Collabrary Toolkit for Multimedia Groupware

Collabrary Toolkit for Multimedia Groupware Michael Boyle Saul Greenberg University of Calgary

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

What is the Shared Dictionary? • Notification Server + Persistent Data • Hierarchy of key/value pairs • Subscription-based notifications • Central-server architecture • Simple, flexible programmatic API

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

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

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

Automagic • Reconnection on network failure • Data tied to client lifetimes Example: SD.Open “tcp://myserver.com:TestDictionaryName

Shared Dictionary Advantages • Simple API • Integrated support for multimedia • Performance • Persistence

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 aren’t needed for prototyping groupware!

Shared Dictionary In Action • Examples • Notification Collage • Graffiti Video Conferencing

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

Collabrary Toolkit for Multimedia Groupware