Merge #4203

4203: Extract external document docids from docs on deletion by filter r=Kerollmops a=dureuill

This fixes some of the performance regression observed on `diff-indexing` when doing delete-by-filter with a filter matching many documents.

To delete 19 768 771 documents (hackernews dataset, all documents matching `type = comment`), here are the observed time:

|branch (commit sha1sum)|time|speed-down factor (lower is better)|
|--|--|--|
|`main` (48865470d7)|1212.885536s (~20min)|x1.0 (baseline)|
|`diff-indexing` (523519fdbf)|5385.550543s (90min)|x4.44|
|**`diff-indexing-extract-primary-key`**(f8289cd974)|2582.323324s (43min) | x2.13|

So we're still suffering a speed-down of x2.13, but that's much better than x4.44.

---

Changes:

- Refactor the logic of PrimaryKey extraction to a struct
- Add a trait to abstract the extraction of field id from a name between `DocumentBatch` and `FieldIdMap`.
- Add `Index::external_id_of` to get the external ids of a bitmap of internal ids.
- Use this new method to add new Transform and Batch methods to remove documents that are known to be from the DB.
- Modify delete-by-filter to use the new method

Co-authored-by: Louis Dureuil <louis@meilisearch.com>

benchmarks/benches/indexing.rs

@@ -864,22 +864,12 @@ fn delete_documents_from_ids(index: Index, document_ids_to_delete: Vec<RoaringBi
 
     let indexer_config = IndexerConfig::default();
     for ids in document_ids_to_delete {
-        let external_documents_ids = index.external_documents_ids();
-        // FIXME: for filters matching a lot of documents, this will allocate a huge vec of external docids (strings).
-        // Since what we have is an iterator, it would be better to delete in chunks
-        let external_to_internal: std::result::Result<Vec<_>, RoaringBitmap> =
-            external_documents_ids
-                .find_external_id_of(&wtxn, ids)
-                .unwrap()
-                .only_external_ids()
-                .collect();
-        let ids = external_to_internal.unwrap();
         let config = IndexDocumentsConfig::default();
 
         let mut builder =
             IndexDocuments::new(&mut wtxn, &index, &indexer_config, config, |_| (), || false)
                 .unwrap();
-        (builder, _) = builder.remove_documents(ids).unwrap();
+        (builder, _) = builder.remove_documents_from_db_no_batch(&ids).unwrap();
         builder.execute().unwrap();
     }
 

index-scheduler/src/batch.rs

@@ -1534,18 +1534,6 @@ fn delete_document_by_filter<'a>(
             }
             e => e.into(),
         })?;
-        let external_documents_ids = index.external_documents_ids();
-        // FIXME: for filters matching a lot of documents, this will allocate a huge vec of external docids (strings).
-        // Since what we have is an iterator, it would be better to delete in chunks
-        let external_to_internal: std::result::Result<Vec<_>, RoaringBitmap> =
-            external_documents_ids
-                .find_external_id_of(wtxn, candidates)?
-                .only_external_ids()
-                .collect();
-        let document_ids = match external_to_internal {
-            Ok(external_ids) => external_ids,
-            Err(remaining_ids) => panic!("Couldn't find some external ids {:?}", remaining_ids),
-        };
 
         let config = IndexDocumentsConfig {
             update_method: IndexDocumentsMethod::ReplaceDocuments,
@@ -1561,13 +1549,10 @@ fn delete_document_by_filter<'a>(
             || must_stop_processing.get(),
         )?;
 
-        let (new_builder, user_result) = builder.remove_documents(document_ids)?;
+        let (new_builder, count) = builder.remove_documents_from_db_no_batch(&candidates)?;
         builder = new_builder;
-        // Uses Invariant: remove documents actually always returns Ok for the inner result
-        let count = user_result.unwrap();
 
         let _ = builder.execute()?;
-
         count
     } else {
         0

milli/src/documents/mod.rs

@@ -1,5 +1,6 @@
 mod builder;
 mod enriched;
+mod primary_key;
 mod reader;
 mod serde_impl;
 
