/// <summary>
/// Create a log file scanner
/// </summary>
/// <param name="pathAndMask">File path and mask with glob syntax (i.e. /var/log/auth*.log)</param>
/// <param name="maxFileSizeBytes">Max size of file (in bytes) before it is deleted or 0 for unlimited</param>
/// <param name="fileProcessingIntervalMilliseconds">How often to process files, in milliseconds, less than 1 for manual processing, in which case <see cref="ProcessFiles"/> must be called as needed.</param>
/// <param name="encoding">Encoding or null for utf-8. The encoding must either be single or variable byte, like ASCII, Ansi, utf-8, etc. UTF-16 and the like are not supported.</param>
/// <param name="maxLineLength">Maximum line length before considering the file a binary file and failing</param>
public LogFileScanner(string pathAndMask, long maxFileSizeBytes = 0, int fileProcessingIntervalMilliseconds = 0, Encoding encoding = null, int maxLineLength = 8192)
{
// glob syntax, replace all backslash to forward slash
PathAndMask = pathAndMask;
PathAndMask.ThrowIfNullOrEmpty(nameof(pathAndMask), "Must pass a non-empty path and mask to log file scanner");
// set properties
this.maxFileSize = maxFileSizeBytes;
this.encoding = encoding ?? Encoding.UTF8;
this.maxLineLength = maxLineLength;
try
{
// add initial files
foreach (WatchedFile file in LogFileScanner.GetFiles(PathAndMask))
{
watchedFiles.Add(file);
}
}
catch
{
// generally catching all exceptions and not reporting is bad, but in this case we don't care,
// we will try to get files on every ProcessFiles call and can throw the exception then
}
// setup timer to process files
if (fileProcessingIntervalMilliseconds > 0)
{
fileProcessingTimer = new System.Timers.Timer(fileProcessingIntervalMilliseconds);
fileProcessingTimer.Elapsed += (sender, args) => ProcessFiles();
fileProcessingTimer.Start();
}
}
private HashSet <WatchedFile> GetCurrentWatchedFiles()
{
// read in existing files that match the mask in the directory being watched
HashSet <WatchedFile> watchedFilesCopy = new HashSet <WatchedFile>();
foreach (WatchedFile file in LogFileScanner.GetFiles(PathAndMask))
{
watchedFilesCopy.Add(file);
}
lock (watchedFiles)
{
// remove files that no longer exist
foreach (WatchedFile existing in watchedFiles.ToArray())
{
if (!watchedFilesCopy.Contains(existing))
{
Logger.Debug("Removing parsed log file {0}", existing.FileName);
watchedFiles.Remove(existing);
}
}
// add new files
foreach (WatchedFile newFile in watchedFilesCopy)
{
// add the file, will fail if it already exists
if (watchedFiles.Add(newFile))
{
Logger.Debug("Adding parsed log file {0}", newFile.FileName);
}
}
// make a copy of everything so we can enumerate outside a lock
watchedFilesCopy.Clear();
foreach (WatchedFile file in watchedFiles)
{
watchedFilesCopy.Add(file);
}
}
return(watchedFilesCopy);
}