Add the new tasks with most of the job done

crates/index-scheduler/src/upgrade/mod.rs

@@ -0,0 +1,43 @@
+use std::path::Path;
+
+use meilisearch_types::{
+    heed,
+    tasks::{KindWithContent, Status, Task},
+};
+use time::OffsetDateTime;
+use tracing::info;
+
+use crate::queue::TaskQueue;
+
+pub fn upgrade_task_queue(tasks_path: &Path, version: (u32, u32, u32)) -> anyhow::Result<()> {
+    info!("Upgrading the task queue");
+    let env = unsafe {
+        heed::EnvOpenOptions::new()
+            .max_dbs(19)
+            // Since that's the only database memory-mapped currently we don't need to check the budget yet
+            .map_size(100 * 1024 * 1024)
+            .open(tasks_path)
+    }?;
+    let mut wtxn = env.write_txn()?;
+    let queue = TaskQueue::new(&env, &mut wtxn)?;
+    let uid = queue.next_task_id(&wtxn)?;
+    queue.register(
+        &mut wtxn,
+        &Task {
+            uid,
+            batch_uid: None,
+            enqueued_at: OffsetDateTime::now_utc(),
+            started_at: None,
+            finished_at: None,
+            error: None,
+            canceled_by: None,
+            details: None,
+            status: Status::Enqueued,
+            kind: KindWithContent::UpgradeDatabase { from: version },
+        },
+    )?;
+    wtxn.commit()?;
+    // Should be pretty much instantaneous since we're the only one reading this env
+    env.prepare_for_closing().wait();
+    Ok(())
+}