private static TryShiftResult TryShift(Context bc, Byte[] Buffer, int Position, int Length)
{
if (bc.State == 0)
{
if (Length >= 4)
{
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
bc.CommandNameLength = s.ReadInt32();
}
if (bc.CommandNameLength < 0 || bc.CommandNameLength > 128)
{
throw new InvalidOperationException("CommandNameLengthOutOfBound");
}
var r = new TryShiftResult {
Command = null, Position = Position + 4
};
bc.State = 1;
return(r);
}
return(null);
}
else if (bc.State == 1)
{
if (Length >= bc.CommandNameLength)
{
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
bc.CommandName = System.Text.Encoding.Unicode.GetString(s.Read(bc.CommandNameLength));
}
var r = new TryShiftResult {
Command = null, Position = Position + bc.CommandNameLength
};
bc.State = 2;
return(r);
}
return(null);
}
else if (bc.State == 2)
{
if (Length >= 4)
{
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
bc.CommandHash = s.ReadUInt32();
}
var r = new TryShiftResult {
Command = null, Position = Position + 4
};
bc.State = 3;
return(r);
}
return(null);
}
if (bc.State == 3)
{
if (Length >= 4)
{
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
bc.ParametersLength = s.ReadInt32();
}
if (bc.ParametersLength < 0 || bc.ParametersLength > Buffer.Length)
{
throw new InvalidOperationException("ParametersLengthOutOfBound");
}
var r = new TryShiftResult {
Command = null, Position = Position + 4
};
bc.State = 4;
return(r);
}
return(null);
}
else if (bc.State == 4)
{
if (Length >= bc.ParametersLength)
{
Byte[] Parameters;
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
Parameters = s.Read(bc.ParametersLength);
}
var cmd = new Command {
CommandName = bc.CommandName, CommandHash = bc.CommandHash, Parameters = Parameters
};
var r = new TryShiftResult {
Command = cmd, Position = Position + bc.ParametersLength
};
bc.CommandNameLength = 0;
bc.CommandName = null;
bc.CommandHash = 0;
bc.ParametersLength = 0;
bc.State = 0;
return(r);
}
return(null);
}
else
{
throw new InvalidOperationException();
}
}
public TryShiftResult TryShift(Byte[] Buffer, int Position, int Length)
{
if (State == 0)
{
if (Length >= 4)
{
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
CommandNameLength = s.ReadInt32();
}
if (CommandNameLength < 0 || CommandNameLength > 128)
{
throw new InvalidOperationException();
}
var r = new TryShiftResult {
Command = null, Position = Position + 4
};
State = 1;
return(r);
}
return(null);
}
else if (State == 1)
{
if (Length >= CommandNameLength)
{
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
CommandName = TextEncoding.UTF16.GetString(s.Read(CommandNameLength));
}
var r = new TryShiftResult {
Command = null, Position = Position + CommandNameLength
};
State = 2;
return(r);
}
return(null);
}
else if (State == 2)
{
if (Length >= 4)
{
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
CommandHash = s.ReadUInt32();
}
var r = new TryShiftResult {
Command = null, Position = Position + 4
};
State = 3;
return(r);
}
return(null);
}
if (State == 3)
{
if (Length >= 4)
{
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
ParametersLength = s.ReadInt32();
}
if (ParametersLength < 0 || ParametersLength > 8 * 1024)
{
throw new InvalidOperationException();
}
var r = new TryShiftResult {
Command = null, Position = Position + 4
};
State = 4;
return(r);
}
return(null);
}
else if (State == 4)
{
if (Length >= ParametersLength)
{
Byte[] Parameters;
using (var s = new ByteArrayStream(Buffer, Position, Length))
{
Parameters = s.Read(ParametersLength);
}
var cmd = new Command {
CommandName = CommandName, CommandHash = CommandHash, Parameters = Parameters
};
var r = new TryShiftResult {
Command = cmd, Position = Position + ParametersLength
};
CommandNameLength = 0;
CommandName = null;
CommandHash = 0;
ParametersLength = 0;
State = 0;
return(r);
}
return(null);
}
else
{
throw new InvalidOperationException();
}
}
