// No Cache
private void GetFeatureMatrixNoCache(FeatureIndexSet indexes, List<Vector<double>[]> vectors)
{
IList<FeatureSet> list = null;
if (indexes.Indexes != null)
{
list = new List<FeatureSet>(indexes.Indexes.Count);
foreach (int idx in indexes.Indexes)
{
try
{
list.Add(DataFeatureProvider[idx]);
}
catch (Exception ex)
{
throw new InvalidOperationException("Cannot retrive item '" + idx + "' from " + DataFeatureProvider + ". See inner exception for details.", ex);
}
}
}
else // if (indexes.IndexRange != null)
{
try
{
list = DataFeatureProvider.GetItems(indexes.IndexRange.Value.MinValue, indexes.IndexRange.Value.MaxValue + 1);
}
catch (Exception ex)
{
throw new InvalidOperationException("Cannot retrive items '" + indexes.IndexRange + "' from " + DataFeatureProvider + ". See inner exception for details.", ex);
}
}
Debug.Assert(list.Count == vectors.Capacity);
foreach (var set in list) vectors.Add(GetFeatureVectorsOf(set));
}
private FeatureMatrix GetFeatureMatrixInternal(FeatureIndexSet indexes)
{
Contract.Requires(!indexes.IsEmpty);
var vectors = new List<Vector<double>[]>(indexes.Count);
var cache = VectorCache.Cache;
if (cache == null)
{
GetFeatureMatrixNoCache(indexes, vectors);
}
else
{
GetFeatureMatrixCache(indexes, vectors, cache);
}
if (indexes.Randomize) vectors = vectors.OrderByRandom().ToList();
return ToFeatureMatrix(vectors);
}
// Cache
private void GetFeatureMatrixCache(FeatureIndexSet indexes, List<Vector<double>[]> vectors, ICache cache)
{
//var sl = new SpinLock();
//Parallel.ForEach(indexes, (index) =>
//{
// string key = index.ToString() + uid;
// var cv = cache[key] as Vector<double>[];
// if (cv == null)
// {
// cv = GetFeatureVectorsOf(RetrieveFeatureSet(index));
// cache.Add(key, cv);
// }
// bool taken = false;
// try
// {
// sl.Enter(ref taken);
// vectors.Add(cv);
// }
// finally
// {
// if (taken) sl.Exit();
// }
//});
foreach (int index in indexes)
{
string key = index.ToString() + uid;
var cv = cache[key] as Vector<double>[];
if (cv != null)
{
vectors.Add(cv);
}
else
{
cv = GetFeatureVectorsOf(RetrieveFeatureSet(index));
cache.Add(key, cv);
vectors.Add(cv);
}
}
}
public FeatureMatrix GetFeatureMatrix(FeatureIndexSet indexes)
{
Contract.Requires(!indexes.IsEmpty);
Contract.Ensures(Contract.Result<FeatureMatrix>() != null);
lock (SyncRoot)
{
// Ensure initialization
InitializeLocked();
return GetFeatureMatrixInternal(indexes);
}
}
