Hi,
Am Sonntag 01 August 2004 18:13 schrieb Stas Bekman:
> Does anybody have any statistics on the percentage of HEAD requests vs.
> GET? The purpose of HEAD request is not to save your CPU cycles, but to
> avoid data transfer which is precisely what Apache 2.0 does, without
> making you do the extra work to deal with HEAD requests.
>
> > also The comment implies, that I get a Content-Length header for a HEAD
> > request, if I waste my time and generate the body of the message. I tried
> > it and got _no_ Content-Length header!
> >
> > $apr->content_type($media_type) unless $apr->main;
> > if ( $apr->header_only ) {
> > $apr->print( ' ' x $size ); # just to see if I got a content-length
> > header return DONE;
> > }
> >
> > The only way to get the Content-Length header for a HEAD request is
> >
> > $apr->headers_out->{'Content-Length'} = $size ;
> > $apr->content_type($media_type) unless $apr->main;
> > if ( $apr->header_only ) {
> > $apr->rflush;
> > return DONE;
> > }
> >
> > But I fail to see why this works, I thought the data walks the same
> > filter chain only in more buckets.
>
> In dynamic scripts you never get the C-L header unless you set it
> explicitly and some filter doesn't remove it. It's not possible for
> Apache to add one, since headers are sent *before* it knows how much
> data your handler is going to send. So HEAD or GET, you won't get it.
But my point is, for a HEAD request, there is no data so apache should not
touch my content-length header. I really dislike to generate the full data
for the request and apache throws it away ( and even the I get no
Content-Length header ).
>
> So HEAD on dynamic scripts that doesn't set their own C-L is a wasted
> operation on behalf of the client. Unless you use some E-Tag (but I
> haven't checked the RFC).
>
> BTW, what's wrong with $r->set_content_length()?
Nothing, I searched for the function, but I did not find it! I know I should
use mp2doc, but as I searched for it, I did not think on the tool. I tryed
first with perldoc Apache::RequestRec and then I searched
http://perl.apache.org/docs/2.0/api/Apache/RequestRec.html
For some reason I thought if there is no function content_length then I have
no function like this.
> http://perl.apache.org/docs/2.0/api/Apache/Response.html#C_set_content_leng
>th_ Neither you need to rflush. Neither you should return DONE, but OK.
I tried it now and even with set_content_length and return OK I got no
content-length header.
PS: Much thanks for the pointer to Apache::Response, I found more functions
that I missed already!
--
Boris
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