@@ -11,6 +12,7 @@ use bimap::BiHashMap;
 pub use builder::DocumentsBatchBuilder;
 pub use enriched::{EnrichedDocument, EnrichedDocumentsBatchCursor, EnrichedDocumentsBatchReader};
 use obkv::KvReader;
+pub use primary_key::{DocumentIdExtractionError, FieldIdMapper, PrimaryKey, DEFAULT_PRIMARY_KEY};
 pub use reader::{DocumentsBatchCursor, DocumentsBatchCursorError, DocumentsBatchReader};
 use serde::{Deserialize, Serialize};
 
@@ -87,6 +89,12 @@ impl DocumentsBatchIndex {
     }
 }
 
+impl FieldIdMapper for DocumentsBatchIndex {
+    fn id(&self, name: &str) -> Option<FieldId> {
+        self.id(name)
+    }
+}
+
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
     #[error("Error parsing number {value:?} at line {line}: {error}")]

milli/src/documents/primary_key.rs

@@ -0,0 +1,172 @@
+use std::iter;
+use std::result::Result as StdResult;
+
+use serde_json::Value;
+
+use crate::{FieldId, InternalError, Object, Result, UserError};
+
+/// The symbol used to define levels in a nested primary key.
+const PRIMARY_KEY_SPLIT_SYMBOL: char = '.';
+
+/// The default primary that is used when not specified.
+pub const DEFAULT_PRIMARY_KEY: &str = "id";
+
+/// Trait for objects that can map the name of a field to its [`FieldId`].
+pub trait FieldIdMapper {
+    /// Attempts to map the passed name to its [`FieldId`].
+    ///
+    /// `None` if the field with this name was not found.
+    fn id(&self, name: &str) -> Option<FieldId>;
+}
+
+/// A type that represent the type of primary key that has been set
+/// for this index, a classic flat one or a nested one.
+#[derive(Debug, Clone, Copy)]
+pub enum PrimaryKey<'a> {
+    Flat { name: &'a str, field_id: FieldId },
+    Nested { name: &'a str },
+}
+
+pub enum DocumentIdExtractionError {
+    InvalidDocumentId(UserError),
+    MissingDocumentId,
+    TooManyDocumentIds(usize),
+}
+
+impl<'a> PrimaryKey<'a> {
+    pub fn new(path: &'a str, fields: &impl FieldIdMapper) -> Option<Self> {
+        Some(if path.contains(PRIMARY_KEY_SPLIT_SYMBOL) {
+            Self::Nested { name: path }
+        } else {
+            let field_id = fields.id(path)?;
+            Self::Flat { name: path, field_id }
+        })
+    }
+
+    pub fn name(&self) -> &str {
+        match self {
+            PrimaryKey::Flat { name, .. } => name,
+            PrimaryKey::Nested { name } => name,
+        }
+    }
+
+    pub fn document_id(
+        &self,
+        document: &obkv::KvReader<FieldId>,
+        fields: &impl FieldIdMapper,
+    ) -> Result<StdResult<String, DocumentIdExtractionError>> {
+        match self {
+            PrimaryKey::Flat { name: _, field_id } => match document.get(*field_id) {
+                Some(document_id_bytes) => {
+                    let document_id = serde_json::from_slice(document_id_bytes)
+                        .map_err(InternalError::SerdeJson)?;
+                    match validate_document_id_value(document_id)? {
+                        Ok(document_id) => Ok(Ok(document_id)),
+                        Err(user_error) => {
+                            Ok(Err(DocumentIdExtractionError::InvalidDocumentId(user_error)))
+                        }
+                    }
+                }
+                None => Ok(Err(DocumentIdExtractionError::MissingDocumentId)),
+            },
+            nested @ PrimaryKey::Nested { .. } => {
+                let mut matching_documents_ids = Vec::new();
+                for (first_level_name, right) in nested.possible_level_names() {
+                    if let Some(field_id) = fields.id(first_level_name) {
+                        if let Some(value_bytes) = document.get(field_id) {
