[Zope-CMF] Re: [Performance] "listFilteredActionsFor" unnecessarily expensive

[Tres Seaver]

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Florent Guillaume wrote:
> Dieter Maurer  <dieter at handshake.de> wrote:
> 
>>In our regular profiles, "listFilteredActionsFor" belongs to
>>the top consumers of CPU time.
>>
>>Recently, I found the main culprit (in CMF 1.4):
>>
>>   It is the completely unnecessary:
>>
>>      if not action in catlist:
>>
>>In our case, "listFilteredActionsFor" spends about 70 percent
>>of its complete time in the checking of "action in catlist".
>>
>>How in hell should the same action be defined more than once
>>such that we need to prevent such a case by an explicit check --
>>especially by such an expensive one?
>>
>>A comment before the line indicates that the author intended
>>to check by identity. But, of course, "action in catlist"
>>does *NOT* check by identity but by equality.
>>
>>
>>I propose to remove the check altogether...
> 
> 
> +1.
> 
> The three lines above could be reduced to one using .setdefault() too.

We could also use a 'seen' dictionary:

  key = (category, action.id)
  if key not in seen:
      seen[key] = 1
      ....


Tres.
- --
===============================================================
Tres Seaver                                tseaver at zope.com
Zope Corporation      "Zope Dealers"       http://www.zope.com
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