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Posted to pubscribe-dev@ws.apache.org by ku...@itg.hitachi.co.jp on 2005/06/15 11:06:31 UTC

Two questions about topic space implementation of Hermes

Hello.

My name is Masahiro Kurosawa.
I have two questions, one is about FileSystem example and another is WSN
implementation of Hermes.

(1) m_topicSpaceSet.addTopicSpace() is never called in 
  AbstractFilesystemResource/FilesystemResource class, so I think no topics
  are registered to Filesystem resource after calling 
  TopicUtils.initNotificationProducerProperties at
  FilesystemResource.init().
  Is that right? If so, a 'TODO' comment should be added to show developers
  that this fact.

(2) WS-Topics specification says a NotificationProducer can support one or
  more Topics from multiple Topic Spaces and entire Topic Tree, or just a 
  subset of the Topics in that Topic Tree. Concept of TopicSpaceSet
  interface and TopicUtils class, however, seem be against this description
  because all topics of paticular Topic Space are registerd to the topic 
  set of the NotificationProducer.
  I feel TopicList of Globus Toolkit 4 was easier to use.
  Or I'm misunderstanding the spec?

At last, a lot of thanks for reading my poor English :-)p
Regards.

-----
Masahiro Kurosawa
 - Hitachi, Ltd., Software Divisition
 - kurosawa@itg.hitachi.co.jp


Re: Two questions about topic space implementation of Hermes

Posted by ku...@itg.hitachi.co.jp.
Hello, Ian.

Thank you for your reply.

>For now, note that you can build up a TopicSpace that contains only select 
>root topics, rather than all of them. Also, we've added a "visible" flag 
>on the Topic interface that tells 
>TopicUtils#initNotificationProducerProperties() not to advertise that 
>topic via the wsnt:Topic resource property (not sure if this feature made 
>it into 1.0 beta though).

Yes, for the moment, Topic Space as metadata and instances of it are nearly
equal in implementation, so I'll just instantiate a TopicSpace object as a 
kind of ad-hoc one, add select topics to them and register it to the 
TopicSpaceSet object of abstract resource class as you say. When we can 
retrieve the schema of Topic Space from WS-Resources, "visible" flag will 
be very useful because we need divide topic instances bound to a particular 
resource instance from those metadata (although there are no ways in specs 
to do such a thing).

Thanks.


>Hi Masahiro,
>
>We'll work on improving the generated TODOs in XXXResource#init().
>
>My answer to #2 is inline below.
>
>Regards,
>Ian
>
>kurosaw@itg.hitachi.co.jp wrote:
>> Hello.
>> 
>> As to fisrt question, I found a solution from email exchanges between
>> Ian and Gennady. I understand addTopicSpace() should be called at 
>> FilesystemResource.init() as was expected. Anyway, please condier
>> some 'TODO' comments in WsnWsdl2Java-generated source or implementation
>> in given 'filesys_resource_init.txt'.
>> 
>> Second one remains.
>> 
>> Thanks.
>---
>>>Hello.
>>>
>>>My name is Masahiro Kurosawa.
>>>I have two questions, one is about FileSystem example and another is WSN
>>>implementation of Hermes.
>>>
>>>(1) m_topicSpaceSet.addTopicSpace() is never called in 
>>> AbstractFilesystemResource/FilesystemResource class, so I think no topics
>>> are registered to Filesystem resource after calling 
>>> TopicUtils.initNotificationProducerProperties at
>>> FilesystemResource.init().
>>> Is that right? If so, a 'TODO' comment should be added to show developers
>>> that this fact.
>>>
>>>(2) WS-Topics specification says a NotificationProducer can support one or
>>> more Topics from multiple Topic Spaces and entire Topic Tree, or just a 
>>> subset of the Topics in that Topic Tree. Concept of TopicSpaceSet
>>> interface and TopicUtils class, however, seem be against this description
>>> because all topics of paticular Topic Space are registerd to the topic 
>>> set of the NotificationProducer.
>>> I feel TopicList of Globus Toolkit 4 was easier to use.
>>> Or I'm misunderstanding the spec?
>
>Your understanding of the spec is correct. I have also been thinking of 
>the issue that you bring up - that the current APIs don't allow you to add 
>a subtree of a TopicSpace. I have some ideas on how to remedy this. The 
>tricky part will be getting the topic expression evaluators to work 
>correctly when evaluating against a topic set that contains subtrees, 
>particularly subtrees that do not have a root topic as their root node; 
>this will be tricky because topic expressions are always relative to the 
>root of a topic space.
>
>For now, note that you can build up a TopicSpace that contains only select 
>root topics, rather than all of them. Also, we've added a "visible" flag 
>on the Topic interface that tells 
>TopicUtils#initNotificationProducerProperties() not to advertise that 
>topic via the wsnt:Topic resource property (not sure if this feature made 
>it into 1.0 beta though).
>
>>>At last, a lot of thanks for reading my poor English :-)p
>>>Regards.
>>>
>>>-----
>>>Masahiro Kurosawa
>>>- Hitachi, Ltd., Software Divisition
>>>- kurosawa@itg.hitachi.co.jp
>>>
>>>
>> 
>> 
>> 
>> ------------------------------------------------------------------------
>> 
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: hermes-dev-unsubscribe@ws.apache.org
>> For additional commands, e-mail: hermes-dev-help@ws.apache.org
>
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: hermes-dev-unsubscribe@ws.apache.org
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>
>

-----
Masahiro Kurosawa
 - Hitachi, Ltd., Software Divisition
 - kurosawa@itg.hitachi.co.jp


Re: Two questions about topic space implementation of Hermes

Posted by Ian Springer <ip...@apache.org>.
Hi Masahiro,

We'll work on improving the generated TODOs in XXXResource#init().

