private void WriteToDisk()
{
var tasksToNotify = new List<Action<Exception>>();
while (true)
{
if (cts.IsCancellationRequested)
{
FlushToDisk(tasksToNotify, closing: true);
return;
}
WriteState item;
if (hadWrites)
{
if ((DateTime.UtcNow - lastWrite) > options.MaxTimeToWaitForFlush)
{
// we have to flush to disk now, because we have writes and nothing else is forthcoming
// or we have so many writes, that we need to flush to clear the buffers
FlushToDisk(tasksToNotify);
continue;
}
}
if (itemsToWrite.TryDequeue(out item) == false)
{
if (hadWrites)
{
FlushToDisk(tasksToNotify);
}
else
{
if (deleteCount > (eventsCount / 4)) // we have > 25% wasted space
{
// we waited enough time to be pretty sure we are idle
// and can run compaction without too much problems.
if (hasItems.Wait(options.IdleTime, cts.Token) == false)
{
Compact();
continue;
}
}
else
{
hasItems.Wait(cts.Token);
}
hasItems.Reset();
}
continue;
}
StreamInformation info;
idToPos.TryGetValue(item.Id, out info);
var prevPos = info == null ? DoesNotExists : info.LastPosition;
var currentPos = file.Position;
var persistedEvent = new PersistedEvent
{
Id = item.Id,
Data = item.Data,
State = item.State,
Previous = prevPos,
Metadata = item.Metadata
};
WriteItem(persistedEvent, binaryWriter);
var action = CreateCompletionAction(tasksToNotify, item, currentPos);
tasksToNotify.Add(action);
hadWrites = true;
}
}
private static void WriteItem(PersistedEvent item, BinaryWriter binaryWriter)
{
binaryWriter.Write(item.Id);
binaryWriter.Write(item.Previous);
binaryWriter.Write(item.StreamLength);
binaryWriter.Write((int)item.State);
item.Metadata.WriteTo(new BsonWriter(binaryWriter));
item.Data.WriteTo(new BsonWriter(binaryWriter));
}
