size_of;
 
+use heed::BytesDecode;
 use roaring::RoaringBitmap;
 
+use crate::heed_codec::BytesDecodeOwned;
+
 pub struct BoRoaringBitmapCodec;
 
 impl BoRoaringBitmapCodec {
@@ -13,7 +16,7 @@ impl BoRoaringBitmapCodec {
     }
 }
 
-impl heed::BytesDecode<'_> for BoRoaringBitmapCodec {
+impl BytesDecode<'_> for BoRoaringBitmapCodec {
     type DItem = RoaringBitmap;
 
     fn bytes_decode(bytes: &[u8]) -> Option<Self::DItem> {
@@ -28,6 +31,14 @@ impl heed::BytesDecode<'_> for BoRoaringBitmapCodec {
     }
 }
 
+impl BytesDecodeOwned for BoRoaringBitmapCodec {
+    type DItem = RoaringBitmap;
+
+    fn bytes_decode_owned(bytes: &[u8]) -> Option<Self::DItem> {
+        Self::bytes_decode(bytes)
+    }
+}
+
 impl heed::BytesEncode<'_> for BoRoaringBitmapCodec {
     type EItem = RoaringBitmap;
 

milli/src/heed_codec/roaring_bitmap/cbo_roaring_bitmap_codec.rs

@@ -5,6 +5,8 @@ use std::mem::size_of;
 use byteorder::{NativeEndian, ReadBytesExt, WriteBytesExt};
 use roaring::RoaringBitmap;
 
+use crate::heed_codec::BytesDecodeOwned;
+
 /// This is the limit where using a byteorder became less size efficient
 /// than using a direct roaring encoding, it is also the point where we are able
 /// to determine the encoding used only by using the array of bytes length.
@@ -103,6 +105,14 @@ impl heed::BytesDecode<'_> for CboRoaringBitmapCodec {
     }
 }
 
+impl BytesDecodeOwned for CboRoaringBitmapCodec {
+    type DItem = RoaringBitmap;
+
+    fn bytes_decode_owned(bytes: &[u8]) -> Option<Self::DItem> {
+        Self::deserialize_from(bytes).ok()
+    }
+}
+
 impl heed::BytesEncode<'_> for CboRoaringBitmapCodec {
     type EItem = RoaringBitmap;
 

milli/src/heed_codec/roaring_bitmap/roaring_bitmap_codec.rs

@@ -2,6 +2,8 @@ use std::borrow::Cow;
 
 use roaring::RoaringBitmap;
 
+use crate::heed_codec::BytesDecodeOwned;
+
 pub struct RoaringBitmapCodec;
 
 impl heed::BytesDecode<'_> for RoaringBitmapCodec {
@@ -12,6 +14,14 @@ impl heed::BytesDecode<'_> for RoaringBitmapCodec {
     }
 }
 
+impl BytesDecodeOwned for RoaringBitmapCodec {
+    type DItem = RoaringBitmap;
+
+    fn bytes_decode_owned(bytes: &[u8]) -> Option<Self::DItem> {
+        RoaringBitmap::deserialize_from(bytes).ok()
+    }
+}
+
 impl heed::BytesEncode<'_> for RoaringBitmapCodec {
     type EItem = RoaringBitmap;
 

milli/src/heed_codec/roaring_bitmap_length/bo_roaring_bitmap_len_codec.rs

@@ -1,11 +1,23 @@
 use std::mem;
 
+use heed::BytesDecode;
+
+use crate::heed_codec::BytesDecodeOwned;
+
 pub struct BoRoaringBitmapLenCodec;
 
