/ 
Fuse-DBI-0.08
River stage zero No dependents
/ Fuse::DBI

NAME

Fuse::DBI - mount your database as filesystem and use it

SYNOPSIS

use Fuse::DBI;
Fuse::DBI->mount( ... );

See run below for examples how to set parameters.

DESCRIPTION

This module will use Fuse module, part of FUSE (Filesystem in USErspace) available at http://fuse.sourceforge.net/ to mount your database as file system.

That will give you possibility to use normal file-system tools (cat, grep, vi) to manipulate data in database.

It's actually opposite of Oracle's intention to put everything into database.

METHODS

mount

Mount your database as filesystem.

Let's suppose that your database have table files with following structure:

id:		int
filename:	text
size:		int
content:	text
writable:	boolean

Following is example how to mount table like that to /mnt:

  my $mnt = Fuse::DBI->mount({
	'filenames' => 'select id,filename,size,writable from files',
	'read' => 'select content from files where id = ?',
	'update' => 'update files set content = ? where id = ?',
	'dsn' => 'DBI:Pg:dbname=test_db',
	'user' => 'database_user',
	'password' => 'database_password',
	'invalidate' => sub { ... },
  });

Options:

filenames

SQL query which returns id (unique id for that row), filename, size and writable boolean flag.

read

SQL query which returns only one column with content of file and has placeholder ? for id.

update

SQL query with two pace-holders, one for new content and one for id.

dsn

DBI dsn to connect to (contains database driver and name of database).

user

User with which to connect to database

password

Password for connecting to database

invalidate

Optional anonymous code reference which will be executed when data is updated in database. It can be used as hook to delete cache (for example on-disk-cache) which is created from data edited through Fuse::DBI.

fork

Optional flag which forks after mount so that executing script will continue running. Implementation is experimental.

is_mounted

Check if fuse filesystem is mounted

if ($mnt->is_mounted) { ... }

umount

Unmount your database as filesystem.

$mnt->umount;

This will also kill background process which is translating database to filesystem.

fuse_module_loaded

Checks if fuse module is loaded in kernel.

die "no fuse module loaded in kernel"
	unless (Fuse::DBI::fuse_module_loaded);

This function in called by mount, but might be useful alone also.

EXPORT

Nothing.

BUGS

Size information (ls -s) is wrong. It's a problem in upstream Fuse module (for which I'm to blame lately), so when it gets fixes, Fuse::DBI will automagically pick it up.

SEE ALSO

FUSE (Filesystem in USErspace) website http://fuse.sourceforge.net/

Example for WebGUI which comes with this distribution in directory examples/webgui.pl. It also contains a lot of documentation about design of this module, usage and limitations.

AUTHOR

Dobrica Pavlinusic, <dpavlin@rot13.org>

COPYRIGHT AND LICENSE

Copyright (C) 2004 by Dobrica Pavlinusic

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.4 or, at your option, any later version of Perl 5 you may have available.