public IAsyncResult BeginReadPacket(AsyncCallback callback, object stateObject)
{
TdsAsyncResult ar = new TdsAsyncResult(callback, stateObject);
stream.BeginRead(tmpBuf, 0, 8, new AsyncCallback(OnReadPacketCallback), ar);
return(ar);
}
public void OnReadPacketCallback(IAsyncResult socketAsyncResult)
{
TdsAsyncResult ar = (TdsAsyncResult)socketAsyncResult.AsyncState;
int nread = stream.EndRead(socketAsyncResult);
int n;
while (nread < 8)
{
n = Read(tmpBuf, nread, 8 - nread);
if (n <= 0)
{
socket = null;
stream.Close();
throw new IOException(n == 0 ? "Connection lost" : "Connection error");
}
nread += n;
}
TdsPacketType packetType = (TdsPacketType)tmpBuf[0];
if (packetType != TdsPacketType.Logon && packetType != TdsPacketType.Query && packetType != TdsPacketType.Reply)
{
throw new Exception(String.Format("Unknown packet type {0}", tmpBuf[0]));
}
// figure out how many bytes are remaining in this packet.
int len = Ntohs(tmpBuf, 2) - 8;
if (len >= inBuffer.Length)
{
inBuffer = new byte[len];
}
if (len < 0)
{
throw new Exception(String.Format("Confused by a length of {0}", len));
}
GetPhysicalPacketData(len);
int value = len + 8;
ar.ReturnValue = ((object)value); // packet size
ar.MarkComplete();
}
public IAsyncResult BeginReadPacket (AsyncCallback callback, object stateObject)
{
TdsAsyncResult ar = new TdsAsyncResult (callback, stateObject);
stream.BeginRead (tmpBuf, 0, 8, new AsyncCallback(OnReadPacketCallback), ar);
return ar;
}
protected IAsyncResult BeginExecuteQueryInternal (string sql, bool wantResults,
AsyncCallback callback, object state)
{
InitExec ();
TdsAsyncResult ar = new TdsAsyncResult (callback, state);
ar.TdsAsyncState.WantResults = wantResults;
Comm.StartPacket (TdsPacketType.Query);
Comm.Append (sql);
try {
Comm.SendPacket ();
Comm.BeginReadPacket (new AsyncCallback(OnBeginExecuteQueryCallback),
ar);
} catch (IOException ex) {
connected = false;
throw new TdsInternalException ("Server closed the connection.", ex);
}
return ar;
}
protected IAsyncResult BeginExecuteQueryInternal (string sql, bool wantResults,
AsyncCallback callback, object state)
{
moreResults = true;
doneProc = false;
messages.Clear ();
outputParameters.Clear ();
TdsAsyncResult ar = new TdsAsyncResult (callback, state);
ar.TdsAsyncState.WantResults = wantResults;
Comm.StartPacket (TdsPacketType.Query);
Comm.Append (sql);
Comm.SendPacket ();
Comm.BeginReadPacket (new AsyncCallback(OnBeginExecuteQueryCallback),
ar);
return ar;
}