-impl heed::BytesDecode<'_> for BoRoaringBitmapLenCodec {
+impl BytesDecode<'_> for BoRoaringBitmapLenCodec {
     type DItem = u64;
 
     fn bytes_decode(bytes: &[u8]) -> Option<Self::DItem> {
         Some((bytes.len() / mem::size_of::<u32>()) as u64)
     }
 }
+
+impl BytesDecodeOwned for BoRoaringBitmapLenCodec {
+    type DItem = u64;
+
+    fn bytes_decode_owned(bytes: &[u8]) -> Option<Self::DItem> {
+        Self::bytes_decode(bytes)
+    }
+}

milli/src/heed_codec/roaring_bitmap_length/cbo_roaring_bitmap_len_codec.rs

@@ -1,11 +1,14 @@
 use std::mem;
 
+use heed::BytesDecode;
+
 use super::{BoRoaringBitmapLenCodec, RoaringBitmapLenCodec};
 use crate::heed_codec::roaring_bitmap::cbo_roaring_bitmap_codec::THRESHOLD;
+use crate::heed_codec::BytesDecodeOwned;
 
 pub struct CboRoaringBitmapLenCodec;
 
-impl heed::BytesDecode<'_> for CboRoaringBitmapLenCodec {
+impl BytesDecode<'_> for CboRoaringBitmapLenCodec {
     type DItem = u64;
 
     fn bytes_decode(bytes: &[u8]) -> Option<Self::DItem> {
@@ -20,3 +23,11 @@ impl heed::BytesDecode<'_> for CboRoaringBitmapLenCodec {
         }
     }
 }
+
+impl BytesDecodeOwned for CboRoaringBitmapLenCodec {
+    type DItem = u64;
+
+    fn bytes_decode_owned(bytes: &[u8]) -> Option<Self::DItem> {
+        Self::bytes_decode(bytes)
+    }
+}

milli/src/heed_codec/roaring_bitmap_length/roaring_bitmap_len_codec.rs

@@ -3,6 +3,8 @@ use std::mem;
 
 use byteorder::{LittleEndian, ReadBytesExt};
 
+use crate::heed_codec::BytesDecodeOwned;
+
 const SERIAL_COOKIE_NO_RUNCONTAINER: u32 = 12346;
 const SERIAL_COOKIE: u16 = 12347;
 
@@ -59,6 +61,14 @@ impl heed::BytesDecode<'_> for RoaringBitmapLenCodec {
     }
 }
 
+impl BytesDecodeOwned for RoaringBitmapLenCodec {
+    type DItem = u64;
+
+    fn bytes_decode_owned(bytes: &[u8]) -> Option<Self::DItem> {
+        RoaringBitmapLenCodec::deserialize_from_slice(bytes).ok()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use heed::BytesEncode;

milli/src/search/mod.rs

@@ -29,6 +29,7 @@ pub struct Search<'a> {
     offset: usize,
     limit: usize,
     sort_criteria: Option<Vec<AscDesc>>,
+    searchable_attributes: Option<&'a [String]>,
     geo_strategy: new::GeoSortStrategy,
     terms_matching_strategy: TermsMatchingStrategy,
     scoring_strategy: ScoringStrategy,
@@ -47,6 +48,7 @@ impl<'a> Search<'a> {
             offset: 0,
             limit: 20,
             sort_criteria: None,
+            searchable_attributes: None,
             geo_strategy: new::GeoSortStrategy::default(),
             terms_matching_strategy: TermsMatchingStrategy::default(),
             scoring_strategy: Default::default(),
@@ -82,6 +84,11 @@ impl<'a> Search<'a> {
         self
     }
 
+    pub fn searchable_attributes(&mut self, searchable: &'a [String]) -> &mut Search<'a> {
+        self.searchable_attributes = Some(searchable);
+        self
+    }
+
     pub fn terms_matching_strategy(&mut self, value: TermsMatchingStrategy) -> &mut Search<'a> {
         self.terms_matching_strategy = value;
         self
@@ -117,6 +124,11 @@ impl<'a> Search<'a> {
 
