private string AppendSuffix(string parentId, string suffix, char delimiter)
{
#if DEBUG
suffix = OperationName.Replace('.', '-') + "-" + suffix;
#endif
if (parentId.Length + suffix.Length < RequestIdMaxLength)
{
return(parentId + suffix + delimiter);
}
//Id overflow:
//find position in RequestId to trim
int trimPosition = RequestIdMaxLength - 9; // overflow suffix + delimiter length is 9
while (trimPosition > 1)
{
if (parentId[trimPosition - 1] == '.' || parentId[trimPosition - 1] == '_')
{
break;
}
trimPosition--;
}
//ParentId is not valid Request-Id, let's generate proper one.
if (trimPosition == 0)
{
return(GenerateRootId());
}
//generate overflow suffix
string overflowSuffix = ((int)GetRandomNumber()).ToString("x8");
return(parentId.Substring(0, trimPosition) + overflowSuffix + '#');
}
private string GenerateRootId()
{
if (s_uniqPrefix == null)
{
// Here we make an ID to represent the Process/AppDomain. Ideally we use process ID but
// it is unclear if we have that ID handy. Currently we use low bits of high freq tick
// as a unique random number (which is not bad, but loses randomness for startup scenarios).
Interlocked.CompareExchange(ref s_uniqPrefix, GenerateInstancePrefix(), null);
}
#if DEBUG
string ret = s_uniqPrefix + "-" + OperationName.Replace('.', '-') + "-" + Interlocked.Increment(ref s_currentRootId).ToString("x") + '.';
#else // To keep things short, we drop the operation name
string ret = s_uniqPrefix + "-" + Interlocked.Increment(ref s_currentRootId).ToString("x") + '.';
#endif
return(ret);
}
