fix: restart caching loop automatically upon fail

brownie/network/middlewares/caching.py

@@ -105,17 +105,21 @@ def __init__(self, w3: Web3) -> None:
  self.cur = Cursor(_get_data_folder().joinpath("cache.db"))
  self.cur.execute(f"CREATE TABLE IF NOT EXISTS {self.table_key} (method, params, result)")
 
- latest = w3.eth.get_block("latest")
+ self.lock = threading.Lock()
+ self.event = threading.Event()
+ self.start()
+
+ def start(self):
+ latest = self.w3.eth.get_block("latest")
  self.last_block = latest.hash
  self.last_block_seen = latest.timestamp
- self.last_request = 0.0
+ self.last_request = time.time()
  self.block_cache: OrderedDict = OrderedDict()
- self.block_filter = w3.eth.filter("latest")
+ self.block_filter = self.w3.eth.filter("latest")
 
- self.lock = threading.Lock()
- self.event = threading.Event()
  self.is_killed = False
- threading.Thread(target=self.block_filter_loop, daemon=True).start()
+ self.loop_thread = threading.Thread(target=self.loop_exception_handler, daemon=True)
+ self.loop_thread.start()
 
  @classmethod
  def get_layer(cls, w3: Web3, network_type: str) -> Optional[int]:
@@ -138,6 +142,13 @@ def get_layer(cls, w3: Web3, network_type: str) -> Optional[int]:
  def time_since(self) -> float:
  return time.time() - self.last_request
 
+ def loop_exception_handler(self) -> None:
+ try:
+ self.block_filter_loop()
+ except Exception:
+ self.block_cache.clear()
+ self.is_killed = True
+
  def block_filter_loop(self) -> None:
  while not self.is_killed:
  # if the last RPC request was > 60 seconds ago, reduce the rate of updates.
@@ -215,6 +226,9 @@ def process_request(self, make_request: Callable, method: str, params: List) ->
  data = HexBytes(data)
  return {"id": "cache", "jsonrpc": "2.0", "result": data}
 
+ if not self.loop_thread.is_alive():
+ self.start()
+
  with self.lock:
  self.last_request = time.time()
  self.event.set()