Collabrary Toolkit for Multimedia Groupware

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Collabrary Toolkit for Multimedia Groupware

• Michael Boyle
• Saul Greenberg
• University of Calgary

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What is the Collabrary?

• COM object library
• Rapid prototyping of novel, multimedia groupware
• Multimedia capture, analysis, manipulation
• Shared Dictionary (network service)

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What is the Shared Dictionary?

• Notification Server Persistent Data
• Hierarchy of key/value pairs
• Subscription-based notifications
• Central-server architecture
• Simple, flexible programmatic API

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Programmatic API

• Looks like a typical dictionary/hash table
• String keys look like file-system paths

Client 1 SD(/users/joe/name) Joe Smith
/users/joe/name /users/joe/photo /users/mary/email

Client 2 /users/joe/name changed
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Programmatic API

• Subscriptions asynchronous notifications
• Glob-like pattern-matching language

Dim Subscr As Subscription Set Subscr
SD.Subscribe(/users//name) Subscr_Notified(key
,inst,val,reason,prev) Update GUI to reflect
change in user name End
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Automagic

• Data marshalling
• Primitives 54.25, Hello world!
• Complex data types
• Pictures
• Sounds
• Binary data 01293ab92c03f023d
• Structs and marshal-by-value objects

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Automagic

• Reconnection on network failure
• Data tied to client lifetimes

Example SD.Open tcp//myserver.comTestDictionar
yName
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Shared Dictionary Advantages

• Simple API
• Integrated support for multimedia
• Performance
• Persistence

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Absent from the Shared Dictionary

• Authentication and authorization
• Encryption (possible, but not automatic)
• Sophisticated concurrency control algorithms
• Transactions
• Super-high scalability (e.g., federations)
• These arent needed for prototyping groupware!

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Shared Dictionary In Action

• Examples
• Notification Collage
• Graffiti Video Conferencing

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Summary

• Collabrary toolkit for prototyping multimedia
  groupware
• Notifications Persistence Multimedia
• Flexible, feature-rich design
• Simple programmatic interface