Updating existing JDK code to use InputStream.transferTo()
Remi Forax
forax at univ-mlv.fr
Wed May 13 23:06:41 UTC 2015
Hi Chris,
On 05/14/2015 12:40 AM, Chris Hegarty wrote:
>
>> On 13 May 2015, at 22:45, Remi Forax <forax at univ-mlv.fr
>> <mailto:forax at univ-mlv.fr>> wrote:
>>
>>>
>>> may return 0, is when len == 0. And it's never the case here.
>>> Unless, of course,
>>> some misbehaving implementation of InputStream is used.
>>
>> The other reason to have read that returns 0 is if the underlying
>> channel is in non-blocking mode.
>> A read on an InputStream created by Channels.newInputStream on a
>> SelectableChannel may return 0
>> and the code will go in a loop until the SelectableChannel can read
>> something.
>> while(read() > 0) avoid that issue.
>
> Remi, is this right? I’d have to write a simple test to fully satisfy
> myself, but ChannelInputStream appears to put a SelectableChannel into
> blocking mode before reading, if it is non-blocking.
No, it seems, i'm wrong on that.
I have taken a look to ChannelInputStream and
SocketAdapter.SocketInputStream and both don't accept non-blocking
SelectableChannel.
Sorry for the noise.
>
>
>> The other things that may be a problem with this patch is that a lot
>> of codes replaced by transferTo use
>> either a bigger or a smaller size of buffer than transferTo.
>> Given that we don't know if the buffer size is something important
>> for a code or if the buffer size can be changed, i think it's better
>> to split this patch in several parts and to send each parts to the
>> right mailing list.
>
> You are probably right, anything that is not a like for like
> replacement with the transferTo implementation should have a thorough
> review from the appropriate component team.
>
> -Chris.
regards,
Rémi
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