From dd306c21f777178ae1988f69a01702e0153abc88 Mon Sep 17 00:00:00 2001
From: hrxi <hrrrxi@gmail.com>
Date: Mon, 27 Jan 2025 16:19:45 +0100
Subject: [PATCH] Make `BlsCache` locking more granular

---
 web-client/src/client/bls_cache.rs | 23 ++++++++++++++++-------
 web-client/src/client/lib.rs       |  8 ++++----
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/web-client/src/client/bls_cache.rs b/web-client/src/client/bls_cache.rs
index 4295610d58..ffd715e84f 100644
--- a/web-client/src/client/bls_cache.rs
+++ b/web-client/src/client/bls_cache.rs
@@ -1,3 +1,5 @@
+use std::cell::RefCell;
+
 use idb::{Database, Error, KeyPath, ObjectStore, TransactionMode};
 use nimiq_bls::{LazyPublicKey, PublicKey};
 use nimiq_serde::{Deserialize, Serialize};
@@ -5,7 +7,7 @@ use nimiq_serde::{Deserialize, Serialize};
 /// Caches decompressed BlsPublicKeys in an IndexedDB
 pub(crate) struct BlsCache {
     db: Option<Database>,
-    keys: Vec<LazyPublicKey>,
+    keys: RefCell<Vec<LazyPublicKey>>,
 }
 
 #[derive(Deserialize, Serialize)]
@@ -34,7 +36,10 @@ impl BlsCache {
             }
         };
 
-        BlsCache { db, keys: vec![] }
+        BlsCache {
+            db,
+            keys: RefCell::new(vec![]),
+        }
     }
 
     /// Add the given keys into IndexedDB.
@@ -66,7 +71,7 @@ impl BlsCache {
 
     /// Fetches all bls keys from the IndexedDB and stores them, which makes
     /// the decompressed keys available in other places.
-    pub async fn init(&mut self) -> Result<(), Error> {
+    pub async fn init(&self) -> Result<(), Error> {
         if let Some(db) = &self.db {
             let transaction = db.transaction(&[BLS_KEYS], TransactionMode::ReadOnly)?;
             let bls_keys_store = transaction.object_store(BLS_KEYS)?;
@@ -74,10 +79,14 @@ impl BlsCache {
             let js_keys = bls_keys_store.get_all(None, None)?.await?;
             log::info!(num = js_keys.len(), "loaded keys from idb");
 
-            for js_key in &js_keys {
-                let value: BlsKeyEntry = serde_wasm_bindgen::from_value(js_key.clone()).unwrap();
-                let public_key = PublicKey::trusted_deserialize(&value.public_key);
-                self.keys.push(LazyPublicKey::from(public_key));
+            {
+                let mut keys = self.keys.borrow_mut();
+                for js_key in &js_keys {
+                    let value: BlsKeyEntry =
+                        serde_wasm_bindgen::from_value(js_key.clone()).unwrap();
+                    let public_key = PublicKey::trusted_deserialize(&value.public_key);
+                    keys.push(LazyPublicKey::from(public_key));
+                }
             }
             transaction.await?;
         } else {
diff --git a/web-client/src/client/lib.rs b/web-client/src/client/lib.rs
index d7c1dd9ef4..1117855edc 100644
--- a/web-client/src/client/lib.rs
+++ b/web-client/src/client/lib.rs
@@ -116,7 +116,7 @@ pub struct Client {
     /// Used to await transaction events in `send_transaction`.
     transaction_oneshots: Rc<RefCell<HashMap<String, oneshot::Sender<PlainTransactionDetails>>>>,
 
-    bls_cache: Rc<RefCell<BlsCache>>,
+    bls_cache: Rc<BlsCache>,
 }
 
 #[wasm_bindgen]
@@ -198,7 +198,7 @@ impl Client {
             peer_changed_listeners: Rc::new(RefCell::new(HashMap::with_capacity(1))),
             transaction_listeners: Rc::new(RefCell::new(HashMap::new())),
             transaction_oneshots: Rc::new(RefCell::new(HashMap::new())),
-            bls_cache: Rc::new(RefCell::new(bls_cache)),
+            bls_cache: Rc::new(bls_cache),
         };
 
         client.setup_offline_online_event_handlers();
@@ -207,7 +207,7 @@ impl Client {
         client.setup_network_events();
         client.setup_transaction_events().await;
 
-        if let Err(err) = client.bls_cache.borrow_mut().init().await {
+        if let Err(err) = client.bls_cache.init().await {
             log::warn!("Failed loading bls cache {}", err);
         }
 
@@ -1125,7 +1125,7 @@ impl Client {
                         .iter()
                         .map(|validator| validator.voting_key.clone())
                         .collect::<Vec<LazyPublicKey>>();
-                    if let Err(error) = bls_cache.borrow_mut().add_keys(bls_keys).await {
+                    if let Err(error) = bls_cache.add_keys(bls_keys).await {
                         log::warn!(%error, "failed caching BLS keys");
                     }
                 }