+                            let object = serde_json::from_slice(value_bytes)
+                                .map_err(InternalError::SerdeJson)?;
+                            fetch_matching_values(object, right, &mut matching_documents_ids);
+
+                            if matching_documents_ids.len() >= 2 {
+                                return Ok(Err(DocumentIdExtractionError::TooManyDocumentIds(
+                                    matching_documents_ids.len(),
+                                )));
+                            }
+                        }
+                    }
+                }
+
+                match matching_documents_ids.pop() {
+                    Some(document_id) => match validate_document_id_value(document_id)? {
+                        Ok(document_id) => Ok(Ok(document_id)),
+                        Err(user_error) => {
+                            Ok(Err(DocumentIdExtractionError::InvalidDocumentId(user_error)))
+                        }
+                    },
+                    None => Ok(Err(DocumentIdExtractionError::MissingDocumentId)),
+                }
+            }
+        }
+    }
+
+    /// Returns an `Iterator` that gives all the possible fields names the primary key
+    /// can have depending of the first level name and depth of the objects.
+    pub fn possible_level_names(&self) -> impl Iterator<Item = (&str, &str)> + '_ {
+        let name = self.name();
+        name.match_indices(PRIMARY_KEY_SPLIT_SYMBOL)
+            .map(move |(i, _)| (&name[..i], &name[i + PRIMARY_KEY_SPLIT_SYMBOL.len_utf8()..]))
+            .chain(iter::once((name, "")))
+    }
+}
+
+fn fetch_matching_values(value: Value, selector: &str, output: &mut Vec<Value>) {
+    match value {
+        Value::Object(object) => fetch_matching_values_in_object(object, selector, "", output),
+        otherwise => output.push(otherwise),
+    }
+}
+
+fn fetch_matching_values_in_object(
+    object: Object,
+    selector: &str,
+    base_key: &str,
+    output: &mut Vec<Value>,
+) {
+    for (key, value) in object {
+        let base_key = if base_key.is_empty() {
+            key.to_string()
+        } else {
+            format!("{}{}{}", base_key, PRIMARY_KEY_SPLIT_SYMBOL, key)
+        };
+
+        if starts_with(selector, &base_key) {
+            match value {
+                Value::Object(object) => {
+                    fetch_matching_values_in_object(object, selector, &base_key, output)
+                }
+                value => output.push(value),
+            }
+        }
+    }
+}
+
+fn starts_with(selector: &str, key: &str) -> bool {
+    selector.strip_prefix(key).map_or(false, |tail| {
+        tail.chars().next().map(|c| c == PRIMARY_KEY_SPLIT_SYMBOL).unwrap_or(true)
+    })
+}
+
+// FIXME: move to a DocumentId struct
+
+fn validate_document_id(document_id: &str) -> Option<&str> {
+    if !document_id.is_empty()
+        && document_id.chars().all(|c| matches!(c, 'a'..='z' | 'A'..='Z' | '0'..='9' | '-' | '_'))
+    {
+        Some(document_id)
+    } else {
+        None
+    }
+}
+
+pub fn validate_document_id_value(document_id: Value) -> Result<StdResult<String, UserError>> {
+    match document_id {
+        Value::String(string) => match validate_document_id(&string) {
+            Some(s) if s.len() == string.len() => Ok(Ok(string)),
+            Some(s) => Ok(Ok(s.to_string())),
+            None => Ok(Err(UserError::InvalidDocumentId { document_id: Value::String(string) })),
+        },
+        Value::Number(number) if number.is_i64() => Ok(Ok(number.to_string())),
+        content => Ok(Err(UserError::InvalidDocumentId { document_id: content })),
+    }
+}

