refactor: [#1264] return wether swarm stats have change or not after upserting a peer

When you upsert a new peer (announce requests) the swarm stats migth
change if the peer announced that has completed the download. If that
case we return `true` given the caller the opportunity to know if stats
have changed.

In the current implementation we get stats before and after upserintg
the peer, and we compare them to check if they have changed. However
stats migth have change due to a parallel (race condition) announce from
another peer.

This is the only way to know exactly if this announce request has
altered the stats (incremented the number of downloads).

Author: josecelano

packages/axum-http-tracker-server/src/environment.rs

@@ -22,7 +22,7 @@ pub struct Environment<S> {
 impl<S> Environment<S> {
     /// Add a torrent to the tracker
     pub fn add_torrent_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) {
-        let () = self
+        let _stats_updated = self
             .container
             .tracker_core_container
             .in_memory_torrent_repository

packages/axum-rest-tracker-api-server/src/environment.rs

@@ -33,7 +33,7 @@ where
 {
     /// Add a torrent to the tracker
     pub fn add_torrent_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) {
-        let () = self
+        let _stats_updated = self
             .container
             .tracker_core_container
             .in_memory_torrent_repository

packages/torrent-repository/src/entry/single.rs

@@ -66,6 +66,8 @@ impl Entry for EntrySingle {
                 }
             }
             _ => {
+                // `Started` event (first announced event) or
+                // `None` event (announcements done at regular intervals).
                 drop(self.swarm.upsert(Arc::new(*peer)));
             }
         }

packages/torrent-repository/src/repository/dash_map_mutex_std.rs

@@ -23,13 +23,15 @@ where
     EntryMutexStd: EntrySync,
     EntrySingle: Entry,
 {
-    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) {
+    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> bool {
         if let Some(entry) = self.torrents.get(info_hash) {
-            entry.upsert_peer(peer);
+            entry.upsert_peer(peer)
         } else {
             let _unused = self.torrents.insert(*info_hash, Arc::default());
             if let Some(entry) = self.torrents.get(info_hash) {
-                entry.upsert_peer(peer);
+                entry.upsert_peer(peer)
+            } else {
+                false
             }
         }
     }

packages/torrent-repository/src/repository/mod.rs

@@ -24,7 +24,7 @@ pub trait Repository<T>: Debug + Default + Sized + 'static {
     fn remove(&self, key: &InfoHash) -> Option<T>;
     fn remove_inactive_peers(&self, current_cutoff: DurationSinceUnixEpoch);
     fn remove_peerless_torrents(&self, policy: &TrackerPolicy);
-    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer);
+    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> bool;
     fn get_swarm_metadata(&self, info_hash: &InfoHash) -> Option<SwarmMetadata>;
 }
 
@@ -37,6 +37,6 @@ pub trait RepositoryAsync<T>: Debug + Default + Sized + 'static {
     fn remove(&self, key: &InfoHash) -> impl std::future::Future<Output = Option<T>> + Send;
     fn remove_inactive_peers(&self, current_cutoff: DurationSinceUnixEpoch) -> impl std::future::Future<Output = ()> + Send;
     fn remove_peerless_torrents(&self, policy: &TrackerPolicy) -> impl std::future::Future<Output = ()> + Send;
-    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> impl std::future::Future<Output = ()> + Send;
+    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> impl std::future::Future<Output = bool> + Send;
     fn get_swarm_metadata(&self, info_hash: &InfoHash) -> impl std::future::Future<Output = Option<SwarmMetadata>> + Send;
 }

packages/torrent-repository/src/repository/rw_lock_std.rs

@@ -46,12 +46,12 @@ impl Repository<EntrySingle> for TorrentsRwLockStd
 where
     EntrySingle: Entry,
 {
-    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) {
+    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> bool {
         let mut db = self.get_torrents_mut();
 
         let entry = db.entry(*info_hash).or_insert(EntrySingle::default());
 
-        entry.upsert_peer(peer);
+        entry.upsert_peer(peer)
     }
 
     fn get_swarm_metadata(&self, info_hash: &InfoHash) -> Option<SwarmMetadata> {

packages/torrent-repository/src/repository/rw_lock_std_mutex_std.rs

@@ -33,7 +33,7 @@ where
     EntryMutexStd: EntrySync,
     EntrySingle: Entry,
 {
-    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) {
+    fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> bool {
         let maybe_entry = self.get_torrents().get(info_hash).cloned();
 
         let entry = if let Some(entry) = maybe_entry {
@@ -44,7 +44,7 @@ where
             entry.clone()
         };
 
-        entry.upsert_peer(peer);
+        entry.upsert_peer(peer)
     }
 
     fn get_swarm_metadata(&self, info_hash: &InfoHash) -> Option<SwarmMetadata> {

packages/torrent-repository/src/repository/rw_lock_std_mutex_tokio.rs

@@ -37,7 +37,7 @@ where
     EntryMutexTokio: EntryAsync,
     EntrySingle: Entry,
 {
-    async fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) {
+    async fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> bool {
         let maybe_entry = self.get_torrents().get(info_hash).cloned();
 
         let entry = if let Some(entry) = maybe_entry {
@@ -48,7 +48,7 @@ where
             entry.clone()
         };
 
-        entry.upsert_peer(peer).await;
+        entry.upsert_peer(peer).await
     }
 
     async fn get_swarm_metadata(&self, info_hash: &InfoHash) -> Option<SwarmMetadata> {

packages/torrent-repository/src/repository/rw_lock_tokio.rs

@@ -47,12 +47,12 @@ impl RepositoryAsync<EntrySingle> for TorrentsRwLockTokio
 where
     EntrySingle: Entry,
 {
-    async fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) {
+    async fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> bool {
         let mut db = self.get_torrents_mut().await;
 
         let entry = db.entry(*info_hash).or_insert(EntrySingle::default());
 
-        entry.upsert_peer(peer);
+        entry.upsert_peer(peer)
     }
 
     async fn get_swarm_metadata(&self, info_hash: &InfoHash) -> Option<SwarmMetadata> {

packages/torrent-repository/src/repository/rw_lock_tokio_mutex_std.rs

@@ -35,7 +35,7 @@ where
     EntryMutexStd: EntrySync,
     EntrySingle: Entry,
 {
-    async fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) {
+    async fn upsert_peer(&self, info_hash: &InfoHash, peer: &peer::Peer) -> bool {
         let maybe_entry = self.get_torrents().await.get(info_hash).cloned();
 
         let entry = if let Some(entry) = maybe_entry {
@@ -46,7 +46,7 @@ where
             entry.clone()
         };
 
-        entry.upsert_peer(peer);
+        entry.upsert_peer(peer)
     }
 
     async fn get_swarm_metadata(&self, info_hash: &InfoHash) -> Option<SwarmMetadata> {