internal override IEnumerable <Row> GetEntities(DataExtractorHelper schema)
{
foreach (var record in page.Records)
{
var dataRow = schema.NewRow();
var readState = new RecordReadState(schema.Columns.Count(x => x.UnderlyingType == ColumnType.Bit));
int columnIndex = 0;
foreach (DataColumn col in dataRow.Columns)
{
var sqlType = SqlTypeFactory.Create(col, readState, new CompressionContext(CompressionLevel.Row, true));
IVariableLengthDataProxy dataProxy = record.GetPhysicalColumnBytes(columnIndex);
if (dataProxy == null)
{
dataRow[col] = null;
}
else
{
dataRow[col] = sqlType.GetValue(dataProxy.GetBytes().ToArray());
}
columnIndex++;
}
yield return(dataRow);
}
}
internal override IEnumerable <Row> GetEntities(DataExtractorHelper schema)
{
foreach (var record in page.Records)
{
// Don't process forwarded blob fragments as they should only be processed from the referenced record
if (_recordsToSkip.Contains(record.Type) || record.IsGhostForwardedRecord)
{
continue;
}
short fixedOffset = 0;
short variableColumnIndex = 0;
var dataRow = schema.NewRow();
var readState = new RecordReadState(schema.BitColumnsCount);
var bitColumnBytes = new byte[0];
foreach (var col in schema.Columns)
{
var sqlType = SqlTypeFactory.Create(col, readState, compression);
object columnValue = null;
// Sparse columns needs to retrieve their values from the sparse vector, contained in the very last
// variable length column in the record.
if (col.IsSparse)
{
// We may encounter records that don't have any sparse vectors, for instance if no sparse columns have values
if (record.SparseVector != null)
{
// Column ID's are stored as ints in general. In the sparse vector though, they're stored as shorts.
if (record.SparseVector.ColumnValues.ContainsKey((short)col.ColumnID))
{
columnValue = sqlType.GetValue(record.SparseVector.ColumnValues[(short)col.ColumnID]);
}
}
}
else
{
var nonSparseIndex = schema.NonSparseIndexes[col.Name];
// Before we even try to parse the column & make a null bitmap lookup, ensure that it's present in the record.
// There may be columns > record.NumberOfColumns caused by nullable columns added to the schema after the record was written.
if (nonSparseIndex < record.NumberOfColumns && col.UnderlyingType != ColumnType.Computed)
{
if (sqlType.IsVariableLength)
{
// If there's either no null bitmap, or the null bitmap defines the column as non-null.
if (!record.HasNullBitmap || !record.NullBitmap[nonSparseIndex])
{
// If the current variable length column index exceeds the number of stored
// variable length columns, the value is empty by definition (that is, 0 bytes, but not null).
if (variableColumnIndex < record.NumberOfVariableLengthColumns)
{
var data = record.VariableLengthColumnData[variableColumnIndex].GetBytes()?.ToArray();
columnValue = sqlType.GetValue(data ?? new byte[0]);
}
else
{
columnValue = sqlType.GetValue(new byte[0]);
}
}
variableColumnIndex++;
}
else
{
// Must cache type FixedLength as it may change after getting a value (e.g. SqlBit)
var fixedLength = sqlType.FixedLength.Value;
if ((!record.HasNullBitmap || !record.NullBitmap[nonSparseIndex]) && col.UnderlyingType != ColumnType.Bit)
{
var valueBytes = record.FixedLengthData.Skip(fixedOffset).Take(fixedLength).ToArray();
// We may run out of fixed length bytes. In certain conditions a null integer may have been added without
// there being a null bitmap. In such a case, we detect the null condition by there not being enough fixed
// length bytes to process.
if (valueBytes.Length > 0)
{
columnValue = sqlType.GetValue(valueBytes);
}
}
else if (col.UnderlyingType == ColumnType.Bit && !schema.IsDroppedColumn(col))
{
if (readState.IsFirstBit)
{
bitColumnBytes = record.FixedLengthData.Skip(fixedOffset).Take(fixedLength).ToArray();
}
var value = sqlType.GetValue(bitColumnBytes);
columnValue = !record.HasNullBitmap || !record.NullBitmap[nonSparseIndex] ? value : null;
}
fixedOffset += fixedLength;
}
}
else if (col.UnderlyingType == ColumnType.Computed)
{
columnValue = sqlType.GetValue(null);
}
else if (!col.IsNullable)
{
columnValue = schema.GetDefaultValue(col, sqlType);
}
}
if (!schema.IsDroppedColumn(col))
{
dataRow[col] = columnValue;
}
}
yield return(dataRow);
}
}
