[Scid-users] Re: Scid-users digest, Vol 1 #110 - 3 msgs (scid bookmarking ideas)

[Michael T. <zg...@be...>]

Shawn K. Quinn wrote:
This could be solved by adding a 32-bit unique game ID to each game and
keying the bookmark off of that. 
Tying a unique game identifier to each game which is guaranteed never to
change (and keeping track of each number thus used) would pretty much
quash the current issue with game numbers that get changed every time
the database is resorted.

John Wiegley replied:

When a database is changed, it knows any bookmarks related to it will
need to be changed.  Thus, before every changing operation, it should
build a very small table of "database index -> bookmark -> game".
Then, every time an index changes, look it up in the table, and adjust
the bookmarks accordingly.  If the code for this can be placed at a
very basic level (generic database operations), then the database
would stay in sync with the bookmarks at all times.

Doing it the other way around, where the database itself has to know
at all times what the bookmark relationships are, seems like a huge
waste of space.  The moments in time when the knowledge is required
are very few, so it's worth the little bit of extra CPU to handle the
updating then.

Michael Thomas replied:

    Makes sense to me. One or two extra functions to the sorting routines.