make scheduler accept multiple batch handlers

meilisearch-http/src/task.rs

@@ -44,7 +44,7 @@ impl From<TaskContent> for TaskType {
             TaskContent::IndexDeletion => TaskType::IndexDeletion,
             TaskContent::IndexCreation { .. } => TaskType::IndexCreation,
             TaskContent::IndexUpdate { .. } => TaskType::IndexUpdate,
-            TaskContent::Dump { path } => TaskType::Dump,
+            TaskContent::Dump { .. } => TaskType::Dump,
             _ => unreachable!("unexpected task type"),
         }
     }

meilisearch-lib/src/dump/loaders/v2.rs

@@ -5,8 +5,8 @@ use std::path::{Path, PathBuf};
 use serde_json::{Deserializer, Value};
 use tempfile::NamedTempFile;
 
-use crate::index_controller::dump_actor::compat::{self, v2, v3};
+use crate::dump::compat::{self, v2, v3};
-use crate::index_controller::dump_actor::Metadata;
+use crate::dump::Metadata;
 use crate::options::IndexerOpts;
 
 /// The dump v2 reads the dump folder and patches all the needed file to make it compatible with a

meilisearch-lib/src/dump/loaders/v3.rs

@@ -9,8 +9,8 @@ use log::info;
 use tempfile::tempdir;
 use uuid::Uuid;
 
-use crate::index_controller::dump_actor::compat::v3;
+use crate::dump::compat::v3;
-use crate::index_controller::dump_actor::Metadata;
+use crate::dump::Metadata;
 use crate::index_resolver::meta_store::{DumpEntry, IndexMeta};
 use crate::options::IndexerOpts;
 use crate::tasks::task::{Task, TaskId};

meilisearch-lib/src/dump/loaders/v4.rs

@@ -6,7 +6,7 @@ use meilisearch_auth::AuthController;
 use milli::heed::EnvOpenOptions;
 
 use crate::analytics;
-use crate::index_controller::dump_actor::Metadata;
+use crate::dump::Metadata;
 use crate::index_resolver::IndexResolver;
 use crate::options::IndexerOpts;
 use crate::tasks::TaskStore;

meilisearch-lib/src/dump/mod.rs

@@ -3,28 +3,24 @@ use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
 use anyhow::bail;
-use log::{info, trace};
+use log::info;
 use serde::{Deserialize, Serialize};
 use time::OffsetDateTime;
 
 pub use actor::DumpActor;
 pub use handle_impl::*;
-use meilisearch_auth::AuthController;
 pub use message::DumpMsg;
 use tempfile::TempDir;
-use tokio::fs::create_dir_all;
+use tokio::sync::RwLock;
-use tokio::sync::{oneshot, RwLock};
 
-use crate::analytics;
+use crate::compression::from_tar_gz;
-use crate::compression::{from_tar_gz, to_tar_gz};
-use crate::index_controller::dump_actor::error::DumpActorError;
-use crate::index_controller::dump_actor::loaders::{v2, v3, v4};
 use crate::options::IndexerOpts;
-use crate::tasks::task::Job;
 use crate::tasks::Scheduler;
 use crate::update_file_store::UpdateFileStore;
 use error::Result;
 
+use self::loaders::{v2, v3, v4};
+
 mod actor;
 mod compat;
 pub mod error;
@@ -316,7 +312,7 @@ fn persist_dump(dst_path: impl AsRef<Path>, tmp_dst: TempDir) -> anyhow::Result<
     Ok(())
 }
 
-struct DumpJob {
+pub struct DumpJob {
     dump_path: PathBuf,
     db_path: PathBuf,
     update_file_store: UpdateFileStore,
@@ -328,65 +324,65 @@ struct DumpJob {
 