milli/src/fields_ids_map.rs

@@ -81,6 +81,12 @@ impl Default for FieldsIdsMap {
     }
 }
 
+impl crate::documents::FieldIdMapper for FieldsIdsMap {
+    fn id(&self, name: &str) -> Option<FieldId> {
+        self.id(name)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

milli/src/index.rs

@@ -12,6 +12,7 @@ use rstar::RTree;
 use time::OffsetDateTime;
 
 use crate::distance::NDotProductPoint;
+use crate::documents::PrimaryKey;
 use crate::error::{InternalError, UserError};
 use crate::fields_ids_map::FieldsIdsMap;
 use crate::heed_codec::facet::{
@@ -1176,6 +1177,36 @@ impl Index {
         self.iter_documents(rtxn, self.documents_ids(rtxn)?)
     }
 
+    pub fn external_id_of<'a, 't: 'a>(
+        &'a self,
+        rtxn: &'t RoTxn,
+        ids: impl IntoIterator<Item = DocumentId> + 'a,
+    ) -> Result<impl IntoIterator<Item = Result<String>> + 'a> {
+        let fields = self.fields_ids_map(rtxn)?;
+
+        // uses precondition "never called on an empty index"
+        let primary_key = self.primary_key(rtxn)?.ok_or(InternalError::DatabaseMissingEntry {
+            db_name: db_name::MAIN,
+            key: Some(main_key::PRIMARY_KEY_KEY),
+        })?;
+        let primary_key = PrimaryKey::new(primary_key, &fields).ok_or_else(|| {
+            InternalError::FieldIdMapMissingEntry(crate::FieldIdMapMissingEntry::FieldName {
+                field_name: primary_key.to_owned(),
+                process: "external_id_of",
+            })
+        })?;
+        Ok(self.iter_documents(rtxn, ids)?.map(move |entry| -> Result<_> {
+            let (_docid, obkv) = entry?;
+            match primary_key.document_id(&obkv, &fields)? {
+                Ok(document_id) => Ok(document_id),
+                Err(_) => Err(InternalError::DocumentsError(
+                    crate::documents::Error::InvalidDocumentFormat,
+                )
+                .into()),
+            }
+        }))
+    }
+
     pub fn facets_distribution<'a>(&'a self, rtxn: &'a RoTxn) -> FacetDistribution<'a> {
         FacetDistribution::new(rtxn, self)
     }

milli/src/update/index_documents/enrich.rs

@@ -1,20 +1,17 @@
+use std::fmt;
 use std::io::{BufWriter, Read, Seek};
 use std::result::Result as StdResult;
-use std::{fmt, iter};
 
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
-use crate::documents::{DocumentsBatchIndex, DocumentsBatchReader, EnrichedDocumentsBatchReader};
+use crate::documents::{
+    DocumentIdExtractionError, DocumentsBatchIndex, DocumentsBatchReader,
+    EnrichedDocumentsBatchReader, PrimaryKey, DEFAULT_PRIMARY_KEY,
+};
 use crate::error::{GeoError, InternalError, UserError};
 use crate::update::index_documents::{obkv_to_object, writer_into_reader};
-use crate::{FieldId, Index, Object, Result};
+use crate::{FieldId, Index, Result};
-
-/// The symbol used to define levels in a nested primary key.
-const PRIMARY_KEY_SPLIT_SYMBOL: char = '.';
-
-/// The default primary that is used when not specified.
-const DEFAULT_PRIMARY_KEY: &str = "id";
 
 /// This function validates and enrich the documents by checking that:
 ///  - we can infer a primary key,
@@ -41,14 +38,12 @@ pub fn enrich_documents_batch<R: Read + Seek>(
     // The primary key *field id* that has already been set for this index or the one
     // we will guess by searching for the first key that contains "id" as a substring.
     let primary_key = match index.primary_key(rtxn)? {
-        Some(primary_key) if primary_key.contains(PRIMARY_KEY_SPLIT_SYMBOL) => {
+        Some(primary_key) => match PrimaryKey::new(primary_key, &documents_batch_index) {
-            PrimaryKey::nested(primary_key)
+            Some(primary_key) => primary_key,
-        }
+            None if autogenerate_docids => PrimaryKey::Flat {
-        Some(primary_key) => match documents_batch_index.id(primary_key) {
+                name: primary_key,
-            Some(id) => PrimaryKey::flat(primary_key, id),
+                field_id: documents_batch_index.insert(primary_key),
-            None if autogenerate_docids => {
+            },
-                PrimaryKey::flat(primary_key, documents_batch_index.insert(primary_key))
-            }
             None => {
                 return match cursor.next_document()? {
                     Some(first_document) => Ok(Err(UserError::MissingDocumentId {
@@ -76,14 +71,14 @@ pub fn enrich_documents_batch<R: Read + Seek>(
             });
 
