public SequenceSize ReadNext(ReadOnlySequence <byte> sequence)
{
int bytesCount = 0;
if (_baseColumnReader == null)
{
foreach (var mem in sequence)
{
if (_nullFlagPosition == _rowCount)
{
break;
}
foreach (var byteVal in mem.Span)
{
if (byteVal != 0)
{
if (_nullFlags == null)
{
_nullFlags = new BitArray(_rowCount, false);
}
_nullFlags[_nullFlagPosition] = true;
}
bytesCount++;
if (_rowCount == ++_nullFlagPosition)
{
break;
}
}
}
if (_nullFlagPosition < _rowCount)
{
return(new SequenceSize(bytesCount, 0));
}
_baseColumnReader = _underlyingType.CreateColumnReader(_rowCount);
}
var baseResult = _baseColumnReader.ReadNext(sequence.Slice(bytesCount));
return(new SequenceSize(bytesCount + baseResult.Bytes, baseResult.Elements));
}
public SequenceSize ReadNext(ReadOnlySequence <byte> sequence)
{
if (_position >= _rowCount)
{
throw new ClickHouseException(ClickHouseErrorCodes.DataReaderError, "Internal error. Attempt to read after the end of the column.");
}
var result = new SequenceSize(0, 0);
var slice = sequence;
if (_baseColumnReader == null)
{
var header = TryReadHeader(slice);
if (header == null)
{
return(result);
}
_baseRowCount = header.Value.keyCount;
_keySize = header.Value.keySize;
_baseColumnReader = _baseType.CreateColumnReader(_baseRowCount);
slice = slice.Slice(header.Value.bytesRead);
result = result.AddBytes(header.Value.bytesRead);
}
if (_baseRowCount > 0)
{
var baseResult = _baseColumnReader.ReadNext(slice);
_baseRowCount -= baseResult.Elements;
slice = slice.Slice(baseResult.Bytes);
result = result.AddBytes(baseResult.Bytes);
}
if (_baseRowCount > 0)
{
return(result);
}
if (_buffer == null)
{
if (slice.Length < sizeof(ulong))
{
return(result);
}
ulong length = 0;
slice.Slice(0, sizeof(ulong)).CopyTo(MemoryMarshal.AsBytes(MemoryMarshal.CreateSpan(ref length, 1)));
if ((int)length != _rowCount)
{
throw new ClickHouseException(ClickHouseErrorCodes.DataReaderError, $"Internal error. Row count check failed: {_rowCount} rows expected, {length} rows detected.");
}
_buffer = new byte[_rowCount * _keySize];
slice = slice.Slice(sizeof(ulong));
result = result.AddBytes(sizeof(ulong));
}
var elementCount = Math.Min(_rowCount - _position, (int)(slice.Length / _keySize));
var byteCount = elementCount * _keySize;
slice.Slice(0, byteCount).CopyTo(new Span <byte>(_buffer, _position * _keySize, byteCount));
_position += elementCount;
result += new SequenceSize(byteCount, elementCount);
return(result);
}
