private void ReadAllFromDisk()
{
file.Position = ReadOffsets(Path.GetFileName(streamSource.GetLatestName(dataPath)));
while (true)
{
using (var reader = new BinaryReader(file, Encoding.UTF8, leaveOpen: true))
{
var itemPos = file.Position;
PersistedEvent persistedEvent;
try
{
persistedEvent = ReadPersistedEvent(reader);
eventsCount++;
}
catch (EndOfStreamException)
{
lastWriteSnapshotCount = eventsCount;
lastWriteSnapshotTime = DateTime.UtcNow;
return;
}
catch (Exception e)
{
log.WarnException("Error during initial events read, file corrupted", e);
if (options.AllowRecovery == false)
throw;
file.SetLength(itemPos);
log.Warn("Recovered from corrupted file by truncating file to last known good position: " + itemPos);
return;
}
switch (persistedEvent.State)
{
case EventState.Event:
case EventState.Snapshot:
idToPos.AddOrUpdate(persistedEvent.Id, s => new StreamInformation
{
LastPosition = itemPos,
StreamLength = 1
}, (s, information) => new StreamInformation
{
LastPosition = itemPos,
StreamLength = information.StreamLength + 1
});
break;
case EventState.Delete:
deleteCount++;
var streamInformation = new StreamInformation
{
LastPosition = Deleted,
StreamLength = 0
};
idToPos.AddOrUpdate(persistedEvent.Id, s => streamInformation, (s, information) =>
{
deleteCount += information.StreamLength;
return streamInformation;
});
break;
default:
throw new ArgumentOutOfRangeException(persistedEvent.State.ToString());
}
}
}
}
private void HandleFlushSuccessful(WriteState item, long currentPos)
{
switch (item.State)
{
case EventState.Event:
case EventState.Snapshot:
idToPos.AddOrUpdate(item.Id, s => new StreamInformation
{
LastPosition = currentPos,
StreamLength = 1
}, (s, l) => new StreamInformation
{
LastPosition = currentPos,
StreamLength = l.StreamLength + 1
});
break;
case EventState.Delete:
var streamInformation = new StreamInformation
{
LastPosition = Deleted,
StreamLength = 0
};
idToPos.AddOrUpdate(item.Id, s => streamInformation, (s, l) =>
{
deleteCount += l.StreamLength;
return streamInformation;
});
break;
default:
throw new ArgumentOutOfRangeException(item.State.ToString());
}
item.TaskCompletionSource.SetResult(null);
}
private long ReadOffsets(string currentFileName)
{
long position;
if (streamSource.Exists(offsetsPath) == false)
return 0;
using (var offsets = streamSource.OpenRead(offsetsPath))
using(var reader = new BinaryReader(offsets))
{
var fileName = reader.ReadString();
if(fileName != currentFileName)
{
// wrong file, skipping
streamSource.DeleteOnClose(offsetsPath);
return 0;
}
position = reader.ReadInt64();
while (true)
{
string key;
try
{
key = reader.ReadString();
}
catch (EndOfStreamException)
{
break;
}
var pos = reader.ReadInt64();
var count = reader.ReadInt32();
idToPos[key] = new StreamInformation
{
LastPosition = pos,
StreamLength = count
};
}
}
return position;
}
public void Compact()
{
var newPositions = new Dictionary<string, StreamInformation>(StringComparer.InvariantCultureIgnoreCase);
var newFilePath = dataPath + ".compacting";
streamSource.DeleteIfExists(newFilePath);
using (var newFile = streamSource.OpenReadWrite(newFilePath))
using (var newWriter = new BinaryWriter(newFile))
using (var current = streamSource.OpenRead(dataPath))
using (var reader = new BinaryReader(current))
{
while (true)
{
PersistedEvent persistedEvent;
try
{
persistedEvent = ReadPersistedEvent(reader);
}
catch (EndOfStreamException)
{
break;
}
StreamInformation value;
if (idToPos.TryGetValue(persistedEvent.Id, out value) == false)
continue;
if (value.LastPosition == Deleted || value.LastPosition == DoesNotExists)
continue;
StreamInformation information;
if (newPositions.TryGetValue(persistedEvent.Id, out information) == false)
{
information =new StreamInformation
{
LastPosition = DoesNotExists,
StreamLength = 0
};
}
persistedEvent.Previous = information.LastPosition;
newPositions[persistedEvent.Id] = new StreamInformation
{
LastPosition = newFile.Position,
StreamLength = persistedEvent.StreamLength
};
WriteItem(persistedEvent, newWriter);
}
streamSource.Flush(newFile);
compactionLock.EnterWriteLock();
try
{
newFile.Close();
streamSource.DeleteOnClose(dataPath);
Stream result;
while (cachedReadStreams.TryDequeue(out result))
{
result.Dispose();
}
binaryWriter.Dispose();
file.Dispose();
streamSource.RenameToLatest(newFilePath, dataPath);
file = streamSource.OpenReadWrite(dataPath);
binaryWriter = new BinaryWriter(file, Encoding.UTF8, leaveOpen: true);
streamSource.DeleteIfExists("data.offsets");
FlushOffsets();
idToPos.Clear();
foreach (var val in newPositions)
{
idToPos[val.Key] = val.Value;
}
}
finally
{
compactionLock.ExitWriteLock();
}
}
}
