[jsr369-experts] Re: [servlet-spec users] Re: Re: Re: Re: Re: Re: Re: Re: Trailer header implementation

From: Stuart Douglas <sdouglas_at_redhat.com>
Date: Fri, 12 May 2017 06:23:17 +1000

On Fri, May 12, 2017 at 1:29 AM, Greg Wilkins <gregw_at_webtide.com> wrote:
> On 11 May 2017 at 16:35, Martin Mulholland <mmulholl_at_us.ibm.com> wrote:
>> If getTrailerFileds() is called before -1 is read on the request, why
>> would we throw an exception if the headers have already been received?
> Because allowing access to the trailers before a well specified event is
> opening up applications to be dependent on particular server behaviour.
> For example, Jetty has a mode where we delay dispatching a request to the
> servlet container until at least one content packet has arrived. This can
> avoid dispatching a thread only to immediately block trying to read content.
> An app run on jetty would thus often be able to see trailers before -1 is
> read, because Jetty will have waited for the body before calling the
> servlet, yet it would fail on a container that did not delay dispatch.
> So for portability, we need a precise condition that must be met before
> trailers are made available. Containers that have the trailers in advance
> must not make them available until the application has met its part of the
> contract.



> cheers
> --
> Greg Wilkins <gregw@webtide.com> CTO http://webtide.com