swarm-controller: bulk-read endpoint for agent config-PR status

swarm-controller/src/config_pr.rs

@@ -93,6 +93,18 @@ impl ConfigPrCache {
             .cloned()
     }
 
+    /// Every agent with an open PR, per the last successful scan (plus any
+    /// webhook upserts since). The bulk counterpart to [`Self::get`] — for
+    /// `GET /api/agents/config-prs` (swarm-ui's config-PR table), which needs
+    /// every agent's status in one round trip rather than one request per
+    /// agent.
+    pub fn snapshot(&self) -> HashMap<String, ConfigPrStatus> {
+        self.0
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .clone()
+    }
+
     /// ⚠️ Can race [`Self::apply_webhook_delivery`]: a scan started before a
     /// PR opened may finish *after* the webhook already upserted it, and
     /// this snapshot — taken before that PR existed — will overwrite the
@@ -221,6 +233,21 @@ mod tests {
         assert_eq!(status.pr_number, 6);
     }
 
+    #[test]
+    fn snapshot_returns_every_agent_with_an_open_pr() {
+        let cache = ConfigPrCache::new();
+        assert!(
+            cache.snapshot().is_empty(),
+            "an unpopulated cache snapshots empty, not missing"
+        );
+        cache.apply_webhook_delivery(&payload("damocles", 5, "open"));
+        cache.apply_webhook_delivery(&payload("iris", 9, "open"));
+        let snapshot = cache.snapshot();
+        assert_eq!(snapshot.len(), 2);
+        assert_eq!(snapshot["damocles"].pr_number, 5);
+        assert_eq!(snapshot["iris"].pr_number, 9);
+    }
+
     #[test]
     fn a_malformed_payload_leaves_the_cache_unchanged() {
         let cache = ConfigPrCache::new();