/// <summary>
/// Updates the index for the log
/// </summary>
/// <param name="progress">Action to report indexing progress</param>
/// <param name="cancellationToken">CancellationToken for cancelling the index update</param>
public bool Update(Action <double> progress, CancellationToken cancellationToken)
{
var sw = Stopwatch.StartNew();
var updated = false;
IsUpdating = true;
// find all files of the log on disk
var files = FindFiles();
// remove indexed file which are no longer present
foreach (var file in _index.Files.Where(f => !files.Any(p => p.Item1 == f.Item1 && p.Item2 == f.Item2)))
{
_index.Remove(file.Item1, file.Item2);
updated = true;
}
// find the files which were changed since the last indexing or which are not present in the index
var indexFiles = _index.Files;
var indexTimestamp = indexFiles.Select(f => f.Item3).Concat(new[] { DateTime.MinValue }).Max();
var changedFiles = files
.GroupJoin(indexFiles, f => f.Item1 + f.Item2, f => f.Item1 + f.Item2, (file, index) => new { file, index = index.FirstOrDefault() })
.Where(a => a.index == null || a.file.Item3 > a.index.Item3)
.Select(a => a.file)
.ToList();
// when the tailing log file has changed just process the new lines, otherwise completely index all changed files
if (changedFiles.Count > 0)
{
// update the maximum progress value
_progressMaximum = changedFiles.Sum(f => f.Item4);
// update the index with the changed files
var progressCount = 0L;
var stateCollection = new ConcurrentStack <object[]>();
Parallel.ForEach(changedFiles,
element =>
{
// create the indexer state for the file
var state = _indexers.Select(i => i.Initialize(element.Item5, element.Item1, element.Item2, element.Item4, element.Item3, false)).ToArray();
// create a stream for the file or archive member
var length = 0L;
var stream = OpenFileStream(element.Item1, element.Item2, out length);
// read and tokenize the file
CountingReader streamreader = null;
TokenReader tokenreader = null;
var sw2 = Stopwatch.StartNew();
try
{
var buffer = new Token[1024];
streamreader = new CountingReader(stream, p => progress?.Invoke(Interlocked.Add(ref progressCount, p) * 100.0 / _progressMaximum), cancellationToken);
tokenreader = new TokenReader(streamreader, element.Item1, element.Item2, 0, streamreader.CurrentEncoding);
var count = 0;
while ((count = tokenreader.Read(buffer, 0, buffer.Length)) > 0)
{
for (var i = 0; i < _indexers.Length; i++)
{
_indexers[i].Update(state[i], buffer, count);
}
}
}
finally
{
if (tokenreader != null)
{
tokenreader.Dispose();
}
else if (streamreader != null)
{
streamreader.Dispose();
}
sw2.Stop();
_logger.Info($"Log::Read(): Reading {element.Item1}:{element.Item2} completed in {sw2.ElapsedMilliseconds}ms");
}
// complete the files on the indexers
for (var i = 0; i < _indexers.Length; i++)
{
_indexers[i].Complete(state[i]);
}
});
// complete the indexers
for (var i = 0; i < _indexers.Length; i++)
{
_indexers[i].Complete();
}
updated = true;
}
// send the collection changed event
if (updated)
{
CollectionChanged?.Invoke(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
}
sw.Stop();
// signal the end of the update
IsUpdating = false;
// raise property changes
if (updated)
{
_logger.Info($"Log::Update(): Updating index completed in {sw.ElapsedMilliseconds}ms");
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Files)));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Count)));
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Tokens)));
}
else
{
_logger.Info("Log::Update(): Index is up to date");
}
return(updated);
}
