Re: Request for XML Filter (AXIS2-1085)

[Takahide Nogayama]

>Henry said:
><henry>
>One of the possible use cases for filter is for checking uniqness of a
>piece of data, if this is implemented in using filter, the check and
>enforcement can be done during the parsing of the message. This will save
>the walking of the OM tree again.
></henry>
>
>A uniquenes check requires the inspection of the entire message.
>If a uniquess check is performed with a handler solution, there are several undesirable outcomes:
>1) the OM tree will be traversed, which is expensive.
>2) the OM tree will be expanded and cached, which kills performance.
>
>If a uniquess check is performed with a filter and handler solution:
>1) The filter can inspect the StAX events as they are read. The filter will not affect the caching of the OM tree. The filter will not pull StAX events.
>2) The filter will store its results on the MessageContext.
>
>Handlers pull StAX events.
> Filters don't pull StAX events. They intercept and propogate StAX events.
>
>Comments ? Takahide / Henry can you provide more justifications or feedback for this request ?

Thanks,  Let me add comment to the second outcomes of the handler solution,
(2) the OM tree will be expanded and cached, which kills performance <takahide>and consuming memory space</takahide>

Regards,
---------------------------
Takahide Nogayama