# HG changeset patch
# User Brendan Cully <brendan@kublai.com>
# Date 1158938365 25200
# Node ID e4ea47c214806b1617a5d43160a7c3c036e30c23
# Parent  8342ad5abe0be4da22ca29abc2cddf47bc2027e4
Add cachefunc to abstract function call cache

diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -24,6 +24,22 @@ defaultdateformats = ('%Y-%m-%d %H:%M:%S
 class SignalInterrupt(Exception):
     """Exception raised on SIGTERM and SIGHUP."""
 
+def cachefunc(func):
+    '''cache the result of function calls'''
+    cache = {}
+    if func.func_code.co_argcount == 1:
+        def f(arg):
+            if arg not in cache:
+                cache[arg] = func(arg)
+            return cache[arg]
+    else:
+        def f(*args):
+            if args not in cache:
+                cache[args] = func(*args)
+            return cache[args]
+
+    return f
+
 def pipefilter(s, cmd):
     '''filter string S through command CMD, returning its output'''
     (pout, pin) = popen2.popen2(cmd, -1, 'b')