NAME

       HTTP::Proxy::FilterStack - A class to manage filter stacks

DESCRIPTION

       This class is used internally by HTTP::Proxy to manage its four filter stacks.

       From the point of view of HTTP::Proxy::FilterStack, a filter is actually a ("matchsub", "filterobj")
       pair. The match subroutine (generated by HTTP::Proxy's "push_filter()" method) is run against the current
       HTTP::Message object to find out which filters must be kept in the stack when handling this message.

       The filter stack maintains a set of buffers where the filters can store data. This data is appended at
       the beginning of the next chunk of data, until all the data has been sent.

METHODS

       The class provides the following methods:

       new( $isbody )
           Create a new instance of HTTP::Proxy::FilterStack. If $isbody is true, then the stack will manage
           body filters (subclasses of HTTP::Proxy::BodyFilter).

       select_filters( $message )
           $message is the current HTTP::Message handled by the proxy.  It is used (with the help of each
           filter's match subroutine) to select the subset of filters that will be applied on the given message.

       filter( @args )
           This method calls all the currently selected filters in turn, with the appropriate arguments.

       filter_last()
           This method calls all the currently selected filters in turn, to filter the data remaining in the
           buffers in a single pass.

       will_modify()
           Return a boolean value indicating if the list of selected filters in the stack will modify the body
           content. The value is computed from the result of calling "will_modify()" on all selected filters.

       all()
           Return a list of all filters in the stack.

       eod()
           Used for END OF DATA bookkeeping.

       push()
           Push the given "[ match, filterobj ]" pairs at the top of the stack.

       insert( $idx, @pairs )
           Insert the given "[ match, filterobj ]" pairs at position $idx in the stack.

       remove( $idx )
           Remove the "[ match, filterobj ]" pair at position $idx in the stack.

AUTHOR

       Philippe "BooK" Bruhat, <book@cpan.org>.

COPYRIGHT

       Copyright 2002-2015, Philippe Bruhat.

LICENSE

       This module is free software; you can redistribute it or modify it under the same terms as Perl itself.