Hello,
at first sorry for a quite longer mail(and for a bad english).
I am a student working on a project including an apache output filter. I
encountered a strange behavior of a bucket brigade
when it is traversed from the last bucket (APR_BRIGADE_LAST(..)) to the first
one (APR_BRIGADE_FIRST(..)) using
APR_BUCKET_PREV(..).
For testing purposes I splitted incoming bucket brigade (size 18567) using:
b=APR_BRIGADE_FIRST(bb);
if(apr_bucket_split(b,100)!=APR_SUCCESS) my_error(1);
b=APR_BUCKET_NEXT(b);
if(apr_bucket_split(b,100)!=APR_SUCCESS) my_error(2);
b=APR_BUCKET_NEXT(b);
if(apr_bucket_split(b,100)!=APR_SUCCESS) my_error(3);
Then I try to traverse the brigade from the last bucket to the first one:
b=APR_BRIGADE_LAST(bb);
while(b!=APR_BRIGADE_SENTINEL(bb)) {
..dump the contents of bucket into file to see it's contents
b=APR_BUCKET_PREV(b);
}
I got a set of files with the contents of individual buckets.
Then I traverse the brigade from the first bucket to the last one:
b=APR_BRIGADE_FIRST(bb);
while(b!=APR_BRIGADE_SENTINEL(bb)) {
..dump the contents of bucket into file to see it's contents
b=APR_BUCKET_NEXT(b);
}
I got an another set files with the contents of individual buckets.
The problem is, that the bucket contents set I get when traversing from the
last to the first is not complete.
This way I get five files sized 0, 8000, 100, 100 and 100 -> that is 8300 total
instead of 16888
While traversing from the first to the last I got 7 files sized 100, 100, 100,
8000, 8000 and 2267
-> that is correctly 18567.
I wonder, why there is a difference. The contents of corresponding files are
right. After a brief look
into the apache sources (apr_bucket_shared_split, apr_bucket_simple_split,
APR_BUCKET_INSERT_AFTER,
APR_RING_INSERT_AFTER, APR_RING_SPLICE_AFTER) everything seems OK to me
(connecting buckets).
Please does anyone have an idea why this is not working? Is the way I split the
buckets correct?
I am not sure if it is a bug in apache or in my code. I use apache 2.0.55 from
debian testing.
I look forward to any reply, greetings
Vlastimil Pavicek, CTU Prague
