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Posted to dev@perl.apache.org by Stas Bekman <st...@stason.org> on 2003/05/15 11:07:30 UTC
rfc: Apache::DebugFilter
At some point this should end up at CPAN. Comments on this module and requests
for other filter debug handlers/functions are welcome.
I've temporary added this code to t/conf/modperl_extra.pl as I find it quite
useful to debug filter tests.
package Apache::DebugFilter;
require 5.006;
require mod_perl 1.99;
use strict;
use warnings FATAL => 'all';
$Apache::DebugFilter::VERSION = '0.01';
use base qw(Apache::Filter);
use Apache::FilterRec ();
use APR::Brigade ();
use APR::Bucket ();
use Apache::Const -compile => qw(OK DECLINED);
use APR::Const -compile => ':common';
sub snoop_connection : FilterConnectionHandler { snoop("connection", @_) }
sub snoop_request : FilterRequestHandler { snoop("request", @_) }
sub snoop {
my $type = shift;
my($filter, $bb, $mode, $block, $readbytes) = @_; # filter args
# $mode, $block, $readbytes are passed only for input filters
my $stream = defined $mode ? "input" : "output";
# read the data and pass-through the bucket brigades unchanged
if (defined $mode) {
# input filter
my $rv = $filter->next->get_brigade($bb, $mode, $block, $readbytes);
return $rv unless $rv == APR::SUCCESS;
_snoop_bb_dump($type, $stream, $bb, \*STDERR);
}
else {
# output filter
_snoop_bb_dump($type, $stream, $bb, \*STDERR);
my $rv = $filter->next->pass_brigade($bb);
return $rv unless $rv == APR::SUCCESS;
}
#if ($bb->empty) {
# return -1;
#}
return Apache::OK;
}
sub _snoop_bb_dump {
my($type, $stream, $bb, $fh) = @_;
# send the sniffed info to STDERR so not to interfere with normal
# output
my $direction = $stream eq 'output' ? ">>>" : "<<<";
print $fh "\n$direction $type $stream filter\n";
bb_dump($bb, $fh);
}
sub bb_dump {
my($bb, $fh) = @_;
my @data;
for (my $b = $bb->first; $b; $b = $bb->next($b)) {
$b->read(my $bdata);
$bdata = '' unless defined $bdata;
push @data, $b->type->name, $bdata;
}
return \@data unless $fh;
unless (@data) {
print $fh " No buckets\n";
return;
}
my $c = 1;
while (my($btype, $data) = splice @data, 0, 2) {
print $fh " o bucket $c: $btype\n";
print $fh "[$data]\n";
$c++;
}
}
1;
__END__
=head1 NAME
Apache::DebugFilter - Get/Set/Unset Environment Variables on the C level
=head1 Synopsis
# httpd.conf
# ----------
PerlModule Apache::DebugFilter
# Connection snooping (everything)
PerlInputFilterHandler Apache::DebugFilter::snoop_connection
PerlOutputFilterHandler Apache::DebugFilter::snoop_connection
# HTTP Request snooping (only HTTP request body)
<Location /foo>
PerlInputFilterHandler Apache::DebugFilter::snoop_request
PerlOutputFilterHandler Apache::DebugFilter::snoop_request
</Location>
# in handlers
#------------
use Apache::DebugFilter;
# convert bb to an array of bucket_type => data pairs
my $ra_data = bb_dump($bb);
while (my($btype, $data) = splice @data, 0, 2) {
print "$btype => $data\n";
}
# dump pretty formatted bb's content to a filehandle of your choice
bb_dump($bb, \*STDERR);
=head1 Filter Handlers
=head2 C<snoop_connection()>
The C<snoop_connection()> filter handler snoops on request and
response data flow. For example if the HTTP protocol request is
filtered it'll show both the headers and the body of the request and
response.
Notice that in order to see request's input body, the response handler
must consume it.
The same handler is used for input and output filtering. It internally
figures out what kind of stream it's working on.
To configure the input snooper, add to the top level server or virtual
host configuration in httpd.conf:
PerlInputFilterHandler Apache::DebugFilter::snoop_connection
To snoop on response output, add:
PerlOutputFilterHandler Apache::DebugFilter::snoop_connection
Both can be configured at the same time.
