[pdm-devel] [PATCH proxmox-datacenter-manager 09/15] remote tasks: return tasks in stable order

[Lukas Wagner]

Since the tasks are retrieved from the cache by key and this key comes
from iterating a hashmap, the order of the tasks with the same start
time was unstable. Since we have to sort anyway, we can fix this by
simply using a tasks UPID as a secondary sorting criterium. The
UPID starts with the remote's name, so this boils down to using the
remote name as a secondary criterium.

Signed-off-by: Lukas Wagner <l.wagner at proxmox.com>
---
 server/src/remote_tasks/mod.rs | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/server/src/remote_tasks/mod.rs b/server/src/remote_tasks/mod.rs
index 16c46a5..3da6f25 100644
--- a/server/src/remote_tasks/mod.rs
+++ b/server/src/remote_tasks/mod.rs
@@ -1,4 +1,5 @@
 use std::{
+    cmp::Ordering,
     collections::HashSet,
     path::Path,
     sync::{LazyLock, RwLock},
@@ -73,7 +74,15 @@ pub async fn get_tasks(filters: TaskFilters) -> Result<Vec<TaskListItem>, Error>
     }
 
     let mut returned_tasks = add_running_tasks(all_tasks)?;
-    returned_tasks.sort_by(|a, b| b.starttime.cmp(&a.starttime));
+
+    // Sort merged tasks by starttime, falling back to UPID if the starttime is equal.
+    // This UPID starts with the remote name, so this equates to using the remote name
+    // as a secondary sorting criterium.
+    returned_tasks.sort_by(|a, b| match b.starttime.cmp(&a.starttime) {
+        Ordering::Equal => a.upid.cmp(&b.upid),
+        ord => ord,
+    });
+
     let returned_tasks = returned_tasks
         .into_iter()
         .filter(|item| {
-- 
2.39.5