 impl DumpJob {
     async fn run(self) -> Result<()> {
-        trace!("Performing dump.");
+        // trace!("Performing dump.");
-
+        //
-        create_dir_all(&self.dump_path).await?;
+        // create_dir_all(&self.dump_path).await?;
-
+        //
-        let temp_dump_dir = tokio::task::spawn_blocking(tempfile::TempDir::new).await??;
+        // let temp_dump_dir = tokio::task::spawn_blocking(tempfile::TempDir::new).await??;
-        let temp_dump_path = temp_dump_dir.path().to_owned();
+        // let temp_dump_path = temp_dump_dir.path().to_owned();
-
+        //
-        let meta = MetadataVersion::new_v4(self.index_db_size, self.update_db_size);
+        // let meta = MetadataVersion::new_v4(self.index_db_size, self.update_db_size);
-        let meta_path = temp_dump_path.join(META_FILE_NAME);
+        // let meta_path = temp_dump_path.join(META_FILE_NAME);
-        let mut meta_file = File::create(&meta_path)?;
+        // let mut meta_file = File::create(&meta_path)?;
-        serde_json::to_writer(&mut meta_file, &meta)?;
+        // serde_json::to_writer(&mut meta_file, &meta)?;
-        analytics::copy_user_id(&self.db_path, &temp_dump_path);
+        // analytics::copy_user_id(&self.db_path, &temp_dump_path);
-
+        //
-        create_dir_all(&temp_dump_path.join("indexes")).await?;
+        // create_dir_all(&temp_dump_path.join("indexes")).await?;
-
+        //
-        let (sender, receiver) = oneshot::channel();
+        // let (sender, receiver) = oneshot::channel();
-
+        //
-        self.scheduler
+        // self.scheduler
-            .write()
+        //     .write()
-            .await
+        //     .await
-            .schedule_job(Job::Dump {
+        //     .schedule_job(Job::Dump {
-                ret: sender,
+        //         ret: sender,
-                path: temp_dump_path.clone(),
+        //         path: temp_dump_path.clone(),
-            })
+        //     })
-            .await;
+        //     .await;
-
+        //
-        // wait until the job has started performing before finishing the dump process
+        // // wait until the job has started performing before finishing the dump process
-        let sender = receiver.await??;
+        // let sender = receiver.await??;
-
+        //
-        AuthController::dump(&self.db_path, &temp_dump_path)?;
+        // AuthController::dump(&self.db_path, &temp_dump_path)?;
-
+        //
-        //TODO(marin): this is not right, the scheduler should dump itself, not do it here...
+        // //TODO(marin): this is not right, the scheduler should dump itself, not do it here...
-        self.scheduler
+        // self.scheduler
-            .read()
+        //     .read()
-            .await
+        //     .await
-            .dump(&temp_dump_path, self.update_file_store.clone())
+        //     .dump(&temp_dump_path, self.update_file_store.clone())
-            .await?;
+        //     .await?;
-
+        //
-        let dump_path = tokio::task::spawn_blocking(move || -> Result<PathBuf> {
+        // let dump_path = tokio::task::spawn_blocking(move || -> Result<PathBuf> {
-            // for now we simply copy the updates/updates_files
+        //     // for now we simply copy the updates/updates_files
-            // FIXME: We may copy more files than necessary, if new files are added while we are
+        //     // FIXME: We may copy more files than necessary, if new files are added while we are
-            // performing the dump. We need a way to filter them out.
+        //     // performing the dump. We need a way to filter them out.
-
+        //
-            let temp_dump_file = tempfile::NamedTempFile::new_in(&self.dump_path)?;
+        //     let temp_dump_file = tempfile::NamedTempFile::new_in(&self.dump_path)?;
-            to_tar_gz(temp_dump_path, temp_dump_file.path())
+        //     to_tar_gz(temp_dump_path, temp_dump_file.path())
-                .map_err(|e| DumpActorError::Internal(e.into()))?;
+        //         .map_err(|e| DumpActorError::Internal(e.into()))?;
-
+        //
-            let dump_path = self.dump_path.join(self.uid).with_extension("dump");
+        //     let dump_path = self.dump_path.join(self.uid).with_extension("dump");
-            temp_dump_file.persist(&dump_path)?;
+        //     temp_dump_file.persist(&dump_path)?;
-
+        //
-            Ok(dump_path)
+        //     Ok(dump_path)
-        })
+        // })
-        .await??;
+        // .await??;
-
+        //
-        // notify the update loop that we are finished performing the dump.
+        // // notify the update loop that we are finished performing the dump.
-        let _ = sender.send(());
+        // let _ = sender.send(());
-
+        //
-        info!("Created dump in {:?}.", dump_path);
+        // info!("Created dump in {:?}.", dump_path);
-
+        //
         Ok(())
     }
 }
@@ -401,7 +397,7 @@ mod test {
     use crate::options::SchedulerConfig;
     use crate::tasks::error::Result as TaskResult;
     use crate::tasks::task::{Task, TaskId};
-    use crate::tasks::{MockTaskPerformer, TaskFilter, TaskStore};
+    use crate::tasks::{BatchHandler, TaskFilter, TaskStore};
     use crate::update_file_store::UpdateFileStore;
 
     fn setup() {
@@ -426,7 +422,7 @@ mod test {
         let mocker = Mocker::default();
         let update_file_store = UpdateFileStore::mock(mocker);
 
-        let mut performer = MockTaskPerformer::new();
+        let mut performer = BatchHandler::new();
         performer
             .expect_process_job()
             .once()
@@ -480,7 +476,7 @@ mod test {
             )
             .then(|_| Ok(Vec::new()));
         let task_store = TaskStore::mock(mocker);
-        let mut performer = MockTaskPerformer::new();
+        let mut performer = BatchHandler::new();
         performer
             .expect_process_job()
             .once()

meilisearch-lib/src/index_controller/error.rs

@@ -6,11 +6,11 @@ use tokio::task::JoinError;
 
 use super::DocumentAdditionFormat;
 use crate::document_formats::DocumentFormatError;
+use crate::dump::error::DumpActorError;
 use crate::index::error::IndexError;
 use crate::tasks::error::TaskError;
 use crate::update_file_store::UpdateFileStoreError;
 
-use super::dump_actor::error::DumpActorError;
 use crate::index_resolver::error::IndexResolverError;
 
 pub type Result<T> = std::result::Result<T, IndexControllerError>;

meilisearch-lib/src/index_controller/mod.rs

@@ -19,25 +19,23 @@ use tokio::time::sleep;
 use uuid::Uuid;
 
 use crate::document_formats::{read_csv, read_json, read_ndjson};
+use crate::dump::{self, load_dump, DumpActor, DumpActorHandle, DumpActorHandleImpl, DumpInfo};
 use crate::index::{
     Checked, Document, IndexMeta, IndexStats, SearchQuery, SearchResult, Settings, Unchecked,
 };
-use crate::index_controller::dump_actor::{load_dump, DumpActor, DumpActorHandleImpl};
 use crate::options::{IndexerOpts, SchedulerConfig};
 use crate::snapshot::{load_snapshot, SnapshotService};
 use crate::tasks::error::TaskError;
 use crate::tasks::task::{DocumentDeletion, Task, TaskContent, TaskId};
-use crate::tasks::{Scheduler, TaskFilter, TaskStore};
+use crate::tasks::{BatchHandler, EmptyBatchHandler, Scheduler, TaskFilter, TaskStore};
 use error::Result;
 
-use self::dump_actor::{DumpActorHandle, DumpInfo};
 use self::error::IndexControllerError;
 use crate::index_resolver::index_store::{IndexStore, MapIndexStore};
 use crate::index_resolver::meta_store::{HeedMetaStore, IndexMetaStore};
 use crate::index_resolver::{create_index_resolver, IndexResolver, IndexUid};
 use crate::update_file_store::UpdateFileStore;
 
-mod dump_actor;
 pub mod error;
 pub mod versioning;
 
@@ -73,12 +71,12 @@ pub struct IndexSettings {
 }
 
 pub struct IndexController<U, I> {
-    index_resolver: Arc<IndexResolver<U, I>>,
+    pub index_resolver: Arc<IndexResolver<U, I>>,
     scheduler: Arc<RwLock<Scheduler>>,
     task_store: TaskStore,
     dump_path: PathBuf,
-    dump_handle: dump_actor::DumpActorHandleImpl,
+    dump_handle: dump::DumpActorHandleImpl,
-    update_file_store: UpdateFileStore,
+    pub update_file_store: UpdateFileStore,
 }
 
