Added delete option to database storage.

venv/Lib/site-packages/cachetools/decorators.py

@@ -0,0 +1,88 @@
+import functools
+
+from .keys import hashkey
+
+
+def cached(cache, key=hashkey, lock=None):
+    """Decorator to wrap a function with a memoizing callable that saves
+    results in a cache.
+
+    """
+    def decorator(func):
+        if cache is None:
+            def wrapper(*args, **kwargs):
+                return func(*args, **kwargs)
+        elif lock is None:
+            def wrapper(*args, **kwargs):
+                k = key(*args, **kwargs)
+                try:
+                    return cache[k]
+                except KeyError:
+                    pass  # key not found
+                v = func(*args, **kwargs)
+                try:
+                    cache[k] = v
+                except ValueError:
+                    pass  # value too large
+                return v
+        else:
+            def wrapper(*args, **kwargs):
+                k = key(*args, **kwargs)
+                try:
+                    with lock:
+                        return cache[k]
+                except KeyError:
+                    pass  # key not found
+                v = func(*args, **kwargs)
+                try:
+                    with lock:
+                        cache[k] = v
+                except ValueError:
+                    pass  # value too large
+                return v
+        return functools.update_wrapper(wrapper, func)
+    return decorator
+
+
+def cachedmethod(cache, key=hashkey, lock=None):
+    """Decorator to wrap a class or instance method with a memoizing
+    callable that saves results in a cache.
+
+    """
+    def decorator(method):
+        if lock is None:
+            def wrapper(self, *args, **kwargs):
+                c = cache(self)
+                if c is None:
+                    return method(self, *args, **kwargs)
+                k = key(*args, **kwargs)
+                try:
+                    return c[k]
+                except KeyError:
+                    pass  # key not found
+                v = method(self, *args, **kwargs)
+                try:
+                    c[k] = v
+                except ValueError:
+                    pass  # value too large
+                return v
+        else:
+            def wrapper(self, *args, **kwargs):
+                c = cache(self)
+                if c is None:
+                    return method(self, *args, **kwargs)
+                k = key(*args, **kwargs)
+                try:
+                    with lock(self):
+                        return c[k]
+                except KeyError:
+                    pass  # key not found
+                v = method(self, *args, **kwargs)
+                try:
+                    with lock(self):
+                        c[k] = v
+                except ValueError:
+                    pass  # value too large
+                return v
+        return functools.update_wrapper(wrapper, method)
+    return decorator