private static Field FieldFromFlatbuffer(Flatbuf.Field flatbufField, ref DictionaryMemo dictionaryMemo)
{
Field[] childFields = flatbufField.ChildrenLength > 0 ? new Field[flatbufField.ChildrenLength] : null;
for (int i = 0; i < flatbufField.ChildrenLength; i++)
{
Flatbuf.Field?childFlatbufField = flatbufField.Children(i);
childFields[i] = FieldFromFlatbuffer(childFlatbufField.Value, ref dictionaryMemo);
}
Flatbuf.DictionaryEncoding?dictionaryEncoding = flatbufField.Dictionary;
IArrowType type = GetFieldArrowType(flatbufField, childFields);
if (dictionaryEncoding.HasValue)
{
Flatbuf.Int?indexTypeAsInt = dictionaryEncoding.Value.IndexType;
IArrowType indexType = indexTypeAsInt.HasValue ?
GetNumberType(indexTypeAsInt.Value.BitWidth, indexTypeAsInt.Value.IsSigned) :
GetNumberType(Int32Type.Default.BitWidth, Int32Type.Default.IsSigned);
type = new DictionaryType(indexType, type, dictionaryEncoding.Value.IsOrdered);
}
Dictionary <string, string> metadata = flatbufField.CustomMetadataLength > 0 ? new Dictionary <string, string>() : null;
for (int i = 0; i < flatbufField.CustomMetadataLength; i++)
{
Flatbuf.KeyValue keyValue = flatbufField.CustomMetadata(i).GetValueOrDefault();
metadata[keyValue.Key] = keyValue.Value;
}
var arrowField = new Field(flatbufField.Name, type, flatbufField.Nullable, metadata, copyCollections: false);
if (dictionaryEncoding.HasValue)
{
dictionaryMemo ??= new DictionaryMemo();
dictionaryMemo.AddField(dictionaryEncoding.Value.Id, arrowField);
}
return(arrowField);
}
internal static Schema GetSchema(Flatbuf.Schema schema, ref DictionaryMemo dictionaryMemo)
{
List <Field> fields = new List <Field>();
for (int i = 0; i < schema.FieldsLength; i++)
{
Flatbuf.Field field = schema.Fields(i).GetValueOrDefault();
fields.Add(FieldFromFlatbuffer(field, ref dictionaryMemo));
}
Dictionary <string, string> metadata = schema.CustomMetadataLength > 0 ? new Dictionary <string, string>() : null;
for (int i = 0; i < schema.CustomMetadataLength; i++)
{
Flatbuf.KeyValue keyValue = schema.CustomMetadata(i).GetValueOrDefault();
metadata[keyValue.Key] = keyValue.Value;
}
return(new Schema(fields, metadata, copyCollections: false));
}
public ArrowFooter(Flatbuf.Footer footer, ref DictionaryMemo dictionaryMemo)
: this(Ipc.MessageSerializer.GetSchema(footer.Schema.GetValueOrDefault(), ref dictionaryMemo), GetDictionaries(footer),
GetRecordBatches(footer))
{
}
