void AppendToStream(IIdentity id, string envelopeId, Applied then, string explanation)
{
var stream = _factory.GetOrCreateStream(IdentityConvert.ToStream(id));
var b = new EnvelopeBuilder("unknown");
b.AddString("caused-by", envelopeId);
if (!String.IsNullOrEmpty(explanation))
{
b.AddString("explain", explanation);
}
foreach (var e in then.Events)
{
b.AddItem((object)e);
}
var data = _streamer.SaveEnvelopeData(b.Build());
Context.Debug("?? Append {0} at v{3} to '{1}' in thread {2}", then.Events.Count,
IdentityConvert.ToStream(id),
Thread.CurrentThread.ManagedThreadId,
then.Version);
if (!stream.TryAppend(data, TapeAppendCondition.VersionIs(then.Version)))
{
throw new InvalidOperationException("Failed to update the stream - it has been changed concurrently");
}
}
public long TryAppend(byte[] buffer, TapeAppendCondition appendCondition = new TapeAppendCondition())
{
if (buffer == null)
throw new ArgumentNullException("buffer");
if (buffer.Length == 0)
throw new ArgumentException("Buffer must contain at least one byte.");
long version;
int lastBlockSize;
long offset;
long firstVersion;
long count;
List<string> blockNames;
var blob = _container.GetBlockBlobReference(_blobName);
if (blob.Exists())
{
var blockList = blob.DownloadBlockList().ToArray();
blockNames = blockList.Select(bl => bl.Name).ToList();
var lastBlock = blockList.LastOrDefault();
if (default(ListBlockItem) == lastBlock)
{
version = 0;
lastBlockSize = int.MaxValue;
offset = 0;
firstVersion = 1;
count = 0;
}
else
{
var nameInfo = Naming.GetInfo(DecodeName(lastBlock.Name));
firstVersion = nameInfo.FirstVersion;
version = nameInfo.FirstVersion - 1 + nameInfo.Count;
count = nameInfo.Count;
if (lastBlock.Size > int.MaxValue)
throw new InvalidOperationException("last block size must be in 'int' range");
lastBlockSize = (int) lastBlock.Size;
offset = blockList.Reverse().Skip(1).Sum(l => l.Size);
}
}
else
{
version = 0;
lastBlockSize = int.MaxValue;
offset = 0;
firstVersion = 1;
count = 0;
blockNames = new List<string>();
}
if (!appendCondition.Satisfy(version))
return 0;
if (version > long.MaxValue - 1)
throw new IndexOutOfRangeException("Version is more than long.MaxValue.");
if (buffer.Length > FourMb)
throw new ArgumentException("buffer size must be less than or equal to 4 Mb", "buffer");
using (var outStream = new MemoryStream())
{
if (buffer.Length < MaxBlockSize && lastBlockSize <= MaxBlockSize - buffer.Length)
{
// read old block
using (var s = blob.OpenRead())
{
s.Seek(offset, SeekOrigin.Begin);
s.CopyTo(outStream);
TapeStreamSerializer.WriteRecord(outStream, buffer, version + 1);
count++;
blockNames.RemoveAt(blockNames.Count - 1);
}
}
else
{
TapeStreamSerializer.WriteRecord(outStream, buffer, version + 1);
firstVersion = version + 1;
count = 1;
}
var blockId = EncodeName(Naming.GetName(firstVersion, count));
string md5Hash;
outStream.Seek(0, SeekOrigin.Begin);
using (var md5 = MD5.Create()) {
md5Hash = Convert.ToBase64String(md5.ComputeHash(outStream));
}
outStream.Seek(0, SeekOrigin.Begin);
blob.PutBlock(blockId, outStream, md5Hash);
blockNames.Add(blockId);
blob.PutBlockList(blockNames);
return version+1;
}
}
void Dispatch(string id, IEnumerable <ICommand> commands)
{
var stream = _factory.GetOrCreateStream(id);
var records = stream.ReadRecords(0, int.MaxValue).ToList();
var events = records
.Select(tr => _streamer.ReadAsEnvelopeData(tr.Data))
.SelectMany(i => i.Items)
.Select(i => (IEvent)i.Content)
.ToList();
var then = AggregateFactory
.LoadProject(events, commands)
.Select(e => new MessageBuilder(e.GetType(), e)).ToList();
if (then.Count == 0)
{
return;
}
// events are stored here as envelopes )
var b = new EnvelopeBuilder("unknown");
foreach (var e in then)
{
b.Items.Add(e);
}
var version = records.Count == 0 ? 0 : records.Last().Version;
var data = _streamer.SaveEnvelopeData(b.Build());
var result = stream.TryAppend(data, TapeAppendCondition.VersionIs(version));
if (!result)
{
throw new InvalidOperationException(
"Data was modified concurrently, and we don't have merging implemented, yet");
}
var args = _path.Split(':');
IQueueWriterFactory factory;
if (!_queue.TryGet(args[0], out factory))
{
throw new InvalidOperationException("Not found " + _path);
}
var arVersion = events.Count + 1;
var arName = id;
for (int i = 0; i < then.Count; i++)
{
var name = string.Format("{0}/{1}/{2}", arName, arVersion, i);
var builder = new EnvelopeBuilder(name);
builder.Items.Add(then[i]);
builder.AddString("from-entity", arName);
factory.GetWriteQueue(args[1]).PutMessage(builder.Build());
}
}