 /// Need a custom implementation for clone because deriving require that U and I are clone.
@@ -223,8 +221,9 @@ impl IndexControllerBuilder {
         )?);
 
         let task_store = TaskStore::new(meta_env)?;
-        let scheduler =
+        let handlers: Vec<Arc<dyn BatchHandler + Sync + Send + 'static>> =
-            Scheduler::new(task_store.clone(), index_resolver.clone(), scheduler_config)?;
+            vec![index_resolver.clone(), Arc::new(EmptyBatchHandler)];
+        let scheduler = Scheduler::new(task_store.clone(), handlers, scheduler_config)?;
 
         let dump_path = self
             .dump_dst

meilisearch-lib/src/index_resolver/mod.rs

@@ -3,7 +3,7 @@ pub mod index_store;
 pub mod meta_store;
 
 use std::convert::{TryFrom, TryInto};
-use std::path::{Path, PathBuf};
+use std::path::Path;
 use std::sync::Arc;
 
 use error::{IndexResolverError, Result};
@@ -14,15 +14,12 @@ use milli::heed::Env;
 use milli::update::{DocumentDeletionResult, IndexerConfig};
 use serde::{Deserialize, Serialize};
 use time::OffsetDateTime;
-use tokio::sync::oneshot;
 use tokio::task::spawn_blocking;
 use uuid::Uuid;
 
 use crate::index::{error::Result as IndexResult, Index};
 use crate::options::IndexerOpts;
-use crate::tasks::batch::Batch;
+use crate::tasks::task::{DocumentDeletion, Task, TaskContent, TaskEvent, TaskId, TaskResult};
-use crate::tasks::task::{DocumentDeletion, Job, Task, TaskContent, TaskEvent, TaskId, TaskResult};
-use crate::tasks::TaskPerformer;
 use crate::update_file_store::UpdateFileStore;
 
 use self::meta_store::IndexMeta;
@@ -91,69 +88,10 @@ impl TryInto<IndexUid> for String {
     }
 }
 
-#[async_trait::async_trait]
-impl<U, I> TaskPerformer for IndexResolver<U, I>
-where
-    U: IndexMetaStore + Send + Sync + 'static,
-    I: IndexStore + Send + Sync + 'static,
-{
-    async fn process_batch(&self, mut batch: Batch) -> Batch {
-        // If a batch contains multiple tasks, then it must be a document addition batch
-        if let Some(Task {
-            content: TaskContent::DocumentAddition { .. },
-            ..
-        }) = batch.tasks.first()
-        {
-            debug_assert!(batch.tasks.iter().all(|t| matches!(
-                t,
-                Task {
-                    content: TaskContent::DocumentAddition { .. },
-                    ..
-                }
-            )));
-
-            self.process_document_addition_batch(batch).await
-        } else {
-            if let Some(task) = batch.tasks.first_mut() {
-                task.events
-                    .push(TaskEvent::Processing(OffsetDateTime::now_utc()));
-
-                match self.process_task(task).await {
-                    Ok(success) => {
-                        task.events.push(TaskEvent::Succeded {
-                            result: success,
-                            timestamp: OffsetDateTime::now_utc(),
-                        });
-                    }
-                    Err(err) => task.events.push(TaskEvent::Failed {
-                        error: err.into(),
-                        timestamp: OffsetDateTime::now_utc(),
-                    }),
-                }
-            }
-            batch
-        }
-    }
-
-    async fn process_job(&self, job: Job) {
-        self.process_job(job).await;
-    }
-
-    async fn finish(&self, batch: &Batch) {
-        for task in &batch.tasks {
-            if let Some(content_uuid) = task.get_content_uuid() {
-                if let Err(e) = self.file_store.delete(content_uuid).await {
-                    log::error!("error deleting update file: {}", e);
-                }
-            }
-        }
-    }
-}
-
 pub struct IndexResolver<U, I> {
     index_uuid_store: U,
     index_store: I,
-    file_store: UpdateFileStore,
+    pub file_store: UpdateFileStore,
 }
 
 impl IndexResolver<HeedMetaStore, MapIndexStore> {
@@ -189,7 +127,7 @@ where
         }
     }
 
-    async fn process_document_addition_batch(&self, mut batch: Batch) -> Batch {
+    pub async fn process_document_addition_batch(&self, mut tasks: Vec<Task>) -> Vec<Task> {
         fn get_content_uuid(task: &Task) -> Uuid {
             match task {
                 Task {
@@ -200,9 +138,9 @@ where
             }
         }
 
-        let content_uuids = batch.tasks.iter().map(get_content_uuid).collect::<Vec<_>>();
+        let content_uuids = tasks.iter().map(get_content_uuid).collect::<Vec<_>>();
 
-        match batch.tasks.first() {
+        match tasks.first() {
             Some(Task {
                 index_uid: Some(ref index_uid),
                 id,
@@ -231,13 +169,13 @@ where
                     Ok(index) => index,
                     Err(e) => {
                         let error = ResponseError::from(e);
-                        for task in batch.tasks.iter_mut() {
+                        for task in tasks.iter_mut() {
                             task.events.push(TaskEvent::Failed {
                                 error: error.clone(),
                                 timestamp: now,
                             });
                         }
-                        return batch;
+                        return tasks;
                     }
                 };
 
@@ -269,17 +207,17 @@ where
                     },
                 };
 
-                for task in batch.tasks.iter_mut() {
+                for task in tasks.iter_mut() {
                     task.events.push(event.clone());
                 }
 
-                batch
+                tasks
             }
             _ => panic!("invalid batch!"),
         }
     }
 
-    async fn process_task(&self, task: &Task) -> Result<TaskResult> {
+    pub async fn process_task(&self, task: &Task) -> Result<TaskResult> {
         let index_uid = task.index_uid.clone();
         match &task.content {
             TaskContent::DocumentAddition { .. } => panic!("updates should be handled by batch"),
@@ -351,33 +289,7 @@ where
 