If you want to snoop on what an output filter MyApache::Filter::output
does, put the snooper filter after it:
PerlOutputFilterHandler MyApache::Filter::output
PerlOutputFilterHandler Apache::DebugFilter::snoop_connection
On the contrary, to snoop on what an input filter
MyApache::Filter::input does, put the snooper filter before it:
PerlInputFilterHandler Apache::DebugFilter::snoop_connection
PerlInputFilterHandler MyApache::Filter::input
This is because C<snoop_connection> is going to be invoked first and
immediately call C<MyApache::Filter::input> the input filter for
data. Only when the latter returns, C<snoop_connection> will do its
work.
=head2 C<snoop_request()>
The C<snoop_request()> filter handler snoops only on HTTP request and
response bodies. Otherwise it's similar to C<snoop_connection()>. Only
normally it's configured for a specific C<E<lt>LocationE<gt>>. For
example:
<Location /foo>
PerlInputFilterHandler Apache::DebugFilter::snoop_request
PerlOutputFilterHandler Apache::DebugFilter::snoop_request
</Location>
=head1 Functions
=head2 C<bb_dump()>
my $ra_data = bb_dump($bb);
If only a bucket brigade C<$bb> is passed, C<bb_dump> will convert bb
to an array of bucket_type => data pairs, and return a reference to
it. This later can be used as in the following example:
while (my($btype, $data) = splice @data, 0, 2) {
print "$btype => $data\n";
}
If the second argument (expected to be an open filehandle) is passed,
as in:
bb_dump($bb, \*STDERR);
C<bb_dump> will print pretty formatted bb's content to that
filehandle.
=head1 Author
Stas Bekman E<lt>stas@stason.orgE<gt>
=head1 See Also
L<perl>.
=cut
__________________________________________________________________
Stas Bekman JAm_pH ------> Just Another mod_perl Hacker
http://stason.org/ mod_perl Guide ---> http://perl.apache.org
mailto:stas@stason.org http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org http://ticketmaster.com
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Re: rfc: Apache::DebugFilter
Posted by "Philippe M. Chiasson" <go...@cpan.org>.
On Tue, 2003-05-20 at 06:45, Stas Bekman wrote:
> Philippe M. Chiasson wrote:
>
> >>It will probably be useful beyond filters debug, as its base functions allow
> >>you to dump contents of buckets and brigades, which could be useful in
> >>response handlers, protocol handlers or when users create and manipulate their
> >>own brigades. So may be the name should be different, or split into several
> >>names. e.g. Apache::DebugFilter (for filters) and Apache::DebugBB (to debug
> >>bucket brigades).
> >
> >
> > Why not more simply: Apache::Debug::*, APR::Debug::* ?
> >
> > I prefer Apache::Debug::Filter to Apache::DebugFilter or
> > Apache::FilterDebug
>
> That will work. How about packaging, will Apache-Debug-Filter-0.01.tar.gz do?
Yup yup! Absolutely fine. That's just how it should be.
--
-- -----------------------------------------------------------------------------
Philippe M. Chiasson /gozer\@(cpan|ectoplasm)\.org/ 88C3A5A5 (122FF51B/C634E37B)
http://gozer.ectoplasm.org/ F9BF E0C2 480E 7680 1AE5 3631 CB32 A107 88C3 A5A5
Q: It is impossible to make anything foolproof because fools are so ingenious.
perl -e'$$=\${gozer};{$_=unpack(P7,pack(L,$$));/^JAm_pH\n$/&&print||$$++&&redo}'
Re: rfc: Apache::DebugFilter
Posted by Stas Bekman <st...@stason.org>.
Philippe M. Chiasson wrote:
>>It will probably be useful beyond filters debug, as its base functions allow
>>you to dump contents of buckets and brigades, which could be useful in
>>response handlers, protocol handlers or when users create and manipulate their
>>own brigades. So may be the name should be different, or split into several
>>names. e.g. Apache::DebugFilter (for filters) and Apache::DebugBB (to debug
>>bucket brigades).
>
>
> Why not more simply: Apache::Debug::*, APR::Debug::* ?
>
> I prefer Apache::Debug::Filter to Apache::DebugFilter or
> Apache::FilterDebug
That will work. How about packaging, will Apache-Debug-Filter-0.01.tar.gz do?
--
__________________________________________________________________
Stas Bekman JAm_pH ------> Just Another mod_perl Hacker
http://stason.org/ mod_perl Guide ---> http://perl.apache.org
mailto:stas@stason.org http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org http://ticketmaster.com
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
For additional commands, e-mail: dev-help@perl.apache.org
Re: rfc: Apache::DebugFilter
Posted by "Philippe M. Chiasson" <go...@cpan.org>.