     pub fn execute(&self) -> Result<SearchResult> {
         let mut ctx = SearchContext::new(self.index, self.rtxn);
+
+        if let Some(searchable_attributes) = self.searchable_attributes {
+            ctx.searchable_attributes(searchable_attributes)?;
+        }
+
         let PartialSearchResult { located_query_terms, candidates, documents_ids, document_scores } =
             execute_search(
                 &mut ctx,
@@ -154,6 +166,7 @@ impl fmt::Debug for Search<'_> {
             offset,
             limit,
             sort_criteria,
+            searchable_attributes,
             geo_strategy: _,
             terms_matching_strategy,
             scoring_strategy,
@@ -169,6 +182,7 @@ impl fmt::Debug for Search<'_> {
             .field("offset", offset)
             .field("limit", limit)
             .field("sort_criteria", sort_criteria)
+            .field("searchable_attributes", searchable_attributes)
             .field("terms_matching_strategy", terms_matching_strategy)
             .field("scoring_strategy", scoring_strategy)
             .field("exhaustive_number_hits", exhaustive_number_hits)

milli/src/search/new/db_cache.rs

@@ -4,12 +4,13 @@ use std::hash::Hash;
 
 use fxhash::FxHashMap;
 use heed::types::ByteSlice;
-use heed::{BytesDecode, BytesEncode, Database, RoTxn};
+use heed::{BytesEncode, Database, RoTxn};
 use roaring::RoaringBitmap;
 
 use super::interner::Interned;
 use super::Word;
-use crate::heed_codec::StrBEU16Codec;
+use crate::heed_codec::{BytesDecodeOwned, StrBEU16Codec};
+use crate::update::{merge_cbo_roaring_bitmaps, MergeFn};
 use crate::{
     CboRoaringBitmapCodec, CboRoaringBitmapLenCodec, Result, RoaringBitmapCodec, SearchContext,
 };
@@ -22,50 +23,104 @@ use crate::{
 #[derive(Default)]
 pub struct DatabaseCache<'ctx> {
     pub word_pair_proximity_docids:
-        FxHashMap<(u8, Interned<String>, Interned<String>), Option<&'ctx [u8]>>,
+        FxHashMap<(u8, Interned<String>, Interned<String>), Option<Cow<'ctx, [u8]>>>,
     pub word_prefix_pair_proximity_docids:
-        FxHashMap<(u8, Interned<String>, Interned<String>), Option<&'ctx [u8]>>,
+        FxHashMap<(u8, Interned<String>, Interned<String>), Option<Cow<'ctx, [u8]>>>,
     pub prefix_word_pair_proximity_docids:
-        FxHashMap<(u8, Interned<String>, Interned<String>), Option<&'ctx [u8]>>,
-    pub word_docids: FxHashMap<Interned<String>, Option<&'ctx [u8]>>,
-    pub exact_word_docids: FxHashMap<Interned<String>, Option<&'ctx [u8]>>,
-    pub word_prefix_docids: FxHashMap<Interned<String>, Option<&'ctx [u8]>>,
-    pub exact_word_prefix_docids: FxHashMap<Interned<String>, Option<&'ctx [u8]>>,
+        FxHashMap<(u8, Interned<String>, Interned<String>), Option<Cow<'ctx, [u8]>>>,
+    pub word_docids: FxHashMap<Interned<String>, Option<Cow<'ctx, [u8]>>>,
+    pub exact_word_docids: FxHashMap<Interned<String>, Option<Cow<'ctx, [u8]>>>,
+    pub word_prefix_docids: FxHashMap<Interned<String>, Option<Cow<'ctx, [u8]>>>,
+    pub exact_word_prefix_docids: FxHashMap<Interned<String>, Option<Cow<'ctx, [u8]>>>,
 
     pub words_fst: Option<fst::Set<Cow<'ctx, [u8]>>>,
-    pub word_position_docids: FxHashMap<(Interned<String>, u16), Option<&'ctx [u8]>>,
-    pub word_prefix_position_docids: FxHashMap<(Interned<String>, u16), Option<&'ctx [u8]>>,
+    pub word_position_docids: FxHashMap<(Interned<String>, u16), Option<Cow<'ctx, [u8]>>>,
+    pub word_prefix_position_docids: FxHashMap<(Interned<String>, u16), Option<Cow<'ctx, [u8]>>>,
     pub word_positions: FxHashMap<Interned<String>, Vec<u16>>,
     pub word_prefix_positions: FxHashMap<Interned<String>, Vec<u16>>,
 