             match guesses.as_slice() {
-                [] if autogenerate_docids => PrimaryKey::flat(
+                [] if autogenerate_docids => PrimaryKey::Flat {
-                    DEFAULT_PRIMARY_KEY,
+                    name: DEFAULT_PRIMARY_KEY,
-                    documents_batch_index.insert(DEFAULT_PRIMARY_KEY),
+                    field_id: documents_batch_index.insert(DEFAULT_PRIMARY_KEY),
-                ),
+                },
                 [] => return Ok(Err(UserError::NoPrimaryKeyCandidateFound)),
                 [(field_id, name)] => {
                     log::info!("Primary key was not specified in index. Inferred to '{name}'");
-                    PrimaryKey::flat(name, *field_id)
+                    PrimaryKey::Flat { name, field_id: *field_id }
                 }
                 multiple => {
                     return Ok(Err(UserError::MultiplePrimaryKeyCandidatesFound {
@@ -156,92 +151,24 @@ fn fetch_or_generate_document_id(
     uuid_buffer: &mut [u8; uuid::fmt::Hyphenated::LENGTH],
     count: u32,
 ) -> Result<StdResult<DocumentId, UserError>> {
-    match primary_key {
+    Ok(match primary_key.document_id(document, documents_batch_index)? {
-        PrimaryKey::Flat { name: primary_key, field_id: primary_key_id } => {
+        Ok(document_id) => Ok(DocumentId::Retrieved { value: document_id }),
-            match document.get(primary_key_id) {
+        Err(DocumentIdExtractionError::InvalidDocumentId(user_error)) => Err(user_error),
-                Some(document_id_bytes) => {
+        Err(DocumentIdExtractionError::MissingDocumentId) if autogenerate_docids => {
-                    let document_id = serde_json::from_slice(document_id_bytes)
-                        .map_err(InternalError::SerdeJson)?;
-                    match validate_document_id_value(document_id)? {
-                        Ok(document_id) => Ok(Ok(DocumentId::retrieved(document_id))),
-                        Err(user_error) => Ok(Err(user_error)),
-                    }
-                }
-                None if autogenerate_docids => {
             let uuid = uuid::Uuid::new_v4().as_hyphenated().encode_lower(uuid_buffer);
-                    Ok(Ok(DocumentId::generated(uuid.to_string(), count)))
+            Ok(DocumentId::Generated { value: uuid.to_string(), document_nth: count })
         }
-                None => Ok(Err(UserError::MissingDocumentId {
+        Err(DocumentIdExtractionError::MissingDocumentId) => Err(UserError::MissingDocumentId {
-                    primary_key: primary_key.to_string(),
+            primary_key: primary_key.name().to_string(),
             document: obkv_to_object(document, documents_batch_index)?,
-                })),
+        }),
-            }
+        Err(DocumentIdExtractionError::TooManyDocumentIds(_)) => {
-        }
+            Err(UserError::TooManyDocumentIds {
-        nested @ PrimaryKey::Nested { .. } => {
+                primary_key: primary_key.name().to_string(),
-            let mut matching_documents_ids = Vec::new();
-            for (first_level_name, right) in nested.possible_level_names() {
-                if let Some(field_id) = documents_batch_index.id(first_level_name) {
-                    if let Some(value_bytes) = document.get(field_id) {
-                        let object = serde_json::from_slice(value_bytes)
-                            .map_err(InternalError::SerdeJson)?;
-                        fetch_matching_values(object, right, &mut matching_documents_ids);
-
-                        if matching_documents_ids.len() >= 2 {
-                            return Ok(Err(UserError::TooManyDocumentIds {
-                                primary_key: nested.name().to_string(),
                 document: obkv_to_object(document, documents_batch_index)?,
-                            }));
+            })
-                        }
-                    }
-                }
-            }
-
-            match matching_documents_ids.pop() {
-                Some(document_id) => match validate_document_id_value(document_id)? {
-                    Ok(document_id) => Ok(Ok(DocumentId::retrieved(document_id))),
-                    Err(user_error) => Ok(Err(user_error)),
-                },
-                None => Ok(Err(UserError::MissingDocumentId {
-                    primary_key: nested.name().to_string(),
-                    document: obkv_to_object(document, documents_batch_index)?,
-                })),
-            }
-        }
-    }
-}
-
-/// A type that represent the type of primary key that has been set
-/// for this index, a classic flat one or a nested one.
-#[derive(Debug, Clone, Copy)]
-enum PrimaryKey<'a> {
-    Flat { name: &'a str, field_id: FieldId },
-    Nested { name: &'a str },
-}
-
-impl PrimaryKey<'_> {
-    fn flat(name: &str, field_id: FieldId) -> PrimaryKey {
-        PrimaryKey::Flat { name, field_id }
-    }
-
-    fn nested(name: &str) -> PrimaryKey {
-        PrimaryKey::Nested { name }
-    }
-
-    fn name(&self) -> &str {
-        match self {
-            PrimaryKey::Flat { name, .. } => name,
-            PrimaryKey::Nested { name } => name,
-        }
-    }
-
-    /// Returns an `Iterator` that gives all the possible fields names the primary key
-    /// can have depending of the first level name and deepnes of the objects.
-    fn possible_level_names(&self) -> impl Iterator<Item = (&str, &str)> + '_ {
-        let name = self.name();
-        name.match_indices(PRIMARY_KEY_SPLIT_SYMBOL)
-            .map(move |(i, _)| (&name[..i], &name[i + PRIMARY_KEY_SPLIT_SYMBOL.len_utf8()..]))
-            .chain(iter::once((name, "")))
         }
+    })
 }
 
