Saving before slight refactor

TODO.md

@@ -28,6 +28,7 @@ someday:
 - [x] favicons for Web UI
 
 refactor:
+- [ ] session persistence: should add torrents even if we haven't resolved it yet
 - [x] where are peers stored
 - [x] http api pause/unpause etc
 - [x] when a live torrent fails writing to disk, it should transition to error state
@@ -35,7 +36,6 @@ refactor:
 - [x] silence this: WARN torrent{id=0}:external_peer_adder: librqbit::spawn_utils: finished with error: no longer live
 
 - [x] start from error state should be possible from UI
-- [ ] if the torrent was completed, not need to re-check it
 - [x] checking is very slow on raspberry
   checked. nothing much can be done here. Even if raspberry's own libssl.so is used it's still super slow (sha1)
 - [ ] .rqbit-session.json file has 0 bytes when disk full. I guess fs::rename does this when disk is full? at least on linux. Couldn't repro on MacOS

crates/dht/src/dht.rs

@@ -130,7 +130,7 @@ impl DhtState {
     fn spawn_request(self: &Arc<Self>, request: Request, addr: SocketAddr) {
         let this = self.clone();
         spawn(
-            error_span!(parent: None, "dht_request", addr=addr.to_string(), request=format!("{:?}", request)),
+            error_span!(parent: None, "dht_spawn_request", addr=addr.to_string(), request=format!("{:?}", request)),
             async move {
                 match this.send_request_and_handle_response(request, addr).await {
                     Ok(_) => {}
@@ -421,7 +421,13 @@ impl DhtState {
                 spawn(
                     error_span!("peers_requester", info_hash = format!("{:?}", info_hash)),
                     async move {
+                        let mut iteration = 0usize;
                         loop {
+                            if !this.get_peers_subscribers.contains_key(&info_hash) {
+                                debug!("no more subscribers, closing peers_requester");
+                                return Ok(());
+                            }
+                            trace!("iteration {iteration}");
                             // We don't need to allocate/collect here, but the borrow checker is not happy otherwise.
                             let nodes_to_query = this
                                 .routing_table
@@ -442,6 +448,7 @@ impl DhtState {
                                 }
                             }
                             tokio::time::sleep(REQUERY_INTERVAL).await;
+                            iteration += 1;
                         }
                     },
                 );
@@ -635,9 +642,10 @@ impl DhtState {
     ) -> anyhow::Result<()> {
         self.routing_table_add_node(source, source_addr);
 
-        let bsender = match self.get_peers_subscribers.get(&info_hash) {
-            Some(s) => s,
-            None => {
+        use dashmap::mapref::entry::Entry;
+        let bsender = match self.get_peers_subscribers.entry(info_hash) {
+            Entry::Occupied(o) => o,
+            Entry::Vacant(_) => {
                 warn!(
                     "ignoring get_peers response, no subscribers for {:?}",
                     info_hash
@@ -647,7 +655,6 @@ impl DhtState {
         };
 
         {
-            use dashmap::mapref::entry::Entry;
             let n = MaybeUsefulNode {
                 id: source,
                 addr: source_addr,
@@ -682,9 +689,29 @@ impl DhtState {
                 }
                 let addr = SocketAddr::V4(peer.addr);
                 if seen.insert(addr) {
-                    bsender
-                        .send(addr)
-                        .context("error sending peers to subscribers")?;
+                    match bsender.get().send(addr) {
+                        Ok(_) => {}
+                        Err(_) => {
+                            debug!("no more subscribers for {:?}, cleaning up", info_hash);
+                            // bsender.remove();
+
+                            // let this = self.clone();
+                            // spawn(
+                            //     error_span!("cleanup", info_hash = format!("{info_hash:?}")),
+                            //     async move {
+                            //         tokio::time::sleep(Duration::from_secs(10)).await;
+                            //         if !this.get_peers_subscribers.contains_key(&info_hash) {
+                            //             debug!("no more subscribers for {:?}, removed it from seen peers", info_hash);
+                            //             this.seen_peers.remove(&info_hash);
+                            //             this.closest_responding_nodes_for_info_hash
+                            //                 .remove(&info_hash);
+                            //         }
+                            //         Ok(())
+                            //     },
+                            // );
+                            return Ok(());
+                        }
+                    }
                 }
             }
         };