-    pub word_fid_docids: FxHashMap<(Interned<String>, u16), Option<&'ctx [u8]>>,
-    pub word_prefix_fid_docids: FxHashMap<(Interned<String>, u16), Option<&'ctx [u8]>>,
+    pub word_fid_docids: FxHashMap<(Interned<String>, u16), Option<Cow<'ctx, [u8]>>>,
+    pub word_prefix_fid_docids: FxHashMap<(Interned<String>, u16), Option<Cow<'ctx, [u8]>>>,
     pub word_fids: FxHashMap<Interned<String>, Vec<u16>>,
     pub word_prefix_fids: FxHashMap<Interned<String>, Vec<u16>>,
 }
 impl<'ctx> DatabaseCache<'ctx> {
-    fn get_value<'v, K1, KC>(
+    fn get_value<'v, K1, KC, DC>(
         txn: &'ctx RoTxn,
         cache_key: K1,
         db_key: &'v KC::EItem,
-        cache: &mut FxHashMap<K1, Option<&'ctx [u8]>>,
+        cache: &mut FxHashMap<K1, Option<Cow<'ctx, [u8]>>>,
         db: Database<KC, ByteSlice>,
-    ) -> Result<Option<&'ctx [u8]>>
+    ) -> Result<Option<DC::DItem>>
     where
         K1: Copy + Eq + Hash,
         KC: BytesEncode<'v>,
+        DC: BytesDecodeOwned,
     {
-        let bitmap_ptr = match cache.entry(cache_key) {
-            Entry::Occupied(bitmap_ptr) => *bitmap_ptr.get(),
-            Entry::Vacant(entry) => {
-                let bitmap_ptr = db.get(txn, db_key)?;
-                entry.insert(bitmap_ptr);
-                bitmap_ptr
+        if let Entry::Vacant(entry) = cache.entry(cache_key) {
+            let bitmap_ptr = db.get(txn, db_key)?.map(Cow::Borrowed);
+            entry.insert(bitmap_ptr);
+        }
+
+        match cache.get(&cache_key).unwrap() {
+            Some(Cow::Borrowed(bytes)) => {
+                DC::bytes_decode_owned(bytes).ok_or(heed::Error::Decoding.into()).map(Some)
             }
-        };
-        Ok(bitmap_ptr)
+            Some(Cow::Owned(bytes)) => {
+                DC::bytes_decode_owned(bytes).ok_or(heed::Error::Decoding.into()).map(Some)
+            }
+            None => Ok(None),
+        }
+    }
+
+    fn get_value_from_keys<'v, K1, KC, DC>(
+        txn: &'ctx RoTxn,
+        cache_key: K1,
+        db_keys: &'v [KC::EItem],
+        cache: &mut FxHashMap<K1, Option<Cow<'ctx, [u8]>>>,
+        db: Database<KC, ByteSlice>,
+        merger: MergeFn,
+    ) -> Result<Option<DC::DItem>>
+    where
+        K1: Copy + Eq + Hash,
+        KC: BytesEncode<'v>,
+        DC: BytesDecodeOwned,
+        KC::EItem: Sized,
+    {
+        if let Entry::Vacant(entry) = cache.entry(cache_key) {
+            let bitmap_ptr: Option<Cow<'ctx, [u8]>> = match db_keys {
+                [] => None,
+                [key] => db.get(txn, key)?.map(Cow::Borrowed),
+                keys => {
+                    let bitmaps = keys
+                        .iter()
+                        .filter_map(|key| db.get(txn, key).transpose())
+                        .map(|v| v.map(Cow::Borrowed))
+                        .collect::<std::result::Result<Vec<Cow<[u8]>>, _>>()?;
+
+                    if bitmaps.is_empty() {
+                        None
+                    } else {
+                        Some(merger(&[], &bitmaps[..])?)
+                    }
+                }
+            };
+
+            entry.insert(bitmap_ptr);
+        }
+
+        match cache.get(&cache_key).unwrap() {
+            Some(Cow::Borrowed(bytes)) => {
+                DC::bytes_decode_owned(bytes).ok_or(heed::Error::Decoding.into()).map(Some)
+            }
+            Some(Cow::Owned(bytes)) => {
+                DC::bytes_decode_owned(bytes).ok_or(heed::Error::Decoding.into()).map(Some)
+            }
+            None => Ok(None),
+        }
     }
 }
+
 impl<'ctx> SearchContext<'ctx> {
     pub fn get_words_fst(&mut self) -> Result<fst::Set<Cow<'ctx, [u8]>>> {
         if let Some(fst) = self.db_cache.words_fst.clone() {
@@ -99,30 +154,41 @@ impl<'ctx> SearchContext<'ctx> {
 
