[jbosscache-dev] Re: Any reason not to use ExposedByteArrayOutputStream instead of ByteArrayOutputStream ?

[Manik Surtani]

On 4 Jul 2008, at 12:32, Bela Ban wrote:

> Manik Surtani wrote:
>> But that would involve JGroups code calling Buffer.copy() again,  
>> which is the same as using a normal BAOS.  Just that it happens a  
>> bit later in the chain of events.
>
> No: the byte[] buffer with offset and length are passed down to the  
> TCP or datagram socket and *NOT* copied at all !

Ok, makes more sense.  Misleading copy() method on the class had me  
thinking it was actually used somewhere.  :-)

>> This should have far-reaching consequences as I'm not aware of  
>> anyone else but JBossCache to use Marshaller. Or maybe, to be on  
>> the safe side, I could create a Marshaller2 so existing code  
>> doesn't break (extending Marshaller)... http://jira.jboss.com/jira/browse/JGRP-796That 
>>  should
>>
>> I wasn't talking about reusing stream instances, I was referring to  
>> the same problem you have above with JGroups is going to be  
>> encountered with every cache loader impl in that the byte[]  
>> retrieved may be larger than necessary and contain uninitialized  
>> values.
>
> So JBC has to switch to a Buffer-like implementation too. At least  
> where it is important. I suggest do it immediately wherever code can  
> be changed (e.g. internal code) and defer it to later in cases where  
> external code might rely on it, in order not to break anything.

Ok, so once we have a Marshaller interface that uses this Buffer I can  
switch to it.

> We need to reduce copying wherever possible !
+100
--
Manik Surtani
Lead, JBoss Cache
manik at jboss.org