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Message-ID: <01ce01c39a1b$62627500$23020a0a@hw0393>
From: "Guido Casper" <gcasper@s-und-n.de>
To: <dev@cocoon.apache.org>
References: <84F0A43A4248CE45B5C0E20F4C40779C600904@naomi.webworks.nl>
Subject: Re: repository block (was Re: [RT] Source extensions)
Date: Fri, 24 Oct 2003 12:41:29 +0200
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Unico Hommes <Unico@hippo.nl> wrote:
>>> A related change I need to make is described here:
>>> http://nagoya.apache.org/bugzilla/show_bug.cgi?id=23699 this will
>>> not only improve performance of querying for a specific property
>>> but is prerequisite for setting properties via the
>>> SourceDescriptionManager.
>>
>> I'm not sure.
>> What exactly is the meaning of the returned Strings?
>>
>
> They identify a property type: namespace + "#" + propname. The
> previous implementation of the inspector manager's
> getSourceProperty() method was looping over all registered inspectors
> until it found the property it was looking for.
>
> In order to make this process more efficient the manager needs to
> register the individual inspectors to handle specific properties. The
> getExposedPropertyTypes() method enables this.
>
>> Is it all properties "supported" by a particular SourceInspector
>> implementation?
>
> Yes.
>
>> What if it supports any within a particular namespace?
>> What if it support any within any namespace?
>>
>> How would that be represented?
>
> Nothing in place for that yet, but we could add it easily. Just need a
> convention. What about using wildcards for this:
>
> *#myprop
> myns#*
> *#*
>
> This way a simple jdbc descriptor that stores properties as key value
> pairs in a database can assert it is general enough to handle any
> property. The manager then looks for an inspector in order from most
> specific (exact match) to least specific (*#*).

The way the manager caches the values for lookups looks to me like
sacrifying a lot of flexibility. I don't really see a way to avoid the
looping (Is it really that costly?).

Caching the set of supported properties is ok, but it should be a
concern of the individual SourceInspector implementation IMO, since it
could change at runtime (think access control for instance). That might
also be a reason for the above lookup mechanism to break.

Guido