public InvertHashHelper(NgramHashTransform parent, string[][] friendlyNames, Func <int, bool> inputPred, int[] invertHashMaxCounts)
{
Contracts.AssertValue(parent);
Contracts.AssertValue(friendlyNames);
Contracts.Assert(friendlyNames.Length == parent._bindings.InfoCount);
Contracts.AssertValue(inputPred);
Contracts.AssertValue(invertHashMaxCounts);
Contracts.Assert(invertHashMaxCounts.Length == parent._bindings.InfoCount);
_parent = parent;
// One per iinfo (some may be null).
_iinfoToCollector = new InvertHashCollector <NGram> [_parent._bindings.InfoCount];
// One per source column (some may be null).
_srcTextGetters = new ValueMapper <uint, StringBuilder> [_parent.Source.Schema.ColumnCount];
_invertHashMaxCounts = invertHashMaxCounts;
for (int i = 0; i < _srcTextGetters.Length; ++i)
{
if (inputPred(i))
{
_srcTextGetters[i] = InvertHashUtils.GetSimpleMapper <uint>(_parent.Source.Schema, i);
}
}
_friendlyNames = friendlyNames;
}
protected override ValueMapper <KeyValuePair <int, T>, StringBuilder> GetTextMap()
{
var simple = InvertHashUtils.GetSimpleMapper <T>(Row.Schema, _info.Source);
return(InvertHashUtils.GetPairMapper(simple));
}
protected virtual ValueMapper <T, StringBuilder> GetTextMap()
{
return(InvertHashUtils.GetSimpleMapper <T>(Row.Schema, _info.Source));
}