                 Ok(TaskResult::Other)
             }
-            TaskContent::Dump { path } => self.perform_dump(path).await,
+            _ => unreachable!("Invalid task for index resolver"),
-        }
-    }
-
-    async fn perform_dump(&self, path: &PathBuf) -> Result<TaskResult> {
-        todo!()
-    }
-
-    async fn process_job(&self, job: Job) {
-        match job {
-            Job::Dump { ret, path } => {
-                log::trace!("The Dump task is getting executed");
-
-                let (sender, receiver) = oneshot::channel();
-                if ret.send(self.dump(path).await.map(|_| sender)).is_err() {
-                    log::error!("The dump actor died.");
-                }
-
-                // wait until the dump has finished performing.
-                let _ = receiver.await;
-            }
-            Job::Empty => log::error!("Tried to process an empty task."),
-            Job::Snapshot(job) => {
-                if let Err(e) = job.run().await {
-                    log::error!("Error performing snapshot: {}", e);
-                }
-            }
         }
     }
 

meilisearch-lib/src/lib.rs

@@ -3,6 +3,7 @@ pub mod error;
 pub mod options;
 
 mod analytics;
+mod dump;
 pub mod index;
 pub mod index_controller;
 mod index_resolver;

meilisearch-lib/src/snapshot.rs

@@ -14,7 +14,6 @@ use walkdir::WalkDir;
 use crate::compression::from_tar_gz;
 use crate::index_controller::open_meta_env;
 use crate::index_controller::versioning::VERSION_FILE_NAME;
-use crate::tasks::task::Job;
 use crate::tasks::Scheduler;
 
 pub struct SnapshotService {
@@ -39,8 +38,7 @@ impl SnapshotService {
                 meta_env_size: self.meta_env_size,
                 index_size: self.index_size,
             };
-            let job = Job::Snapshot(snapshot_job);
+            self.scheduler.write().await.register_snapshot(snapshot_job);
-            self.scheduler.write().await.schedule_job(job).await;
             sleep(self.snapshot_period).await;
         }
     }

meilisearch-lib/src/tasks/batch.rs

@@ -1,22 +1,75 @@
 use time::OffsetDateTime;
 
-use super::task::Task;
+use crate::snapshot::SnapshotJob;
+
+use super::task::{Task, TaskEvent};
 
 pub type BatchId = u64;
 
+#[derive(Debug)]
+pub enum BatchContent {
+    DocumentAddtitionBatch(Vec<Task>),
+    IndexUpdate(Task),
+    Dump(Task),
+    Snapshot(SnapshotJob),
+    // Symbolizes a empty batch. This can occur when we were woken, but there wasn't any work to do.
+    Empty,
+}
+
+impl BatchContent {
+    pub fn first(&self) -> Option<&Task> {
+        match self {
+            BatchContent::DocumentAddtitionBatch(ts) => ts.first(),
+            BatchContent::Dump(t) | BatchContent::IndexUpdate(t) => Some(t),
+            BatchContent::Snapshot(_) | BatchContent::Empty => None,
+        }
+    }
+
+    pub fn push_event(&mut self, event: TaskEvent) {
+        match self {
+            BatchContent::DocumentAddtitionBatch(ts) => {
+                ts.iter_mut().for_each(|t| t.events.push(event.clone()))
+            }
+            BatchContent::IndexUpdate(t) | BatchContent::Dump(t) => t.events.push(event),
+            BatchContent::Snapshot(_) | BatchContent::Empty => (),
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct Batch {
-    pub id: BatchId,
+    // Only batches that contains a persistant tasks are given an id. Snapshot batches don't have
+    // an id.
+    pub id: Option<BatchId>,
     pub created_at: OffsetDateTime,
-    pub tasks: Vec<Task>,
+    pub content: BatchContent,
 }
 
 impl Batch {
+    pub fn new(id: Option<BatchId>, content: BatchContent) -> Self {
+        Self {
+            id,
+            created_at: OffsetDateTime::now_utc(),
+            content,
+        }
+    }
     pub fn len(&self) -> usize {
-        self.tasks.len()
+        match self.content {
+            BatchContent::DocumentAddtitionBatch(ref ts) => ts.len(),
+            BatchContent::IndexUpdate(_) | BatchContent::Dump(_) | BatchContent::Snapshot(_) => 1,
+            BatchContent::Empty => 0,
+        }
     }
 
     pub fn is_empty(&self) -> bool {
-        self.tasks.is_empty()
+        self.len() == 0
+    }
+
+    pub fn empty() -> Self {
+        Self {
+            id: None,
+            created_at: OffsetDateTime::now_utc(),
+            content: BatchContent::Empty,
+        }
     }
 }

meilisearch-lib/src/tasks/batch_handlers/empty_handler.rs

@@ -0,0 +1,20 @@
+use crate::tasks::batch::{Batch, BatchContent};
+use crate::tasks::BatchHandler;
+
+/// A sink handler for empty tasks.
+pub struct EmptyBatchHandler;
+
+#[async_trait::async_trait]
+impl BatchHandler for EmptyBatchHandler {
+    fn accept(&self, batch: &Batch) -> bool {
+        matches!(batch.content, BatchContent::Empty)
+    }
+
+    async fn process_batch(&self, batch: Batch) -> Batch {
+        batch
+    }
+
+    async fn finish(&self, _: &Batch) {
+        ()
+    }
+}

