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Message-ID: <5e7fd1eb0811231918jdb3649cp6e57e8214512b060@mail.gmail.com>
Date: Mon, 24 Nov 2008 11:18:16 +0800
From: "Jack Cai" <greensight@gmail.com>
To: dev@harmony.apache.org
Subject: Re: [classlib][luni] Redundant and repeated external properties
 loading using ResourceBundle may degrade performance.
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Well, I think what Kevin suggests to improve the java.util.ResourceBundle
impl. itself? Exception handling is not a good scenario to cite here. Web
applications might be a better scenario, as they usually load a lot of
(localized) messages. Fortunately many Web applications will load all the
messages into memory during startup, so they won't need to read messages
from disk files again and again. I guess this should be a best practise for
developers in case their applications need to read many messages repeatedly.

-Jack


2008/11/21 Tony Wu <wuyuehao@gmail.com>

> Keivn
>
> Sorry for different idea.
>
> First, I dont think exception handling is a right place to talking
> about performance. It's a self-contradictory story.
> If you think it is a good place to improve the performance, there must
> be many exceptions thrown at runtime. But I dont think there should
> be, because to use try/catch as condition judgment itself is a
> performance killer. My understanding is that in the most cases when we
> need to get a localized message, it's time for vm to exit. And why we
> should take care the performance when exit?
>
> Furthermore, resource bundle is designed for decoupling the localized
> messages from logic. It's not a good idea to couple them again with
> hashtable. You can not ask translater to modify the java source code,
> compile, build, and test it ;-)
>
> On Fri, Nov 21, 2008 at 1:34 PM, Jack Cai <greensight@gmail.com> wrote:
> > I agree with Kevin that this might be a place that we could possibly
> > improve. But we should be careful when using a cache, as it always
> > introduces lots of complexity, like cache invalidation and reload. In the
> > case of ResouceBundle, same thing here. What happens if the resource
> files
> > gets updated? This will be a common scenario in long-running Java
> process,
> > e.g., the JEE server environment.
> >
> > - Jack
> >
> > 2008/11/20 Jim Yu <junjie0122@gmail.com>
> >
> >> Hi Kevin,
> >> Making a cache for all the message loaded from ResourceBundle will bring
> >> huge overhead if only few message would be used in an application. Only
> in
> >> some specific scenarios  where lots of duplicate message is needed would
> >> application benefit from such caching mechanism. But I don't think such
> >> case
> >> would be very common. Could you prove your idea by running some
> benchmarks?
> >> My another concern is that it doesn't make sense to use a hashtable to
> >> store
> >> the locale dependent message. How do you define the key for the entry?
> E.g.
> >> "K0046" would not be qualified since no locale info is included. And
> even
> >> if
> >> you find a good method to solve this, the overhead would be incredible
> if
> >> lots of locales need to be supported for the message.
> >> 2008/11/20 Kevin Zhou <zhoukevin83@gmail.com>
> >>
> >> > Jim Yu wrote:
> >> >
> >> >> In addition, using ResourceBundle in Harmony can make the message
> output
> >> >> be
> >> >> easily localized into different languages. And it is very convenient
> to
> >> >> support more locales in the future.
> >> >>
> >> >> 2008/11/20 Sean Qiu <sean.xx.qiu@gmail.com>
> >> >>
> >> >>
> >> >>
> >> >>> We can benefit from it when exceptions are thrown many times.
> >> >>> But we rarely encounter this situation in our application :)
> >> >>> To save the memory, space outweigh time in this case.
> >> >>>
> >> >>> Correct me if I'm wrong.
> >> >>>
> >> >>> 2008/11/20 Kevin Zhou <zhoukevin83@gmail.com>
> >> >>>
> >> >>>
> >> >>>
> >> >>>> Hi,
> >> >>>> I read some code in LUNI module of Harmony.
> >> >>>> (org.apache.harmony.luni.util.Msg/MsgHelp and
> >> java.util.ResourceBundle)
> >> >>>> I found that Harmony uses ResourceBundle to load messages from
> >> external
> >> >>>> properties file.
> >> >>>> e.g. Once it requires a message "K0046", it will always use
> >> >>>> ResourceBundle to go through the
> >> >>>> org.apache.harmony.luni.util.ExternalMessages.properties file to
> >> search
> >> >>>>
> >> >>>>
> >> >>> it.
> >> >>>
> >> >>>
> >> >>>> I think such redundant and repeated I/O operations may degrade our
> >> >>>> performance.
> >> >>>>
> >> >>>> Why not use a hashtable to store all the external messages? It only
> >> >>>> requires several I/O operations initially!
> >> >>>>
> >> >>>>
> >> >>>>
> >> >>>>
> >> >>>>
> >> >>> --
> >> >>> Best Regards
> >> >>> Sean, Xiao Xia Qiu
> >> >>>
> >> >>> China Software Development Lab, IBM
> >> >>>
> >> >>>
> >> >>>
> >> >> Hi Jim,
> >> > I think that you misunderstand.
> >> > I don't mean to discard using ResourceBundle for localization.
> >> > I just suggest that we should use ResourceBundle to load all the
> external
> >> > properties and store them in a hashtable initially.
> >> > Then you don't need to repeat calling ResourceBundle to scan property
> >> files
> >> > any more, but turn to the hashtable. This may improve performance.
> >> >
> >> > Hi Sean and Regis,
> >> > I think that external messages are not only designed for exceptions
> >> > handling.
> >> > Some may also use such a useful mechanism in their applications.
> >> >
> >> > Let's assume that one application execute on HARMONY.
> >> > As a side effect, all jars on the bootpath will be loaded to search
> for
> >> the
> >> > ResourceBundle class the first time an external message is required.
> >> > Obviously, application have to wait utill ResourceBundle class is
> loaded
> >> > and it successfully finds the required message, which takes seconds.
> >> >
> >> > Note that if we can initially load all of the external properties
> before
> >> > the first application class is loaded.
> >> > This can provide a faster startup time and quick responses when it
> >> requires
> >> > any external messages.
> >> >
> >> >
> >>
> >>
> >> --
> >> Best Regards,
> >> Jim, Jun Jie Yu
> >>
> >> China Software Development Lab, IBM
> >>
> >
>
>
>
> --
> Tony Wu
> China Software Development Lab, IBM
>

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