Re: libapreq2 upload gotcha

[Stas Bekman]

John Williams wrote:
I've been having problems getting uploads to work using libapreq2-2.03_04-dev.
I finally have it working, but I thought I would post my story for the benefit
of others.
Originally I was doing the upload like this:
        my $bb = $r->upload('file')->bb();
        open(OUT,">/tmp/test_file");
        while (1) {
                my $b = $bb->first;
                last unless $b;
                $b->remove;
                my $data;
                $b->read($data);
                print OUT $data;
        }
        close OUT;
Small files were working ok, but large files where being truncated at about 270k
(which is suspiciously close to the 256k "zero copy limit" I saw mentioned on
[EMAIL PROTECTED]).
Interesting. What's the type of the bucket? Is that a file bucket? Try 
this code:

use APR::Brigade ();
use APR::Bucket ();
use APR::BucketType ();
my $bb = $r->upload('file')->bb();
bb_dump($bb);
sub bb_dump {
    my($bb) = @_;
    my @data;
    for (my $b = $bb->first; $b; $b = $bb->next($b)) {
        $b->read(my $bdata);
        push @data, $b->type->name, $bdata;
    }
    unless (@data) {
        print STDERR "  No buckets\n";
        return;
    }
    my $c = 1;
    while (my($btype, $data) = splice @data, 0, 2) {
        print STDERR "    o bucket $c: $btype\n";
        print STDERR "[$data]\n";
        $c++;
    }
}
To make a long story short, here is the version that works:
        my $bb = $r->upload('file')->bb();
        open(OUT,">/tmp/test_file");
        while (1) {
                my $b = $bb->first;
                last unless $b;
                my $data;
                $b->read($data);
                print OUT $data;
                $b->remove;      # <--- ta da!
        }
        close OUT;
Notice that the only thing which changed was the position of the $b->remove
call.  Call it too soon and your upload is unreliable.

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Stas Bekman            JAm_pH ------> Just Another mod_perl Hacker
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