From 49d52941806f930cd855facf025295e0d85e2142 Mon Sep 17 00:00:00 2001
From: Borja Aranda <borja@ephemerahq.com>
Date: Mon, 17 Feb 2025 14:33:24 +0100
Subject: [PATCH] Use parking_lot mutex

---
 Cargo.lock                                    |  1 +
 mls_validation_service/Cargo.toml             |  1 +
 .../src/cached_signature_verifier.rs          | 32 +++++++++++--------
 mls_validation_service/src/config.rs          |  1 +
 4 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 6bc113286..7a680f7e2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3586,6 +3586,7 @@ dependencies = [
  "lru",
  "openmls",
  "openmls_rust_crypto",
+ "parking_lot 0.12.3",
  "rand",
  "thiserror 2.0.6",
  "tokio",
diff --git a/mls_validation_service/Cargo.toml b/mls_validation_service/Cargo.toml
index a924b93ef..504bff052 100644
--- a/mls_validation_service/Cargo.toml
+++ b/mls_validation_service/Cargo.toml
@@ -21,6 +21,7 @@ hex = { workspace = true }
 lru = "0.13.0"
 openmls = { workspace = true }
 openmls_rust_crypto = { workspace = true }
+parking_lot.workspace = true
 thiserror.workspace = true
 tokio = { workspace = true, features = ["signal", "rt-multi-thread"] }
 tonic = { workspace = true }
diff --git a/mls_validation_service/src/cached_signature_verifier.rs b/mls_validation_service/src/cached_signature_verifier.rs
index 634531029..4961da4fd 100644
--- a/mls_validation_service/src/cached_signature_verifier.rs
+++ b/mls_validation_service/src/cached_signature_verifier.rs
@@ -1,6 +1,6 @@
 use lru::LruCache;
+use parking_lot::Mutex;
 use std::num::NonZeroUsize;
-use tokio::sync::Mutex;
 
 use ethers::types::{BlockNumber, Bytes};
 use xmtp_id::associations::AccountId;
@@ -40,7 +40,7 @@ impl SmartContractSignatureVerifier for CachedSmartContractSignatureVerifier {
         block_number: Option<BlockNumber>,
     ) -> Result<ValidationResponse, VerifierError> {
         if let Some(cached_response) = {
-            let mut cache = self.cache.lock().await;
+            let mut cache = self.cache.lock();
             cache.get(&hash).cloned()
         } {
             return Ok(cached_response);
@@ -51,7 +51,7 @@ impl SmartContractSignatureVerifier for CachedSmartContractSignatureVerifier {
             .is_valid_signature(account_id, hash, signature, block_number)
             .await?;
 
-        let mut cache = self.cache.lock().await;
+        let mut cache = self.cache.lock();
         cache.put(hash, response.clone());
 
         Ok(response)
@@ -67,14 +67,14 @@ mod tests {
         VerifierError,
     };
 
-    #[test]
-    fn test_cache_eviction() {
+    #[tokio::test]
+    async fn test_cache_eviction() {
         let mut cache: LruCache<CacheKey, ValidationResponse> =
             LruCache::new(NonZeroUsize::new(1).unwrap());
-        let hash1 = [0u8; 32];
-        let hash2 = [1u8; 32];
+        let key1 = [0u8; 32];
+        let key2 = [1u8; 32];
 
-        assert_ne!(hash1, hash2);
+        assert_ne!(key1, key2);
 
         let val1: ValidationResponse = ValidationResponse {
             is_valid: true,
@@ -87,16 +87,20 @@ mod tests {
             error: None,
         };
 
-        cache.put(hash1, val1.clone());
-        let response = cache.get(&hash1).unwrap();
+        cache.put(key1, val1.clone());
+        let response = cache.get(&key1).unwrap();
+
+        // key1 is correctly cached
         assert_eq!(response.is_valid, val1.is_valid);
         assert_eq!(response.block_number, val1.block_number);
 
-        cache.put(hash2, val2.clone());
-        assert!(cache.get(&hash1).is_none());
+        cache.put(key2, val2.clone());
+
+        // key1 is evicted, shouldn't exist
+        assert!(cache.get(&key1).is_none());
 
-        // And key2 is correctly cached.
-        let response2 = cache.get(&hash2).unwrap();
+        // And key2 is correctly cached
+        let response2 = cache.get(&key2).unwrap();
         assert_eq!(response2.is_valid, val2.is_valid);
         assert_eq!(response2.block_number, val2.block_number);
     }
diff --git a/mls_validation_service/src/config.rs b/mls_validation_service/src/config.rs
index 76d364f7b..2440950a2 100644
--- a/mls_validation_service/src/config.rs
+++ b/mls_validation_service/src/config.rs
@@ -1,5 +1,6 @@
 use clap::Parser;
 use std::num::NonZeroUsize;
+
 // Gather the command line arguments into a struct
 #[derive(Parser, Debug)]
 #[command(about = "MLS Validation Server")]