Introducing FSter

FSterGuglielmo’s Hyper File System

Lorenzo Bellini, Roberto Guido,Marco Loregian, Michele Tameni

<name.surname>@itsme.it

Itsme – Fster: Guglielmo's Hyper File System 2

What is FSter?

➔FSter is a virtual file system implementation, based on Fuse technology and exploiting Tracker metadata technology to allow access to files according to the metadata they’re associated to


Sample scenarios

➔Browsing the content of a drive, according to a user-defined hierarchy based on metadata;

➔Associating metadata to files whenever operations are performed on them;

➔Generating “virtual” files from metadata, e.g., a vCard file dynamically built from metadata


Requirements anddomain architecture

FSter uses libtracker-client to build and execute sparql query on tracker-store

Queries are built according to a user-defined (XML) filesystem hierarchy


Configuration file

➔A configuration file defines what the user will see in FSter directories

➔Configuration files must follow XML 1.0 standards➔An XML schema of the configuration file is avalaible (Fster.xsd)


Xml element: folder

➔Shows each RDF subject matching with defined conditions as a folder and:

➔defines both inheritable and self conditions➔Allows generating a folder name from metadata➔allows nesting content object inside it➔defines editing policies for the content


Xml element: set_folder

➔Shows each RDF object used with a specific RDF predicate as a folder and:

➔defines a RDF predicate to get the set of RDF objects used with it➔defines inheritable conditions➔allows nesting content objects inside it➔defines the editing policies of the content


Xml element: file

➔Shows each RDF subject matching with defined conditions as a file and:

➔defines self conditions➔Allows generating a file name from metadata➔defines whether to expose the real file or a dump of file metadata from the repository


Examples: Fster media library (1)➔Media grouped by images, audio and video


Examples: Fster media library (2)➔Building the SPARQL query for folder element

static GList* collect_children_from_storage (HierarchyNode *node, ItemHandler *parent){

(..)

more_statements = condition_policy_to_sparql (&(node->priv->self_policy), parent, &values_offset);statements = g_list_concat (statements, more_statements);if (node->priv->child_policy.inherit == TRUE) { parent_node = node->priv->node; while (parent_node != NULL) { more_statements = condition_policy_to_sparql (&(parent_node->priv->child_policy), parent, &values_offset); statements = g_list_concat (statements, more_statements); if (parent_node->priv->child_policy.inherit == TRUE) parent_node = parent_node->priv->node; else break; } } sparql = build_sparql_query (NULL, var, statements);

(..)

}


Examples: Fster media library (3)➔ <condition metadata="rdf:type" value="nfo:Audio" />

<name value="$self{nie:title}" />

SELECT ?item ?a WHERE { ?item nie:title ?a . ?item rdf:type nfo:Audio }

➔ <condition metadata="rdf:type" value="nfo:Image" /><name value="$self{nfo:fileName}" />

SELECT ?item ?a WHERE { ?item nfo:fileName ?a . ?item rdf:type nfo:Image }

➔ <condition metadata="rdf:type" value="nfo:Video" /><name value="$self{nfo:fileName}" />

SELECT ?item ?a WHERE { ?item nfo:fileName ?a . ?item rdf:type nfo:Video }


Examples: Fster music library (1)➔Music grouped by artist, album or genre


Examples: Fster music library (2)➔Building the SPARQL query for folder_set element

static GList* collect_children_set (HierarchyNode *node, ItemHandler *parent){

(..)

statements = g_list_append (statements, g_strdup_printf ("?item %s ?a", node->priv->additional_option));more_statements = condition_policy_to_sparql (&(node->priv->self_policy), parent, &values_offset);statements = g_list_concat (statements, more_statements);if (node->priv->child_policy.inherit == TRUE) { parent_node = node->priv->node; while (parent_node != NULL) { more_statements = condition_policy_to_sparql (&(parent_node->priv->child_policy), parent, &values_offset); statements = g_list_concat (statements, more_statements); if (parent_node->priv->child_policy.inherit == TRUE) parent_node = parent_node->priv->node; else break; }}sparql = build_sparql_query ("SELECT DISTINCT(?a)", 'a', statements);

(..)

}


Examples: Fster music library (3)➔ <folder>

<condition metadata="rdf:type" value=" nmm:MusicAlbum" />

SELECT ?item ?a WHERE { ?item nmm:albumTitle ?a . ?item rdf:type nmm:MusicAlbum }

➔ <condition metadata="nmm:musicAlbum" value="$parent{/subject}" />

SELECT ?item ?a WHERE { ?item nie:title ?a . ?item nmm:musicAlbum "urn:album:Ci%20Vuole%20Orecchio" }

➔ <set_folder metadata="nfo:genre">

SELECT DISTINCT(?a) WHERE { ?item nfo:genre ?a }

➔ <condition metadata="nfo:genre" value="$parent{nfo:genre}" />

SELECT ?item ?a WHERE { ?item nie:title ?a . ?item nfo:genre "Folk" }


Examples: Fster music library (4)


Future development

➔SparQL in the <condition> tag

➔Plugin architecture allowing FSter to render metadata exposing them in standard format files (e.g., vcard, ...);

➔User-friendly configuration editing interface

➔Creation of folders


References

➔Code: http://gitorious.org/itsme/fster

➔Wiki: http://gitorious.org/itsme/pages/Fster

➔Mailing lists: http://lists.itsme.it/

➔Support: #itsme-dev on irc.freenode.net

Thank you for your attention

www.itsme.it

Lorenzo Bellini, Roberto Guido,Marco Loregian, Michele Tameni<name.surname>@itsme.it

Introducing FSter

Technology

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