//todo: refactor using of poolName
//todo: exceptions handling + logging
//todo: add unit test
/// <summary>
/// It reads the lastest log file till the end and is triggered again after appearance the new log file.
/// </summary>
public void Start()
{
_logger.InfoFormat("Started IIS log reading. App name: {0}.", Settings.AppName);
var currentLogFilePath = _logFilePath; //to ensure the last reading
var currentCursor = 0;
while (true)
{
var logRecords = W3CEnumerable.FromFile(currentLogFilePath).ToArray();
if (!logRecords.Any())
{
Thread.Sleep(Settings.ReadingInterval);
continue;
}
if (currentCursor == logRecords.Length)
{
lock (_locker)
{
EnsureLastReading(ref currentLogFilePath, ref currentCursor);
}
Thread.Sleep(Settings.ReadingInterval);
continue;
}
var newRecords = logRecords.Skip(currentCursor);
foreach (var record in newRecords)
{
WriteMetrics(record);
}
_logger.InfoFormat("Added {0} records. App name: {1}", logRecords.Length - currentCursor, Settings.AppName);
currentCursor = logRecords.Length;
Thread.Sleep(Settings.ReadingInterval);
}
}
private void EnsureLastReading(ref string logPath, ref int cursor)
{
var isNewLogFileReady = logPath != null && logPath != _logFilePath;
if (isNewLogFileReady)
{
var logRecords = W3CEnumerable.FromFile(logPath).ToArray();
var newRecords = logRecords.Skip(cursor);
foreach (var record in newRecords)
{
WriteMetrics(record);
}
_logger.InfoFormat("Switched to new file {0} -> {1}. Got {2} records. App name: {3}.",
logPath, _logFilePath, cursor, Settings.AppName);
logPath = _logFilePath;
cursor = 0;
}
}