I agree; this seems like a workaround for one application that picked the
wrong datatype. Maybe we should warn about BigDecimal being slow somewhere?
If someone wants to do some performance tests of GWT-RPC serialization,
publishing the results would be useful to the community.

My recommendation in this case would be create a new class named "Id" or
Key" that simply contains the BigDecimal, then modify the code to use it,
then change the implementation to store the data in a string field instead.
In the end you'll have more readable code.

- Brian


On Thu, Jun 13, 2013 at 12:03 PM, David <[email protected]> wrote:

> John,
>
> Well, if I don't have support for this patch then I better stop working on
> it. I can understand that this is not seen as a priority for GWT. Worst
> case I just replace the BigInteger/BigDecimal class in the project itself,
> that is basically what I did right now.
>
> Oracle sequences can be configured as a range between -10ˆ-26 and 10ˆ27.
> The Oracle JDBC drivers return
> a BigInteger if you force it to the extremes.
>
> Changing the application is not feasible, that will be too much work, we
> are talking about many thousands of dependencies in a huge codebase where
> BigIntegers and BigDecimals are used - while handling this optimisation on
> the RPC level can be done in just a few lines of code.
>
> In many cases we send large lists of objects that contain BigInteger,
> BigDecimals but only a few will actually be interacted with. So in that
> case we only need to convert the Strings to BigInteger (or BigDecimal) when
> really needed.
>
> David
>
> On Thu, Jun 13, 2013 at 7:52 PM, John A. Tamplin <[email protected]> wrote:
>
>> On Thu, Jun 13, 2013 at 3:14 AM, David <[email protected]> wrote:
>>
>>> The lazy parsing would only happen during deserialisation in the client.
>>> I think it is safe to assume that a BigInteger created through toString on
>>> the server will not result in a parse exception in the client code - or are
>>> there known incompatibilities ?
>>>
>>> I don't want that the regular constructor of BigInteger( String ) or
>>> BigInteger( String, int) would behave differently than before. Not even in
>>> the client when those BigInts are created in the client. That's why I was
>>> asking about the possibility to have different serialisers on client and
>>> server side.
>>>
>>> As the why, well currently the custom field serializer converts the
>>> BigInteger to a String, the client side needs to parse the string and
>>> convert it to an int array, which involves multiple substring,
>>> Integer.parseInt and multiply and add operations. Somehow IE8 has a problem
>>> with this. IE9 and other browsers are more efficient, but still that is a
>>> lot of CPU operations that can be avoided in my use case.
>>>
>>> In my particular use case they used BigInteger to represent a key in the
>>> database (oracle uses sequence numbers that are bigger than what can be
>>> represented with long). That might have not been the best idea, but those
>>> decisions have been made a long time ago, when I was not around. On the
>>> server side there is a usage of equals and compareTo happening, which would
>>> be hard to implement without a BigInteger, so there is logic in the choice.
>>> They obviously don't want to have an extra layer of objects to avoid the
>>> BigInteger in the GWT client since a lot of code is independent of client
>>> or server, this would hinder code sharing between the tiers.
>>>
>>> On the client side these id's are only send forth and back between
>>> client and server, no operation is ever performed, so making the custom
>>> field serialiser and the BigInteger cooperate gives a big performance
>>> improvement. They only operation needed on the client-side is equals,
>>> which can also be optimized to do a String comparison when bother have not
>>> been parsed after RPC.
>>>
>> 
>> I'm beginning to think such a change does not belong in GWT.  In your
>> example, wouldn't you be better served by only sending strings to the
>> client rather than BigDecimals, if they client never does anything with
>> them but send them back?  I think it is going to be pretty rare in normal
>> situations that you instantiate a BigDecimal but never actually use it in
>> the client, so it seems the special-case hack for your use-case should be
>> performed in your code instead.
>>
>> Too often people want to send things to the client that really don't
>> belong there, and that includes particular representations of it.  I know
>> DTOs are extra work over just shipping your regular objects over the wire
>> and GWT RPC makes that easy, but in many cases it is the wrong thing to do.
>>  Think about if you were building a proto for the communication -- would
>> you send the data in the current form?  If not, you shouldn't be sending it
>> that way via RPC just because it is easy to do so.
>>
>> BTW, I thought Oracle sequence numbers did fit in long (aren't they
>> int64?) -- at least all the JDBC code I see for manipulating them stores
>> them in a Java long.
>>
>> --
>> John A. Tamplin
>>
>> --
>> http://groups.google.com/group/Google-Web-Toolkit-Contributors
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>>
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