From 19c6f8303fe5baaf3358b5c4fabf773500537337 Mon Sep 17 00:00:00 2001
From: Kerollmops <clement@meilisearch.com>
Date: Mon, 10 Oct 2022 16:19:23 +0200
Subject: [PATCH] Make sure that the index-scheduler tick loop is rerun after
 processing

---
 index-scheduler/src/lib.rs | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/index-scheduler/src/lib.rs b/index-scheduler/src/lib.rs
index 28f88d411..220d484c9 100644
--- a/index-scheduler/src/lib.rs
+++ b/index-scheduler/src/lib.rs
@@ -217,7 +217,8 @@ impl IndexScheduler {
             run.wake_up.wait();
 
             match run.tick() {
-                Ok(()) => (),
+                Ok(0) => (),
+                Ok(_) => run.wake_up.signal(),
                 Err(e) => log::error!("{}", e),
             }
         });
@@ -361,14 +362,16 @@ impl IndexScheduler {
     }
 
     /// Create and execute and store the result of one batch of registered tasks.
-    fn tick(&self) -> Result<()> {
+    ///
+    /// Returns the number of processed tasks.
+    fn tick(&self) -> Result<usize> {
         #[cfg(test)]
         self.test_breakpoint_sdr.send(Breakpoint::Start).unwrap();
 
         let rtxn = self.env.read_txn()?;
         let batch = match self.create_next_batch(&rtxn)? {
             Some(batch) => batch,
-            None => return Ok(()),
+            None => return Ok(0),
         };
         // we don't need this transaction any longer.
         drop(rtxn);
@@ -376,6 +379,7 @@ impl IndexScheduler {
         // 1. store the starting date with the bitmap of processing tasks.
         let mut ids = batch.ids();
         ids.sort_unstable();
+        let processed_tasks = ids.len();
         let processing_tasks = RoaringBitmap::from_sorted_iter(ids.iter().copied()).unwrap();
         let started_at = OffsetDateTime::now_utc();
         *self.processing_tasks.write().unwrap() = (started_at, processing_tasks);
@@ -401,8 +405,7 @@ impl IndexScheduler {
                 for mut task in tasks {
                     task.started_at = Some(started_at);
                     task.finished_at = Some(finished_at);
-                    // the info field should've been set by the process_batch function
-
+                    // TODO the info field should've been set by the process_batch function
                     self.update_task(&mut wtxn, &task)?;
                     task.remove_data()?;
                 }
@@ -433,7 +436,7 @@ impl IndexScheduler {
             .send(Breakpoint::AfterProcessing)
             .unwrap();
 
-        Ok(())
+        Ok(processed_tasks)
     }
 
     /// Notify the scheduler there is or may be work to do.