> > > stoddard 01/02/21 13:14:33
> > >
> > > Modified: modules/http http_protocol.c
> > > Log:
> > > BUFF is gone!
> >
> > BUFF may be gone, but were these issues ever REALLY investigated?
> >
> > Ryan
> >
SAFEREAD is an optimiation for handling pipelined requests. When we receive a
pipelined request, we want to pipeline the respose back (e.g., combine
mulltiple responses in a single buffer until thebuffer is filled before
flushing to the network).
Here is how SAFEREAD mode worked
Issuing a bread() on a BUFF in SAFEREAD mode caused the BUFF code to first
issue a select() on the socket to see if there was more bytes available (i.e.,
a pipelined request). If more bytes were available, bread() returned those
bytes. If no bytes were available, any response hanging around in BUFF was
flushed before the blocking read was issued. Fairly straightforward.
check_pipeline_flush() in http_request.c is intended to do the same thing, but
I've not actually tested it because I don't like the function is implemented.
check_pipeline_flush() issues an ap_get_brigade(r->input_filters, bb,
AP_MODE_PEEK) which seems overkill. This function would be much cleaner if
it used an apr_select call on the socket to see if bytes were available to be
read. If no bytes were available, then send the flush down the filter chain.
If bytes are available, handle the crlf on the end of POST requests in the
input chain rather than in the AP_MODE_PEEK code. In fact, I would suggest
getting rid of AP_MODE_PEEK altogether.
Bill
