Focus:LDAPRegistry

LDAP Global Format Registry

About Global Format Registry

The Global Format Registry (GFR) serves as a main repository for file format and application information. As GFR is mainly for querying rather than updating data inside, the Lightweight Directory Access Protocol (LDAP) was chosen to base GFR.

Among various LDAP frameworks and platforms, we chose to use OpenLDAP as our server. For Java LDAP library, we are using JLDAP from Novell. We also set up the phpLDAPadmin to provide an administrative interface to our GFR.

You can see the LDAP admin interface at http://naradev05.umiacs.umd.edu/phpldapadmin/

Design of Global Format Registry

Shown below is the LDAP hierarchy for Global Format Registry.

Each leaf node under the node with ou=Applications represents an application whereas that under the node with ou=Formats is for a file format.

A leaf node has a set of attributes that have the detailed information on the object. Two example sets of attributes for an application node and a format node are as follows.

dn: cn=PDF1.4,ou=Formats,ou=Format-registry,dc=umiacs,dc=umd,dc=edu

objectclass: frFormat
frDesc: Adobe Portable Document Format (PDF)
frSupportedLevel: Supported
frSupportedUntil: Unknown
frAlias: MIME type application/pdf
frVersion: 1.4
frOwnerName: Adobe Systems Incorporated
frOwnerType: Commercial (for-profit) entity
frWebSite: http://www.adobe.com/
frSupportedBy: Adobe Systems Incorporated
frSignObligation: Optional
frSignType: Extension
frSignValue: .pdf
frReader: cn=AdobeAcrobatReader_v5.0,ou=Applications,ou=format-registry,dc=umiacs,dc=umd,dc=edu
frReader: cn=AdobeAcrobatProf_v5.0,ou=Applications,ou=format-registry,dc=umiacs,dc=umd,dc=edu
frWriter: cn=AdobeAcrobatProf_v5.0,ou=Applications,ou=format-registry,dc=umiacs,dc=umd,dc=edu
frWriter: cn=AdobeAcrobatReader_v5.0,ou=Applications,ou=format-registry,dc=umiacs,dc=umd,dc=edu
frVerifier: cn=JHOVE,ou=Applications,ou=format-registry,ou=adapt,dc=umiacs,dc=umd,dc=edu
frConverter: cn=pdf2doc_1,ou=Applications,ou=format-registry,ou=adapt,dc=umiacs,dc=umd,dc=edu
frConverter: cn=pdf2doc_2,ou=Applications,ou=format-registry,ou=adapt,dc=umiacs,dc=umd,dc=edu
frConverter: cn=pdf2tiff_1,ou=Applications,ou=format-registry,ou=adapt,dc=umiacs,dc=umd,dc=edu
frConverter: cn=pdf2jpeg_1,ou=Applications,ou=format-registry,ou=adapt,dc=umiacs,dc=umd,dc=edu
frConverter: cn=pdf2ps_1,ou=Applications,ou=format-registry,ou=adapt,dc=umiacs,dc=umd,dc=edu
cn: PDF1.4

dn: cn=AdobeAcrobatReader_v6,ou=Applications,ou=Format-registry,dc=umiacs,dc=umd,dc=edu

objectclass: frApplication
frDesc: Adobe Acrobat Reader
frVersion: 6.0
frSupportedLevel: Supported
frSupportedUntil: Unknown
frOwnerName: Adobe Systems Incorporated
frOwnerType: Commercial
frWebSite: http://www.adobe.com
frOperatingSystem: Windows95,NT4.0 ME,2000
frCategory: Reader
frServiceType: Stand-alone
frFormatRead: cn=PDF1.4,ou=Formats,ou=Format-registry,dc=umiacs,dc=umd,dc=edu
frFormatRead: cn=PDF1.3,ou=Formats,ou=Format-registry,dc=umiacs,dc=umd,dc=edu
frFormatRead: cn=PDF1.2,ou=Formats,ou=Format-registry,dc=umiacs,dc=umd,dc=edu
frFormatRead: cn=PDF1.1,ou=Formats,ou=Format-registry,dc=umiacs,dc=umd,dc=edu
frFormatRead: cn=PDF1.0,ou=Formats,ou=Format-registry,dc=umiacs,dc=umd,dc=edu
frFormatWritten: cn=PDF1.4,ou=Formats,ou=Format-registry,dc=umiacs,dc=umd,dc=edu
cn: !AdobeAcrobatReader_v6