NAME
APR::Brigade - Perl API for manipulating APR Bucket Brigades
Synopsis
use APR::Brigade ();
$bb = APR::Brigade->new($r->pool, $c->bucket_alloc);
$ba = $bb->bucket_alloc();
$pool = $bb->pool;
$bb->insert_head($b);
$bb->insert_tail($b);
$b_first = $bb->first;
$b_last = $bb->last;
$b_prev = $bb->prev($b_last);
$b_next = $bb->next($b);
$bb2 = APR::Brigade->new($r->pool, $c->bucket_alloc);
$bb1->concat($bb2);
$len = $bb->flatten($data);
$len = $bb2->flatten($data, $wanted);
$len = $bb->length;
$bb3 = $bb->split($b_last);
last if $bb->is_empty();
$bb->cleanup();
$bb->destroy();
Description
APR::Brigade
allows you to create, manipulate and delete APR bucket brigades.
API
APR::Brigade
provides the following functions and/or methods:
cleanup
Empty out an entire bucket brigade:
$bb->cleanup;
- obj:
$bb
(APR::Brigade object
) -
The brigade to cleanup
- ret: no return value
- since: 2.0.00
This method destroys all of the buckets within the bucket brigade's bucket list. This is similar to destroy()
, except that it does not deregister the brigade's pool()
cleanup function.
Generally, you should use destroy()
. This function can be useful in situations where you have a single brigade that you wish to reuse many times by destroying all of the buckets in the brigade and putting new buckets into it later.
concat
Concatenate brigade $bb2
onto the end of brigade $bb1
, leaving brigade $bb2
empty:
$bb1->concat($bb2);
- obj:
$bb1
(APR::Brigade object
) -
The brigade to concatenate to.
- arg1:
$bb2
(APR::Brigade object
) -
The brigade to concatenate and empty afterwards.
- ret: no return value
- since: 2.0.00
destroy
destroy an entire bucket brigade, includes all of the buckets within the bucket brigade's bucket list.
$bb->destroy();
- obj:
$bb
(APR::Brigade object
) -
The bucket brigade to destroy.
- ret: no return value
- excpt:
APR::Error
- since: 2.0.00
is_empty
Test whether the bucket brigade is empty
$ret = $bb->is_empty();
- obj:
$bb
(APR::Brigade object
) - ret:
$ret
( boolean ) - since: 2.0.00
first
Return the first bucket in a brigade
$b_first = $bb->first;
- obj:
$bb
(APR::Brigade object
) - ret:
$b_first
(APR::Bucket object
) -
The first bucket in the bucket brigade
$bb
.undef
is returned if there are no buckets in$bb
. - since: 2.0.00
flatten
Get the data from buckets in the bucket brigade as one string
$len = $bb->flatten($buffer);
$len = $bb->flatten($buffer, $wanted);
- obj:
$bb
(APR::Brigade object
) - arg1:
$buffer
( SCALAR ) -
The buffer to fill. All previous data will be lost.
- opt arg2:
$wanted
( number ) -
If no argument is passed then all data will be returned. If
$wanted
is specified -- that number or less bytes will be returned. - ret:
$len
( number ) -
How many bytes were actually read.
$buffer
gets populated with the string that is read. It will contain an empty string if there was nothing to read. - since: 2.0.00
- excpt:
APR::Error
insert_head
Insert a list of buckets at the front of a brigade
$bb->insert_head($b);
- obj:
$bb
(APR::Brigade object
) -
Brigade to insert into
- arg1:
$b
(APR::Bucket object
) -
the bucket to insert. More buckets could be attached to that bucket.
- ret: no return value
- since: 2.0.00
insert_tail
Insert a list of buckets at the end of a brigade
$bb->insert_tail($b);
- obj:
$bb
(APR::Brigade object
) -
Brigade to insert into
- arg1:
$b
(APR::Bucket object
) -
the bucket to insert. More buckets could be attached to that bucket.