 /// A type that represents a document id that has been retrieved from a document or auto-generated.
@@ -255,14 +182,6 @@ pub enum DocumentId {
 }
 
 impl DocumentId {
-    fn retrieved(value: String) -> DocumentId {
-        DocumentId::Retrieved { value }
-    }
-
-    fn generated(value: String, document_nth: u32) -> DocumentId {
-        DocumentId::Generated { value, document_nth }
-    }
-
     fn debug(&self) -> String {
         format!("{:?}", self)
     }
@@ -290,66 +209,6 @@ impl fmt::Debug for DocumentId {
     }
 }
 
-fn starts_with(selector: &str, key: &str) -> bool {
-    selector.strip_prefix(key).map_or(false, |tail| {
-        tail.chars().next().map(|c| c == PRIMARY_KEY_SPLIT_SYMBOL).unwrap_or(true)
-    })
-}
-
-pub fn fetch_matching_values(value: Value, selector: &str, output: &mut Vec<Value>) {
-    match value {
-        Value::Object(object) => fetch_matching_values_in_object(object, selector, "", output),
-        otherwise => output.push(otherwise),
-    }
-}
-
-pub fn fetch_matching_values_in_object(
-    object: Object,
-    selector: &str,
-    base_key: &str,
-    output: &mut Vec<Value>,
-) {
-    for (key, value) in object {
-        let base_key = if base_key.is_empty() {
-            key.to_string()
-        } else {
-            format!("{}{}{}", base_key, PRIMARY_KEY_SPLIT_SYMBOL, key)
-        };
-
-        if starts_with(selector, &base_key) {
-            match value {
-                Value::Object(object) => {
-                    fetch_matching_values_in_object(object, selector, &base_key, output)
-                }
-                value => output.push(value),
-            }
-        }
-    }
-}
-
-pub fn validate_document_id(document_id: &str) -> Option<&str> {
-    if !document_id.is_empty()
-        && document_id.chars().all(|c| matches!(c, 'a'..='z' | 'A'..='Z' | '0'..='9' | '-' | '_'))
-    {
-        Some(document_id)
-    } else {
-        None
-    }
-}
-
-/// Parses a Json encoded document id and validate it, returning a user error when it is one.
-pub fn validate_document_id_value(document_id: Value) -> Result<StdResult<String, UserError>> {
-    match document_id {
-        Value::String(string) => match validate_document_id(&string) {
-            Some(s) if s.len() == string.len() => Ok(Ok(string)),
-            Some(s) => Ok(Ok(s.to_string())),
-            None => Ok(Err(UserError::InvalidDocumentId { document_id: Value::String(string) })),
-        },
-        Value::Number(number) if number.is_i64() => Ok(Ok(number.to_string())),
-        content => Ok(Err(UserError::InvalidDocumentId { document_id: content })),
-    }
-}
-
 /// Try to extract an `f64` from a JSON `Value` and return the `Value`
 /// in the `Err` variant if it failed.
 pub fn extract_finite_float_from_value(value: Value) -> StdResult<f64, Value> {

milli/src/update/index_documents/mod.rs

@@ -20,10 +20,7 @@ use slice_group_by::GroupBy;
 use typed_chunk::{write_typed_chunk_into_index, TypedChunk};
 
