private static IState ElectState(
ElectStateContext context,
IEnumerable <IElectStateFilter> filters)
{
var statesToAppend = new List <IState>();
foreach (var filter in filters)
{
var oldState = context.CandidateState;
filter.OnStateElection(context);
if (oldState != context.CandidateState)
{
statesToAppend.Add(oldState);
}
}
if (statesToAppend.Count > 0)
{
using (var transaction = context.Connection.CreateWriteTransaction())
{
foreach (var state in statesToAppend)
{
transaction.AddJobState(context.JobId, state);
}
transaction.Commit();
}
}
return(context.CandidateState);
}
public bool ChangeState(StateContext context, IState toState, string oldStateName)
{
try
{
var filterInfo = GetFilters(context.Job);
var electStateContext = new ElectStateContext(context, toState, oldStateName);
var electedState = ElectState(electStateContext, filterInfo.ElectStateFilters);
var applyStateContext = new ApplyStateContext(context, electedState, oldStateName);
ApplyState(applyStateContext, filterInfo.ApplyStateFilters);
// State transition was succeeded.
return(true);
}
catch (Exception ex)
{
var failedState = new FailedState(ex)
{
Reason = "An exception occurred during the transition of job's state"
};
var applyStateContext = new ApplyStateContext(context, failedState, oldStateName);
// We should not use any state changed filters, because
// some of the could cause an exception.
ApplyState(applyStateContext, Enumerable.Empty <IApplyStateFilter>());
// State transition was failed due to exception.
return(false);
}
}