public string CreateInState(
Job job,
IDictionary <string, string> parameters,
IState state)
{
if (job == null)
{
throw new ArgumentNullException("job");
}
if (parameters == null)
{
throw new ArgumentNullException("parameters");
}
if (state == null)
{
throw new ArgumentNullException("state");
}
var createdAt = DateTime.UtcNow;
var jobId = _connection.CreateExpiredJob(
job,
parameters,
createdAt,
TimeSpan.FromHours(1));
var context = new StateContext(jobId, job, createdAt, _connection);
_stateChangeProcess.ChangeState(context, state, null);
return(jobId);
}
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;
}
}
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);
}
}
public ApplyStateContext(StateContext context, IState newState, string oldStateName)
: base(context)
{
if (newState == null) throw new ArgumentNullException("newState");
OldStateName = oldStateName;
NewState = newState;
JobExpirationTimeout = TimeSpan.FromDays(1);
}
public void CopyCtor_CopiesAllProperties()
{
var context = CreateContext();
var contextCopy = new StateContext(context);
Assert.Equal(context.JobId, contextCopy.JobId);
Assert.Equal(context.CreatedAt, contextCopy.CreatedAt);
Assert.Same(context.Job, contextCopy.Job);
Assert.Same(context.Connection, contextCopy.Connection);
}
internal ElectStateContext(StateContext context, IState candidateState, string currentState)
: base(context)
{
if (candidateState == null)
{
throw new ArgumentNullException("candidateState");
}
CandidateState = candidateState;
CurrentState = currentState;
}
public ApplyStateContext(StateContext context, IState newState, string oldStateName)
: base(context)
{
if (newState == null)
{
throw new ArgumentNullException("newState");
}
OldStateName = oldStateName;
NewState = newState;
JobExpirationTimeout = TimeSpan.FromDays(1);
}
public string CreateInState(
Job job,
IDictionary<string, string> parameters,
IState state)
{
if (job == null) throw new ArgumentNullException("job");
if (parameters == null) throw new ArgumentNullException("parameters");
if (state == null) throw new ArgumentNullException("state");
var createdAt = DateTime.UtcNow;
var jobId = _connection.CreateExpiredJob(
job,
parameters,
createdAt,
TimeSpan.FromHours(1));
var context = new StateContext(jobId, job, createdAt, _connection);
_stateChangeProcess.ChangeState(context, state, null);
return jobId;
}
public bool TryToChangeState(
string jobId, IState toState, string[] fromStates)
{
if (jobId == null)
{
throw new ArgumentNullException("jobId");
}
if (toState == null)
{
throw new ArgumentNullException("toState");
}
if (fromStates != null && fromStates.Length == 0)
{
throw new ArgumentException("From states array should be null or non-empty.", "fromStates");
}
// To ensure that job state will be changed only from one of the
// specified states, we need to ensure that other users/workers
// are not able to change the state of the job during the
// execution of this method. To guarantee this behavior, we are
// using distributed application locks and rely on fact, that
// any state transitions will be made only within a such lock.
using (_connection.AcquireDistributedLock(
String.Format("job:{0}:state-lock", jobId),
JobLockTimeout))
{
var jobData = _connection.GetJobData(jobId);
if (jobData == null)
{
// The job does not exist. This may happen, because not
// all storage backends support foreign keys.
return(false);
}
if (fromStates != null && !fromStates.Contains(jobData.State, StringComparer.OrdinalIgnoreCase))
{
return(false);
}
bool loadSucceeded = true;
try
{
jobData.EnsureLoaded();
}
catch (JobLoadException ex)
{
// If the job type could not be loaded, we are unable to
// load corresponding filters, unable to process the job
// and sometimes unable to change its state (the enqueued
// state depends on the type of a job).
if (!toState.IgnoreJobLoadException)
{
toState = new FailedState(ex.InnerException)
{
Reason = String.Format(
"Can not change the state of a job to '{0}': target method was not found.",
toState.Name)
};
loadSucceeded = false;
}
}
var context = new StateContext(jobId, jobData.Job, jobData.CreatedAt, _connection);
var stateChanged = _stateChangeProcess.ChangeState(context, toState, jobData.State);
return(loadSucceeded && stateChanged);
}
}
internal StateContext(StateContext context)
: this(context.JobId, context.Job, context.CreatedAt, context.Connection)
{
}
internal StateContext(StateContext context)
: this(context.JobId, context.Job, context.CreatedAt, context.Connection)
{
}
public bool TryToChangeState(
string jobId, IState toState, string[] fromStates)
{
if (jobId == null) throw new ArgumentNullException("jobId");
if (toState == null) throw new ArgumentNullException("toState");
if (fromStates != null && fromStates.Length == 0)
{
throw new ArgumentException("From states array should be null or non-empty.", "fromStates");
}
// To ensure that job state will be changed only from one of the
// specified states, we need to ensure that other users/workers
// are not able to change the state of the job during the
// execution of this method. To guarantee this behavior, we are
// using distributed application locks and rely on fact, that
// any state transitions will be made only within a such lock.
using (_connection.AcquireDistributedLock(
String.Format("job:{0}:state-lock", jobId),
JobLockTimeout))
{
var jobData = _connection.GetJobData(jobId);
if (jobData == null)
{
// The job does not exist. This may happen, because not
// all storage backends support foreign keys.
return false;
}
if (fromStates != null && !fromStates.Contains(jobData.State, StringComparer.OrdinalIgnoreCase))
{
return false;
}
bool loadSucceeded = true;
try
{
jobData.EnsureLoaded();
}
catch (JobLoadException ex)
{
// If the job type could not be loaded, we are unable to
// load corresponding filters, unable to process the job
// and sometimes unable to change its state (the enqueued
// state depends on the type of a job).
if (!toState.IgnoreJobLoadException)
{
toState = new FailedState(ex.InnerException)
{
Reason = String.Format(
"Can not change the state of a job to '{0}': target method was not found.",
toState.Name)
};
loadSucceeded = false;
}
}
var context = new StateContext(jobId, jobData.Job, jobData.CreatedAt, _connection);
var stateChanged = _stateChangeProcess.ChangeState(context, toState, jobData.State);
return loadSucceeded && stateChanged;
}
}