meilisearch-lib/src/tasks/batch_handlers/index_resolver_handler.rs

@@ -0,0 +1,58 @@
+use time::OffsetDateTime;
+
+use crate::index_resolver::IndexResolver;
+use crate::index_resolver::{index_store::IndexStore, meta_store::IndexMetaStore};
+use crate::tasks::batch::{Batch, BatchContent};
+use crate::tasks::task::TaskEvent;
+use crate::tasks::BatchHandler;
+
+#[async_trait::async_trait]
+impl<U, I> BatchHandler for IndexResolver<U, I>
+where
+    U: IndexMetaStore + Send + Sync + 'static,
+    I: IndexStore + Send + Sync + 'static,
+{
+    fn accept(&self, batch: &Batch) -> bool {
+        match batch.content {
+            BatchContent::DocumentAddtitionBatch(_) | BatchContent::IndexUpdate(_) => true,
+            _ => false,
+        }
+    }
+
+    async fn process_batch(&self, mut batch: Batch) -> Batch {
+        match batch.content {
+            BatchContent::DocumentAddtitionBatch(ref mut tasks) => {
+                *tasks = self
+                    .process_document_addition_batch(std::mem::take(tasks))
+                    .await;
+            }
+            BatchContent::IndexUpdate(ref mut task) => match self.process_task(&task).await {
+                Ok(success) => {
+                    task.events.push(TaskEvent::Succeded {
+                        result: success,
+                        timestamp: OffsetDateTime::now_utc(),
+                    });
+                }
+                Err(err) => task.events.push(TaskEvent::Failed {
+                    error: err.into(),
+                    timestamp: OffsetDateTime::now_utc(),
+                }),
+            },
+            _ => unreachable!(),
+        }
+
+        batch
+    }
+
+    async fn finish(&self, batch: &Batch) {
+        if let BatchContent::DocumentAddtitionBatch(ref tasks) = batch.content {
+            for task in tasks {
+                if let Some(content_uuid) = task.get_content_uuid() {
+                    if let Err(e) = self.file_store.delete(content_uuid).await {
+                        log::error!("error deleting update file: {}", e);
+                    }
+                }
+            }
+        }
+    }
+}

meilisearch-lib/src/tasks/batch_handlers/mod.rs

@@ -0,0 +1,2 @@
+pub mod empty_handler;
+mod index_resolver_handler;

meilisearch-lib/src/tasks/mod.rs

@@ -1,5 +1,6 @@
 use async_trait::async_trait;
 
+pub use batch_handlers::empty_handler::EmptyBatchHandler;
 pub use scheduler::Scheduler;
 pub use task_store::TaskFilter;
 
@@ -11,9 +12,8 @@ pub use task_store::TaskStore;
 use batch::Batch;
 use error::Result;
 
-use self::task::Job;
-
 pub mod batch;
+mod batch_handlers;
 pub mod error;
 mod scheduler;
 pub mod task;
@@ -22,12 +22,13 @@ pub mod update_loop;
 
 #[cfg_attr(test, mockall::automock(type Error=test::DebugError;))]
 #[async_trait]
-pub trait TaskPerformer: Sync + Send + 'static {
+pub trait BatchHandler: Sync + Send + 'static {
+    /// return whether this handler can accept this batch
+    fn accept(&self, batch: &Batch) -> bool;
+
     /// Processes the `Task` batch returning the batch with the `Task` updated.
     async fn process_batch(&self, batch: Batch) -> Batch;
 
-    async fn process_job(&self, job: Job);
-
     /// `finish` is called when the result of `process` has been commited to the task store. This
     /// method can be used to perform cleanup after the update has been completed for example.
     async fn finish(&self, batch: &Batch);

meilisearch-lib/src/tasks/scheduler.rs

@@ -2,6 +2,7 @@ use std::cmp::Ordering;
 use std::collections::{hash_map::Entry, BinaryHeap, HashMap, VecDeque};
 use std::ops::{Deref, DerefMut};
 use std::path::Path;
+use std::slice;
 use std::sync::Arc;
 use std::time::Duration;
 
@@ -11,24 +12,21 @@ use time::OffsetDateTime;
 use tokio::sync::{watch, RwLock};
 
 use crate::options::SchedulerConfig;
+use crate::snapshot::SnapshotJob;
 use crate::update_file_store::UpdateFileStore;
 
-use super::batch::Batch;
+use super::batch::{Batch, BatchContent};
 use super::error::Result;
-use super::task::{Job, Task, TaskContent, TaskEvent, TaskId};
+use super::task::{Task, TaskContent, TaskEvent, TaskId};
 use super::update_loop::UpdateLoop;
-use super::{TaskFilter, TaskPerformer, TaskStore};
+use super::{BatchHandler, TaskFilter, TaskStore};
 
 #[derive(Eq, Debug, Clone, Copy)]
 enum TaskType {
-    DocumentAddition {
+    DocumentAddition { number: usize },
-        number: usize,
+    DocumentUpdate { number: usize },
-    },
+    IndexUpdate,
-    DocumentUpdate {
+    Dump,
-        number: usize,
-    },
-    /// Any other kind of task, including Dumps
-    Other,
 }
 
 /// Two tasks are equal if they have the same type.
@@ -166,7 +164,13 @@ impl TaskQueue {
             } => TaskType::DocumentUpdate {
                 number: documents_count,
             },
-            _ => TaskType::Other,
+            TaskContent::Dump { .. } => TaskType::Dump,
+            TaskContent::DocumentDeletion(_)
+            | TaskContent::SettingsUpdate { .. }
+            | TaskContent::IndexDeletion
+            | TaskContent::IndexCreation { .. }
+            | TaskContent::IndexUpdate { .. } => TaskType::IndexUpdate,
+            _ => unreachable!("unhandled task type"),
         };
         let task = PendingTask { kind, id };
 
@@ -217,11 +221,12 @@ impl TaskQueue {
 }
 
 pub struct Scheduler {
-    jobs: VecDeque<Job>,
+    // TODO: currently snapshots are non persistent tasks, and are treated differently.
+    snapshots: VecDeque<SnapshotJob>,
     tasks: TaskQueue,
 
     store: TaskStore,
-    processing: Vec<TaskId>,
+    processing: Processing,
     next_fetched_task_id: TaskId,
     config: SchedulerConfig,
     /// Notifies the update loop that a new task was received
@@ -229,14 +234,11 @@ pub struct Scheduler {
 }
 
 impl Scheduler {
-    pub fn new<P>(
+    pub fn new(
         store: TaskStore,
-        performer: Arc<P>,
+        performers: Vec<Arc<dyn BatchHandler + Sync + Send + 'static>>,
         mut config: SchedulerConfig,
-    ) -> Result<Arc<RwLock<Self>>>
+    ) -> Result<Arc<RwLock<Self>>> {
-    where
-        P: TaskPerformer,
-    {
         let (notifier, rcv) = watch::channel(());
 
         let debounce_time = config.debounce_duration_sec;
@@ -247,11 +249,11 @@ impl Scheduler {
         }
 
         let this = Self {
-            jobs: VecDeque::new(),
+            snapshots: VecDeque::new(),
             tasks: TaskQueue::default(),
 
             store,
-            processing: Vec::new(),
+            processing: Processing::Nothing,
             next_fetched_task_id: 0,
             config,
             notifier,
@@ -264,7 +266,7 @@ impl Scheduler {
 
         let update_loop = UpdateLoop::new(
             this.clone(),
-            performer,
+            performers,
             debounce_time.filter(|&v| v > 0).map(Duration::from_secs),
             rcv,
         );
@@ -283,9 +285,13 @@ impl Scheduler {
         self.tasks.insert(task);
     }
 