My answer to #2 is inline below.

Regards,
Ian

kurosaw@itg.hitachi.co.jp wrote:
> Hello.
> 
> As to fisrt question, I found a solution from email exchanges between
> Ian and Gennady. I understand addTopicSpace() should be called at 
> FilesystemResource.init() as was expected. Anyway, please condier
> some 'TODO' comments in WsnWsdl2Java-generated source or implementation
> in given 'filesys_resource_init.txt'.
> 
> Second one remains.
> 
> Thanks.
---
>>Hello.
>>
>>My name is Masahiro Kurosawa.
>>I have two questions, one is about FileSystem example and another is WSN
>>implementation of Hermes.
>>
>>(1) m_topicSpaceSet.addTopicSpace() is never called in 
>> AbstractFilesystemResource/FilesystemResource class, so I think no topics
>> are registered to Filesystem resource after calling 
>> TopicUtils.initNotificationProducerProperties at
>> FilesystemResource.init().
>> Is that right? If so, a 'TODO' comment should be added to show developers
>> that this fact.
>>
>>(2) WS-Topics specification says a NotificationProducer can support one or
>> more Topics from multiple Topic Spaces and entire Topic Tree, or just a 
>> subset of the Topics in that Topic Tree. Concept of TopicSpaceSet
>> interface and TopicUtils class, however, seem be against this description
>> because all topics of paticular Topic Space are registerd to the topic 
>> set of the NotificationProducer.
>> I feel TopicList of Globus Toolkit 4 was easier to use.
>> Or I'm misunderstanding the spec?

Your understanding of the spec is correct. I have also been thinking of 
the issue that you bring up - that the current APIs don't allow you to add 
a subtree of a TopicSpace. I have some ideas on how to remedy this. The 
tricky part will be getting the topic expression evaluators to work 
correctly when evaluating against a topic set that contains subtrees, 
particularly subtrees that do not have a root topic as their root node; 
this will be tricky because topic expressions are always relative to the 
root of a topic space.

For now, note that you can build up a TopicSpace that contains only select 
root topics, rather than all of them. Also, we've added a "visible" flag 
on the Topic interface that tells 
TopicUtils#initNotificationProducerProperties() not to advertise that 
topic via the wsnt:Topic resource property (not sure if this feature made 
it into 1.0 beta though).

>>At last, a lot of thanks for reading my poor English :-)p
>>Regards.
>>
>>-----
>>Masahiro Kurosawa
>>- Hitachi, Ltd., Software Divisition
>>- kurosawa@itg.hitachi.co.jp
>>
>>
> 
> 
> 
> ------------------------------------------------------------------------
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: hermes-dev-unsubscribe@ws.apache.org
> For additional commands, e-mail: hermes-dev-help@ws.apache.org


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Re:Two questions about topic space implementation of Hermes

Posted by ku...@itg.hitachi.co.jp.
Hello.

As to fisrt question, I found a solution from email exchanges between
Ian and Gennady. I understand addTopicSpace() should be called at 
FilesystemResource.init() as was expected. Anyway, please condier
some 'TODO' comments in WsnWsdl2Java-generated source or implementation
in given 'filesys_resource_init.txt'.

Second one remains.

Thanks.

>Hello.
>
>My name is Masahiro Kurosawa.
>I have two questions, one is about FileSystem example and another is WSN
>implementation of Hermes.
>
>(1) m_topicSpaceSet.addTopicSpace() is never called in 
>  AbstractFilesystemResource/FilesystemResource class, so I think no topics
>  are registered to Filesystem resource after calling 
>  TopicUtils.initNotificationProducerProperties at
>  FilesystemResource.init().
>  Is that right? If so, a 'TODO' comment should be added to show developers
>  that this fact.
>
>(2) WS-Topics specification says a NotificationProducer can support one or
>  more Topics from multiple Topic Spaces and entire Topic Tree, or just a 
>  subset of the Topics in that Topic Tree. Concept of TopicSpaceSet
>  interface and TopicUtils class, however, seem be against this description
>  because all topics of paticular Topic Space are registerd to the topic 
>  set of the NotificationProducer.
>  I feel TopicList of Globus Toolkit 4 was easier to use.
>  Or I'm misunderstanding the spec?
>
>At last, a lot of thanks for reading my poor English :-)p
>Regards.
>
>-----
>Masahiro Kurosawa
> - Hitachi, Ltd., Software Divisition
> - kurosawa@itg.hitachi.co.jp
>
>