f Move empty-key checks before taking locks

Author: tnull

lightning-persister/src/fs_store.rs

@@ -52,32 +52,32 @@ impl KVStore for FilesystemStore {
 	type Reader = FilesystemReader;
 
 	fn read(&self, namespace: &str, key: &str) -> std::io::Result<Self::Reader> {
-		let mut outer_lock = self.locks.lock().unwrap();
-		let lock_key = (namespace.to_string(), key.to_string());
-		let inner_lock_ref = Arc::clone(&outer_lock.entry(lock_key).or_default());
-
 		if key.is_empty() {
 			let msg = format!("Failed to read {}/{}: key may not be empty.", namespace, key);
 			return Err(std::io::Error::new(std::io::ErrorKind::Other, msg));
 		}
 
+		let mut outer_lock = self.locks.lock().unwrap();
+		let lock_key = (namespace.to_string(), key.to_string());
+		let inner_lock_ref = Arc::clone(&outer_lock.entry(lock_key).or_default());
+
 		let mut dest_file_path = self.data_dir.clone();
 		dest_file_path.push(namespace);
 		dest_file_path.push(key);
 		FilesystemReader::new(dest_file_path, inner_lock_ref)
 	}
 
 	fn write(&self, namespace: &str, key: &str, buf: &[u8]) -> std::io::Result<()> {
-		let mut outer_lock = self.locks.lock().unwrap();
-		let lock_key = (namespace.to_string(), key.to_string());
-		let inner_lock_ref = Arc::clone(&outer_lock.entry(lock_key).or_default());
-		let _guard = inner_lock_ref.write().unwrap();
-
 		if key.is_empty() {
 			let msg = format!("Failed to write {}/{}: key may not be empty.", namespace, key);
 			return Err(std::io::Error::new(std::io::ErrorKind::Other, msg));
 		}
 
+		let mut outer_lock = self.locks.lock().unwrap();
+		let lock_key = (namespace.to_string(), key.to_string());
+		let inner_lock_ref = Arc::clone(&outer_lock.entry(lock_key).or_default());
+		let _guard = inner_lock_ref.write().unwrap();
+
 		let mut dest_file_path = self.data_dir.clone();
 		dest_file_path.push(namespace);
 		dest_file_path.push(key);
@@ -143,17 +143,17 @@ impl KVStore for FilesystemStore {
 	}
 
 	fn remove(&self, namespace: &str, key: &str) -> std::io::Result<()> {
+		if key.is_empty() {
+			let msg = format!("Failed to remove {}/{}: key may not be empty.", namespace, key);
+			return Err(std::io::Error::new(std::io::ErrorKind::Other, msg));
+		}
+
 		let mut outer_lock = self.locks.lock().unwrap();
 		let lock_key = (namespace.to_string(), key.to_string());
 		let inner_lock_ref = Arc::clone(&outer_lock.entry(lock_key.clone()).or_default());
 
 		let _guard = inner_lock_ref.write().unwrap();
 
-		if key.is_empty() {
-			let msg = format!("Failed to remove {}/{}: key may not be empty.", namespace, key);
-			return Err(std::io::Error::new(std::io::ErrorKind::Other, msg));
-		}
-
 		let mut dest_file_path = self.data_dir.clone();
 		dest_file_path.push(namespace);
 		dest_file_path.push(key);