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From Aljoscha Krettek <aljos...@apache.org>
Subject Re: Understanding code of CountTrigger
Date Wed, 03 Feb 2016 12:37:59 GMT
Hi Nirmalya,
the result of Evictor.evict() is used internally by the window operator. The flow is as follows:
1. Trigger fires
2. Evictor is called if it exists
3. Elements are evicted from window buffer if evictor returned number > 0
4. User-provided window function is called to emit window results

Cheers,
Aljoscha
> On 03 Feb 2016, at 12:46, Nirmalya Sengupta <sengupta.nirmalya@gmail.com> wrote:
> 
> Hello Till <trohrmann@apache.org>,
> 
> From your prompt reply:
> 
> '... the CountTrigger always works together with the CountEvictor which will make sure
that only .. ' - that explains it. Thanks.  I missed it.
> 
> A related question I have is this:
> 
> Between the PURGE facility of Trigger and REMOVAL facility of Evictor, is there really
a difference? Who uses the value that an 
> 
> Evictor.evict(Iterable<StreamRecord<Object>> elements, int size, W window)
{
> .....
> 
> }
> 
> returns? A trigger doesn't seem to do it.
> 
> -- Nirmalya
> 
> 
> 
> 
> 
> 
> 
> -- 
> Software Technologist
> http://www.linkedin.com/in/nirmalyasengupta
> "If you have built castles in the air, your work need not be lost. That is where they
should be.
> Now put the foundation under them."


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