Esempio n. 1
0
 @Override
 public void process(Pair<Long, Iterable<NumericIDValue>> input, Emitter<String> emitter) {
   StringLongMapping mapping = idMapping.getIDMapping();
   Iterable<NumericIDValue> recs = TopN.selectTopN(input.second().iterator(), numRecs);
   String userID = mapping.toString(input.first());
   for (NumericIDValue rec : recs) {
     emitter.emit(
         DelimitedDataUtils.encode(
             ',', userID, mapping.toString(rec.getID()), Float.toString(rec.getValue())));
   }
 }
Esempio n. 2
0
  @Override
  public void process(
      Pair<Pair<Long, Integer>, Iterable<NumericIDValue>> input,
      Emitter<Pair<Long, NumericIDValue>> emitter) {
    Pair<Long, Integer> key = input.first();
    long currentUserID = key.first();

    if (key.second() == BEFORE) {

      // Last old data had no match, just output it
      if (previousUserPrefs != null) {
        Preconditions.checkNotNull(previousUserID);
        output(previousUserID, previousUserPrefs, null, null, emitter);
        previousUserPrefs = null;
        previousUserID = null;
      }

      LongFloatMap oldPrefs = new LongFloatMap();
      for (NumericIDValue itemPref : input.second()) {
        float oldPrefValue = itemPref.getValue();
        Preconditions.checkState(!Float.isNaN(oldPrefValue), "No prior pref value?");
        // Apply decay factor here, if applicable:
        oldPrefs.increment(itemPref.getID(), doDecay ? oldPrefValue * decayFactor : oldPrefValue);
      }

      previousUserPrefs = oldPrefs;
      previousUserID = currentUserID;

    } else {
      // Last old data had no match, just output it
      if (previousUserPrefs != null && currentUserID != previousUserID) {
        Preconditions.checkNotNull(previousUserID);
        output(previousUserID, previousUserPrefs, null, null, emitter);
        previousUserPrefs = null;
        previousUserID = null;
      }

      LongFloatMap newPrefs = new LongFloatMap();
      LongSet removedItemIDs = new LongSet();
      for (NumericIDValue itemPref : input.second()) {
        long itemID = itemPref.getID();
        float newPrefValue = itemPref.getValue();
        if (Float.isNaN(newPrefValue)) {
          removedItemIDs.add(itemID);
        } else {
          newPrefs.increment(itemID, newPrefValue);
        }
      }

      output(currentUserID, previousUserPrefs, newPrefs, removedItemIDs, emitter);

      previousUserPrefs = null;
      previousUserID = null;
    }
  }