[Checkins] SVN: zope.interface/branches/jinty-mem/src/zope/interface/interface.py Improve CPU performance of previous memory optimization

[Wichert Akkerman]

On 11/9/10 14:22 , Brian Sutherland wrote:
> Log message for revision 118295:
>    Improve CPU performance of previous memory optimization
>
> Changed:
>    U   zope.interface/branches/jinty-mem/src/zope/interface/interface.py
>
> -=-
> Modified: zope.interface/branches/jinty-mem/src/zope/interface/interface.py
> ===================================================================
> --- zope.interface/branches/jinty-mem/src/zope/interface/interface.py	2010-11-09 08:31:37 UTC (rev 118294)
> +++ zope.interface/branches/jinty-mem/src/zope/interface/interface.py	2010-11-09 13:22:27 UTC (rev 118295)
> @@ -51,6 +51,7 @@
>       # infrastructure in place.
>       #
>       #implements(IElement)
> +    __tagged_values = None
>
>       def __init__(self, __name__, __doc__=''):
>           """Create an 'attribute' description
> @@ -72,22 +73,27 @@
>
>       def getTaggedValue(self, tag):
>           """ Returns the value associated with 'tag'. """
> -        return getattr(self, '_Element__tagged_values', {})[tag]
> +        if self.__tagged_values is None:
> +            return default
> +        return self.__tagged_values[tag]

You can even optimise this further:

       tv = self.__tagged_values
       if tv is None:
           return default
       return tv[tv]

that avoids a second attribute lookup. You may also want to benchmark 
that versus using a __tagged_values={} on the class and doing a simple 
return self.__tagged_values.get(tag, default_

Wichert.