 use self::enrich::enrich_documents_batch;
-pub use self::enrich::{
+pub use self::enrich::{extract_finite_float_from_value, validate_geo_from_json, DocumentId};
-    extract_finite_float_from_value, validate_document_id, validate_document_id_value,
-    validate_geo_from_json, DocumentId,
-};
 pub use self::helpers::{
     as_cloneable_grenad, create_sorter, create_writer, fst_stream_into_hashset,
     fst_stream_into_vec, merge_btreeset_string, merge_cbo_roaring_bitmaps, merge_roaring_bitmaps,
@@ -197,6 +194,39 @@ where
         Ok((self, Ok(deleted_documents)))
     }
 
+    /// Removes documents from db using their internal document ids.
+    ///
+    /// # Warning
+    ///
+    /// This function is dangerous and will only work correctly if:
+    ///
+    /// - All the passed ids currently exist in the database
+    /// - No batching using the standards `remove_documents` and `add_documents` took place
+    ///
+    /// TODO: make it impossible to call `remove_documents` or `add_documents` on an instance that calls this function.
+    pub fn remove_documents_from_db_no_batch(
+        mut self,
+        to_delete: &RoaringBitmap,
+    ) -> Result<(Self, u64)> {
+        puffin::profile_function!();
+
+        // Early return when there is no document to add
+        if to_delete.is_empty() {
+            return Ok((self, 0));
+        }
+
+        let deleted_documents = self
+            .transform
+            .as_mut()
+            .expect("Invalid document deletion state")
+            .remove_documents_from_db_no_batch(to_delete, self.wtxn, &self.should_abort)?
+            as u64;
+
+        self.deleted_documents += deleted_documents;
+
+        Ok((self, deleted_documents))
+    }
+
     #[logging_timer::time("IndexDocuments::{}")]
     pub fn execute(mut self) -> Result<DocumentAdditionResult> {
         puffin::profile_function!();

milli/src/update/index_documents/transform.rs

@@ -421,52 +421,13 @@ impl<'a, 'i> Transform<'a, 'i> {
             // Then we push the document in sorters in deletion mode.
             let deleted_from_db = match external_documents_ids.get(wtxn, &to_remove)? {
                 Some(docid) => {
-                    self.replaced_documents_ids.insert(docid);
+                    self.remove_document_from_db(
-
+                        docid,
-                    // fetch the obkv document
+                        to_remove,
-                    let original_key = BEU32::new(docid);
+                        wtxn,
-                    let base_obkv = self
+                        &mut document_sorter_key_buffer,
-                        .index
-                        .documents
-                        .remap_data_type::<heed::types::ByteSlice>()
-                        .get(wtxn, &original_key)?
-                        .ok_or(InternalError::DatabaseMissingEntry {
-                            db_name: db_name::DOCUMENTS,
-                            key: None,
-                        })?;
-
-                    // Key is the concatenation of the internal docid and the external one.
-                    document_sorter_key_buffer.clear();
-                    document_sorter_key_buffer.extend_from_slice(&docid.to_be_bytes());
-                    document_sorter_key_buffer.extend_from_slice(to_remove.as_bytes());
-                    // push it as to delete in the original_sorter
-                    document_sorter_value_buffer.clear();
-                    document_sorter_value_buffer.push(Operation::Deletion as u8);
-                    into_del_add_obkv(
-                        KvReaderU16::new(base_obkv),
-                        true,
-                        false,
                         &mut document_sorter_value_buffer,
                     )?;
-                    self.original_sorter
-                        .insert(&document_sorter_key_buffer, &document_sorter_value_buffer)?;
-
-                    // flatten it and push it as to delete in the flattened_sorter
-                    let flattened_obkv = KvReader::new(base_obkv);
-                    if let Some(obkv) = self.flatten_from_fields_ids_map(flattened_obkv)? {
-                        // we recreate our buffer with the flattened documents
-                        document_sorter_value_buffer.clear();
-                        document_sorter_value_buffer.push(Operation::Deletion as u8);
-                        into_del_add_obkv(
-                            KvReaderU16::new(&obkv),
-                            true,
-                            false,
-                            &mut document_sorter_value_buffer,
-                        )?;
-                    }
-                    self.flattened_sorter
-                        .insert(docid.to_be_bytes(), &document_sorter_value_buffer)?;
-
                     true
                 }
                 None => false,
@@ -481,6 +442,97 @@ impl<'a, 'i> Transform<'a, 'i> {
         Ok(documents_deleted)
     }
 
