implements the automatic batch deletion

crates/index-scheduler/src/batch.rs

@@ -17,13 +17,14 @@ tasks individually, but should be much faster since we are only performing
 one indexing operation.
 */
 
-use std::collections::{BTreeSet, HashSet};
+use std::collections::{BTreeSet, HashMap, HashSet};
 use std::ffi::OsStr;
 use std::fmt;
 use std::fs::{self, File};
 use std::io::BufWriter;
 
 use dump::IndexMetadata;
+use meilisearch_types::batches::BatchId;
 use meilisearch_types::error::Code;
 use meilisearch_types::heed::{RoTxn, RwTxn};
 use meilisearch_types::milli::documents::{obkv_to_object, DocumentsBatchReader};
@@ -1675,6 +1676,8 @@ impl IndexScheduler {
         let mut affected_statuses = HashSet::new();
         let mut affected_kinds = HashSet::new();
         let mut affected_canceled_by = RoaringBitmap::new();
+        // The tasks that have been removed *per batches*.
+        let mut affected_batches: HashMap<BatchId, RoaringBitmap> = HashMap::new();
 
         for task_id in to_delete_tasks.iter() {
             let task = self.get_task(wtxn, task_id)?.ok_or(Error::CorruptedTaskQueue)?;
@@ -1696,18 +1699,21 @@ impl IndexScheduler {
             if let Some(canceled_by) = task.canceled_by {
                 affected_canceled_by.insert(canceled_by);
             }
+            if let Some(batch_uid) = task.batch_uid {
+                affected_batches.entry(batch_uid).or_default().insert(task_id);
+            }
         }
 
-        for index in affected_indexes {
-            self.update_index(wtxn, &index, |bitmap| *bitmap -= &to_delete_tasks)?;
+        for index in affected_indexes.iter() {
+            self.update_index(wtxn, index, |bitmap| *bitmap -= &to_delete_tasks)?;
         }
 
-        for status in affected_statuses {
-            self.update_status(wtxn, status, |bitmap| *bitmap -= &to_delete_tasks)?;
+        for status in affected_statuses.iter() {
+            self.update_status(wtxn, *status, |bitmap| *bitmap -= &to_delete_tasks)?;
         }
 
-        for kind in affected_kinds {
-            self.update_kind(wtxn, kind, |bitmap| *bitmap -= &to_delete_tasks)?;
+        for kind in affected_kinds.iter() {
+            self.update_kind(wtxn, *kind, |bitmap| *bitmap -= &to_delete_tasks)?;
         }
 
         for task in to_delete_tasks.iter() {
@@ -1723,6 +1729,48 @@ impl IndexScheduler {
                 }
             }
         }
+        for (batch_id, to_delete_tasks) in affected_batches {
+            if let Some(mut tasks) = self.batch_to_tasks_mapping.get(wtxn, &batch_id)? {
+                tasks -= &to_delete_tasks;
+                // We must remove the batch entirely
+                if tasks.is_empty() {
+                    self.all_batches.delete(wtxn, &batch_id)?;
+                    self.batch_to_tasks_mapping.delete(wtxn, &batch_id)?;
+                }
+                // Anyway, we must remove the batch from all its reverse indexes.
+                // The only way to do that is to check
+
+                for index in affected_indexes.iter() {
+                    let index_tasks = self.index_tasks(wtxn, index)?;
+                    let remaining_index_tasks = index_tasks & &tasks;
+                    if remaining_index_tasks.is_empty() {
+                        self.update_batch_index(wtxn, index, |bitmap| {
+                            bitmap.remove(batch_id);
+                        })?;
+                    }
+                }
+
+                for status in affected_statuses.iter() {
+                    let status_tasks = self.get_status(wtxn, *status)?;
+                    let remaining_status_tasks = status_tasks & &tasks;
+                    if remaining_status_tasks.is_empty() {
+                        self.update_batch_status(wtxn, *status, |bitmap| {
+                            bitmap.remove(batch_id);
+                        })?;
+                    }
+                }
+
+                for kind in affected_kinds.iter() {
+                    let kind_tasks = self.get_kind(wtxn, *kind)?;
+                    let remaining_kind_tasks = kind_tasks & &tasks;
+                    if remaining_kind_tasks.is_empty() {
+                        self.update_batch_kind(wtxn, *kind, |bitmap| {
+                            bitmap.remove(batch_id);
+                        })?;
+                    }
+                }
+            }
+        }
 
         Ok(to_delete_tasks)
     }

crates/index-scheduler/src/snapshots/lib.rs/task_deletion_delete_same_task_twice/task_deletion_processed.snap

@@ -41,22 +41,19 @@ catto: { number_of_documents: 1, field_distribution: {"id": 1} }
 [timestamp] [2,3,]
 ----------------------------------------------------------------------
 ### All Batches:
-0 {uid: 0, }
 1 {uid: 1, }
 ----------------------------------------------------------------------
 ### Batch to tasks mapping:
-0 [0,]
 1 [2,3,]
 ----------------------------------------------------------------------
 ### Batches Status:
-succeeded [0,1,]
+succeeded [1,]
 ----------------------------------------------------------------------
 ### Batches Kind:
-"documentAdditionOrUpdate" [0,]
+"documentAdditionOrUpdate" []
 "taskDeletion" [1,]
 ----------------------------------------------------------------------
 ### Batches Index Tasks:
-catto [0,]
 ----------------------------------------------------------------------
 ### Batches Enqueued At:
 [timestamp] [0,]

crates/index-scheduler/src/snapshots/lib.rs/task_deletion_deleteable/task_deletion_processed.snap

@@ -39,22 +39,19 @@ catto: { number_of_documents: 1, field_distribution: {"id": 1} }
 [timestamp] [2,]
 ----------------------------------------------------------------------
 ### All Batches:
-0 {uid: 0, }
 1 {uid: 1, }
 ----------------------------------------------------------------------
 ### Batch to tasks mapping:
-0 [0,]
 1 [2,]
 ----------------------------------------------------------------------
 ### Batches Status:
-succeeded [0,1,]
+succeeded [1,]
 ----------------------------------------------------------------------
 ### Batches Kind:
-"documentAdditionOrUpdate" [0,]
+"documentAdditionOrUpdate" []
 "taskDeletion" [1,]
 ----------------------------------------------------------------------
 ### Batches Index Tasks:
-catto [0,]
 ----------------------------------------------------------------------
 ### Batches Enqueued At:
 [timestamp] [0,]