/**
* Adds songs which did not get any rating data assigned for a long time (or never) to the
* {proposedSongs} list. This ensures reaching regions in the music space which are not explored
* yet (or have been forgotten about).<br>
* The agents vote for these songs is set to {@value #LONG_NOT_RATED_SONG_VOTE}.
*
* @param proposedSongs The proposal list
* @param agentVotes The votes list
*/
private void addLongTimeNotListenedSongProposals() {
// Fetch long not rated songs
List<BaseSong<BaseArtist, BaseAlbum>> longNotRatedSongs;
try {
longNotRatedSongs =
statisticsProvider.getLongNotRatedSongs(
LONG_NOT_RATED_SONG_COUNT, LONG_NOT_RATED_THRESHOLD);
} catch (DataUnavailableException e) {
// Just ignore the warning and do not add any songs
Log.w(getTag(), e);
longNotRatedSongs = new LinkedList<BaseSong<BaseArtist, BaseAlbum>>();
}
// Prepare agent votes for songs
Map<IAgent, Float> agentVotesForProposedSongs = new HashMap<IAgent, Float>();
for (IAgent agent : agentManager.getAgents()) {
agentVotesForProposedSongs.put(agent, (float) LONG_NOT_RATED_SONG_VOTE);
}
// Add long not played songs as proposals
for (BaseSong<BaseArtist, BaseAlbum> song : longNotRatedSongs) {
proposedSongs.add(song);
songVotes.put(song, LONG_NOT_RATED_SONG_VOTE);
agentVotesBySong.put(song, agentVotesForProposedSongs);
}
}
/**
* Returns the set of songs which are proposed by the agents.
*
* @param proposalTimes
* @return The songs
*/
private List<BaseSong<BaseArtist, BaseAlbum>> getProposedSongs(AgentsTiming proposalTimes) {
Set<IAgent> agents = agentManager.getAgents();
// Using set here to ensure no duplicate entries
Set<BaseSong<BaseArtist, BaseAlbum>> proposedSongs =
new HashSet<BaseSong<BaseArtist, BaseAlbum>>(SONG_PROPOSAL_USAGE_COUNT * agents.size());
for (IAgent agent : agents) {
throwIfAborted();
StopWatch stopWatch = StopWatch.start();
List<BaseSong<BaseArtist, BaseAlbum>> agentProposals =
new ArrayList<BaseSong<BaseArtist, BaseAlbum>>(agent.suggestSongs(SONG_PROPOSAL_COUNT));
// Get #SONG_PROPOSAL_USAGE_COUNT items of them at random
while (agentProposals.size() > SONG_PROPOSAL_USAGE_COUNT) {
agentProposals.remove(RandomProvider.getRandom().nextInt(agentProposals.size()));
}
proposedSongs.addAll(agentProposals);
proposalTimes.addAgentTiming(agent, stopWatch.stop());
}
return new ArrayList<BaseSong<BaseArtist, BaseAlbum>>(proposedSongs);
}
/**
* Returns the average votes of the agents for the given songs. The votes gets weighted by the
* importance of the agents.
*
* @param proposedSongs The proposed songs
* @param agentsVotes (out) The votes for all the songs by agent
* @param voteTimes
* @return The weighted mean votes for the songs
*/
private Map<BaseSong<BaseArtist, BaseAlbum>, Double> getVotesForProposed(
List<BaseSong<BaseArtist, BaseAlbum>> proposedSongs,
Map<IAgent, List<SongVote>> agentsVotes,
AgentsTiming voteTimes) {
Set<IAgent> agents = agentManager.getAgents();
// Init the ratings list & the weight sum table
Map<BaseSong<BaseArtist, BaseAlbum>, Double> votes =
new HashMap<BaseSong<BaseArtist, BaseAlbum>, Double>();
Map<BaseSong<BaseArtist, BaseAlbum>, Double> weightSums =
new HashMap<BaseSong<BaseArtist, BaseAlbum>, Double>(agents.size());
for (BaseSong<BaseArtist, BaseAlbum> song : proposedSongs) {
votes.put(song, 0.0d);
weightSums.put(song, 0.0d);
}
// Calculate the song ratings
for (IAgent agent : agents) {
throwIfAborted();
// Get the agent vote
List<SongVote> agentVotes;
StopWatch stopWatch = StopWatch.start();
{
agentVotes = agent.vote(Collections.unmodifiableList(proposedSongs));
}
voteTimes.addAgentTiming(agent, stopWatch.stop());
// Fill up the list to ensure that a vote for all songs exist
List<BaseSong<BaseArtist, BaseAlbum>> noVote =
new ArrayList<BaseSong<BaseArtist, BaseAlbum>>(proposedSongs);
for (int i = 0; i < agentVotes.size(); ) {
final SongVote vote = agentVotes.get(i);
int idx = noVote.indexOf(vote.getSong());
if (idx >= 0) {
noVote.remove(idx);
++i;
} else {
// No vote for this song is required
agentVotes.remove(i);
}
}
for (BaseSong<BaseArtist, BaseAlbum> song : noVote) {
agentVotes.add(new SongVote(song, 0.0f));
}
agentsVotes.put(agent, agentVotes);
for (SongVote vote : agentVotes) {
final BaseSong<BaseArtist, BaseAlbum> song = vote.getSong();
double oldRating = votes.get(song);
