/// <inheritdoc />
public async Task<Dictionary<IStream, IEnumerable<IEvent>>> GetChanges(ICommand command, Time time)
{
var activeBranch = _manager.ActiveBranch;
var branch = $"{command.GetType().Name}-{time.ToUnixTimeMilliseconds()}";
await _manager.Branch(branch, time, deleteExisting: true);
var copy = command;
copy.Timeline = branch;
var handler = _commandRegistry.GetHandler(copy);
if (handler == null)
throw new InvalidOperationException($"No handler found for command {command.GetType().Name}");
await handler.Handle(copy);
await _manager.Branch(activeBranch);
var dict = new Dictionary<IStream, IEnumerable<IEvent>>();
var changes = await _manager.GetChanges(branch);
_log.StopWatch.Start("GetChanges.Read");
foreach (var c in changes)
{
var stream = await _streamLocator.FindBranched(c.Key, branch);
var e = await _eventStore.ReadStream<IEvent>(stream, stream.Version - c.Value + 1, c.Value).ToList();
dict[c.Key] = e;
}
_log.StopWatch.Stop("GetChanges.Read");
await _manager.DeleteBranch(branch);
return dict;
}
/// <inheritdoc />
protected override BranchState[] GetStates(BranchState current)
{
var activeBranch = _manager.ActiveBranch;
var commands = GetCommands(current).ToList();
var states = new BranchState[commands.Count];
var iState = 0;
foreach (var command in commands)
{
states[iState] = ApplyCommands(command, current.Timeline).Result;
iState++;
}
_manager.Branch(activeBranch).Wait();
return(states);
}
/// <summary>
/// Branch mutation
/// </summary>
/// <param name="branch">Branch id</param>
/// <returns>Branch result</returns>
public bool Branch(string branch)
{
if (branch == string.Empty)
{
_manager.Reset();
}
else
{
_manager.Branch(branch).Wait();
}
return(true);
}
/// <inheritdoc />
/// <summary>
/// Wrap the handler and redirect all exception to <see cref="IErrorLog"/>
/// </summary>
public async Task Handle(T command)
{
_log.Trace($"{command.GetType().Name}", this);
var timeline = _timeline.Id;
if (!(command is IRetroactiveCommand) && command.Timestamp == default)
{
command.Timestamp = _timeline.Now;
}
if (command.LocalId == default)
{
command.LocalId = new EventId(Configuration.ReplicaName, command.Timestamp);
}
if (command.OriginId == default)
{
command.OriginId = new EventId(Configuration.ReplicaName, command.Timestamp);
}
command.Timeline = timeline;
try
{
await _handler.Handle(command);
if (command.StoreInLog && !command.Pure)
{
await _commandLog.AppendCommand(command);
}
}
catch (Exception e)
{
_errorLog.Add(e);
// check that we didn't end up on wrong timeline
if (_timeline.Id != timeline)
{
var tException = new InvalidOperationException($"Execution started on {timeline} but ended on {_timeline.Id}");
_errorLog.Add(tException);
// throw tException;
await _branchManager.Branch(timeline);
}
await _commandLog.AddFailedCommand(command);
}
}