/// <summary>
/// Perform the roll for the next date.
/// </summary>
/// <param name="rollDateTime">The roll date.</param>
internal void PerformRoll(DateTime rollDateTime)
{
string actualFileName = ((FileStream)((StreamWriter)this.owner.writer).BaseStream).Name;
if (this.owner.rollFileExistsBehavior == RollFileExistsBehavior.Overwrite &&
string.IsNullOrEmpty(this.owner.timestampPattern))
{
// no roll will be actually performed: no timestamp pattern is available, and
// the roll behavior is overwrite, so the original file will be truncated
this.owner.writer.Close();
File.WriteAllText(actualFileName, string.Empty);
}
else
{
// calculate archive name
string archiveFileName = this.ComputeArchiveFileName(actualFileName, rollDateTime);
// close file
this.owner.writer.Close();
// move file
SafeMove(actualFileName, archiveFileName, rollDateTime);
// purge if necessary
this.PurgeArchivedFiles(actualFileName);
}
this.owner.writer.Dispose();
this.owner.writer = new TallyKeepingFileStreamWriter(this.owner.file.Open(FileMode.Append, FileAccess.Write, FileShare.Read));
this.managedWriter = null;
this.nextRollDateTime = null;
this.UpdateRollingInformationIfNecessary();
}
/// <summary>
/// Updates book keeping information necessary for rolling, as required by the specified rolling configuration.
/// </summary>
/// <returns>true if update was successful, false if an error occurred.</returns>
public bool UpdateRollingInformationIfNecessary()
{
StreamWriter currentWriter = null;
// replace writer with the tally keeping version if necessary for size rolling
if (this.owner.rollSizeInBytes > 0 && this.managedWriter == null)
{
currentWriter = this.owner.writer as StreamWriter;
if (currentWriter == null)
{
// TWTL couldn't acquire the writer - abort
return(false);
}
var actualFileName = ((FileStream)currentWriter.BaseStream).Name;
currentWriter.Close();
FileStream fileStream = null;
try
{
fileStream = File.Open(actualFileName, FileMode.Append, FileAccess.Write, FileShare.Read);
this.managedWriter = new TallyKeepingFileStreamWriter(fileStream, GetEncodingWithFallback());
}
catch (IOException)
{
// there's a slight chance of error here - abort if this occurs and just let TWTL handle it without attempting to roll
return(false);
}
this.owner.writer = this.managedWriter;
}
// compute the next roll date if necessary
if (this.owner.rollInterval != RollInterval.None && this.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
this.nextRollDateTime
= this.CalculateNextRollDate(File.GetCreationTime(((FileStream)((StreamWriter)this.owner.writer).BaseStream).Name));
}
catch (IOException)
{
this.nextRollDateTime = DateTime.MaxValue; // disable rolling if no 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);
}
/// <summary>
/// Initializes a new instance of the <see cref="RollingFlatFileSink"/> class with the specified values.
/// </summary>
/// <param name="fileName">The filename where the entries will be logged.</param>
/// <param name="rollSizeKB">The maximum file size (KB) before rolling.</param>
/// <param name="timestampPattern">The date format that will be appended to the new roll file.</param>
/// <param name="rollFileExistsBehavior">Expected behavior that will be used when the roll file has to be created.</param>
/// <param name="rollInterval">The time interval that makes the file to be rolled.</param>
/// <param name="maxArchivedFiles">The maximum number of archived files to keep.</param>
/// <param name="isAsync">Specifies if the writing should be done asynchronously, or synchronously with a blocking call.</param>
public RollingFlatFileSink(string fileName, int rollSizeKB, string timestampPattern, RollFileExistsBehavior rollFileExistsBehavior, RollInterval rollInterval, int maxArchivedFiles, bool isAsync)
{
this.file = FileUtil.ProcessFileNameForLogging(fileName);
if (rollInterval == RollInterval.None)
{
if (!string.IsNullOrWhiteSpace(timestampPattern))
{
Guard.ValidateTimestampPattern(timestampPattern, "timestampPattern");
}
}
else
{
Guard.ValidateTimestampPattern(timestampPattern, "timestampPattern");
}
this.writer = new TallyKeepingFileStreamWriter(this.file.Open(FileMode.Append, FileAccess.Write, FileShare.Read));
this.rollSizeInBytes = rollSizeKB * 1024L;
this.timestampPattern = timestampPattern;
this.rollFileExistsBehavior = rollFileExistsBehavior;
this.rollInterval = rollInterval;
this.maxArchivedFiles = maxArchivedFiles;
this.isAsync = isAsync;
this.rollingHelper = new StreamWriterRollingHelper(this);
if (rollInterval == RollInterval.Midnight && !isAsync)
{
var now = this.rollingHelper.DateTimeProvider.CurrentDateTime;
var midnight = now.AddDays(1).Date;
var callback = new TimerCallback(delegate(object o)
{
lock (this.lockObject)
{
this.rollingHelper.RollIfNecessary();
}
});
this.timer = new Timer(callback, null, midnight.Subtract(now), TimeSpan.FromDays(1));
}
this.flushSource.SetResult(true);
if (isAsync)
{
this.cancellationTokenSource = new CancellationTokenSource();
this.pendingEntries = new BlockingCollection <string>();
this.asyncProcessorTask = Task.Factory.StartNew((Action)this.WriteEntries, TaskCreationOptions.LongRunning);
}
}