public SagaContext(SagaCollaborator sagaCollaborator,
ILogger logger)
{
this._sagaCollaborator = sagaCollaborator;
this._sagaDataConverter = SagaGlobal.CurrentSagaDataConverter;
this._sagaResolver = SagaGlobal.CurrentSagaResolver;
this._logger = logger;
this._sagaSession = null;
}
public async Task <string> Start <T>(T form) where T : class, SagaData
{
var xid = await _sagaCollaborator.CreateGlobalTxAsync();
_logger.LogInformation($"created xid {xid}");
// bind xid to current call context
CallContext.SetData(SagaGlobal.SAGA_XID_CONTEXT_KEY, xid);
// 用一个branchCaller服务去带着xid和sagaData去调用现有的SagaService的方法，
// 从而包装好分支事务的注册
_sagaSession = new SagaSession <T>(xid, _sagaCollaborator,
_sagaDataConverter, _sagaResolver, _logger);
CallContext.SetData(SagaGlobal.SAGA_SESSION_CONTEXT_KEY, _sagaSession);
// 上面这里的CallContext.SetData后的值下个线程就取不到了. 可能是因为不在同一个async CPS中?. 所以返回后要调用Bind()
// 初始化saga data避免以后回滚时得到null sagaData
await _sagaCollaborator.InitSagaDataAsync(xid, _sagaDataConverter.Serialize(form.GetType(), form));
return(xid);
}