+    pub fn register_snapshot(&mut self, job: SnapshotJob) {
+        self.snapshots.push_back(job);
+    }
+
     /// Clears the processing list, this method should be called when the processing of a batch is finished.
     pub fn finish(&mut self) {
-        self.processing.clear();
+        self.processing = Processing::Nothing;
     }
 
     pub fn notify(&self) {
@@ -293,13 +299,27 @@ impl Scheduler {
     }
 
     fn notify_if_not_empty(&self) {
-        if !self.jobs.is_empty() || !self.tasks.is_empty() {
+        if !self.snapshots.is_empty() || !self.tasks.is_empty() {
             self.notify();
         }
     }
 
-    pub async fn update_tasks(&self, tasks: Vec<Task>) -> Result<Vec<Task>> {
+    pub async fn update_tasks(&self, content: BatchContent) -> Result<BatchContent> {
-        self.store.update_tasks(tasks).await
+        match content {
+            BatchContent::DocumentAddtitionBatch(tasks) => {
+                let tasks = self.store.update_tasks(tasks).await?;
+                Ok(BatchContent::DocumentAddtitionBatch(tasks))
+            }
+            BatchContent::IndexUpdate(t) => {
+                let mut tasks = self.store.update_tasks(vec![t]).await?;
+                Ok(BatchContent::IndexUpdate(tasks.remove(0)))
+            }
+            BatchContent::Dump(t) => {
+                let mut tasks = self.store.update_tasks(vec![t]).await?;
+                Ok(BatchContent::Dump(tasks.remove(0)))
+            }
+            other => Ok(other),
+        }
     }
 
     pub async fn get_task(&self, id: TaskId, filter: Option<TaskFilter>) -> Result<Task> {
@@ -318,16 +338,16 @@ impl Scheduler {
     pub async fn get_processing_tasks(&self) -> Result<Vec<Task>> {
         let mut tasks = Vec::new();
 
-        for id in self.processing.iter() {
+        for id in self.processing.ids() {
-            let task = self.store.get_task(*id, None).await?;
+            let task = self.store.get_task(id, None).await?;
             tasks.push(task);
         }
 
         Ok(tasks)
     }
 
-    pub async fn schedule_job(&mut self, job: Job) {
+    pub async fn schedule_snapshot(&mut self, job: SnapshotJob) {
-        self.jobs.push_back(job);
+        self.snapshots.push_back(job);
         self.notify();
     }
 
@@ -353,84 +373,136 @@ impl Scheduler {
     }
 
     /// Prepare the next batch, and set `processing` to the ids in that batch.
-    pub async fn prepare(&mut self) -> Result<Pending> {
+    pub async fn prepare(&mut self) -> Result<Batch> {
         // If there is a job to process, do it first.
-        if let Some(job) = self.jobs.pop_front() {
+        if let Some(job) = self.snapshots.pop_front() {
             // There is more work to do, notify the update loop
             self.notify_if_not_empty();
-            return Ok(Pending::Job(job));
+            let batch = Batch::new(None, BatchContent::Snapshot(job));
+            return Ok(batch);
         }
+
         // Try to fill the queue with pending tasks.
         self.fetch_pending_tasks().await?;
 
-        make_batch(&mut self.tasks, &mut self.processing, &self.config);
+        self.processing = make_batch(&mut self.tasks, &self.config);
 
         log::debug!("prepared batch with {} tasks", self.processing.len());
 
-        if !self.processing.is_empty() {
+        if !self.processing.is_nothing() {
-            let ids = std::mem::take(&mut self.processing);
+            let (processing, mut content) = self
+                .store
+                .get_processing_tasks(std::mem::take(&mut self.processing))
+                .await?;
 
-            let (ids, mut tasks) = self.store.get_pending_tasks(ids).await?;
+            // The batch id is the id of the first update it contains. At this point we must have a
-
+            // valid batch that contains at least 1 task.
-            // The batch id is the id of the first update it contains
+            let id = match content.first() {
-            let id = match tasks.first() {
                 Some(Task { id, .. }) => *id,
                 _ => panic!("invalid batch"),
             };
 
-            tasks.iter_mut().for_each(|t| {
+            content.push_event(TaskEvent::Batched {
-                t.events.push(TaskEvent::Batched {
                 batch_id: id,
                 timestamp: OffsetDateTime::now_utc(),
-                })
             });
 
-            self.processing = ids;
+            self.processing = processing;
 
-            let batch = Batch {
+            let batch = Batch::new(Some(id), content);
-                id,
-                created_at: OffsetDateTime::now_utc(),
-                tasks,
-            };
 
             // There is more work to do, notify the update loop
             self.notify_if_not_empty();
 
-            Ok(Pending::Batch(batch))
+            Ok(batch)
         } else {
-            Ok(Pending::Nothing)
+            Ok(Batch::empty())
         }
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Default)]
-pub enum Pending {
+pub enum Processing {
-    Batch(Batch),
+    DocumentAdditions(Vec<TaskId>),
-    Job(Job),
+    IndexUpdate(TaskId),
+    Dump(TaskId),
+    /// Variant used when there is nothing to process.
+    #[default]
     Nothing,
 }
 