     /// Retrieve or insert the given value in the `word_docids` database.
     fn get_db_word_docids(&mut self, word: Interned<String>) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
-            self.txn,
-            word,
-            self.word_interner.get(word).as_str(),
-            &mut self.db_cache.word_docids,
-            self.index.word_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| RoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        match &self.restricted_fids {
+            Some(restricted_fids) => {
+                let interned = self.word_interner.get(word).as_str();
+                let keys: Vec<_> = restricted_fids.iter().map(|fid| (interned, *fid)).collect();
+
+                DatabaseCache::get_value_from_keys::<_, _, CboRoaringBitmapCodec>(
+                    self.txn,
+                    word,
+                    &keys[..],
+                    &mut self.db_cache.word_docids,
+                    self.index.word_fid_docids.remap_data_type::<ByteSlice>(),
+                    merge_cbo_roaring_bitmaps,
+                )
+            }
+            None => DatabaseCache::get_value::<_, _, RoaringBitmapCodec>(
+                self.txn,
+                word,
+                self.word_interner.get(word).as_str(),
+                &mut self.db_cache.word_docids,
+                self.index.word_docids.remap_data_type::<ByteSlice>(),
+            ),
+        }
     }
 
     fn get_db_exact_word_docids(
         &mut self,
         word: Interned<String>,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        DatabaseCache::get_value::<_, _, RoaringBitmapCodec>(
             self.txn,
             word,
             self.word_interner.get(word).as_str(),
             &mut self.db_cache.exact_word_docids,
             self.index.exact_word_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| RoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
 
     pub fn word_prefix_docids(&mut self, prefix: Word) -> Result<Option<RoaringBitmap>> {
@@ -150,30 +216,41 @@ impl<'ctx> SearchContext<'ctx> {
         &mut self,
         prefix: Interned<String>,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
-            self.txn,
-            prefix,
-            self.word_interner.get(prefix).as_str(),
-            &mut self.db_cache.word_prefix_docids,
-            self.index.word_prefix_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| RoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        match &self.restricted_fids {
+            Some(restricted_fids) => {
+                let interned = self.word_interner.get(prefix).as_str();
+                let keys: Vec<_> = restricted_fids.iter().map(|fid| (interned, *fid)).collect();
+
+                DatabaseCache::get_value_from_keys::<_, _, CboRoaringBitmapCodec>(
+                    self.txn,
+                    prefix,
+                    &keys[..],
+                    &mut self.db_cache.word_prefix_docids,
+                    self.index.word_prefix_fid_docids.remap_data_type::<ByteSlice>(),
+                    merge_cbo_roaring_bitmaps,
+                )
+            }
+            None => DatabaseCache::get_value::<_, _, RoaringBitmapCodec>(
+                self.txn,
+                prefix,
+                self.word_interner.get(prefix).as_str(),
+                &mut self.db_cache.word_prefix_docids,
+                self.index.word_prefix_docids.remap_data_type::<ByteSlice>(),
+            ),
+        }
     }
 
