[Snap-photo-devel] faster scanning

[Jimmy D. <cri...@gm...>]

Hey guys,

So I think I've got the ScanFaster branch working pretty well. Please
check it out and see if you can break it. I'll merge it into the main
trunk if you guys approve.

Major Changes:
 * Faster scanning by storing all IPictureInfos directly into a
List<>. Previously, the database inserts during scans were slowing
things down a lot (about 4 times slower with database inserts). We now
have a separate thread that periodically syncs the current list of
IPictureInfos into a file by serializing it. SQLite is no longer used
for storing the cache because syncing the pictures to an SQLite DB
took about 20 *seconds* for only 60 pictures. With serialization, it
took less than 1 second to sync almost 1000 pictures.
Overall, for around 1900 pictures, scanning went from about 8 minutes
to 3 minutes.

 * New design also results in quicker discovery of missing files upon
startup. For example, close the app, remove all pictures, and start
the app again. Before, if you had a lot of pictures, they would slowly
disappear from the UI. Now, all removed pictures will disappear right
away.

 * Preliminary UI for showing scan progress.


Jimmy