=head1 NAME

Data::Hub::FileSystem::Node - 

=head1 SYNOPSIS



=head1 EXPORTS

Nothing exported by default

=over



=back

=head1 DEPENDENCIES

This module requires these other modules and libraries:

    Error::Logical
    Error::Programatic
    Perl::Module
    Fcntl
    Data::Hub::Util
    Data::Hub::Container
    Data::Hub::FileSystem::AccessLog
    Data::OrderedHash
    Tie::Hash

=head1 DESCRIPTION




=head1 PUBLIC INTERFACE

=head2 Add_Handler

=over

=item Add a filesystem node handler




criteria:


  -type=d         # Directory
  -type=f         # Regular file
  -type=T         # Text file
  -type=B         # Binary file
  -type=!         # Does not exist
  -path=$regex    # Path (with filename) matches $regex
  -crown=$regex   # File's crown matches $regex




=back


=head2 new

=over

=item Consructor






=back


=head2 get_path

=over

=item Return the full physical path to this node.



Base method.



=back


=head2 get_addr

=over

=item Return the full physical path to this node.



Base method.



=back


=head2 get_name

=over

=item Return the file name of this node.



Base method.



=back


=head2 get_type

=over

=item Return the Hub type signature for this node



Base method.



=back


=head2 set_data

=over

=item Set the data segment of this node






=back


=head2 get_data

=over

=item Return the data segment of this node






=back


=head2 set_content

=over

=item Set the content segment of this node






=back


=head2 get_content

=over

=item Return the content segment of this node






=back


=head2 set_raw_content

=over

=item Set the literal contents






=back


=head2 get_raw_content

=over

=item Return the literal contents






=back


=head2 get_stat

=over

=item Get the stat record for this node






=back


=head2 get_mtime

=over

=item Modified time of persistent storage






=back


=head2 save

=over

=item Save changes made to this node






=back


=head2 expire

=over

=item Detect changes made in persistent storage on next access






=back


=head2 refresh

=over

=item Detect changes made in persistent storage






=back


=head2 reload

=over

=item Force this node to reload itself






=back


=head2 is_valid

=over

=item Are we still a valid handler for this path?






=back


=head1 PACKAGE INTERNALS

=head2 TIEHASH

=over

=item See C<perltie>






=back


=head2 FIRSTKEY

=over

=item See C<perltie>



Scan for changes. This allows cached instances to refresh themselves upon 
member access.



=back


=head2 FETCH

=over

=item See C<perltie>



Scan for changes.



=back


=head2 EXISTS

=over

=item See C<perltie>



Scan for changes.



=back


=head2 STORE

=over

=item See C<perltie>



Scan for changes and update modified time.



=back


=head2 DELETE

=over

=item See C<perltie>



Scan for changes and update modified time.



=back


=head2 SCALAR

=over

=item See C<perltie>



Scan for changes and return node contents.



=back


=head2 __read_from_disk

=over

=item Read instance data from persistent storage



Base method.



=back


=head2 __write_to_disk

=over

=item Write instance data to persistent storage



Abstract base method.



=back


=head2 __scan

=over

=item Read from disk if necessary




When C<$key> is provided, this resource is then instantiated if necessary.
This allows L<Data::Hub::FileSystem::Directory> to maintain a key/value pair of
filename/undef when reading the directory and delay instantiating (and hence
recursively reading) the value until it is called upon.



=back



=head1 AUTHORS

    Ryan Gies <ryangies@cpan.org>

=head1 COPYRIGHT

    Copyright (C) 2014-2016 by Ryan Gies. All rights reserved.
    Copyright (C) 2006-2013 by Livesite Networks, LLC. All rights reserved.
    Copyright (C) 2000-2005 by Ryan Gies. All rights reserved.
    Redistribution and use in source and binary forms, with or without 
    modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright notice, 
    this list of conditions and the following disclaimer.
    * The origin of this software must not be misrepresented; you must not 
    claim that you wrote the original software. If you use this software in a 
    product, an acknowledgment in the product documentation would be 
    appreciated but is not required.
    * Altered source versions must be plainly marked as such, and must not be 
    misrepresented as being the original software.
    * The name of the author may not be used to endorse or promote products 
    derived from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED 
    WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
    MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 
    EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
    OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
    IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
    OF SUCH DAMAGE.
    To the best of our knowledge, no patented algorithms have been used. However, we
    do not have the resources to carry out a patent search, and therefore cannot 
    give any guarantee of the above statement.

=cut

