From 842e23d3e386169d9a90cef2a634c55a3e5fdd8e Mon Sep 17 00:00:00 2001
From: Aldo Cortesi <aldo@nullcube.com>
Date: Sun, 22 Mar 2015 21:00:41 +1300
Subject: Replace far-too-clever decorator LRU cache with something simpler

---
 libmproxy/utils.py | 53 +++++++++++++++++++++++------------------------------
 1 file changed, 23 insertions(+), 30 deletions(-)

(limited to 'libmproxy/utils.py')

diff --git a/libmproxy/utils.py b/libmproxy/utils.py
index 51f2dc26..5ed70a45 100644
--- a/libmproxy/utils.py
+++ b/libmproxy/utils.py
@@ -119,40 +119,33 @@ pkg_data = Data(__name__)
 
 class LRUCache:
     """
-        A decorator that implements a self-expiring LRU cache for class
-        methods (not functions!).
-
-        Cache data is tracked as attributes on the object itself. There is
-        therefore a separate cache for each object instance.
+        A simple LRU cache for generated values.
     """
     def __init__(self, size=100):
         self.size = size
+        self.cache = {}
+        self.cacheList  = []
+
+    def get(self, gen, *args):
+        """
+            gen: A (presumably expensive) generator function. The identity of
+            gen is NOT taken into account by the cache.
+            *args: A list of immutable arguments, used to establish identiy by
+            *the cache, and passed to gen to generate values.
+        """
+        if self.cache.has_key(args):
+            self.cacheList.remove(args)
+            self.cacheList.insert(0, args)
+            return self.cache[args]
+        else:
+            ret = gen(*args)
+            self.cacheList.insert(0, args)
+            self.cache[args] = ret
+            if len(self.cacheList) > self.size:
+                d = self.cacheList.pop()
+                self.cache.pop(d)
+            return ret
 
-    def __call__(self, f):
-        cacheName = "_cached_%s"%f.__name__
-        cacheListName = "_cachelist_%s"%f.__name__
-        size = self.size
-
-        @functools.wraps(f)
-        def wrap(self, *args):
-            if not hasattr(self, cacheName):
-                setattr(self, cacheName, {})
-                setattr(self, cacheListName, [])
-            cache = getattr(self, cacheName)
-            cacheList = getattr(self, cacheListName)
-            if cache.has_key(args):
-                cacheList.remove(args)
-                cacheList.insert(0, args)
-                return cache[args]
-            else:
-                ret = f(self, *args)
-                cacheList.insert(0, args)
-                cache[args] = ret
-                if len(cacheList) > size:
-                    d = cacheList.pop()
-                    cache.pop(d)
-                return ret
-        return wrap
 
 def parse_content_type(c):
     """
-- 
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