- ret: no return value
- since: 2.0.00
last
Return the last bucket in the brigade
$b_last = $bb->last;
- obj:
$bb
(APR::Brigade object
) - ret:
$b_last
(APR::Bucket object
) -
The last bucket in the bucket brigade
$bb
.undef
is returned if there are no buckets in$bb
. - since: 2.0.00
length
Return the total length of the data in the brigade (not the number of buckets)
$len = $bb->length;
- obj:
$bb
(APR::Brigade object
) - ret:
$len
( number ) - since: 2.0.00
new
my $nbb = APR::Brigade->new($p, $bucket_alloc);
my $nbb = $bb->new($p, $bucket_alloc);
- obj:
$bb
(APR::Brigade object or class
) - arg1:
$p
(APR::Pool object
) - arg2:
$bucket_alloc
(APR::BucketAlloc object
) - ret:
$nbb
(APR::Brigade object
) -
a newly created bucket brigade object
- since: 2.0.00
Example:
Create a new bucket brigade, using the request object's pool:
use Apache2::Connection ();
use Apache2::RequestRec ();
use APR::Brigade ();
my $bb = APR::Brigade->new($r->pool, $r->connection->bucket_alloc);
bucket_alloc
Get the bucket allocator associated with this brigade.
my $ba = $bb->bucket_alloc();
- obj:
$bb
(APR::Brigade object or class
) - ret:
$ba
(APR::BucketAlloc object
) - since: 2.0.00
next
Return the next bucket in a brigade
$b_next = $bb->next($b);
- obj:
$bb
(APR::Brigade object
) - arg1:
$b
(APR::Bucket object
) -
The bucket after which the next bucket
$b_next
is located - ret:
$b_next
(APR::Bucket object
) -
The next bucket after bucket
$b
.undef
is returned if there is no next bucket (i.e.$b
is the last bucket). - since: 2.0.00
pool
The pool the brigade is associated with.
$pool = $bb->pool;
- obj:
$bb
(APR::Brigade object
) - ret:
$pool
(APR::Pool object
) - since: 2.0.00
The data is not allocated out of the pool, but a cleanup is registered with this pool. If the brigade is destroyed by some mechanism other than pool destruction, the destroying function is responsible for killing the registered cleanup.
prev
Return the previous bucket in the brigade
$b_prev = $bb->prev($b);
- obj:
$bb
(APR::Brigade object
) - arg1:
$b
(APR::Bucket object
) -
The bucket located after bucket
$b_prev
- ret:
$b_prev
(APR::Bucket object
) -
The bucket located before bucket
$b
.undef
is returned if there is no previous bucket (i.e.$b
is the first bucket). - since: 2.0.00
split
Split a bucket brigade into two, such that the given bucket is the first in the new bucket brigade.
$bb2 = $bb->split($b);
- obj:
$bb
(APR::Brigade object
) -
The brigade to split
- arg1:
$b
(APR::Bucket object
) -
The first bucket of the new brigade
- ret:
$bb2
(APR::Brigade object
) -
The new brigade.
- since: 2.0.00
This function is useful when a filter wants to pass only the initial part of a brigade to the next filter.
Example:
Create a bucket brigade with three buckets, and split it into two brigade such that the second brigade will have the last two buckets.
my $bb1 = APR::Brigade->new($r->pool, $c->bucket_alloc);
my $ba = $c->bucket_alloc();
$bb1->insert_tail(APR::Bucket->new($ba, "1"));
$bb1->insert_tail(APR::Bucket->new($ba, "2"));
$bb1->insert_tail(APR::Bucket->new($ba, "3"));
$bb1
now contains buckets "1", "2", "3". Now do the split at the second bucket:
my $b = $bb1->first; # 1
$b = $bb1->next($b); # 2
my $bb2 = $bb1->split($b);
Now $bb1
contains bucket "1". $bb2
contains buckets: "2", "3"
See Also
Copyright
mod_perl 2.0 and its core modules are copyrighted under The Apache Software License, Version 2.0.