public void Scavenge(IIndexScavengerLog log, CancellationToken ct)
{
GetExclusiveBackgroundTask(ct);
var sw = Stopwatch.StartNew();
try
{
Log.Info("Starting scavenge of TableIndex.");
ScavengeInternal(log, ct);
}
finally
{
// Since scavenging indexes is the only place the ExistsAt optimization makes sense (and takes up a lot of memory), we can clear it after an index scavenge has completed.
TFChunkReaderExistsAtOptimizer.Instance.DeOptimizeAll();
lock (_awaitingTablesLock)
{
_backgroundRunning = false;
_backgroundRunningEvent.Set();
TryProcessAwaitingTables();
}
Log.Info("Completed scavenge of TableIndex. Elapsed: {elapsed}", sw.Elapsed);
}
}
private void ScavengeInternal(IIndexScavengerLog log, CancellationToken ct)
{
var toScavenge = _indexMap.InOrder().ToList();
foreach (var pTable in toScavenge)
{
var startNew = Stopwatch.StartNew();
try
{
ct.ThrowIfCancellationRequested();
using (var reader = _tfReaderFactory())
{
var indexmapFile = Path.Combine(_directory, IndexMapFilename);
var scavengeResult = _indexMap.Scavenge(pTable.Id, ct,
(streamId, currentHash) => UpgradeHash(streamId, currentHash),
entry => reader.ExistsAt(entry.Position),
entry => ReadEntry(reader, entry.Position), _fileNameProvider, _ptableVersion,
_indexCacheDepth, _skipIndexVerify);
if (scavengeResult.IsSuccess)
{
_indexMap = scavengeResult.ScavengedMap;
_indexMap.SaveToFile(indexmapFile);
scavengeResult.OldTable.MarkForDestruction();
var entriesDeleted = scavengeResult.OldTable.Count - scavengeResult.NewTable.Count;
log.IndexTableScavenged(scavengeResult.Level, scavengeResult.Index, startNew.Elapsed, entriesDeleted, scavengeResult.NewTable.Count, scavengeResult.SpaceSaved);
}
else
{
log.IndexTableNotScavenged(scavengeResult.Level, scavengeResult.Index, startNew.Elapsed, pTable.Count, "");
}
}
}
catch (OperationCanceledException)
{
log.IndexTableNotScavenged(-1, -1, startNew.Elapsed, pTable.Count, "Scavenge cancelled");
throw;
}
catch (Exception ex)
{
log.IndexTableNotScavenged(-1, -1, startNew.Elapsed, pTable.Count, ex.Message);
throw;
}
}
}
public void Scavenge(IIndexScavengerLog log, CancellationToken ct)
{
ScavengeCount++;
}
public void Scavenge(IIndexScavengerLog log, CancellationToken ct)
{
throw new NotImplementedException();
}
