public ColumnType GetMetadataTypeOrNull(string kind, int col)
{
if (string.IsNullOrEmpty(kind))
{
throw MetadataUtils.ExceptGetMetadata();
}
CheckColumnInRange(col);
var column = SchemaDefn.Columns[col];
return(column.Metadata.ContainsKey(kind) ? column.Metadata[kind].MetadataType : null);
}
public void GetMetadata <TValue>(string kind, int col, ref TValue value)
{
var metadataType = GetMetadataTypeOrNull(kind, col);
if (metadataType == null)
{
throw MetadataUtils.ExceptGetMetadata();
}
var metadata = SchemaDefn.Columns[col].Metadata[kind];
metadata.GetGetter <TValue>()(ref value);
}
protected override void GetMetadataCore <TValue>(string kind, int iinfo, ref TValue value)
{
Contracts.Assert(0 <= iinfo && iinfo < OutputColInfos.Length);
var meta = OutputColInfos[iinfo].Metadata;
int mcol;
if (meta == null || !meta.Schema.TryGetColumnIndex(kind, out mcol))
{
throw MetadataUtils.ExceptGetMetadata();
}
// REVIEW: Again, since this is a shim, not going to sweat the potential for inappropriate exception message.
meta.GetGetter <TValue>(mcol)(ref value);
}
public void GetMetadata <TValue>(string kind, int col, ref TValue value)
{
Contracts.CheckNonEmpty(kind, nameof(kind));
Contracts.CheckParam(col == 0, nameof(col));
if (kind == MetadataUtils.Kinds.SlotNames)
{
_getSlotNames.Marshal(col, ref value);
}
else
{
throw MetadataUtils.ExceptGetMetadata();
}
}
private void GetSlotNames(int iinfo, ref VBuffer <ReadOnlyMemory <char> > dst)
{
Host.Assert(0 <= iinfo && iinfo < Infos.Length);
int size = _types[iinfo].VectorSize;
if (size == 0)
{
throw MetadataUtils.ExceptGetMetadata();
}
var values = dst.Values;
if (Utils.Size(values) < size)
{
values = new ReadOnlyMemory <char> [size];
}
var type = Infos[iinfo].TypeSrc;
if (!type.IsVector)
{
Host.Assert(_types[iinfo].VectorSize == 2);
var columnName = Source.Schema.GetColumnName(Infos[iinfo].Source);
values[0] = columnName.AsMemory();
values[1] = (columnName + IndicatorSuffix).AsMemory();
}
else
{
Host.Assert(type.IsKnownSizeVector);
Host.Assert(size == 2 * type.VectorSize);
// REVIEW: Do we need to verify that there is metadata or should we just call GetMetadata?
var typeNames = Source.Schema.GetMetadataTypeOrNull(MetadataUtils.Kinds.SlotNames, Infos[iinfo].Source);
if (typeNames == null || typeNames.VectorSize != type.VectorSize || !typeNames.ItemType.IsText)
{
throw MetadataUtils.ExceptGetMetadata();
}
var names = default(VBuffer <ReadOnlyMemory <char> >);
Source.Schema.GetMetadata(MetadataUtils.Kinds.SlotNames, Infos[iinfo].Source, ref names);
// We both assert and check. If this fails, there is a bug somewhere (possibly in this code
// but more likely in the implementation of Base. On the other hand, we don't want to proceed
// if we've received garbage.
Host.Check(names.Length == type.VectorSize, "Unexpected slot name vector size");
var sb = new StringBuilder();
int slot = 0;
foreach (var kvp in names.Items(all: true))
{
Host.Assert(0 <= slot && slot < size);
Host.Assert(slot % 2 == 0);
sb.Clear();
if (kvp.Value.IsEmpty)
{
sb.Append('[').Append(slot / 2).Append(']');
}
else
{
sb.AppendMemory(kvp.Value);
}
int len = sb.Length;
sb.Append(IndicatorSuffix);
var str = sb.ToString();
values[slot++] = str.AsMemory().Slice(0, len);
values[slot++] = str.AsMemory();
}
Host.Assert(slot == size);
}
dst = new VBuffer <ReadOnlyMemory <char> >(size, values, dst.Indices);
}
