util: add the code path to "cachefunc()" for the function taking no arguments
authorFUJIWARA Katsunori <foozy@lares.dti.ne.jp>
Sat, 15 Feb 2014 19:52:26 +0900
changeset 20835 0e8417131a29
parent 20834 8c210b169c69
child 20836 a8b4541bb961
util: add the code path to "cachefunc()" for the function taking no arguments Before this patch, "util.cachefunc()" caches the value returned by the specified function into dictionary "cache", even if the specified function takes no arguments. In such case, "cache" has at most one entry, and distinction between entries in "cache" is meaningless. This patch adds the code path to "cachefunc()" for the function taking no arguments for efficiency: to store only one cached value, using list "cache" is a little faster than using dictionary "cache".
mercurial/util.py
--- a/mercurial/util.py	Wed Mar 26 12:52:57 2014 -0500
+++ b/mercurial/util.py	Sat Feb 15 19:52:26 2014 +0900
@@ -188,6 +188,13 @@
 def cachefunc(func):
     '''cache the result of function calls'''
     # XXX doesn't handle keywords args
+    if func.func_code.co_argcount == 0:
+        cache = []
+        def f():
+            if len(cache) == 0:
+                cache.append(func())
+            return cache[0]
+        return f
     cache = {}
     if func.func_code.co_argcount == 1:
         # we gain a small amount of time because