memoize IntType constructor

[p2pool.git] / p2pool / util / memoize.py

diff --git a/p2pool/util/memoize.py b/p2pool/util/memoize.py
index b5efab2..bf0fafc 100644 (file)
--- a/p2pool/util/memoize.py
+++ b/p2pool/util/memoize.py
@@ -1,3 +1,21 @@
+import itertools
+
+class LRUDict(object):
+    def __init__(self, n):
+        self.n = n
+        self.inner = {}
+        self.counter = itertools.count()
+    def get(self, key, default=None):
+        if key in self.inner:
+            x, value = self.inner[key]
+            self.inner[key] = self.counter.next(), value
+            return value
+        return default
+    def __setitem__(self, key, value):
+        self.inner[key] = self.counter.next(), value
+        while len(self.inner) > self.n:
+            self.inner.pop(min(self.inner, key=lambda k: self.inner[k][0]))
+
 _nothing = object()
 
 def memoize_with_backing(backing, has_inverses=set()):
@@ -19,3 +37,31 @@ def memoize_with_backing(backing, has_inverses=set()):
 
 def memoize(f):
     return memoize_with_backing({})(f)
+
+
+class cdict(dict):
+    def __init__(self, func):
+        dict.__init__(self)
+        self._func = func
+    
+    def __missing__(self, key):
+        value = self._func(key)
+        self[key] = value
+        return value
+
+def fast_memoize_single_arg(func):
+    return cdict(func).__getitem__
+
+class cdict2(dict):
+    def __init__(self, func):
+        dict.__init__(self)
+        self._func = func
+    
+    def __missing__(self, key):
+        value = self._func(*key)
+        self[key] = value
+        return value
+
+def fast_memoize_multiple_args(func):
+    f = cdict2(func).__getitem__
+    return lambda *args: f(args)