/// <summary>
/// Skips a token within a stream based on token type
/// </summary>
/// <param name="tokenType">Type of the token to ignore</param>
/// <param name="stream">Stream that contains the token</param>
private static void IgnoreToken(TDSTokenType tokenType, MemoryStream stream)
{
switch (((byte)tokenType >> 4) & 0x3)
{
// Variable count token
case 0:
{
throw new NotSupportedException();
}
// Zero length token
case 1:
{
return;
}
// Variable length token
case 2:
{
if (tokenType == TDSTokenType.DataClassification)
{
throw new NotSupportedException();
}
ushort length = LittleEndianUtilities.ReadUShort(stream);
for (int i = 0; i < length; i++)
{
stream.ReadByte();
}
return;
}
// Fixed length token
case 3:
{
var bytesToRead = Math.Pow(2, ((byte)tokenType >> 2) & 0x3);
if (tokenType == TDSTokenType.Done || tokenType == TDSTokenType.DoneInProc || tokenType == TDSTokenType.DoneProc)
{
bytesToRead = 12; // Untill support is added
}
for (int i = 0; i < bytesToRead; i++)
{
stream.ReadByte();
}
return;
}
default:
{
throw new InvalidOperationException();
}
}
}
/// <summary>
/// Reconstruct token sequence from the stream
/// </summary>
/// <returns>Token collection</returns>
public static IList <TDSPacketToken> Create(Stream source)
{
// Prepare collection
IList <TDSPacketToken> tokens = new List <TDSPacketToken>();
// Process the whole stream
while (source.Position < source.Length)
{
// Read token type
TDSTokenType tokenType = (TDSTokenType)source.ReadByte();
// Call corresponding constructor based on the token type
switch (tokenType)
{
case TDSTokenType.EnvironmentChange:
{
tokens.Add(new TDSEnvChangeToken());
break;
}
case TDSTokenType.Info:
{
tokens.Add(new TDSInfoToken());
break;
}
case TDSTokenType.Error:
{
tokens.Add(new TDSErrorToken());
break;
}
case TDSTokenType.Done:
{
tokens.Add(new TDSDoneToken());
break;
}
case TDSTokenType.DoneInProc:
{
tokens.Add(new TDSDoneInProcToken());
break;
}
case TDSTokenType.DoneProcedure:
{
tokens.Add(new TDSDoneProcedureToken());
break;
}
case TDSTokenType.LoginAcknowledgement:
{
tokens.Add(new TDSLoginAckToken());
break;
}
case TDSTokenType.ColumnInfo:
{
tokens.Add(new TDSColInfoToken());
break;
}
case TDSTokenType.ColumnMetadata:
{
tokens.Add(new TDSColMetadataToken());
break;
}
case TDSTokenType.Row:
{
// Find column metadata token
TDSColMetadataToken columnMetadata = tokens.Where(t => t is TDSColMetadataToken).LastOrDefault() as TDSColMetadataToken;
// Column metadata must be immediately preceeding row
if (columnMetadata == null)
{
throw new Exception("No column metadata is available for row token");
}
tokens.Add(new TDSRowToken(columnMetadata));
break;
}
case TDSTokenType.NBCRow:
{
// Find column metadata token
TDSColMetadataToken columnMetadata = tokens.Where(t => t is TDSColMetadataToken).LastOrDefault() as TDSColMetadataToken;
// Column metadata must be immediately preceeding row
if (columnMetadata == null)
{
throw new Exception("No column metadata is available for null-byte compression row token");
}
tokens.Add(new TDSNBCRowToken(columnMetadata));
break;
}
case TDSTokenType.SSPI:
{
tokens.Add(new TDSSSPIToken());
break;
}
case TDSTokenType.FedAuthInfo:
{
tokens.Add(new TDSFedAuthInfoToken());
break;
}
case TDSTokenType.FeatureExtAck:
{
tokens.Add(new TDSFeatureExtAckToken());
break;
}
case TDSTokenType.SessionState:
{
tokens.Add(new TDSSessionStateToken());
break;
}
case TDSTokenType.ReturnStatus:
{
tokens.Add(new TDSReturnStatusToken());
break;
}
case TDSTokenType.Order:
{
tokens.Add(new TDSOrderToken());
break;
}
default:
{
// Either the token has not been implemented yet or is invalid
throw new NotImplementedException(string.Format("Token \"{0}\" is not recognized", tokenType));
}
}
// Inflate the last token from the stream
if (!tokens.Last().Inflate(source))
{
// Throw exception at this point since this operation is not interruptable (yet)
throw new Exception(string.Format("Token \"{0}\" inflation failed", tokenType));
}
}
return(tokens);
}
