unsubscribe from SubscriptionStreams on Drop

I was subscription memory leaks in notecrumbs. This should fix that.

src/future.rs

@@ -6,6 +6,7 @@ use std::{
 };
 
 use futures::Stream;
+use tracing::error;
 
 /// Used to track query futures
 #[derive(Debug, Clone)]
@@ -23,16 +24,19 @@ pub struct SubscriptionStream {
     ndb: Ndb,
     sub_id: Subscription,
     max_notes: u32,
+    unsubscribe_on_drop: bool,
 }
 
 impl SubscriptionStream {
     pub fn new(ndb: Ndb, sub_id: Subscription) -> Self {
         // Most of the time we only want to fetch a few things. If expecting
         // lots of data, use `set_max_notes_per_await`
         let max_notes = 32;
+        let unsubscribe_on_drop = true;
         SubscriptionStream {
             ndb,
             sub_id,
+            unsubscribe_on_drop,
             max_notes,
         }
     }
@@ -42,6 +46,13 @@ impl SubscriptionStream {
         self
     }
 
+    /// Unsubscribe the subscription when this stream goes out of scope. On
+    /// by default. Recommended unless you want subscription leaks.
+    pub fn unsubscribe_on_drop(mut self, yes: bool) -> Self {
+        self.unsubscribe_on_drop = yes;
+        self
+    }
+
     pub fn sub_id(&self) -> Subscription {
         self.sub_id
     }
@@ -50,8 +61,17 @@ impl SubscriptionStream {
 impl Drop for SubscriptionStream {
     fn drop(&mut self) {
         // Perform cleanup here, like removing the subscription from the global map
-        let mut map = self.ndb.subs.lock().unwrap();
-        map.remove(&self.sub_id);
+        {
+            let mut map = self.ndb.subs.lock().unwrap();
+            map.remove(&self.sub_id);
+        }
+        // unsubscribe
+        if let Err(err) = self.ndb.unsubscribe(self.sub_id) {
+            error!(
+                "Error unsubscribing from {} in SubscriptionStream Drop: {err}",
+                self.sub_id.id()
+            );
+        }
     }
 }
 

src/ndb.rs

@@ -555,9 +555,42 @@ mod tests {
         test_util::cleanup_db(&db);
     }
 
+    #[tokio::test]
+    async fn test_unsub_on_drop() {
+        let db = "target/testdbs/test_unsub_on_drop";
+        test_util::cleanup_db(&db);
+
+        {
+            let mut ndb = Ndb::new(db, &Config::new()).expect("ndb");
+            let sub_id = {
+                let filter = Filter::new().kinds(vec![1]).build();
+                let filters = vec![filter];
+
+                let sub_id = ndb.subscribe(&filters).expect("sub_id");
+                let mut sub = sub_id.stream(&ndb).notes_per_await(1);
+
+                let res = sub.next();
+
+                ndb.process_event(r#"["EVENT","b",{"id": "702555e52e82cc24ad517ba78c21879f6e47a7c0692b9b20df147916ae8731a3","pubkey": "32bf915904bfde2d136ba45dde32c88f4aca863783999faea2e847a8fafd2f15","created_at": 1702675561,"kind": 1,"tags": [],"content": "hello, world","sig": "2275c5f5417abfd644b7bc74f0388d70feb5d08b6f90fa18655dda5c95d013bfbc5258ea77c05b7e40e0ee51d8a2efa931dc7a0ec1db4c0a94519762c6625675"}]"#).expect("process ok");
+
+                let res = res.await.expect("await ok");
+                assert_eq!(res, vec![NoteKey::new(1)]);
+
+                assert!(ndb.subs.lock().unwrap().contains_key(&sub_id));
+                sub_id
+            };
+
+            // ensure subscription state is removed after stream is dropped
+            assert!(!ndb.subs.lock().unwrap().contains_key(&sub_id));
+            assert_eq!(ndb.subscription_count(), 0);
+        }
+
+        test_util::cleanup_db(&db);
+    }
+
     #[tokio::test]
     async fn test_stream() {
-        let db = "target/testdbs/test_callback";
+        let db = "target/testdbs/test_stream";
         test_util::cleanup_db(&db);
 
         {