private void ReadLogFile()
{
_running = true;
_offset = FindInitialOffset();
Util.DebugLog?.WriteLine($"LogWatcher.ReadLogFile: offset={_offset}");
while (!_stop)
{
var fileInfo = new FileInfo(_info.FilePath);
if (fileInfo.Exists)
{
if (!_logFileExists)
{
_logFileExists = true;
OnLogFound?.Invoke(this, new LogFoundEventArgs(_info.Name));
Util.DebugLog?.WriteLine("LogWatcher.ReadLogFile: found " + _info.Name);
}
using (var fs = new FileStream(_info.FilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
fs.Seek(_offset, SeekOrigin.Begin);
if (fs.Length == _offset)
{
Thread.Sleep(_readDelay);
continue;
}
var lines = new List <LogLineItem>();
using (var sr = new StreamReader(fs))
{
string line;
while (!sr.EndOfStream && (line = sr.ReadLine()) != null)
{
if (line.StartsWith("D "))
{
var next = sr.Peek();
if (!sr.EndOfStream && !(next == 'D' || next == 'W'))
{
break;
}
var logLine = new LogLineItem(_info.Name, line);
if ((!_info.HasFilters || (_info.StartsWithFilters?.Any(x => logLine.LineContent.StartsWith(x)) ?? false) ||
(_info.ContainsFilters?.Any(x => logLine.LineContent.Contains(x)) ?? false)) &&
logLine.Time >= _startingPoint)
{
lines.Add(logLine);
}
}
else
{
OnIgnoredLine?.Invoke(this, new RawLogLineEventArgs(line));
}
_offset += Encoding.UTF8.GetByteCount(line + Environment.NewLine);
}
}
OnNewLine?.Invoke(this, new LogLineEventArgs(lines));
}
}
Thread.Sleep(_readDelay);
}
_running = false;
}
private long FindInitialOffset()
{
var fileInfo = new FileInfo(_info.FilePath);
if (fileInfo.Exists)
{
using (var fs = new FileStream(_info.FilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
using (var sr = new StreamReader(fs, Encoding.ASCII))
{
var offset = 0;
while (offset < fs.Length)
{
var sizeDiff = 4096 - Math.Min(fs.Length - offset, 4096);
offset += 4096;
var buffer = new char[4096];
fs.Seek(Math.Max(fs.Length - offset, 0), SeekOrigin.Begin);
sr.ReadBlock(buffer, 0, 4096);
var skip = 0;
for (var i = 0; i < 4096; i++)
{
skip++;
if (buffer[i] == '\n')
{
break;
}
}
offset -= skip;
var lines = (new string(buffer.Skip(skip).ToArray())).Split(new[] { Environment.NewLine }, StringSplitOptions.None).ToArray();
for (int i = lines.Length - 1; i > 0; i--)
{
if (string.IsNullOrWhiteSpace(lines[i].Trim('\0')))
{
continue;
}
var logLine = new LogLineItem(_info.Name, lines[i]);
if (logLine.Time < _startingPoint)
{
var negativeOffset = lines.Take(i + 1).Sum(x => Encoding.UTF8.GetByteCount(x + Environment.NewLine));
return(Math.Max(fs.Length - offset + negativeOffset + sizeDiff, 0));
}
}
}
}
}
return(0);
}