[#3618] Fix client-side cache invalidation for mixed str and bytes Redis keys (#3766)

* Support bytes key for client-side caching * Prepare both versions for lookup * linter fix * cache_key check for only one matched against multiple candidates fix * revert back correct changes

Author: ShubhamKaudewar

redis/cache.py

@@ -212,15 +212,25 @@ def delete_by_cache_keys(self, cache_keys: List[CacheKey]) -> List[bool]:
 
  return response
 
- def delete_by_redis_keys(self, redis_keys: List[bytes]) -> List[bool]:
+ def delete_by_redis_keys(
+ self, redis_keys: Union[List[bytes], List[str]]
+ ) -> List[bool]:
  response = []
  keys_to_delete = []
 
  for redis_key in redis_keys:
- if isinstance(redis_key, bytes):
- redis_key = redis_key.decode()
+ # Prepare both versions for lookup
+ candidates = [redis_key]
+ if isinstance(redis_key, str):
+ candidates.append(redis_key.encode("utf-8"))
+ elif isinstance(redis_key, bytes):
+ try:
+ candidates.append(redis_key.decode("utf-8"))
+ except UnicodeDecodeError:
+ pass # Non-UTF-8 bytes, skip str version
+
  for cache_key in self._cache:
- if redis_key in cache_key.redis_keys:
+ if any(candidate in cache_key.redis_keys for candidate in candidates):
  keys_to_delete.append(cache_key)
  response.append(True)
 

tests/test_cache.py

@@ -1322,6 +1322,40 @@ def test_delete_by_redis_keys_removes_associated_entries(self, mock_connection):
  assert len(cache.collection) == 1
  assert cache.get(cache_key4).cache_value == b"bar3"
 
+ def test_delete_by_redis_keys_with_non_utf8_bytes_key(self, mock_connection):
+ """cache fails to invalidate entries when redis_keys contain non-UTF-8 bytes."""
+ cache = DefaultCache(CacheConfig(max_size=5))
+
+ # Valid UTF-8 key works
+ utf8_key = b"foo"
+ utf8_cache_key = CacheKey(command="GET", redis_keys=(utf8_key,))
+ assert cache.set(
+ CacheEntry(
+ cache_key=utf8_cache_key,
+ cache_value=b"bar",
+ status=CacheEntryStatus.VALID,
+ connection_ref=mock_connection,
+ )
+ )
+
+ # Non-UTF-8 bytes key
+ bad_key = b"f\xffoo"
+ bad_cache_key = CacheKey(command="GET", redis_keys=(bad_key,))
+ assert cache.set(
+ CacheEntry(
+ cache_key=bad_cache_key,
+ cache_value=b"bar2",
+ status=CacheEntryStatus.VALID,
+ connection_ref=mock_connection,
+ )
+ )
+
+ # Delete both keys: utf8 should succeed, non-utf8 exposes bug
+ results = cache.delete_by_redis_keys([utf8_key, bad_key])
+
+ assert results[0] is True
+ assert results[1] is True, "Cache did not remove entry for non-UTF8 bytes key"
+
  def test_flush(self, mock_connection):
  cache = DefaultCache(CacheConfig(max_size=5))