Add Cacheclass

Cacheclass/cacheclass.py

@@ -0,0 +1,48 @@
+import collections
+import time
+class Cache:
+    def __init__(self, maxlen=None):
+        self.maxlen = maxlen
+        self._dict = {}
+        #self._order = collections.deque()
+        self._recency = {}
+
+    def __getitem__(self, key):
+        value = self._dict[key]
+        self._maintain(key)
+        return value
+
+    def __setitem__(self, key, value):
+        self._shrink()
+        self._dict[key] = value
+        self._maintain(key)
+        #print(self._dict, self._recency)
+
+    def _maintain(self, key):
+        self._recency[key] = time.time()
+
+    def _shrink(self):
+        if self.maxlen is None:
+            return
+
+        pop_count = len(self._dict) - self.maxlen
+        if pop_count < 1:
+            return
+
+        keys = sorted(self._recency.keys(), key=self._recency.get)
+        for key in keys[:pop_count]:
+            self._dict.pop(key)
+            self._recency.pop(key)
+
+    def get(self, key, fallback=None):
+        try:
+            return self[key]
+        except KeyError:
+            return fallback
+
+    def remove(self, key):
+        try:
+            self._dict.pop(key)
+            self._recency.pop(key)
+        except KeyError:
+            return