     fn get_db_exact_word_prefix_docids(
         &mut self,
         prefix: Interned<String>,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        DatabaseCache::get_value::<_, _, RoaringBitmapCodec>(
             self.txn,
             prefix,
             self.word_interner.get(prefix).as_str(),
             &mut self.db_cache.exact_word_prefix_docids,
             self.index.exact_word_prefix_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| RoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
 
     pub fn get_db_word_pair_proximity_docids(
@@ -182,7 +259,7 @@ impl<'ctx> SearchContext<'ctx> {
         word2: Interned<String>,
         proximity: u8,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
             self.txn,
             (proximity, word1, word2),
             &(
@@ -192,9 +269,7 @@ impl<'ctx> SearchContext<'ctx> {
             ),
             &mut self.db_cache.word_pair_proximity_docids,
             self.index.word_pair_proximity_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| CboRoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
 
     pub fn get_db_word_pair_proximity_docids_len(
@@ -203,7 +278,7 @@ impl<'ctx> SearchContext<'ctx> {
         word2: Interned<String>,
         proximity: u8,
     ) -> Result<Option<u64>> {
-        DatabaseCache::get_value(
+        DatabaseCache::get_value::<_, _, CboRoaringBitmapLenCodec>(
             self.txn,
             (proximity, word1, word2),
             &(
@@ -213,11 +288,7 @@ impl<'ctx> SearchContext<'ctx> {
             ),
             &mut self.db_cache.word_pair_proximity_docids,
             self.index.word_pair_proximity_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| {
-            CboRoaringBitmapLenCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into())
-        })
-        .transpose()
+        )
     }
 
     pub fn get_db_word_prefix_pair_proximity_docids(
@@ -226,7 +297,7 @@ impl<'ctx> SearchContext<'ctx> {
         prefix2: Interned<String>,
         proximity: u8,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
             self.txn,
             (proximity, word1, prefix2),
             &(
@@ -236,9 +307,7 @@ impl<'ctx> SearchContext<'ctx> {
             ),
             &mut self.db_cache.word_prefix_pair_proximity_docids,
             self.index.word_prefix_pair_proximity_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| CboRoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
     pub fn get_db_prefix_word_pair_proximity_docids(
         &mut self,
@@ -246,7 +315,7 @@ impl<'ctx> SearchContext<'ctx> {
         right: Interned<String>,
         proximity: u8,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
             self.txn,
             (proximity, left_prefix, right),
             &(
@@ -256,9 +325,7 @@ impl<'ctx> SearchContext<'ctx> {
             ),
             &mut self.db_cache.prefix_word_pair_proximity_docids,
             self.index.prefix_word_pair_proximity_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| CboRoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
 
     pub fn get_db_word_fid_docids(
@@ -266,15 +333,18 @@ impl<'ctx> SearchContext<'ctx> {
         word: Interned<String>,
         fid: u16,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        // if the requested fid isn't in the restricted list, return None.
+        if self.restricted_fids.as_ref().map_or(false, |fids| !fids.contains(&fid)) {
+            return Ok(None);
+        }
+
+        DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
             self.txn,
             (word, fid),
             &(self.word_interner.get(word).as_str(), fid),
             &mut self.db_cache.word_fid_docids,
             self.index.word_fid_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| CboRoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
 
     pub fn get_db_word_prefix_fid_docids(
@@ -282,15 +352,18 @@ impl<'ctx> SearchContext<'ctx> {
         word_prefix: Interned<String>,
         fid: u16,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        // if the requested fid isn't in the restricted list, return None.
+        if self.restricted_fids.as_ref().map_or(false, |fids| !fids.contains(&fid)) {
+            return Ok(None);
+        }
+
+        DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
             self.txn,
             (word_prefix, fid),
             &(self.word_interner.get(word_prefix).as_str(), fid),
             &mut self.db_cache.word_prefix_fid_docids,
             self.index.word_prefix_fid_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| CboRoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
 
