public bool IsStreamDeleted(TStreamId streamId) => _readIndex.IsStreamDeleted(streamId);
private void ScavengeChunk(TFChunk oldChunk)
{
var sw = Stopwatch.StartNew();
var chunkNumber = oldChunk.ChunkHeader.ChunkStartNumber;
var newScavengeVersion = oldChunk.ChunkHeader.ChunkScavengeVersion + 1;
var chunkSize = oldChunk.ChunkHeader.ChunkSize;
var tmpChunkPath = Path.Combine(_db.Config.Path, Guid.NewGuid() + ".scavenge.tmp");
var newChunkPath = _db.Config.FileNamingStrategy.GetFilenameFor(chunkNumber, newScavengeVersion);
Log.Trace("Scavenging chunk #{0} ({1}) started. Scavenged chunk: {2} --> {3}.",
chunkNumber,
Path.GetFileName(oldChunk.FileName),
Path.GetFileName(tmpChunkPath),
Path.GetFileName(newChunkPath));
TFChunk newChunk;
try
{
newChunk = TFChunk.CreateNew(tmpChunkPath, chunkSize, chunkNumber, newScavengeVersion);
}
catch (IOException exc)
{
Log.ErrorException(exc, "IOException during creating new chunk for scavenging purposes. Ignoring...");
return;
}
var positionMapping = new List <PosMap>();
var positioningNeeded = false;
var result = oldChunk.TryReadFirst();
int cnt = 0;
while (result.Success)
{
cnt += 1;
var record = result.LogRecord;
switch (record.RecordType)
{
case LogRecordType.Prepare:
{
var prepare = (PrepareLogRecord)record;
if (!_readIndex.IsStreamDeleted(prepare.EventStreamId) ||
(prepare.Flags & PrepareFlags.StreamDelete) != 0) // delete tombstone should be left
{
var posMap = WriteRecord(newChunk, record);
positionMapping.Add(posMap);
positioningNeeded = posMap.LogPos != posMap.ActualPos;
}
break;
}
case LogRecordType.Commit:
{
var posMap = WriteRecord(newChunk, record);
positionMapping.Add(posMap);
positioningNeeded = posMap.LogPos != posMap.ActualPos;
break;
}
default:
throw new ArgumentOutOfRangeException();
}
if (result.NextPosition == -1)
{
break;
}
result = oldChunk.TryReadSameOrClosest((int)result.NextPosition);
}
var oldSize = oldChunk.ChunkFooter.ActualChunkSize + oldChunk.ChunkFooter.MapSize + ChunkHeader.Size + ChunkFooter.Size;
var newSize = newChunk.ActualDataSize
+ (positioningNeeded ? sizeof(ulong) * positionMapping.Count : 0)
+ ChunkHeader.Size
+ ChunkFooter.Size;
if (false && oldSize <= newSize)
{
Log.Trace("Scavenging of chunk #{0} ({1}) completed in {2}.\n"
+ "Old version is kept as it is smaller.\n"
+ "Old chunk size: {3}, scavenged size: {4}.\n"
+ "Scavenged chunk removed.",
chunkNumber,
oldChunk.FileName,
sw.Elapsed,
oldSize,
newSize);
newChunk.Dispose();
File.Delete(newChunk.FileName);
}
else
{
newChunk.CompleteScavenge(positioningNeeded ? positionMapping : null);
newChunk.Dispose();
File.Move(tmpChunkPath, newChunkPath);
newChunk = TFChunk.FromCompletedFile(newChunkPath);
var removedChunk = _db.Manager.SwapChunk(chunkNumber, newChunk);
Debug.Assert(ReferenceEquals(removedChunk, oldChunk)); // only scavenging could switch, so old should be always same
oldChunk.MarkForDeletion();
Log.Trace("Scavenging of chunk #{0} ({1}) completed in {2} into ({3} --> {4}).\n"
+ "Old size: {5}, new size: {6}, new scavenge version: {7}.",
chunkNumber,
Path.GetFileName(oldChunk.FileName),
sw.Elapsed,
Path.GetFileName(tmpChunkPath),
Path.GetFileName(newChunkPath),
oldSize,
newSize,
newScavengeVersion);
}
}
public static bool IsStreamDeleted <TStreamId>(this IReadIndex <TStreamId> self, string streamName)
{
var streamId = self.GetStreamId(streamName);
return(self.IsStreamDeleted(streamId));
}