private void PerformRoll(DateTime rollDateTime)
{
string actualFileName = ((FileStream)((StreamWriter)_owner.Writer).BaseStream).Name;
string archiveFileName = ComputeArchiveFileName(actualFileName, rollDateTime);
_owner.Writer.Close();
SafeMove(actualFileName, archiveFileName, rollDateTime);
PurgeArchivedFiles(actualFileName);
// update writer - let TWTL open the file as needed to keep consistency
_owner.Writer = null;
_tallyWriter = null;
_nextRollDateTime = null;
UpdateRollingInformationIfNecessary();
}
private bool UpdateRollingInformationIfNecessary()
{
// replace writer with the tally keeping version if necessary for size rolling
if (_owner._rollSize > 0 && _tallyWriter == null)
{
var currentWriter = _owner.Writer as StreamWriter;
if (currentWriter == null)
{
// couldn't acquire the writer - abort
return(false);
}
String actualFileName = ((FileStream)currentWriter.BaseStream).Name;
currentWriter.Close();
try {
FileStream fileStream = File.Open(actualFileName, FileMode.Append, FileAccess.Write, FileShare.Read);
_tallyWriter = new TallyStreamWriter(fileStream);
}
catch (Exception) {
// there's a slight chance of error here - abort if this occurs and just let TWTL handle it without attempting to roll
return(false);
}
_owner.Writer = _tallyWriter;
}
// compute the next roll date if necessary
if (_owner._rollInterval != RollInterval.None && _nextRollDateTime == null)
{
try {
// casting should be safe at this point - only file stream writers can be the writers for the owner trace listener.
// it should also happen rarely
_nextRollDateTime = CalculateNextRollDate(
File.GetCreationTime(((FileStream)((StreamWriter)_owner.Writer).BaseStream).Name));
}
catch (Exception) {
_nextRollDateTime = DateTime.MaxValue; // disable rolling if not date could be retrieved.
// there's a slight chance of error here - abort if this occurs and just let TWTL handle it without attempting to roll
return(false);
}
}
return(true);
}
