Timeout per manager instance

[jsikorsky]

Hi,

I created a custom manager which caches get() and get_or_create() functions. Everything works just fine, but I'd like to use different timeouts for different models which use this manager. Consider the following example:

from django.db import models
from memoize import memoize

class CachingManager(models.Manager):
    def __init__(self, cache_timeout = 0):
        self.cache_timeout = cache_timeout
        memoizer = memoize(timeout=self.cache_timeout)
        self.get = memoizer(super(CachingManager, self).get)
        self.get_or_create = memoizer(super(CachingManager, self).get)
        super(CachingManager, self).__init__()


class Host(models.Model):
    hostname = models.CharField(max_length = 30,  unique = True)
    objects = models.Manager()    
    caching = CachingManager(cache_timeout = 5)

This raises IndexError:

....
  File "/usr/lib/python2.7/site-packages/django_memoize-1.2.0-py2.7.egg/memoize/__init__.py", line 239, in _memoize_kwargs_to_args
    arg = repr(args[0])
IndexError: tuple index out of range

I created a patch - seems to work for me, but I'm not sure if it won't break anything else:

diff -rup django_memoize-1.2.0-py2.7.egg.orig/memoize/__init__.py django_memoize-1.2.0-py2.7.egg/memoize/__init__.py
--- django_memoize-1.2.0-py2.7.egg.orig/memoize/__init__.py     2015-10-16 22:13:33.460610061 +0200
+++ django_memoize-1.2.0-py2.7.egg/memoize/__init__.py  2015-10-17 11:52:56.327081228 +0200
@@ -236,7 +236,7 @@ class Memoizer(object):
                 #: this supports instance methods for
                 #: the memoized functions, giving more
                 #: flexibility to developers
-                arg = repr(args[0])
+                arg = repr(argspec.args[i])
                 arg_num += 1
             elif argspec.args[i] in kwargs:
                 arg = kwargs.pop(argspec.args[i])