process rollback

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

@@ -12,7 +12,6 @@ impl IndexScheduler {
         #[cfg(test)]
         self.maybe_fail(crate::test_utils::FailureLocation::ProcessUpgrade)?;
 
-        enum UpgradeIndex {}
         let indexes = self.index_names()?;
 
         for (i, uid) in indexes.iter().enumerate() {
@@ -52,4 +51,41 @@ impl IndexScheduler {
 
         Ok(())
     }
+
+    pub fn process_rollback(&self, db_version: (u32, u32, u32), progress: &Progress) -> Result<()> {
+        let indexes = self.index_names()?;
+
+        tracing::info!("roll backing all indexes");
+        for (i, uid) in indexes.iter().enumerate() {
+            progress.update_progress(VariableNameStep::<UpgradeIndex>::new(
+                format!("Rollbacking index `{uid}`"),
+                i as u32,
+                indexes.len() as u32,
+            ));
+            let index_schd_rtxn = self.env.read_txn()?;
+
+            let rollback_outcome =
+                self.index_mapper.rollback_index(&index_schd_rtxn, uid, db_version)?;
+            if !rollback_outcome.succeeded() {
+                return Err(crate::Error::RollbackFailed { index: uid.clone(), rollback_outcome });
+            }
+        }
+
+        let mut wtxn = self.env.write_txn()?;
+        tracing::info!(?db_version, "roll back index scheduler version");
+        self.version.set_version(&mut wtxn, db_version)?;
+        let db_path = self.scheduler.version_file_path.parent().unwrap();
+        wtxn.commit()?;
+        tracing::info!(?db_path, ?db_version, "roll back version file");
+        meilisearch_types::versioning::create_version_file(
+            db_path,
+            db_version.0,
+            db_version.1,
+            db_version.2,
+        )?;
+
+        Ok(())
+    }
 }
+
+enum UpgradeIndex {}