/// <summary>
/// The Finalize method calculates the values for
/// common session layer fields and assigns those
/// values to their respective fields.
/// </summary>
/// <param name="msg">
/// The FIX message to be finalized.
/// </param>
public static void Finalize(FixMessage msg)
{
// REC: Calculate sending time and add it to the message:
string strTimeStamp = DateTime.UtcNow.ToString("yyyyMMdd-HH:mm:ss.fff");
FixField fldSendingTime = msg.Header.GetField(52);
if (fldSendingTime != null)
{
fldSendingTime.Content = strTimeStamp;
}
else
{
msg.Header.AddField(new FixField(52, strTimeStamp));
}
// REC: Calculate the body length and add it to the message:
int fixBodyLength = FixCalculator.GetBodyLength(msg);
FixField fldBodyLength = msg.Header.GetField(9);
if (fldBodyLength != null)
{
fldBodyLength.Content = fixBodyLength.ToString();
}
else
{
msg.Header.AddField(new FixField(9, fixBodyLength.ToString()));
}
// REC: Calculate the checksum and add it to the message:
string strChecksum = string.Format("{0:000}", FixCalculator.GetChecksum(msg) % 256);
FixField fldChecksum = msg.Trailer.GetField(10);
if (fldChecksum != null)
{
fldChecksum.Content = strChecksum;
}
else
{
msg.Trailer.AddField(new FixField(10, strChecksum));
}
}
/// <summary>
/// The GetChecksum method calculates the checksum for
/// an instance of a FIX message.
/// </summary>
/// <param name="msg">
/// The FIX message to analyze.
/// </param>
/// <returns>
/// The FIX protocol checksum of the message.
/// </returns>
public static int GetChecksum(FixMessage msg)
{
int result = 0;
// REC: Process the header elements:
foreach (IFixElement hdrElement in msg.Header)
{
result += CalculateSum(hdrElement.Tag.ToString());
result += 0x3D;
result += CalculateSum(hdrElement.Content);
result += 0x01;
FixGroup group = hdrElement as FixGroup;
if (group != null)
{
foreach (FixCollection instance in group.Instances)
{
result += CalculateSum(instance);
}
}
}
// REC: Process the message body:
foreach (IFixElement msgElement in msg.Content)
{
result += CalculateSum(msgElement.Tag.ToString());
result += 0x3D;
result += CalculateSum(msgElement.Content);
result += 0x01;
FixGroup group = msgElement as FixGroup;
if (group != null)
{
foreach (FixCollection instance in group.Instances)
{
result += CalculateSum(instance);
}
}
}
// REC: Process the message trailer:
foreach (IFixElement trlElement in msg.Trailer)
{
if (trlElement.Tag == 10)
{
break;
}
result += CalculateSum(trlElement.Tag.ToString());
result += 0x3D;
result += CalculateSum(trlElement.Content);
result += 0x01;
FixGroup group = trlElement as FixGroup;
if (group != null)
{
foreach (FixCollection instance in group.Instances)
{
result += CalculateSum(instance);
}
}
}
return(result);
}
/// <summary>
/// The GetBodyLength method calculates the appropriate
/// value for the FIX BodyLength field of the specified
/// message, in accordance with the FIX Protocol.
/// </summary>
/// <param name="msg">
/// The message that the BodyLength value is to be
/// calculated from.
/// </param>
/// <returns>
/// The body length of the message, calculated according
/// to the method specified in the FIX protocol.
/// </returns>
public static int GetBodyLength(FixMessage msg)
{
int result = 0;
// REC: Calculate the combined length of all
// elements in the header of the message:
bool lengthFound = false;
foreach (IFixElement element in msg.Header)
{
if (lengthFound == true)
{
result += element.Tag.ToString().Length;
result += 1;
result += element.Content.Length;
result += 1;
FixGroup group = element as FixGroup;
if (group != null)
{
foreach (FixCollection instance in group.Instances)
{
result += CalculateLength(instance);
}
}
}
else
{
if (element.Tag == 9)
{
lengthFound = true;
}
}
}
// REC: Calculate the combined length of all
// the body elements in the message:
foreach (IFixElement element in msg.Content)
{
result += element.Tag.ToString().Length;
result += 1;
result += element.Content.Length;
result += 1;
FixGroup group = element as FixGroup;
if (group != null)
{
foreach (FixCollection instance in group.Instances)
{
result += CalculateLength(instance);
}
}
}
// REC: Calculate the combined length of all
// elements in the trailer of the message:
foreach (IFixElement element in msg.Trailer)
{
// REC: Terminate when the checksum field
// is encountered in the trailer:
if (element.Tag == 10)
{
break;
}
result += element.Tag.ToString().Length;
result += 1;
result += element.Content.Length;
result += 1;
FixGroup group = element as FixGroup;
if (group != null)
{
foreach (FixCollection instance in group.Instances)
{
result += CalculateLength(instance);
}
}
}
return(result);
}
