private async Task AppendInternalAsync(PendingWrite mine)
{
using (await _asyncLock.LockAsync())
{
var completed = new List<PendingWrite>();
try
{
if (mine.Done())
return;
await MakeRoomForWrite(mine.Stream.Length, mine.Etag);
var seq = _options.Status.NextSeqeunce();
var room = _currentBufferSize - _memTable.MemTable.ApproximateMemoryUsage;
PendingWrite write;
while (_pending.TryDequeue(out write))
{
var memoryHandle = _memTable.MemTable.Write(write.Stream);
await _memTable.Log.Write7BitEncodedIntAsync(memoryHandle.Size);
using (var stream = _memTable.MemTable.Read(memoryHandle))
{
await _memTable.Log.CopyFromAsync(stream);
}
_memTable.MemTable.Add(seq, ItemType.Value, EtagToSlice(write.Etag), memoryHandle);
room -= memoryHandle.Size;
completed.Add(write);
PendingWrite next;
if (_pending.TryPeek(out next) == false)
break;
if (next.Stream.Length > room) // don't use more than the current mem table allows
break;
}
foreach (var pendingWrite in completed)
{
pendingWrite.Result.SetResult(null);
}
}
catch (Exception e)
{
foreach (var pendingWrite in completed)
{
pendingWrite.Result.SetException(e);
}
throw;
}
finally
{
_writeCompletedEvent.Pulse();
}
}
}
public async Task AppendAsync(RavenJObject data)
{
if (disposed)
throw new ObjectDisposedException("EventStream");
var nextEtag = _options.Status.NextEtag();
data["@etag"] = nextEtag.ToString();
data["@date"] = DateTime.UtcNow.ToString("o");
using (var stream = new BufferPoolMemoryStream(_options.BufferPool))
{
var bsonWriter = new BsonWriter(stream);
data.WriteTo(bsonWriter);
bsonWriter.Flush();
stream.Position = 0;
var mine = new PendingWrite(stream, nextEtag);
_pending.Enqueue(mine);
while (mine.Done() == false && _pending.Peek() != mine)
{
await _writeCompletedEvent.WaitAsync();
}
if (mine.Done())
return;
await AppendInternalAsync(mine);
}
}