private static long ReadFieldLength(ByteArrayReader reader)
{
var leadByte = reader.ReadByte();
switch (leadByte)
{
case 0xFB:
return(-1);
case 0xFC:
return(reader.ReadFixedLengthUInt32(2));
case 0xFD:
return(reader.ReadFixedLengthUInt32(3));
case 0xFE:
return(checked ((long)reader.ReadFixedLengthUInt64(8)));
default:
return(leadByte);
}
}
private ValueTask <Row> ScanRowAsync(IOBehavior ioBehavior, Row row, CancellationToken cancellationToken)
{
// if we've already read past the end of this resultset, Read returns false
if (BufferState == ResultSetState.HasMoreData || BufferState == ResultSetState.NoMoreData || BufferState == ResultSetState.None)
{
return(new ValueTask <Row>((Row)null));
}
using (Command.CancellableCommand.RegisterCancel(cancellationToken))
{
var payloadValueTask = Session.ReceiveReplyAsync(ioBehavior, CancellationToken.None);
return(payloadValueTask.IsCompletedSuccessfully
? new ValueTask <Row>(ScanRowAsyncRemainder(payloadValueTask.Result, row))
: new ValueTask <Row>(ScanRowAsyncAwaited(payloadValueTask.AsTask(), row, cancellationToken)));
}
async Task <Row> ScanRowAsyncAwaited(Task <PayloadData> payloadTask, Row row_, CancellationToken token)
{
PayloadData payloadData;
try
{
payloadData = await payloadTask.ConfigureAwait(false);
}
catch (MySqlException ex)
{
BufferState = State = ResultSetState.NoMoreData;
if (ex.Number == (int)MySqlErrorCode.QueryInterrupted)
{
token.ThrowIfCancellationRequested();
}
throw;
}
return(ScanRowAsyncRemainder(payloadData, row_));
}
Row ScanRowAsyncRemainder(PayloadData payload, Row row_)
{
if (payload.HeaderByte == EofPayload.Signature)
{
var span = payload.AsSpan();
if (Session.SupportsDeprecateEof && OkPayload.IsOk(span, Session.SupportsDeprecateEof))
{
var ok = OkPayload.Create(span, Session.SupportsDeprecateEof, Session.SupportsSessionTrack);
BufferState = (ok.ServerStatus & ServerStatus.MoreResultsExist) == 0 ? ResultSetState.NoMoreData : ResultSetState.HasMoreData;
m_rowBuffered = null;
return(null);
}
if (!Session.SupportsDeprecateEof && EofPayload.IsEof(payload))
{
var eof = EofPayload.Create(span);
BufferState = (eof.ServerStatus & ServerStatus.MoreResultsExist) == 0 ? ResultSetState.NoMoreData : ResultSetState.HasMoreData;
m_rowBuffered = null;
return(null);
}
}
if (row_ is null)
{
bool isBinaryRow = false;
if (payload.HeaderByte == 0 && !Connection.IgnorePrepare)
{
// this might be a binary row, but it might also be a text row whose first column is zero bytes long; try reading
// the row as a series of length-encoded values (the text format) to see if this might plausibly be a text row
var isTextRow = false;
var reader = new ByteArrayReader(payload.AsSpan());
var columnCount = 0;
while (reader.BytesRemaining > 0)
{
int length;
var firstByte = reader.ReadByte();
if (firstByte == 0xFB)
{
// NULL
length = 0;
}
else if (firstByte == 0xFC)
{
// two-byte length-encoded integer
if (reader.BytesRemaining < 2)
{
break;
}
length = unchecked ((int)reader.ReadFixedLengthUInt32(2));
}
else if (firstByte == 0xFD)
{
// three-byte length-encoded integer
if (reader.BytesRemaining < 3)
{
break;
}
length = unchecked ((int)reader.ReadFixedLengthUInt32(3));
}
else if (firstByte == 0xFE)
{
// eight-byte length-encoded integer
if (reader.BytesRemaining < 8)
{
break;
}
length = checked ((int)reader.ReadFixedLengthUInt64(8));
}
else if (firstByte == 0xFF)
{
// invalid length prefix
break;
}
else
{
// single-byte length
