public bool TryGetHeader(BufferValueReader reader, int remaining, ref MessageHeader header)
{
string callCategory = null;
#if TRACE
int c = GetNextCallId();
callCategory = String.Format("{0} {1}:TryGetHeader({2},{3})", this.connectionType, c, reader.Position, remaining);
#endif
Trace.WriteLineIf(NTrace.TraceVerbose, String.Format("Entering {0}", (header == null) ? "without existing header" : "with existing header"), callCategory);
int mlen; bool isContinued; Message msg = null; Protocol p;
int headerLength = BaseHeaderLength;
if (header == null)
{
header = new MessageHeader();
}
else if (header.State == HeaderState.Complete)
{
return(true);
}
else if (header.HeaderLength > 0)
{
headerLength = header.HeaderLength;
}
try
{
if (header.State >= HeaderState.Protocol)
{
p = header.Protocol;
}
else
{
byte pid = reader.ReadByte();
if (!this.protocols.TryGetValue(pid, out p))
{
Trace.WriteLineIf(NTrace.TraceWarning, "Exiting (Protocol " + pid + " not found)", callCategory);
return(true);
}
header.Protocol = p;
header.State = HeaderState.Protocol;
if (this.serializationContext == null)
{
if (this.connection != null)
{
this.serializationContext = new SerializationContext(this.connection, this.protocols);
}
else
{
this.serializationContext = new SerializationContext(this.protocols);
}
}
header.SerializationContext = this.serializationContext;
}
if (header.State < HeaderState.CID)
{
header.ConnectionId = reader.ReadInt32();
header.State = HeaderState.CID;
}
if (header.State >= HeaderState.Type)
{
msg = header.Message;
}
else
{
ushort type = reader.ReadUInt16();
msg = header.Message = p.Create(type);
header.State = HeaderState.Type;
if (msg == null)
{
Trace.WriteLineIf(NTrace.TraceWarning, "Exiting (Message " + type + " not found)", callCategory);
return(true);
}
msg.Header = header;
if (msg.Encrypted)
{
header.IsStillEncrypted = true;
}
Trace.WriteLineIf(NTrace.TraceVerbose, String.Format("Have " + msg.GetType().Name), callCategory);
}
if (header.State >= HeaderState.Length)
{
mlen = header.MessageLength;
}
else
{
mlen = reader.ReadInt32();
if (mlen <= 0)
{
Trace.WriteLineIf(NTrace.TraceWarning, "Exiting (length invalid)", callCategory);
return(true);
}
header.MessageLength = mlen;
header.State = HeaderState.Length;
Trace.WriteLineIf(NTrace.TraceVerbose, String.Format("Have message of length: {0}", mlen), callCategory);
}
if (header.State == HeaderState.IV)
{
if (header.IsStillEncrypted)
{
Trace.WriteLineIf(NTrace.TraceVerbose, "Exiting (message not buffered)", callCategory);
return(!(remaining < mlen));
}
else if (header.Message.Encrypted)
{
reader.Position = 0;
}
}
else if (msg.Encrypted) // && AES != null)
{
int ivLength = reader.ReadInt32(); //AES.IV.Length;
headerLength += ivLength + sizeof(int);
if (remaining < headerLength)
{
reader.Position -= sizeof(int);
Trace.WriteLineIf(NTrace.TraceVerbose, "Exiting (header not buffered (IV))", callCategory);
return(false);
}
byte[] iv = reader.ReadBytes(ivLength);
header.HeaderLength = headerLength;
header.State = HeaderState.IV;
header.IV = iv;
if (remaining < mlen)
{
Trace.WriteLineIf(NTrace.TraceVerbose, "Exiting (message not buffered)", callCategory);
return(false);
}
Trace.WriteLineIf(NTrace.TraceVerbose, "Exiting (need to decrypt)", callCategory);
return(true);
}
if (header.State < HeaderState.MessageId)
{
int identV = reader.ReadInt32();
header.MessageId = identV & ~ResponseFlag;
header.IsResponse = (identV & ResponseFlag) == ResponseFlag;
header.State = (header.IsResponse) ? HeaderState.MessageId : HeaderState.Complete;
Trace.WriteLineIf(NTrace.TraceVerbose, "Have message ID: " + header.MessageId, callCategory);
}
if (header.State < HeaderState.ResponseMessageId)
{
header.ResponseMessageId = reader.ReadInt32();
header.State = HeaderState.Complete;
Trace.WriteLineIf(NTrace.TraceVerbose, "Have message in resoponse to ID: " + header.ResponseMessageId);
}
Trace.WriteLineIf(NTrace.TraceVerbose, "Exiting", callCategory);
return(true);
}
catch (Exception ex)
{
Trace.WriteLineIf(NTrace.TraceError, "Exiting (error): " + ex, callCategory);
header = null;
return(true);
}
}
