Stop sub-classing object (#8249)

synapse/util/caches/__init__.py

@@ -43,7 +43,7 @@ response_cache_total = Gauge("synapse_util_caches_response_cache:total", "", ["n
 
 
 @attr.s
-class CacheMetric(object):
+class CacheMetric:
 
     _cache = attr.ib()
     _cache_type = attr.ib(type=str)

synapse/util/caches/descriptors.py

@@ -64,7 +64,7 @@ cache_pending_metric = Gauge(
 _CacheSentinel = object()
 
 
-class CacheEntry(object):
+class CacheEntry:
     __slots__ = ["deferred", "callbacks", "invalidated"]
 
     def __init__(self, deferred, callbacks):
@@ -80,7 +80,7 @@ class CacheEntry(object):
             self.callbacks.clear()
 
 
-class Cache(object):
+class Cache:
     __slots__ = (
         "cache",
         "name",
@@ -288,7 +288,7 @@ class Cache(object):
         self._pending_deferred_cache.clear()
 
 
-class _CacheDescriptorBase(object):
+class _CacheDescriptorBase:
     def __init__(self, orig: _CachedFunction, num_args, cache_context=False):
         self.orig = orig
 
@@ -705,7 +705,7 @@ def cachedList(
 
     Example:
 
-        class Example(object):
+        class Example:
             @cached(num_args=2)
             def do_something(self, first_arg):
                 ...

synapse/util/caches/dictionary_cache.py

@@ -40,7 +40,7 @@ class DictionaryEntry(namedtuple("DictionaryEntry", ("full", "known_absent", "va
         return len(self.value)
 
 
-class DictionaryCache(object):
+class DictionaryCache:
     """Caches key -> dictionary lookups, supporting caching partial dicts, i.e.
     fetching a subset of dictionary keys for a particular key.
     """
@@ -53,7 +53,7 @@ class DictionaryCache(object):
         self.thread = None
         # caches_by_name[name] = self.cache
 
-        class Sentinel(object):
+        class Sentinel:
             __slots__ = []
 
         self.sentinel = Sentinel()

synapse/util/caches/expiringcache.py

@@ -26,7 +26,7 @@ logger = logging.getLogger(__name__)
 SENTINEL = object()
 
 
-class ExpiringCache(object):
+class ExpiringCache:
     def __init__(
         self,
         cache_name,
@@ -190,7 +190,7 @@ class ExpiringCache(object):
         return False
 
 
-class _CacheEntry(object):
+class _CacheEntry:
     __slots__ = ["time", "value"]
 
     def __init__(self, time, value):

synapse/util/caches/lrucache.py

@@ -30,7 +30,7 @@ def enumerate_leaves(node, depth):
                 yield m
 
 
-class _Node(object):
+class _Node:
     __slots__ = ["prev_node", "next_node", "key", "value", "callbacks"]
 
     def __init__(self, prev_node, next_node, key, value, callbacks=set()):
@@ -41,7 +41,7 @@ class _Node(object):
         self.callbacks = callbacks
 
 
-class LruCache(object):
+class LruCache:
     """
     Least-recently-used cache.
     Supports del_multi only if cache_type=TreeCache

synapse/util/caches/response_cache.py

@@ -23,7 +23,7 @@ from synapse.util.caches import register_cache
 logger = logging.getLogger(__name__)
 
 
-class ResponseCache(object):
+class ResponseCache:
     """
     This caches a deferred response. Until the deferred completes it will be
     returned from the cache. This means that if the client retries the request

synapse/util/caches/treecache.py

@@ -3,7 +3,7 @@ from typing import Dict
 SENTINEL = object()
 
 
-class TreeCache(object):
+class TreeCache:
     """
     Tree-based backing store for LruCache. Allows subtrees of data to be deleted
     efficiently.
@@ -89,7 +89,7 @@ def iterate_tree_cache_entry(d):
             yield d
 
 
-class _Entry(object):
+class _Entry:
     __slots__ = ["value"]
 
     def __init__(self, value):

synapse/util/caches/ttlcache.py

@@ -26,7 +26,7 @@ logger = logging.getLogger(__name__)
 SENTINEL = object()
 
 
-class TTLCache(object):
+class TTLCache:
     """A key/value cache implementation where each entry has its own TTL"""
 
     def __init__(self, cache_name, timer=time.time):
@@ -154,7 +154,7 @@ class TTLCache(object):
 
 
 @attr.s(frozen=True, slots=True)
-class _CacheEntry(object):
+class _CacheEntry:
     """TTLCache entry"""
 
     # expiry_time is the first attribute, so that entries are sorted by expiry.