// Reads the next chunk in a nvarchar(max) data stream.
// This call must be preceeded by a call to ReadPlpLength or ReadDataLength.
// Will not start reading into the next chunk if bytes requested is larger than
// the current chunk length. Do another ReadPlpLength, ReadPlpUnicodeChars in that case.
// Returns the actual chars read
private bool TryReadPlpUnicodeCharsChunk(char[] buff, int offst, int len, TdsParserStateObject stateObj, out int charsRead)
{
Debug.Assert((buff == null && len == 0) || (buff.Length >= offst + len), "Invalid length sent to ReadPlpUnicodeChars()!");
Debug.Assert((stateObj._longlen != 0) && (stateObj._longlen != TdsEnums.SQL_PLP_NULL),
"Out of sync plp read request");
if (stateObj._longlenleft == 0)
{
Debug.Assert(false, "Out of sync read request");
charsRead = 0;
return true;
}
charsRead = len;
// stateObj._longlenleft is in bytes
if ((stateObj._longlenleft >> 1) < (ulong)len)
charsRead = (int)(stateObj._longlenleft >> 1);
for (int ii = 0; ii < charsRead; ii++)
{
if (!stateObj.TryReadChar(out buff[offst + ii]))
{
return false;
}
}
stateObj._longlenleft -= ((ulong)charsRead << 1);
return true;
}