+    /// Removes documents from db using their internal document ids.
+    ///
+    /// # Warning
+    ///
+    /// This function is dangerous and will only work correctly if:
+    ///
+    /// - All the passed ids currently exist in the database
+    /// - No batching using the standards `remove_documents` and `add_documents` took place
+    ///
+    /// TODO: make it impossible to call `remove_documents` or `add_documents` on an instance that calls this function.
+    #[logging_timer::time]
+    pub fn remove_documents_from_db_no_batch<FA>(
+        &mut self,
+        to_remove: &RoaringBitmap,
+        wtxn: &mut heed::RwTxn,
+        should_abort: FA,
+    ) -> Result<usize>
+    where
+        FA: Fn() -> bool + Sync,
+    {
+        puffin::profile_function!();
+
+        let mut documents_deleted = 0;
+        let mut document_sorter_value_buffer = Vec::new();
+        let mut document_sorter_key_buffer = Vec::new();
+        let external_ids = self.index.external_id_of(wtxn, to_remove.iter())?;
+
+        for (internal_docid, external_docid) in to_remove.iter().zip(external_ids) {
+            let external_docid = external_docid?;
+            if should_abort() {
+                return Err(Error::InternalError(InternalError::AbortedIndexation));
+            }
+            self.remove_document_from_db(
+                internal_docid,
+                external_docid,
+                wtxn,
+                &mut document_sorter_key_buffer,
+                &mut document_sorter_value_buffer,
+            )?;
+
+            documents_deleted += 1;
+        }
+
+        Ok(documents_deleted)
+    }
+
+    fn remove_document_from_db(
+        &mut self,
+        internal_docid: u32,
+        external_docid: String,
+        txn: &heed::RoTxn,
+        document_sorter_key_buffer: &mut Vec<u8>,
+        document_sorter_value_buffer: &mut Vec<u8>,
+    ) -> Result<()> {
+        self.replaced_documents_ids.insert(internal_docid);
+
+        // fetch the obkv document
+        let original_key = BEU32::new(internal_docid);
+        let base_obkv = self
+            .index
+            .documents
+            .remap_data_type::<heed::types::ByteSlice>()
+            .get(txn, &original_key)?
+            .ok_or(InternalError::DatabaseMissingEntry {
+                db_name: db_name::DOCUMENTS,
+                key: None,
+            })?;
+
+        // Key is the concatenation of the internal docid and the external one.
+        document_sorter_key_buffer.clear();
+        document_sorter_key_buffer.extend_from_slice(&internal_docid.to_be_bytes());
+        document_sorter_key_buffer.extend_from_slice(external_docid.as_bytes());
+        // push it as to delete in the original_sorter
+        document_sorter_value_buffer.clear();
+        document_sorter_value_buffer.push(Operation::Deletion as u8);
+        into_del_add_obkv(KvReaderU16::new(base_obkv), true, false, document_sorter_value_buffer)?;
+        self.original_sorter.insert(&document_sorter_key_buffer, &document_sorter_value_buffer)?;
+
+        // flatten it and push it as to delete in the flattened_sorter
+        let flattened_obkv = KvReader::new(base_obkv);
+        if let Some(obkv) = self.flatten_from_fields_ids_map(flattened_obkv)? {
+            // we recreate our buffer with the flattened documents
+            document_sorter_value_buffer.clear();
+            document_sorter_value_buffer.push(Operation::Deletion as u8);
+            into_del_add_obkv(KvReaderU16::new(&obkv), true, false, document_sorter_value_buffer)?;
+        }
+        self.flattened_sorter
+            .insert(internal_docid.to_be_bytes(), &document_sorter_value_buffer)?;
+        Ok(())
+    }
+
     // Flatten a document from the fields ids map contained in self and insert the new
     // created fields. Returns `None` if the document doesn't need to be flattened.
     fn flatten_from_fields_ids_map(&mut self, obkv: KvReader<FieldId>) -> Result<Option<Vec<u8>>> {