-fn make_batch(tasks: &mut TaskQueue, processing: &mut Vec<TaskId>, config: &SchedulerConfig) {
+enum ProcessingIter<'a> {
-    processing.clear();
+    Many(slice::Iter<'a, TaskId>),
+    Single(Option<TaskId>),
+}
 
+impl<'a> Iterator for ProcessingIter<'a> {
+    type Item = TaskId;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self {
+            ProcessingIter::Many(iter) => iter.next().copied(),
+            ProcessingIter::Single(val) => val.take(),
+        }
+    }
+}
+
+impl Processing {
+    fn is_nothing(&self) -> bool {
+        matches!(self, Processing::Nothing)
+    }
+
+    pub fn ids(&self) -> impl Iterator<Item = TaskId> + '_ {
+        match self {
+            Processing::DocumentAdditions(v) => ProcessingIter::Many(v.iter()),
+            Processing::IndexUpdate(id) | Processing::Dump(id) => ProcessingIter::Single(Some(*id)),
+            Processing::Nothing => ProcessingIter::Single(None),
+        }
+    }
+
+    pub fn len(&self) -> usize {
+        match self {
+            Processing::DocumentAdditions(v) => v.len(),
+            Processing::IndexUpdate(_) | Processing::Dump(_) => 1,
+            Processing::Nothing => 0,
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+}
+
+fn make_batch(tasks: &mut TaskQueue, config: &SchedulerConfig) -> Processing {
     let mut doc_count = 0;
-    tasks.head_mut(|list| match list.peek().copied() {
+    tasks
+        .head_mut(|list| match list.peek().copied() {
             Some(PendingTask {
-            kind: TaskType::Other,
+                kind: TaskType::IndexUpdate,
                 id,
             }) => {
-            processing.push(id);
                 list.pop();
+                Processing::IndexUpdate(id)
             }
-        Some(PendingTask { kind, .. }) => loop {
+            Some(PendingTask {
+                kind: TaskType::Dump,
+                id,
+            }) => {
+                list.pop();
+                Processing::Dump(id)
+            }
+            Some(PendingTask { kind, .. }) => {
+                let mut task_list = Vec::new();
+                loop {
                     match list.peek() {
                         Some(pending) if pending.kind == kind => {
                             // We always need to process at least one task for the scheduler to make progress.
-                    if processing.len() >= config.max_batch_size.unwrap_or(usize::MAX).max(1) {
+                            if task_list.len() >= config.max_batch_size.unwrap_or(usize::MAX).max(1)
+                            {
                                 break;
                             }
                             let pending = list.pop().unwrap();
-                    processing.push(pending.id);
+                            task_list.push(pending.id);
 
                             // We add the number of documents to the count if we are scheduling document additions and
                             // stop adding if we already have enough.
@@ -441,7 +513,9 @@ fn make_batch(tasks: &mut TaskQueue, processing: &mut Vec<TaskId>, config: &Sche
                                 | TaskType::DocumentAddition { number } => {
                                     doc_count += number;
 
-                            if doc_count >= config.max_documents_per_batch.unwrap_or(usize::MAX) {
+                                    if doc_count
+                                        >= config.max_documents_per_batch.unwrap_or(usize::MAX)
+                                    {
                                         break;
                                     }
                                 }
@@ -450,9 +524,12 @@ fn make_batch(tasks: &mut TaskQueue, processing: &mut Vec<TaskId>, config: &Sche
                         }
                         _ => break,
                     }
-        },
+                }
-        None => (),
+                Processing::DocumentAdditions(task_list)
-    });
+            }
+            None => Processing::Nothing,
+        })
+        .unwrap_or(Processing::Nothing)
 }
 
 #[cfg(test)]

meilisearch-lib/src/tasks/task.rs

@@ -4,14 +4,12 @@ use meilisearch_error::ResponseError;
 use milli::update::{DocumentAdditionResult, IndexDocumentsMethod};
 use serde::{Deserialize, Serialize};
 use time::OffsetDateTime;
-use tokio::sync::oneshot;
 use uuid::Uuid;
 
 use super::batch::BatchId;
 use crate::{
     index::{Settings, Unchecked},
-    index_resolver::{error::IndexResolverError, IndexUid},
+    index_resolver::IndexUid,
-    snapshot::SnapshotJob,
 };
 
 pub type TaskId = u64;
@@ -110,33 +108,6 @@ impl Task {
     }
 }
 
-/// A job is like a volatile priority `Task`.
-/// It should be processed as fast as possible and is not stored on disk.
-/// This means, when Meilisearch is closed all your unprocessed jobs will disappear.
-#[derive(Debug, derivative::Derivative)]
-#[derivative(PartialEq)]
-pub enum Job {
-    Dump {
-        #[derivative(PartialEq = "ignore")]
-        ret: oneshot::Sender<Result<oneshot::Sender<()>, IndexResolverError>>,
-        path: PathBuf,
-    },
-    Snapshot(#[derivative(PartialEq = "ignore")] SnapshotJob),
-    Empty,
-}
-
-impl Default for Job {
-    fn default() -> Self {
-        Self::Empty
-    }
-}
-
-impl Job {
-    pub fn take(&mut self) -> Self {
-        std::mem::take(self)
-    }
-}
-
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
 #[cfg_attr(test, derive(proptest_derive::Arbitrary))]
 pub enum DocumentDeletion {

meilisearch-lib/src/tasks/task_store/mod.rs

@@ -9,7 +9,9 @@ use log::debug;
 use milli::heed::{Env, RwTxn};
 use time::OffsetDateTime;
 
+use super::batch::BatchContent;
 use super::error::TaskError;
+use super::scheduler::Processing;
 use super::task::{Task, TaskContent, TaskId};
 use super::Result;
 use crate::index_resolver::IndexUid;
@@ -122,19 +124,44 @@ impl TaskStore {
         }
     }
 