     pub fn get_db_word_fids(&mut self, word: Interned<String>) -> Result<Vec<u16>> {
@@ -309,7 +382,7 @@ impl<'ctx> SearchContext<'ctx> {
                 for result in remap_key_type {
                     let ((_, fid), value) = result?;
                     // filling other caches to avoid searching for them again
-                    self.db_cache.word_fid_docids.insert((word, fid), Some(value));
+                    self.db_cache.word_fid_docids.insert((word, fid), Some(Cow::Borrowed(value)));
                     fids.push(fid);
                 }
                 entry.insert(fids.clone());
@@ -335,7 +408,9 @@ impl<'ctx> SearchContext<'ctx> {
                 for result in remap_key_type {
                     let ((_, fid), value) = result?;
                     // filling other caches to avoid searching for them again
-                    self.db_cache.word_prefix_fid_docids.insert((word_prefix, fid), Some(value));
+                    self.db_cache
+                        .word_prefix_fid_docids
+                        .insert((word_prefix, fid), Some(Cow::Borrowed(value)));
                     fids.push(fid);
                 }
                 entry.insert(fids.clone());
@@ -350,15 +425,13 @@ impl<'ctx> SearchContext<'ctx> {
         word: Interned<String>,
         position: u16,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
             self.txn,
             (word, position),
             &(self.word_interner.get(word).as_str(), position),
             &mut self.db_cache.word_position_docids,
             self.index.word_position_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| CboRoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
 
     pub fn get_db_word_prefix_position_docids(
@@ -366,15 +439,13 @@ impl<'ctx> SearchContext<'ctx> {
         word_prefix: Interned<String>,
         position: u16,
     ) -> Result<Option<RoaringBitmap>> {
-        DatabaseCache::get_value(
+        DatabaseCache::get_value::<_, _, CboRoaringBitmapCodec>(
             self.txn,
             (word_prefix, position),
             &(self.word_interner.get(word_prefix).as_str(), position),
             &mut self.db_cache.word_prefix_position_docids,
             self.index.word_prefix_position_docids.remap_data_type::<ByteSlice>(),
-        )?
-        .map(|bytes| CboRoaringBitmapCodec::bytes_decode(bytes).ok_or(heed::Error::Decoding.into()))
-        .transpose()
+        )
     }
 
     pub fn get_db_word_positions(&mut self, word: Interned<String>) -> Result<Vec<u16>> {
@@ -393,7 +464,9 @@ impl<'ctx> SearchContext<'ctx> {
                 for result in remap_key_type {
                     let ((_, position), value) = result?;
                     // filling other caches to avoid searching for them again
-                    self.db_cache.word_position_docids.insert((word, position), Some(value));
+                    self.db_cache
+                        .word_position_docids
+                        .insert((word, position), Some(Cow::Borrowed(value)));
                     positions.push(position);
                 }
                 entry.insert(positions.clone());
@@ -424,7 +497,7 @@ impl<'ctx> SearchContext<'ctx> {
                     // filling other caches to avoid searching for them again
                     self.db_cache
                         .word_prefix_position_docids
-                        .insert((word_prefix, position), Some(value));
+                        .insert((word_prefix, position), Some(Cow::Borrowed(value)));
                     positions.push(position);
                 }
                 entry.insert(positions.clone());

milli/src/search/new/mod.rs

@@ -20,7 +20,7 @@ mod sort;
 #[cfg(test)]
 mod tests;
 
