protected override FastIDSet doGetCandidateItems(long[] preferredItemIDs, DataModel dataModel)
{
IEnumerator <long> enumerator = ((IEnumerable <long>)preferredItemIDs).GetEnumerator();
if (preferredItemIDs.Length > this.maxItems)
{
double samplingRate = ((double)this.maxItems) / ((double)preferredItemIDs.Length);
log.info("preferredItemIDs.Length {0}, samplingRate {1}", new object[] { preferredItemIDs.Length, samplingRate });
enumerator = new SamplingLongPrimitiveIterator(enumerator, samplingRate);
}
FastIDSet possibleItemIDs = new FastIDSet();
while (enumerator.MoveNext())
{
long current = enumerator.Current;
PreferenceArray array = dataModel.getPreferencesForItem(current);
int num3 = array.length();
if (num3 > this.maxUsersPerItem)
{
FixedSizeSamplingIterator <Preference> iterator = new FixedSizeSamplingIterator <Preference>(this.maxUsersPerItem, array.GetEnumerator());
while (iterator.MoveNext())
{
this.addSomeOf(possibleItemIDs, dataModel.getItemIDsFromUser(iterator.Current.getUserID()));
}
}
else
{
for (int i = 0; i < num3; i++)
{
this.addSomeOf(possibleItemIDs, dataModel.getItemIDsFromUser(array.getUserID(i)));
}
}
}
possibleItemIDs.removeAll(preferredItemIDs);
return(possibleItemIDs);
}