[jbosscache-dev] Some new Cache usage questions

[Manik Surtani]

Use Cache for cache-wide operations like getRegion(), etc.

Use Node to manipulate data in the node, retrieve child nodes, etc.   
This way refs to Nodes - buckets of data storage - can be cached  
since it is these that would be most frequently used.
--
Manik Surtani

Lead, JBoss Cache
JBoss, a division of Red Hat

Email: manik at jboss.org
Telephone: +44 7786 702 706
MSN: manik at surtani.org
Yahoo/AIM/Skype: maniksurtani


On 5 Sep 2006, at 01:29, Ben Wang wrote:

> It does. But then, does it mean I need to keep both the reference  
> for Cache and "parent" Node at the same time? Although Cache is a  
> wrapper, it does have some additional APIs like evict and also  
> getRegion() that doesn't exist in Node. Or what's your recommendation?
>
> Actually, currently I am keeping the CacheSPI reference (and also  
> possibly NodeSPI in the future when it has life of its own) within  
> my code. Keeping the Node reference doesn't seem to make much sense  
> to me, although this can be just a pattern for the customed cache  
> provider (e.g., PojoCache).
>
> -Ben
>
> -----Original Message-----
> From: Manik Surtani [mailto:manik at jboss.org]
> Sent: Tuesday, September 05, 2006 12:10 AM
> To: Ben Wang
> Cc: Bela Ban; jbosscache-dev at lists.jboss.org
> Subject: Re: [jbosscache-dev] Some new Cache usage questions
>
>
> On 4 Sep 2006, at 16:58, Ben Wang wrote:
>
>> 1. I suspect people using JBC for session management purpose won't
>> store the Node ref but the Cache instead. Brian can say better but  
>> for
>> example of the http session, unless you store the root Node,  
>> otherwise
>> caching the children Node is not that useful.
>
> Node jSessionNode = Cache.getChild(Fqn.fromString("/  
> JSESSIONID"));  // this can be cached...
> Node sessionNode = jSessionNode.getChild(Fqn.fromString
> (sessionId));  // this can be retrieved every time...
>
> Does this help in any way?
>
>
>>
>> 2. ic. Do we have explicit contract for Cache to be "root" Node only?
>> I mean, even getRoot() is just a self pointer, it still serves the
>> purpose, IMO.
>
>  From the javadocs: "The cache is essentially a wrapper around the  
> default root Node."
>
> http://labs.jboss.com/file-access/default/members/jbosscache/freezone/
> docs/Habanero/api/org/jboss/cache/Cache.html
>
>
>>
>> -Ben
>>
>> -----Original Message-----
>> From: Manik Surtani [mailto:manik at jboss.org]
>> Sent: Monday, September 04, 2006 7:06 PM
>> To: Ben Wang
>> Cc: Bela Ban; jbosscache-dev at lists.jboss.org
>> Subject: Re: [jbosscache-dev] Some new Cache usage questions
>>
>> Not in your case, no.  But many other use cases will be able to
>> cache a node and use it directly.
>>
>> I too would rather keep the API clean in this regard.  Also, calling
>> cache.getRoot() is redundant since the Cache interface is a wrapper
>> around the root Node.  In fact, I even think we should get rid of the
>> getRoot() method.
>>
>> Cheers,
>> --
>> Manik Surtani
>>
>> Lead, JBoss Cache
>> JBoss, a division of Red Hat
>>
>> Email: manik at jboss.org
>> Telephone: +44 7786 702 706
>> MSN: manik at surtani.org
>> Yahoo/AIM/Skype: maniksurtani
>>
>>
>> On 1 Sep 2006, at 15:49, Ben Wang wrote:
>>
>>> Thing is I only do put to specific fqn once. So caching it doesn't
>>> buy
>>> you anything.
>>>
>>> -----Original Message-----
>>> From: Bela Ban
>>> Sent: Friday, September 01, 2006 10:22 PM
>>> To: Ben Wang
>>> Cc: jbosscache-dev at lists.jboss.org
>>> Subject: Re: [jbosscache-dev] Some new Cache usage questions
>>>
>>> My 2 cents: I'd rather keep the API clean, at the expense of folks
>>> potentially writing wrapping code (like Ben).
>>>
>>> Your code samples look a bit weird:
>>> #1
>>> Why do you always get the child ? Can't you get the node and cache
>>> it,
>>> e.g.
>>> Node n=cache.getRoot().getChild(fqn);
>>> n.containsKey(PojoInstance.KEY)
>>>
>>> #2
>>> Same as for #1: you don't need to call cache.getRoot().getChild
>>> (fqn) all the time, for example in a loop, simply cache it
>>>
>>>
>>> Ben Wang wrote:
>>>> Manik,
>>>>
>>>> While trying to use the new API in PojoCache, I have found that I
>>>> need to:
>>>>
>>>> 1. To check if a attribute exist, I need to do:
>>>> cache_.getRoot().getChild(fqn_).getData().values().contains
>>>> (PojoInstance.KEY)
>>>>
>>>> 2. And then, I need to do a lot of cache_.getRoot().getChild
>>>> (fqn).put(map)
>>>>
>>>> So looks like I need to write a wrapper layer just to provide
>>>> straight api for:
>>>>
>>>> Cache_.exists(fqn, key)
>>>> And
>>>> Cache_.put(fqn, map)
>>>>
>>>> If this is rare case, then I will bite the bullet. But if it is a
>>>> common one, then that really begs the question whether we should
>>>> provide additional apis or not?
>>>
>>> --
>>> Bela Ban
>>> Lead JGroups / Manager JBoss Clustering Group JBoss - a division of
>>> Red Hat
>>>
>>> _______________________________________________
>>> jbosscache-dev mailing list
>>> jbosscache-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/jbosscache-dev
>>
>