Remove DefaultMapping abstract base class.

2 files changed, 30 insertions, 48 deletions

diff --git a/cachetools/abc.py b/cachetools/abc.py
deleted file mode 100644
index b61e49b..0000000
--- a/cachetools/abc.py
+++ /dev/null
@@ -1,46 +0,0 @@
-from abc import abstractmethod
-from collections.abc import MutableMapping
-
-
-class DefaultMapping(MutableMapping):
-
-    __slots__ = ()
-
-    @abstractmethod
-    def __contains__(self, key):  # pragma: nocover
-        return False
-
-    @abstractmethod
-    def __getitem__(self, key):  # pragma: nocover
-        if hasattr(self.__class__, '__missing__'):
-            return self.__class__.__missing__(self, key)
-        else:
-            raise KeyError(key)
-
-    def get(self, key, default=None):
-        if key in self:
-            return self[key]
-        else:
-            return default
-
-    __marker = object()
-
-    def pop(self, key, default=__marker):
-        if key in self:
-            value = self[key]
-            del self[key]
-        elif default is self.__marker:
-            raise KeyError(key)
-        else:
-            value = default
-        return value
-
-    def setdefault(self, key, default=None):
-        if key in self:
-            value = self[key]
-        else:
-            self[key] = value = default
-        return value
-
-
-DefaultMapping.register(dict)
diff --git a/cachetools/cache.py b/cachetools/cache.py
index 4354ca6..ed3d268 100644
--- a/cachetools/cache.py
+++ b/cachetools/cache.py
@@ -1,7 +1,10 @@
-from .abc import DefaultMapping
+from collections.abc import MutableMapping
 
 
 class _DefaultSize(object):
+
+    __slots__ = ()
+
     def __getitem__(self, _):
         return 1
 
@@ -12,9 +15,11 @@ class _DefaultSize(object):
         return 1
 
 
-class Cache(DefaultMapping):
+class Cache(MutableMapping):
     """Mutable mapping to serve as a simple cache or cache base class."""
 
+    __marker = object()
+
     __size = _DefaultSize()
 
     def __init__(self, maxsize, getsizeof=None):
@@ -73,6 +78,29 @@ class Cache(DefaultMapping):
     def __len__(self):
         return len(self.__data)
 
+    def get(self, key, default=None):
+        if key in self:
+            return self[key]
+        else:
+            return default
+
+    def pop(self, key, default=__marker):
+        if key in self:
+            value = self[key]
+            del self[key]
+        elif default is self.__marker:
+            raise KeyError(key)
+        else:
+            value = default
+        return value
+
+    def setdefault(self, key, default=None):
+        if key in self:
+            value = self[key]
+        else:
+            self[key] = value = default
+        return value
+
     @property
     def maxsize(self):
         """The maximum size of the cache."""