double agentWeight = getAgentWeights().get(agent);
double oldW = weightSums.get(song);
double newW = oldW + agentWeight;
double newRating =
(oldRating * oldW + vote.getVote() * agentWeight)
/ newW; // Continuous, weighted mean calculation
votes.put(song, newRating);
weightSums.put(song, newW);
}
}
return votes;
}
@Override
public void run() {
try {
throwIfAborted();
TimingLogger timingLogger = new TimingLogger(getTag(), "next");
// Begin an immediate transaction
dbDataPortal.beginTransaction();
timingLogger.addSplit("Transaction start");
Set<IAgent> agents = agentManager.getAgents();
agentWeights = agentManager.getAgentWeights();
// Enter a fake rating entry to calculate the next song on the predicted future
Integer meSongId = null;
if (currentSong != null) {
double fractionPlayed = (getCalculationCase() == Case.Positive) ? 0.66d : 0.33d;
playLog.writeToPlayLog(
new Date(),
new PlaylistSong<BaseArtist, BaseAlbum>(currentSong, SongSource.SMART_SHUFFLE),
true,
(int) (currentSong.getDuration() * fractionPlayed));
try {
meSongId = otherDataProvider.getMusicExplorerSongId(currentSong);
} catch (DataUnavailableException e) {
Log.w(getTag(), e);
}
}
timingLogger.addSplit("Rating entry");
// Get the song proposals
AgentsTiming proposalTimes = new AgentsTiming();
{
proposedSongs = getProposedSongs(proposalTimes);
}
timingLogger.addSplit("Proposals");
// Get the agent votes for the proposals
Map<IAgent, List<SongVote>> agentVotes;
AgentsTiming voteTimes = new AgentsTiming();
{
agentVotes = new HashMap<IAgent, List<SongVote>>();
songVotes = getVotesForProposed(proposedSongs, agentVotes, voteTimes);
}
timingLogger.addSplit("Votes");
// Fill the song->agentVotes map
agentVotesBySong =
new HashMap<BaseSong<BaseArtist, BaseAlbum>, Map<IAgent, Float>>(proposedSongs.size());
for (BaseSong<BaseArtist, BaseAlbum> song : proposedSongs) {
agentVotesBySong.put(song, new HashMap<IAgent, Float>(agents.size()));
}
for (Map.Entry<IAgent, List<SongVote>> entry : agentVotes.entrySet()) {
for (SongVote vote : entry.getValue()) {
Map<IAgent, Float> agentVote = agentVotesBySong.get(vote.getSong());
agentVote.put(entry.getKey(), vote.getVote());
}
}
// Add long time not listened songs
addLongTimeNotListenedSongProposals();
/*// Order the next songs by rating
Collections.sort(proposedSongs, new Comparator<BaseSong<BaseArtist, BaseAlbum>>() {
@Override
public int compare(BaseSong<BaseArtist, BaseAlbum> left, BaseSong<BaseArtist, BaseAlbum> right) {
Double leftVote = songVotes.get(left);
Double rightVote = songVotes.get(right);
return rightVote.compareTo(leftVote);
}
});*/
// Randomize the song proposals by their vote
proposedSongs = getShuffledSongsAtWeightedRandom(songVotes);
// FIXME @sämy: this is only for debugging
StringBuffer proposalsSb = new StringBuffer();
proposalsSb.append("song ident:overall vote");
for (IAgent agent : agents) {
proposalsSb.append(':');
proposalsSb.append(agent.getIdentifier());
proposalsSb.append(String.format(" (%.2f)", agentWeights.get(agent)));
}
proposalsSb.append('|');
for (BaseSong<BaseArtist, BaseAlbum> song : proposedSongs) {
proposalsSb.append(song); // song ident
proposalsSb.append(':');
proposalsSb.append(String.format("%.3f", songVotes.get(song))); // overall vote
Map<IAgent, Float> agentVotes2 = agentVotesBySong.get(song);
for (IAgent agent : agents) {
proposalsSb.append(String.format(":%.3f", agentVotes2.get(agent)));
}
proposalsSb.append('|');
}
Log.d(getTag(), "Proposals: " + proposalsSb.toString());
// end debug only
// never ever call dbDataPortal.setTransactionSucessful() !!
dbDataPortal
.endTransaction(); // ROLLBACK the transaction. Things below that line get written
// persistently to the db!
// Write a log entry about this run
NextSongCalculationLogEntry.Builder log =
NextSongCalculationLogEntry.createInstance()
.setPredictionCase(getCalculationCase())
.setCurrentSong((meSongId != null) ? meSongId : 0)
.setProposalTimes(proposalTimes)
.setVoteTimes(voteTimes);
logManager.addLogEntry(log.build());
// Write the time used in the different parts to the debug log
timingLogger.dumpToLog();
} catch (AbortException e) {
// Just ignore it, we want to land here
} finally {
if (dbDataPortal.inTransaction()) {
dbDataPortal.endTransaction(); // never ever call dbDataPortal.setTransactionSucessful() !!
}
}
}