/// <inheritdoc />
protected override TimeSpan RunOnce(CancellationToken token)
{
bool performedWork = false;
LogFileSection section;
while (_pendingModifications.TryDequeue(out section) && !token.IsCancellationRequested)
{
if (section.IsReset)
{
Clear();
_lastLogEntry.Clear();
_currentSourceIndex = 0;
}
else if (section.IsInvalidate)
{
LogLineIndex startIndex = section.Index;
_fullSourceSection = new LogFileSection(0, (int)startIndex);
if (_currentSourceIndex > _fullSourceSection.LastIndex)
{
_currentSourceIndex = (int)section.Index;
}
Invalidate(_currentSourceIndex);
RemoveInvalidatedLines(_lastLogEntry, _currentSourceIndex);
}
else
{
_fullSourceSection = LogFileSection.MinimumBoundingLine(_fullSourceSection, section);
}
performedWork = true;
}
if (!_fullSourceSection.IsEndOfSection(_currentSourceIndex))
{
int remaining = _fullSourceSection.Index + _fullSourceSection.Count - _currentSourceIndex;
int nextCount = Math.Min(remaining, BatchSize);
var nextSection = new LogFileSection(_currentSourceIndex, nextCount);
_source.GetSection(nextSection, _buffer);
for (int i = 0; i < nextCount; ++i)
{
if (token.IsCancellationRequested)
{
break;
}
LogLine line = _buffer[i];
if (_lastLogEntry.Count == 0 || _lastLogEntry[0].LogEntryIndex == line.LogEntryIndex)
{
TryAddLogLine(line);
}
else if (line.LogEntryIndex != _lastLogEntry[0].LogEntryIndex)
{
TryAddLogEntry(_lastLogEntry);
_lastLogEntry.Clear();
TryAddLogLine(line);
}
}
_currentSourceIndex += nextCount;
}
if (_fullSourceSection.IsEndOfSection(_currentSourceIndex))
{
TryAddLogEntry(_lastLogEntry);
Listeners.OnRead(_indices.Count);
if (_source.EndOfSourceReached)
{
SetEndOfSourceReached();
}
}
if (performedWork)
{
return(TimeSpan.Zero);
}
return(_maximumWaitTime);
}
