/// <summary>
/// Performs the actual reading and converting
/// NOTE: This assumes that buffer, index and count are all valid, we're not closed (!IsClosed) and that there is data left (IsDataLeft())
/// </summary>
/// <param name="buffer"></param>
/// <param name="index"></param>
/// <param name="count"></param>
/// <returns></returns>
private int InternalRead(char[] buffer, int index, int count)
{
Debug.Assert(buffer != null, "Null output buffer");
Debug.Assert((index >= 0) && (count >= 0) && (index + count <= buffer.Length), $"Bad count: {count} or index: {index}");
Debug.Assert(!IsClosed, "Can't read while textreader is closed");
try
{
int byteBufferUsed;
byte[] byteBuffer = PrepareByteBuffer(count, out byteBufferUsed);
byteBufferUsed += _reader.GetBytesInternalSequential(_columnIndex, byteBuffer, byteBufferUsed, byteBuffer.Length - byteBufferUsed);
if (byteBufferUsed > 0)
{
return(DecodeBytesToChars(byteBuffer, byteBufferUsed, buffer, index, count));
}
else
{
// Nothing to read, or nothing read
return(0);
}
}
catch (SqlException ex)
{
// Read can't throw a SqlException - so wrap it in an IOException
throw ADP.ErrorReadingFromStream(ex);
}
}
public override int Read(byte[] buffer, int offset, int count)
{
ValidateReadParameters(buffer, offset, count);
if (!CanRead)
{
throw ADP.ObjectDisposed(this);
}
if (_currentTask != null)
{
throw ADP.AsyncOperationPending();
}
try
{
return(_reader.GetBytesInternalSequential(_columnIndex, buffer, offset, count, _readTimeout));
}
catch (SqlException ex)
{
// Stream.Read() can't throw a SqlException - so wrap it in an IOException
throw ADP.ErrorReadingFromStream(ex);
}
}