refactor(indexer): auto-cancel token on Drop

lez/indexer/service/src/lib.rs

@@ -88,7 +88,7 @@ pub async fn run_server(
 
     #[cfg(not(feature = "mock-responses"))]
     let handle = {
-        let service = service::IndexerService::new(config, storage_dir, shutdown)
+        let service = service::IndexerService::new(config, storage_dir, shutdown.child_token())
             .await
             .context("Failed to initialize indexer service")?;
         server.start(service.into_rpc())

lez/indexer/service/src/service.rs

@@ -175,6 +175,10 @@ impl indexer_service_rpc::RpcServer for IndexerService {
 struct SubscriptionService {
     parts: ArcSwap<SubscriptionLoopParts>,
     indexer: IndexerCore,
+    /// Cancellation token that is used to signal the subscription service to shut down.
+    ///
+    /// NOTE: This will auto-cancel on `Drop`, so if your token is shared with other parts
+    /// use [`CancellationToken::child_token()`] instead.
     shutdown: CancellationToken,
 }
 
@@ -292,6 +296,7 @@ impl SubscriptionService {
 
 impl Drop for SubscriptionService {
     fn drop(&mut self) {
+        self.shutdown.cancel();
         self.parts.load().handle.abort();
     }
 }

lez/sequencer/service/src/main.rs

@@ -24,6 +24,8 @@ async fn main() -> Result<()> {
 
     let Args { config_path, port } = Args::parse();
 
+    // TODO: handle this cancellation token more gracefully within Sequencer service
+    // similar to how we do in Indexer
     let cancellation_token = listen_for_shutdown_signal();
 
     let config = sequencer_service::SequencerConfig::from_path(&config_path)?;