On Mon, 2003-05-19 at 13:22, Stas Bekman wrote:
> Philippe M. Chiasson wrote:
> > On Mon, 2003-05-19 at 09:50, Stas Bekman wrote:
> >
> >>Geoffrey Young wrote:
> >>
> >>>
> >>>Stas Bekman wrote:
> >>>
> >>>
> >>>>At some point this should end up at CPAN. Comments on this module and
> >>>>requests for other filter debug handlers/functions are welcome.
> >>>>
> >>>>I've temporary added this code to t/conf/modperl_extra.pl as I find it
> >>>>quite useful to debug filter tests.
> >>>
> >>>
> >>>anything that makes filters easier is a good thing :)
> >>>
> >>>mp1 has some of these helper (Debug, SizeLimit, etc) modules in core, so
> >>>you might want to consider keeping it in core instead of CPAN (unless
> >>>you want more control over when you release new versions :)
> >>
> >>I'm not sure if we want to put it in-core. Like most modules in the perl core,
> >>they have started as CPAN modules and were put into the core after they were
> >>polished.
> >>
> >
> >
> > I'd also lean that way. If it's not required by the core itself, but
> > could be usefull. Ship it on CPAN so the people that _might_ need it can
> > get it. Most users don't need Apache::DebugFilter.
>
> It will probably be useful beyond filters debug, as its base functions allow
> you to dump contents of buckets and brigades, which could be useful in
> response handlers, protocol handlers or when users create and manipulate their
> own brigades. So may be the name should be different, or split into several
> names. e.g. Apache::DebugFilter (for filters) and Apache::DebugBB (to debug
> bucket brigades).
Why not more simply: Apache::Debug::*, APR::Debug::* ?
I prefer Apache::Debug::Filter to Apache::DebugFilter or
Apache::FilterDebug
> > Later, just make Bundle::Apache::Debug or something for the mp hackers.
> >
> > Of course, like stas said, if such a thing becomes really usefull to a
> > large proportion of mp users, then possibly move it in the core.
> __________________________________________________________________
> Stas Bekman JAm_pH ------> Just Another mod_perl Hacker
> http://stason.org/ mod_perl Guide ---> http://perl.apache.org
> mailto:stas@stason.org http://use.perl.org http://apacheweek.com
> http://modperlbook.org http://apache.org http://ticketmaster.com
--
-- -----------------------------------------------------------------------------
Philippe M. Chiasson /gozer\@(cpan|ectoplasm)\.org/ 88C3A5A5 (122FF51B/C634E37B)
http://gozer.ectoplasm.org/ F9BF E0C2 480E 7680 1AE5 3631 CB32 A107 88C3 A5A5
Q: It is impossible to make anything foolproof because fools are so ingenious.
perl -e'$$=\${gozer};{$_=unpack(P7,pack(L,$$));/^JAm_pH\n$/&&print||$$++&&redo}'
Re: rfc: Apache::DebugFilter
Posted by Stas Bekman <st...@stason.org>.
Philippe M. Chiasson wrote:
> On Mon, 2003-05-19 at 09:50, Stas Bekman wrote:
>
>>Geoffrey Young wrote:
>>
>>>
>>>Stas Bekman wrote:
>>>
>>>
>>>>At some point this should end up at CPAN. Comments on this module and
>>>>requests for other filter debug handlers/functions are welcome.
>>>>
>>>>I've temporary added this code to t/conf/modperl_extra.pl as I find it
>>>>quite useful to debug filter tests.
>>>
>>>
>>>anything that makes filters easier is a good thing :)
>>>
>>>mp1 has some of these helper (Debug, SizeLimit, etc) modules in core, so
>>>you might want to consider keeping it in core instead of CPAN (unless
>>>you want more control over when you release new versions :)
>>
>>I'm not sure if we want to put it in-core. Like most modules in the perl core,
>>they have started as CPAN modules and were put into the core after they were
>>polished.
>>
>
>
> I'd also lean that way. If it's not required by the core itself, but
> could be usefull. Ship it on CPAN so the people that _might_ need it can
> get it. Most users don't need Apache::DebugFilter.
It will probably be useful beyond filters debug, as its base functions allow
you to dump contents of buckets and brigades, which could be useful in
response handlers, protocol handlers or when users create and manipulate their
own brigades. So may be the name should be different, or split into several
names. e.g. Apache::DebugFilter (for filters) and Apache::DebugBB (to debug
bucket brigades).