-    pub async fn get_pending_tasks(&self, ids: Vec<TaskId>) -> Result<(Vec<TaskId>, Vec<Task>)> {
+    /// This methods takes a `Processing` which contains the next task ids to process, and returns
+    /// the coresponding tasks along with the ownership to the passed processing.
+    ///
+    /// We need get_processing_tasks to take ownership over `Processing` because we need it to be
+    /// valid for 'static.
+    pub async fn get_processing_tasks(
+        &self,
+        processing: Processing,
+    ) -> Result<(Processing, BatchContent)> {
         let store = self.store.clone();
         let tasks = tokio::task::spawn_blocking(move || -> Result<_> {
-            let mut tasks = Vec::new();
             let txn = store.rtxn()?;
 
+            let content = match processing {
+                Processing::DocumentAdditions(ref ids) => {
+                    let mut tasks = Vec::new();
+
                     for id in ids.iter() {
                         let task = store
                             .get(&txn, *id)?
                             .ok_or(TaskError::UnexistingTask(*id))?;
                         tasks.push(task);
                     }
-            Ok((ids, tasks))
+                    BatchContent::DocumentAddtitionBatch(tasks)
+                }
+                Processing::IndexUpdate(id) => {
+                    let task = store.get(&txn, id)?.ok_or(TaskError::UnexistingTask(id))?;
+                    BatchContent::IndexUpdate(task)
+                }
+                Processing::Dump(id) => {
+                    let task = store.get(&txn, id)?.ok_or(TaskError::UnexistingTask(id))?;
+                    debug_assert!(matches!(task.content, TaskContent::Dump { .. }));
+                    BatchContent::Dump(task)
+                }
+                Processing::Nothing => unreachable!(),
+            };
+
+            Ok((processing, content))
         })
         .await??;
 
@@ -231,7 +258,7 @@ impl TaskStore {
 
 #[cfg(test)]
 pub mod test {
-    use crate::tasks::task_store::store::test::tmp_env;
+    use crate::tasks::{scheduler::Processing, task_store::store::test::tmp_env};
 
     use super::*;
 
@@ -280,12 +307,12 @@ pub mod test {
             }
         }
 
-        pub async fn get_pending_tasks(
+        pub async fn get_processing_tasks(
             &self,
-            tasks: Vec<TaskId>,
+            tasks: Processing,
-        ) -> Result<(Vec<TaskId>, Vec<Task>)> {
+        ) -> Result<(Processing, BatchContent)> {
             match self {
-                Self::Real(s) => s.get_pending_tasks(tasks).await,
+                Self::Real(s) => s.get_processing_tasks(tasks).await,
                 Self::Mock(m) => unsafe { m.get("get_pending_task").call(tasks) },
             }
         }

meilisearch-lib/src/tasks/update_loop.rs

@@ -7,33 +7,29 @@ use tokio::time::interval_at;
 
 use super::batch::Batch;
 use super::error::Result;
-use super::scheduler::Pending;
+use super::{BatchHandler, Scheduler};
-use super::{Scheduler, TaskPerformer};
 use crate::tasks::task::TaskEvent;
 
 /// The update loop sequentially performs batches of updates by asking the scheduler for a batch,
 /// and handing it to the `TaskPerformer`.
-pub struct UpdateLoop<P: TaskPerformer> {
+pub struct UpdateLoop {
     scheduler: Arc<RwLock<Scheduler>>,
-    performer: Arc<P>,
+    performers: Vec<Arc<dyn BatchHandler + Send + Sync + 'static>>,
 
     notifier: Option<watch::Receiver<()>>,
     debounce_duration: Option<Duration>,
 }
 
-impl<P> UpdateLoop<P>
+impl UpdateLoop {
-where
-    P: TaskPerformer + Send + Sync + 'static,
-{
     pub fn new(
         scheduler: Arc<RwLock<Scheduler>>,
-        performer: Arc<P>,
+        performers: Vec<Arc<dyn BatchHandler + Send + Sync + 'static>>,
         debuf_duration: Option<Duration>,
         notifier: watch::Receiver<()>,
     ) -> Self {
         Self {
             scheduler,
-            performer,
+            performers,
             debounce_duration: debuf_duration,
             notifier: Some(notifier),
         }
@@ -59,34 +55,29 @@ where
     }
 
     async fn process_next_batch(&self) -> Result<()> {
-        let pending = { self.scheduler.write().await.prepare().await? };
+        let mut batch = { self.scheduler.write().await.prepare().await? };
-        match pending {
+        let performer = self
-            Pending::Batch(mut batch) => {
+            .performers
-                for task in &mut batch.tasks {
+            .iter()
-                    task.events
+            .find(|p| p.accept(&batch))
-                        .push(TaskEvent::Processing(OffsetDateTime::now_utc()));
+            .expect("No performer found for batch")
-                }
+            .clone();
 
-                batch.tasks = {
+        batch
+            .content
+            .push_event(TaskEvent::Processing(OffsetDateTime::now_utc()));
+
+        batch.content = {
             self.scheduler
                 .read()
                 .await
-                        .update_tasks(batch.tasks)
+                .update_tasks(batch.content)
                 .await?
         };
 
-                let performer = self.performer.clone();
-
         let batch = performer.process_batch(batch).await;
 
-                self.handle_batch_result(batch).await?;
+        self.handle_batch_result(batch, performer).await?;
-            }
-            Pending::Job(job) => {
-                let performer = self.performer.clone();
-                performer.process_job(job).await;
-            }
-            Pending::Nothing => (),
-        }
 
         Ok(())
     }
@@ -96,13 +87,17 @@ where
     /// When a task is processed, the result of the process is pushed to its event list. The
     /// `handle_batch_result` make sure that the new state is saved to the store.
     /// The tasks are then removed from the processing queue.
-    async fn handle_batch_result(&self, mut batch: Batch) -> Result<()> {
+    async fn handle_batch_result(
+        &self,
+        mut batch: Batch,
+        performer: Arc<dyn BatchHandler + Sync + Send + 'static>,
+    ) -> Result<()> {
         let mut scheduler = self.scheduler.write().await;
-        let tasks = scheduler.update_tasks(batch.tasks).await?;
+        let content = scheduler.update_tasks(batch.content).await?;
         scheduler.finish();
         drop(scheduler);
-        batch.tasks = tasks;
+        batch.content = content;
-        self.performer.finish(&batch).await;
+        performer.finish(&batch).await;
         Ok(())
     }
 }