Dirty entity identification.

[Derek Atkins]

Neil Williams <linux at codehelp.co.uk> writes:

> At no time can the set_clean functions be public, these are reserved for the 
> backends. There is no situation where the UI can be allowed to set the book 
> to clean without going through a Save.

Actually that's not true.  An "exit without save" might need to do it,
too.

David: I should point out for clarity that the current implementation
of "is the book dirty" does not do a full object search; it's not
searching _through_ the collections, it's just iterating over the set
of Collections and looking at the metadata on each Collection (not
each object in each collection).  So, this is still pretty fast, as
Neil said.  I don't think we need to cache that information at this
point; checking the metadata on the dozen Collections doesn't take
much time.

-derek
-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
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