[Weekly Report] Week 5: Rhythmbox iPod/MTP Syncing

[Paul A Bellamy <paul a bellamy gmail com>]

  This last week I have been working on the Syncing function for the 
iPod.  I am using the iPod plugin as a way to prototype the syncing 
function before moving the appropriate code up to the 
RBMediaPlayerSource, and into the MTP plugin.

   I after the previous week getting preferences saving, I was focusing 
on the hashing and comparison this week, in an effort to get syncing 
functional.  For syncing we need to build two lists, one of things 
needing to be added to the iPod and one of things needing removal.  
Initially I was having some trouble building these lists.  To build 
these lists I set up two hash tables (one for iPod, one for Library), 
then do a comparison between them.  Primarily my problem was in 
populating the hash of the library contents.  In the process of sorting 
out the hashing problems I learned a lot about the way GHashTables 
work.  I initially thought that they were supposed to have no collisions 
(so I was freaking out, when it gave me tons of collisions).  
Eventually, I figured out that I was getting collisions because I had 
duplicates on my iPod.  There were a few curse words.
   The other part I was having trouble with was getting a list of 
RhythmDBEntry(s) for each playlist.  I eventually discovered 
rb_playlist_source_get_query_model() which is super-helpful, as that is 
exactly what it returns.
   I also added a function rb_ipod_source_add_entries(RBiPodSource *, 
GList *), which mirrors rb_ipod_source_trash_entries, as a way to add 
and remove multiple entries.  When I finally got it to start syncing and 
transferring files, I discovered a few bugs:
   - Undownloaded Podcasts Hang-up the Process
      - I initially thought this was a bug in my code, but 
copying/pasting undownloaded podcasts to the iPod causes it to hang also.
      - I put in a kludge to fix this in syncing for now, but should 
probably be fixed in the track transfer code somewhere.
   - There is a set of 803 songs (for me) that it wants to always re-sync.
       - I think it is a bug in the hashing functions, so that it 
thinks it has not transferred them correctly.

This week I will be working on the UI, so that it can be used to further 
test the syncing mechanism.  Part of that will be working on the 
tree-view for selection of what to sync.

Paul