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

[Tres Seaver]

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On 11/09/2010 08:26 AM, Wichert Akkerman wrote:
> 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_

- -1:  mutable class defaults are a bug magnet.


Tres.
- -- 
===================================================================
Tres Seaver          +1 540-429-0999          tseaver at palladion.com
Palladion Software   "Excellence by Design"    http://palladion.com
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