build: bump version to 0.4.2

When a large number of subscriptions is created with identical names,
we do not send a signal over the abandon-read channel.  This
eventually leads to resource exhaustion.

Cargo.lock

@@ -654,7 +654,7 @@ checksum = "38bf9645c8b145698bb0b18a4637dcacbc421ea49bef2317e4fd8065a387cf21"
 
 [[package]]
 name = "nostr-rs-relay"
-version = "0.4.1"
+version = "0.4.2"
 dependencies = [
  "bitcoin_hashes 0.9.7",
  "config",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "nostr-rs-relay"
-version = "0.4.1"
+version = "0.4.2"
 edition = "2021"
 
 [dependencies]

src/event.rs

@@ -148,9 +148,13 @@ impl Event {
 
         let sig = schnorr::Signature::from_str(&self.sig).unwrap();
         if let Ok(msg) = secp256k1::Message::from_slice(digest.as_ref()) {
-            let pubkey = XOnlyPublicKey::from_str(&self.pubkey).unwrap();
-            let verify = SECP.verify_schnorr(&sig, &msg, &pubkey);
-            matches!(verify, Ok(()))
+            if let Ok(pubkey) = XOnlyPublicKey::from_str(&self.pubkey) {
+                let verify = SECP.verify_schnorr(&sig, &msg, &pubkey);
+                matches!(verify, Ok(()))
+            } else {
+                info!("Client sent malformed pubkey");
+                false
+            }
         } else {
             warn!("Error converting digest to secp256k1 message");
             false

src/main.rs

@@ -280,7 +280,6 @@ async fn nostr_server(
     // maintain a hashmap of a oneshot channel for active subscriptions.
     // when these subscriptions are cancelled, make a message
     // available to the executing query so it knows to stop.
-    //let (abandon_query_tx, _) = oneshot::channel::<()>();
     let mut running_queries: HashMap<String, oneshot::Sender<()>> = HashMap::new();
     // for stats, keep track of how many events the client published,
     // and how many it received from queries.
@@ -348,7 +347,10 @@ async fn nostr_server(
                         let (abandon_query_tx, abandon_query_rx) = oneshot::channel::<()>();
                         match conn.subscribe(s.clone()) {
                             Ok(()) => {
-                                running_queries.insert(s.id.to_owned(), abandon_query_tx);
+                                // when we insert, if there was a previous query running with the same name, cancel it.
+                                if let Some(previous_query) = running_queries.insert(s.id.to_owned(), abandon_query_tx) {
+                                    previous_query.send(()).ok();
+                                }
                                 // start a database query
                                 // show pool stats
                                 debug!("DB pool stats: {:?}", pool.state());