File metadata format draft-garcia-app-area-file-data-format-00.txt

1
File metadata formatdraft-garcia-app-area-file-da
ta-format-00.txt

• 70th IETF
• Applications Area Open meeting WG
• December 2007
• Miguel Garcia ltmiguel.garcia_at_nsn.comgt
• Marcin Matuszewski ltmarcin.matuszewski_at_nokia.comgt

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Background

• Effort started as a next step in the SIP file
  transfer functionality
• We already have a file transfer mechanism with
  SIP/SDP
• draft-ietf-mmusic-file-transfer-mech-05.txt
• It allows to do a exchange of SDP bodies
  describing a file to be exchanged.
• Unable to instantiate all use cases with a
  standard SIP protocol
• Remote file directory
• Subscription to a picture collection available in
  a mobile phone
• Sharing a folder in commercial instant messaging
  systems

• Why SIP? See the (expired) draft
• draft-garcia-sipping-general-events-00.txt
• Work is ongoing in solving these use cases
• draft-garcia-sipping-file-sharing-framework-01.txt
  
• draft-garcia-sipping-file-event-package-01.txt
• draft-garcia-sipping-file-desc-pidf-01.txt
• An XML data format to describe file metadata is
  required
• The data format is independent of SIP.
• Can be used for HTTP and other protocols
• Can be used for catalogs of files

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Full file-metadata XML document

• A file XML document contains descriptions of one
  or more files
• Each file is modeled as an identity and one or
  more instances
• The identity describes the immutable properties
  of the file
• MIME type
• Size
• Hash
• URN
• The instance describes metadata associated to the
  file and the endpoint that hosts the resource
• URI
• Name
• Description
• Icon
• creation/modification/read date
• keywords

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Full file-metadata XML document

• lt?xml version"1.0" encoding"UTF-8"?gt
• ltfile-set xmlns"urnietfparamsxmlnsfile
  " version"123"gt
• ltfile id"id38sh12jd"gt
• ltidentity id"id9d8c9"gt
• ltmime-typegtimage/jpeglt/mime-typegt
• ltsizegt230432lt/sizegt
• ltsha1gt72245FE8653DDAF371362F86D4719
  13EE4A2CE2Elt/sha1gt
• ltidentitygt
• ltinstance id"idc989c00"gt
• ltnamegtcoolpic.jpglt/namegt
• ltdescriptiongtThis is my latest
  cool picture from my summer vacationlt/descriptiongt
  
• ltuser-urigtsipmiguel.garcia_at_example
  .comlt/user-urigt
• ltuser-gruugtsipmiguel.garcia_at_example
  .comgrurnuuidf81d4fae-7dec-11d0-a765-00a0c91e6
  bf6lt/user-gruugt
• lticon-ptrgthttp//www.example.com/co
  olpic-icon.jpglt/icon-ptrgt
• ltcreation-dategt2006-05-09T093047
  0300lt/creation-dategt
• ltmodification-dategt2006-05-09T1024
  340300lt/modification-dategt
• ltread-dategt2006-05-10T142432030
  0lt/read-dategt
• ltkeywordsgt

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Partial in File-Metadata document

• The file-metadata document can also express
  partial changes with respect a previous version.
• Reuses the XML Patch Operations framework
• draft-ietf-simple-xml-patch-ops-04.txt
• Useful with periodic notifications
• Example
• lt?xml version"1.0" encoding"UTF-8"?gt
• ltpatch xmlns"urnietfparamsxmlnsfile"
  version"313"gt
• ltadd sel"file-set/file_at_id'nkcdn0'"gt
• ltinstance id"ak6v3d"gt
• ltnamegtnanotalk.3gplt/namegt
• ltdescriptiongtNanotechnology speechlt/description
  gt
• ltuser-gruugtsipbob_at_example.comgrurnuuidf81d
  4fae-7dec-11d0-5d3a-bbc333431122lt/user-gruugt
• ltuser-urigtsipbob_at_example.comlt/user-urigt
• lt/instancegt
• lt/addgt
• ltreplace sel"id('idea1dof')/read-date/text()"gt20
  06-06-07T1726040300lt/replacegt
• ltreplace sel"file-set/timestamp"gt
• lttimestampgt2007-11-12T180202Zlt/timestampgt

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The questions

• Do we (IETF) need to define a general format for
  describing files?
• If so, how to deal with other similar formats?
• Webdav properties
• METS (Metadata Encoding and Transmission
  Standard)
• MIME
• Perhaps others
• How to continue the work?