-use std::collections::HashSet;
+use std::collections::{BTreeSet, HashSet};
 
 use bucket_sort::{bucket_sort, BucketSortOutput};
 use charabia::TokenizerBuilder;
@@ -46,6 +46,7 @@ use self::geo_sort::GeoSort;
 pub use self::geo_sort::Strategy as GeoSortStrategy;
 use self::graph_based_ranking_rule::Words;
 use self::interner::Interned;
+use crate::error::FieldIdMapMissingEntry;
 use crate::score_details::{ScoreDetails, ScoringStrategy};
 use crate::search::new::distinct::apply_distinct_rule;
 use crate::{
@@ -62,6 +63,7 @@ pub struct SearchContext<'ctx> {
     pub phrase_interner: DedupInterner<Phrase>,
     pub term_interner: Interner<QueryTerm>,
     pub phrase_docids: PhraseDocIdsCache,
+    pub restricted_fids: Option<Vec<u16>>,
 }
 
 impl<'ctx> SearchContext<'ctx> {
@@ -74,8 +76,66 @@ impl<'ctx> SearchContext<'ctx> {
             phrase_interner: <_>::default(),
             term_interner: <_>::default(),
             phrase_docids: <_>::default(),
+            restricted_fids: None,
         }
     }
+
+    pub fn searchable_attributes(&mut self, searchable_attributes: &'ctx [String]) -> Result<()> {
+        let fids_map = self.index.fields_ids_map(self.txn)?;
+        let searchable_names = self.index.searchable_fields(self.txn)?;
+
+        let mut restricted_fids = Vec::new();
+        for field_name in searchable_attributes {
+            let searchable_contains_name =
+                searchable_names.as_ref().map(|sn| sn.iter().any(|name| name == field_name));
+            let fid = match (fids_map.id(field_name), searchable_contains_name) {
+                // The Field id exist and the field is searchable
+                (Some(fid), Some(true)) | (Some(fid), None) => fid,
+                // The field is searchable but the Field id doesn't exist => Internal Error
+                (None, Some(true)) => {
+                    return Err(FieldIdMapMissingEntry::FieldName {
+                        field_name: field_name.to_string(),
+                        process: "search",
+                    }
+                    .into())
+                }
+                // The field is not searchable => User error
+                _otherwise => {
+                    let mut valid_fields: BTreeSet<_> =
+                        fids_map.names().map(String::from).collect();
+
+                    // Filter by the searchable names
+                    if let Some(sn) = searchable_names {
+                        let searchable_names = sn.iter().map(|s| s.to_string()).collect();
+                        valid_fields = &valid_fields & &searchable_names;
+                    }
+
+                    let searchable_count = valid_fields.len();
+
+                    // Remove hidden fields
+                    if let Some(dn) = self.index.displayed_fields(self.txn)? {
+                        let displayable_names = dn.iter().map(|s| s.to_string()).collect();
+                        valid_fields = &valid_fields & &displayable_names;
+                    }
+
+                    let hidden_fields = searchable_count > valid_fields.len();
+                    let field = field_name.to_string();
+                    return Err(UserError::InvalidSearchableAttribute {
+                        field,
+                        valid_fields,
+                        hidden_fields,
+                    }
+                    .into());
+                }
+            };
+
+            restricted_fids.push(fid);
+        }
+
+        self.restricted_fids = Some(restricted_fids);
+
+        Ok(())
+    }
 }
 
 #[derive(Clone, Copy, PartialEq, PartialOrd, Ord, Eq)]

milli/src/update/mod.rs

@@ -4,7 +4,8 @@ pub use self::delete_documents::{DeleteDocuments, DeletionStrategy, DocumentDele
 pub use self::facet::bulk::FacetsUpdateBulk;
 pub use self::facet::incremental::FacetsUpdateIncrementalInner;
 pub use self::index_documents::{
-    DocumentAdditionResult, DocumentId, IndexDocuments, IndexDocumentsConfig, IndexDocumentsMethod,
+    merge_cbo_roaring_bitmaps, merge_roaring_bitmaps, DocumentAdditionResult, DocumentId,
+    IndexDocuments, IndexDocumentsConfig, IndexDocumentsMethod, MergeFn,
 };
 pub use self::indexer_config::IndexerConfig;
 pub use self::prefix_word_pairs::{