length = firstByte;
}
if (reader.BytesRemaining < length)
{
break;
}
reader.Offset += length;
columnCount++;
if (columnCount == ColumnDefinitions.Length)
{
// if we used up all the bytes reading exactly 'ColumnDefinitions' length-encoded columns, then assume this is a text row
if (reader.BytesRemaining == 0)
{
isTextRow = true;
}
break;
}
}
isBinaryRow = !isTextRow;
}
row_ = isBinaryRow ? (Row) new BinaryRow(this) : new TextRow(this);
}
row_.SetData(payload.ArraySegment);
m_rowBuffered = row_;
m_hasRows = true;
BufferState = ResultSetState.ReadingRows;
return(row_);
}
}
static Row?ScanRowAsyncRemainder(ResultSet this_, PayloadData payload, Row?row_)
{
if (payload.HeaderByte == EofPayload.Signature)
{
var span = payload.Span;
if (this_.Session.SupportsDeprecateEof && OkPayload.IsOk(span, this_.Session.SupportsDeprecateEof))
{
var ok = OkPayload.Create(span, this_.Session.SupportsDeprecateEof, this_.Session.SupportsSessionTrack);
this_.BufferState = (ok.ServerStatus & ServerStatus.MoreResultsExist) == 0 ? ResultSetState.NoMoreData : ResultSetState.HasMoreData;
return(null);
}
if (!this_.Session.SupportsDeprecateEof && EofPayload.IsEof(payload))
{
var eof = EofPayload.Create(span);
this_.BufferState = (eof.ServerStatus & ServerStatus.MoreResultsExist) == 0 ? ResultSetState.NoMoreData : ResultSetState.HasMoreData;
return(null);
}
}
if (row_ is null)
{
bool isBinaryRow = false;
if (payload.HeaderByte == 0 && !this_.Connection.IgnorePrepare)
{
// this might be a binary row, but it might also be a text row whose first column is zero bytes long; try reading
// the row as a series of length-encoded values (the text format) to see if this might plausibly be a text row
var isTextRow = false;
var reader = new ByteArrayReader(payload.Span);
var columnCount = 0;
while (reader.BytesRemaining > 0)
{
int length;
var firstByte = reader.ReadByte();
if (firstByte == 0xFB)
{
// NULL
length = 0;
}
else if (firstByte == 0xFC)
{
// two-byte length-encoded integer
if (reader.BytesRemaining < 2)
{
break;
}
length = unchecked ((int)reader.ReadFixedLengthUInt32(2));
}
else if (firstByte == 0xFD)
{
// three-byte length-encoded integer
if (reader.BytesRemaining < 3)
{
break;
}
length = unchecked ((int)reader.ReadFixedLengthUInt32(3));
}
else if (firstByte == 0xFE)
{
// eight-byte length-encoded integer
if (reader.BytesRemaining < 8)
{
break;
}
length = checked ((int)reader.ReadFixedLengthUInt64(8));
}
else if (firstByte == 0xFF)
{
// invalid length prefix
break;
}
else
{
// single-byte length
length = firstByte;
}
if (reader.BytesRemaining < length)
{
break;
}
reader.Offset += length;
columnCount++;
if (columnCount == this_.ColumnDefinitions !.Length)
{
// if we used up all the bytes reading exactly 'ColumnDefinitions' length-encoded columns, then assume this is a text row
if (reader.BytesRemaining == 0)
{
isTextRow = true;
}
break;
}
}
isBinaryRow = !isTextRow;
}
row_ = isBinaryRow ? (Row) new BinaryRow(this_) : new TextRow(this_);
}
row_.SetData(payload.Memory);
this_.m_hasRows = true;
this_.BufferState = ResultSetState.ReadingRows;
return(row_);
}
private static long ReadFieldLength(ByteArrayReader reader)
{
var leadByte = reader.ReadByte();
switch (leadByte)
{
case 0xFB:
return -1;
case 0xFC:
return reader.ReadFixedLengthUInt32(2);
case 0xFD:
return reader.ReadFixedLengthUInt32(3);
case 0xFE:
return checked((long) reader.ReadFixedLengthUInt64(8));
default:
return leadByte;
}
}