> Later, just make Bundle::Apache::Debug or something for the mp hackers.
>
> Of course, like stas said, if such a thing becomes really usefull to a
> large proportion of mp users, then possibly move it in the core.
__________________________________________________________________
Stas Bekman JAm_pH ------> Just Another mod_perl Hacker
http://stason.org/ mod_perl Guide ---> http://perl.apache.org
mailto:stas@stason.org http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org http://ticketmaster.com
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
For additional commands, e-mail: dev-help@perl.apache.org
Re: rfc: Apache::DebugFilter
Posted by "Philippe M. Chiasson" <go...@cpan.org>.
On Mon, 2003-05-19 at 09:50, Stas Bekman wrote:
> Geoffrey Young wrote:
> >
> >
> > Stas Bekman wrote:
> >
> >> At some point this should end up at CPAN. Comments on this module and
> >> requests for other filter debug handlers/functions are welcome.
> >>
> >> I've temporary added this code to t/conf/modperl_extra.pl as I find it
> >> quite useful to debug filter tests.
> >
> >
> > anything that makes filters easier is a good thing :)
> >
> > mp1 has some of these helper (Debug, SizeLimit, etc) modules in core, so
> > you might want to consider keeping it in core instead of CPAN (unless
> > you want more control over when you release new versions :)
>
> I'm not sure if we want to put it in-core. Like most modules in the perl core,
> they have started as CPAN modules and were put into the core after they were
> polished.
>
I'd also lean that way. If it's not required by the core itself, but
could be usefull. Ship it on CPAN so the people that _might_ need it can
get it. Most users don't need Apache::DebugFilter.
Later, just make Bundle::Apache::Debug or something for the mp hackers.
Of course, like stas said, if such a thing becomes really usefull to a
large proportion of mp users, then possibly move it in the core.
> __________________________________________________________________
> Stas Bekman JAm_pH ------> Just Another mod_perl Hacker
> http://stason.org/ mod_perl Guide ---> http://perl.apache.org
> mailto:stas@stason.org http://use.perl.org http://apacheweek.com
> http://modperlbook.org http://apache.org http://ticketmaster.com
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
> For additional commands, e-mail: dev-help@perl.apache.org
--
-- -----------------------------------------------------------------------------
Philippe M. Chiasson /gozer\@(cpan|ectoplasm)\.org/ 88C3A5A5 (122FF51B/C634E37B)
http://gozer.ectoplasm.org/ F9BF E0C2 480E 7680 1AE5 3631 CB32 A107 88C3 A5A5
Q: It is impossible to make anything foolproof because fools are so ingenious.
perl -e'$$=\${gozer};{$_=unpack(P7,pack(L,$$));/^JAm_pH\n$/&&print||$$++&&redo}'
Re: rfc: Apache::DebugFilter
Posted by Stas Bekman <st...@stason.org>.
Geoffrey Young wrote:
>
>
> Stas Bekman wrote:
>
>> At some point this should end up at CPAN. Comments on this module and
>> requests for other filter debug handlers/functions are welcome.
>>
>> I've temporary added this code to t/conf/modperl_extra.pl as I find it
>> quite useful to debug filter tests.
>
>
> anything that makes filters easier is a good thing :)
>
> mp1 has some of these helper (Debug, SizeLimit, etc) modules in core, so
> you might want to consider keeping it in core instead of CPAN (unless
> you want more control over when you release new versions :)
I'm not sure if we want to put it in-core. Like most modules in the perl core,
they have started as CPAN modules and were put into the core after they were
polished.
__________________________________________________________________
Stas Bekman JAm_pH ------> Just Another mod_perl Hacker
http://stason.org/ mod_perl Guide ---> http://perl.apache.org
mailto:stas@stason.org http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org http://ticketmaster.com
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
For additional commands, e-mail: dev-help@perl.apache.org
Re: rfc: Apache::DebugFilter
Posted by Geoffrey Young <ge...@modperlcookbook.org>.
Stas Bekman wrote:
> At some point this should end up at CPAN. Comments on this module and
> requests for other filter debug handlers/functions are welcome.
>
> I've temporary added this code to t/conf/modperl_extra.pl as I find it
> quite useful to debug filter tests.
anything that makes filters easier is a good thing :)
mp1 has some of these helper (Debug, SizeLimit, etc) modules in core, so you
might want to consider keeping it in core instead of CPAN (unless you want
more control over when you release new versions :)
--Geoff
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