Channel attachments?

["이희승 (Trustin Lee)"]

Out of curiosity, what was your expectation?

Thanks,
Trustin

On 06/17/2010 08:54 PM, Marc-André Laverdière wrote:
> Hi Trustin,
> 
> I don't think that ChannelLocal is THAT annoying. But its more related
> to my experience that the attachment isn't working as one would
> intuitively expect.
> 
> Marc-André LAVERDIÈRE
> "Perseverance must finish its work so that you may be mature and
> complete, not lacking anything." -James 1:4
> mlaverd.theunixplace.com/blog
> 
>  /"\
>  \ /    ASCII Ribbon Campaign
>   X      against HTML e-mail
>  / \
> 
> 
> 
> 2010/6/17 "이희승 (Trustin Lee)" <trustin at gmail.com>:
>> It does seem like that many people miss the session attributes in MINA. :)
>>
>> I replaced session attributes with ChannelLocal because of efficiency
>> issues:
>>
>> 1) Session attributes require every channel has a hash map.  When there
>> are not many attributes, the hash map wastes memory.  By contrast,
>> ChannelLocal is much more memory efficient.
>>
>> 2) A user often uses a String as a session attribute key.  It's much
>> slower than ChannelLocal, which requires only identity comparison on
>> Channels.
>>
>> 3) ChannelLocal is type-safe (i.e. generics aware).
>>
>> Also, I did not add an attribute map to ChannelHandlerContext and
>> instead stick to the attachment property because any state attached to
>> the context is not supposed to be accessed by others.  Moreover,
>> accessing many attributes requires many down-casts.  If there are many
>> state variables, I'd define a type with the multiple state variables and
>> store its instance as an attachment.
>>
>> Is ChannelLocal really inconvenient when you have to maintain
>> per-channel state?  I'm not really sure yet, but please feel free to let
>> me know if you have a better idea.
>>
>> Thanks!
>> Trustin
>>
>> On 06/14/2010 11:34 PM, Marc-André Laverdière wrote:
>>> Yikes... that could turn to a maintainability pain. I personally
>>> prefer to write code that works no matter what happens to the
>>> pipeline.
>>> Still... should we have to rely on these various workarounds? Why
>>> can't attachments just _work_ as one would expect?
>>>
>>> Marc-André LAVERDIÈRE
>>> "Perseverance must finish its work so that you may be mature and
>>> complete, not lacking anything." -James 1:4
>>> mlaverd.theunixplace.com/blog
>>>
>>>  /"\
>>>  \ /    ASCII Ribbon Campaign
>>>   X      against HTML e-mail
>>>  / \
>>>
>>>
>>>
>>> 2010/6/11 Jesse Hutton <jesse.hutton at gmail.com>:
>>>> On Fri, Jun 11, 2010 at 11:30 AM, Robert Wahlstedt <rob at isketch.net> wrote:
>>>>>
>>>>> On Jun 10, 2010, at 22:46 , blakeman8192 wrote:
>>>>>
>>>>>> I need a more elegant way to keep track of different objects (i.e. a
>>>>>> Player object) for a Channel.
>>>>>> Is this overlooked in the Netty design, or (more likely) am I missing
>>>>>> something?
>>>>>
>>>>> This is probably a very common functionality needed when building Netty
>>>>> based programs. More attention in the javadocs/documentation for best
>>>>> practices would be nice.
>>>>>
>>>>> I have solved it simply by subclassing DefaultChannelPipeline and putting
>>>>> the variables I need there. That way all of my handlers can access it by
>>>>> ChannelHandlerContext.getPipeline()
>>>>>
>>>>>
>>>>> /Rob
>>>>
>>>>
>>>> Just to add one more variation on the theme, my approach was to add whatever
>>>> state variables I needed to the final upstream handler in my pipeline
>>>> factory. Then, to get access I can do channel.getPipeline().getLast(),
>>>> casting it to the appropriate class.
>>>> Jesse
>>>> _______________________________________________
>>>> netty-users mailing list
>>>> netty-users at lists.jboss.org
>>>> https://lists.jboss.org/mailman/listinfo/netty-users
>>>>
>>>
>>> _______________________________________________
>>> netty-users mailing list
>>> netty-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/netty-users
>>
>> --
>> what we call human nature in actuality is human habit
>> http://gleamynode.net/
>>
>>
>> _______________________________________________
>> netty-users mailing list
>> netty-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/netty-users
>>
> 
> _______________________________________________
> netty-users mailing list
> netty-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/netty-users

-- 
what we call human nature in actuality is human habit
http://gleamynode.net/

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 293 bytes
Desc: OpenPGP digital signature
Url : http://lists.jboss.org/pipermail/netty-users/attachments/20100617/ee65a102/attachment-0001.bin